68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006
Edition: Model Aviation - 2008/07
Page Numbers: 68,69,70,71,72,74,76,78
68 MODEL AVIATION
JIM FELDMANN AND SHAWN RUBUSH
Plane Talk: Great Planes Seawind .60 ARF
A sport-scale model of
the sleek amphibian
Great Planes included a custom cradle to protect the Seawind while out of the water and
on the bench.
This model is at home in the water. Fixed gear is included, or the builder can choose the Robart retract option.
As is the full-scale Seawind, the
model is smooth and fast. Great
Planes engineers did their homework
on its airfoil.
THE FULL-SCALE Seawind is a strange
and wonderful airplane. It is the fastest
production seaplane available today, seats
four, and is a full amphibian with retractable
tricycle landing gear. It is all fiberglass, and
the designers took advantage of that
material’s flexibility to give the aircraft a
unique and beautiful shape.
Great Planes’ 60-size Seawind is a good
representation of the full-scale version. The
kit includes scalelike fixed gear and even
offers the option of duplicating the fullscale
retractable gear (made by Robart).
The model Seawind can be flown from
land with the fixed gear or retracts, or it
can be flown from water with no gear or
with the retracts disabled. However, it
cannot be flown from water with
+•
Stable and easy to fly, but see minuses.
• Attracts lots of attention in the pits and in the air.
• Fast and reasonably aerobatic.
• Two-piece wing.
• Included optional wire fixed landing gear. -•
Unforgiving of careless takeoff and landing techniques when
flown from water.
• High wing loading is always evident.
• Self-bailer lets water in as well as out.
Pluses and Minuses
July 2008 69
The Seawind’s takeoff procedure
must be carried out methodically;
power application is crucial. Come
up on the power slowly as the model
gains speed. Level wing management
is essential.
Model type: Sport-scale amphibian seaplane
Pilot skill level: Intermediate/advanced
Wingspan: 71 inches
Wing area: 676 square inches
Overall length: 56 inches
Weight: 10.25-12.25 pounds
Wing loading: 35-41 ounces/square foot
Engine: Two-stroke .60 or four-stroke .70-.91
Radio system: Five to seven channels with seven to nine servos
Construction: Fiberglass fuselage, engine pod, cowl, wingtips;
ABS canopy/hatch; built-up balsa-and-plywood wings, horizontal
tail surfaces; flat aluminum wing joiner
Covering/finish: MonoKote covering, paint, fuelproof clear
coat on fiberglass parts
Street price: $334.98
Specifications
Engine used: O.S. 61FX, Bisson muffler
Propeller: APC 12 x 6
Fuel: 14.2-ounce-capacity tank, Powermaster 15% Nitro fuel
Radio system: Five- to eight-channel transmitter; sevenchannel
receiver; three microservos; four standard ball-bearing
servos; 1100 mAh, 4.8-volt battery; eight servo extensions; two
Y-harness extensions
Ready-to-fly weight: 11 pounds, 1 ounce
Actual wing loading: 37.7 ounces/square foot
Flight duration: Exceeds 15 minutes with normal throttle
discipline
Test-Model Details
operational retracts. (More about that later.)
I’m a water flier from way back. The Seawind is different,
attractive, and, from the scuttlebutt I hear, both a good flier and a
challenge. I had to give it a try.
My Seawind was well packaged and suffered no shipping damage.
The individual parts appear to be well built and sturdy. The
fiberglass fuselage and wingtips are particularly well done. There
are no visible joints, and the plywood frame inside does not show
through the fiberglass.
The MonoKote covering on the wings and horizontal tail
Although the flaps are optional, the author claims that they are a
necessity for takeoff and landing.
70 MODEL AVIATION
Epoxy mixed with 15 ounces of lead shot in the nose and a sub-Csize,
four-cell battery positioned directly behind balanced the
Seawind at the recommended CG.
The author covered both ends of the wings to waterproof them
and minimize the ways that water can find its way into the wings.
The throttle-servo mount needs to be reversed for a two-stroke
engine. The author slightly modified the mount to improve access
for future maintenance.
The receiver, switch, and battery are mounted as far forward as
possible, which means that many wires are running up to the nose.
Keeping all the radio equipment off the fuselage bottom will help
keep them dry.
The Seawind is highly prefabricated from the box. The
fuselage/engine pod, in particular, is an amazing piece of work.
Static photos by the author Flight photos by Allan Poinsett and Michael E. Brown
The model uses an O.S. 61FX with a Bisson inverted-style muffler,
a 12 x 6 APC propeller, and a Tru-Turn two-blade spinner. This
simple, light, powerful engine package proved to be ideal.
surfaces was well done, with no wrinkles. The two-piece wing
uses a flat aluminum joiner, and the fuselage has a large
canopy/hatch to provide access to the radio equipment and wingattachment
bolts.
One of the nicest surprises is an included foam-and-tube cradle
to support the fuselage during assembly and transportation. All
seaplanes need one of these, but you usually have to make it
yourself.
The hardware and accessories are Great Planes’ usual high quality
and generally seem adequate for the task. A nice aluminum three-blade
spinner is included as well.
Landing-gear mounts, servo mounts, and wheel wells are
installed at the factory. The main gear mounts and wheel wells are
concealed, and a separate fiberglass cover is provided to shield the
nose gear for water flying.
Before assembling the Seawind, decide which landing-gear option
you will use. Installing no gear is the simplest and lightest option.
Weight is important; this is a heavy airplane even without gear.
You can fly the model from water or wet grass without gear, but
hard-surface runways are impractical. The aircraft’s weight in this
configuration is approximately 11 pounds.
Installing the included fixed gear will add 13 ounces and allow
the Seawind to be flown from hard-surface runways. Removing the
fixed gear to fly from water removes only roughly 5 of those 13
ounces and will require the gear mounts to be covered and sealed
and the airplane to be rebalanced.
July 2008 71
The electric-powered Seawind packs
a value-packed punch.
The EP’s light wing loading ensures excellent slowspeed
flight performance.
The magnetically secured plastic hatch
comes with pilot figures installed.
Tight joints ensure that water infiltration is minimized.
With the introduction of the Seawind EP by Great Planes, it was time
to bring my RC interests full circle and combine the three major
elements: land, sea, and air. This model has greatly increased my
options for flying fields.
Using the successful research and development of the 60-size
Seawind, Great Planes and ElectriFly have reproduced this unique
airplane for park flying and preserved the same stylish lines and bold
design of the full-size version. Because the major parts are molded, the
Seawind comes out of the box with little assembly needed.
The Seawind EP came with a custom-designed display stand and
balancing fixture. Those proved to be the most building-intensive part of
the project, which means that not much effort was required.
However, the display stand (made from Depron) was more rigid than
the foam model and had a tendency to ding up the bottom of the fuselage.
Adding the soft side of Velcro to the airplane stand at the four corners
helped prevent damage.
Since the power-system wiring is already in the fuselage, installing the
motor requires only reversing the output shaft. When installing the colletstyle
propeller adapter on the motor, take care not to overtighten the prop
nut. My first one wouldn’t lock down, but the replacement worked much
more successfully.
Assembling the wing consists of installing the servo and gluing on the
wingtips. All control surfaces and control horns are preinstalled. To aid in
fitting the wing, I tapered the alignment dowel and cleared the excess
glue from the hole. With that completed, I quickly realized that the wingmounting
screw didn’t go down quite far enough.
When I removed the screw, it became apparent that excess foam was
the culprit. With the foam removed, the wing mounted to the fuselage
with a nice, tight fit.
The canopy/hatch also comes fully assembled, with rare earth magnets
in place and pilot/co-pilot figures onboard. I had the slightest urge to
modify the pilots with pictures of my son and me, but after careful
inspection I decided to leave the well-glued piece alone. Why fix it if it’s
not broken?
Installing the remaining electronic components was like a nice walk in
the park. I mounted the ESC in the rear area specified. I positioned the
Berg 7P receiver between the elevator and rudder servos, up off the floor
so it won’t get wet if water ever gets inside.
I installed the ElectriFly Power Series 1250 mAh Li-Poly battery as
far forward as it would go. Another 3/4 ounce was needed to obtain the
proper balance. After a lateral balance check I taped slightly less than 1/8
ounce on the right wing.
Flying from water takes a little practice,
but it is much like flying a tail-dragger from
land. Hold a slight amount of up-elevator
Lateral balance, as instructed,
greatly eases the pilot’s wingleveling
workload.
+•
Minimal assembly time required.
• Well-written and -illustrated manual.
• Extremely predictable flight
characteristics and plenty of power
with recommended motor/ESC
combination.
• Watertight with well-engineered,
tight-fitting parts. -•
Foam is easily dinged or scratched.
Adding soft Velcro or foam padding
on included cradle is recommended.
Pluses and Minuses
Sidebar photos by Michael Ramsey
ElectriFly Seawind EP ARF
Sport scale for small ponds
72 MODEL AVIATION
Wingspan: 39.5 inches
Wing area: 234 square inches
Weight: 24-26 ounces (656 grams actual)
Length: 33.5 inches
Requires: Four-channel radio; three miniservos; 6-inch
servo extension; minireceiver; 11.1-volt, 910-2500 mAh
Li-Poly battery; 110-watt outrunner brushless motor
Price: $99.99
• RimFire brushless outrunner motor 28-30-950 kV
• ElectriFly Silver Series 25-amp ESC
• ElectriFly Power Series 1250 mAh 20C Li-Poly battery
• Three Futaba S3114 servos
• Castle Creations Berg 7P Programmable Receiver
Time required to switch back and forth is
perhaps an hour each way. Using the fixed
gear, the model will weigh roughly 11.5
pounds when flown from water and close to
12 pounds when flown from land.
Installing the optional retracts will add
28 ounces to the weight and will allow the
Seawind to be flown from water, grass, or
hard-surface runways. To fly from water
with the retracts installed, they must be
retracted and sealed over. No rebalancing
will be necessary, but no weight will be
removed either. The retracts cannot be used
in the water because the water drag from the
uncovered nose-gear well will prohibit the
airplane from reaching takeoff speed. The
dry weight with retracts will be
approximately 12.5 pounds.
My Seawind will be flown only from
water. All the choices I make will be aimed
at minimizing weight and maximizing
simplicity.
Construction: The 28-page instruction
manual is extremely well done, with
understandable explanations and clear
photos for each assembly step. The manual
includes parts lists, lists of items needed to
complete the model, useful hints, and a
section about flying the Seawind.
Read and heed the instructions for taking
off from the water. There are many sad
stories from people who apparently didn’t.
Not much assembly is required.
Approximately half of the instructions deal
with either the fixed landing gear or the
optional retracts.
For some reason, assembly starts with
mounting the engine. But with that heavy
weight up at the top, moving the fuselage
around to continue the assembly becomes
awkward at best. I decided to skip the
engine, fuel tank, throttle servo, and cowl
installations until later.
The next couple sections of the manual
cover installing the landing gear of your
choice. Since I am not planning to fly this
Seawind from land, all that was required
was to assemble and install the nose-gear
well cover. I used packaging tape to hold the
cover in place in case I decide to install the
gear later.
Two fiberglass tubes pass through the
fuselage to support the stabilizer halves,
which are epoxied in place. In my kit there
were obstructions in the front tube sockets
of both stabilizers. Rather than shorten the
Specifications and Equipment Used
while advancing the throttle to keep the nose out of the water.
As the model comes up on the step (like a boat), the hull’s
surface tension against the water is reduced, so relax the
elevator input. Focus on keeping the wings level (the lateral
balance check helped here) with the ailerons until flying
speed is reached, and the Seawind can lift off cleanly.
Once airborne, the Seawind EP is surprising. It zips along
quickly with the recommended motor and ESC. Drop the
throttle and enjoy stable flying at slow speeds.
Trying only a few maneuvers (on recommended high
rates) proved that this airplane’s flight is as beautiful as its
looks! Rolls, loops, and inverted flight seemed as
comfortable to perform as with a landlubber sport model.
The high-mount motor design causes the Seawind EP to
change attitude in pitch when the throttle position is
changed. This isn’t cause for alarm; the pitch change is
minor and helpful during the landing approach.
At first I had the tendency to come in slightly fast on
landing, causing the Seawind to skip multiple times on the
water. I’ve never skipped a rock that well in my life! The
slight pitch up the nose would do when the throttle was
reduced actually helped me perfect the landings.
A high flight angle of attack slows the Seawind; its clean
outline presents little drag otherwise. With the nose a bit high
on approach, carry a little power through the landing sequence
and the airplane will kiss the water without a splash.
Part of the trick is to always fly the airplane whether it’s in
the air or on the water. Taxi with a small amount of upelevator
to keep the rudder effective and nose high. Teetering
on the hull, it’s important to keep the wings out of the water at
all times with aileron. The ailerons’ large size is helpful at
slow speed.
I have been checking since the first flight. A drop of water
has yet to make it inside the model’s fuselage.
Don’t let the short-coupled look of the Seawind EP fool
you; it’s stable and fun to fly, has great handling
characteristics, and will turn on a dime. The unique profile
against a beautiful blue sky dotted with clouds is icing on the
cake. Great Planes did its homework with this model. MA
Shawn Rubush
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Sources:
ElectriFly
(217) 398-8970
www.electrifly.com
Futaba
(217) 398-3630
www.futaba-rc.com
Castle Creations
(913) 390-6939
www.castlecreations.com
Other Review Articles:
Model Airplane News: February 2008
R/C Report: November 2007
RC Sport Flyer: January 2008
tube to fit, which would weaken the
stabilizer, I cut notches in one end of the
tube and used it as a twist drill to clear the
obstructions.
Cyanoacrylate hinges are used
throughout the Seawind, and when properly
installed they are more than adequate. There
are only two hinges in each aileron. I added
a third for safety, so that any one hinge’s
failure will not cause the loss of the aileron.
Installing the air and water rudders is
straightforward, but the “screw-lock pushrod
connector” for the water rudder has been
changed from the one in the manual to a
larger one with a metal keeper. You must
use one of the smaller screw-lock pushrod
connectors included in the kit, or the air
rudder won’t fit properly.
This water rudder may cause handling
problems. Water rudders are far more
effective than air rudders; if used at high
speed on the takeoff run, they can cause the
airplane to swerve sharply one way or the
other. That’s why full-scale water aircraft
have retractable water rudders.
The Seawind’s water rudder is not
retractable, and it is sensitive. Any rudder
input during the high-speed portion of the
takeoff run could cause disaster.
I left the water rudder off and use the
throttle and the air rudder to steer during
taxi, but that can be tricky. Because the
downwind wing is always in the water,
power causes the airplane to turn downwind.
Throttle back, and the model will weathervane
upwind. Balance the two and you can
taxi crosswind.
Installing the servos is easy, even though
their positioning is different from what one
might expect. To keep the weight down,
apparently, Great Planes calls for metalgeared
miniservos for the elevator, rudder,
and throttle. I used the recommended Futaba
S3102, and the servo mounts fit them
perfectly. Applying a bit of silicone sealant
around the servo prevents water from getting
into the fuselage.
The standard-size flap and aileron servos
(I used Hitec HS425s) are mounted in each
wing under silicone-sealed plastic covers,
which keep water out of the wing. The
rudder, elevator, flap, and aileron servos are
exposed to water and/or fuel residue, but it
doesn’t seem to affect them. I have had no
servo problems, nor have I heard of any.
All the control horns are attached to
hardwood blocks in the control surfaces with
small sheet-metal screws. Make sure to
install the control surfaces with the blocks
on the bottom. I wicked thin cyanoacrylate
under the horns after mounting them just to
be sure, but, again, there were no problems.
Before you install the flap and aileron
servos, make sure the servo connectors will
fit through the wiring holes in the wings’
root ribs. Mine would not, and I had to open
the holes to roughly 7/16 inch in diameter.
I covered both ends of each wing with
scrap white covering material to waterproof
them and seal any unnecessary holes. By the
way, don’t even think about omitting the
flaps; you are going to need them.
When it came time to fit the wings to the
fuselage, I found that the flat aluminum
wing joiner was extremely tight in one wing
and fairly loose in the other. I leave it in the
tight side all the time; that way I can’t
accidentally leave it at home.
The factory slots in the fuselage for the
wing joiner fit perfectly, but the alignmentpin
holes were off by a hair, the servo-wire
holes had to be enlarged to match the
enlarged holes in the wings, and the wingretainer-
bolt holes didn’t line up well
enough to get the bolts through. It was
frustrating but easy to fix with a little filing.
One of those special wing bolts was also
very tight, even after I ran a 1/4-20 tap
through the blind nut. The other bolt fit that
blind nut a little better, so I marked the bolts
right and left. Fortunately they are
reasonably easy to reach.
The radio switch and receiver are easy to
install, under the big canopy hatch, on a tray
that is high off the bottom of the fuselage to
keep the equipment out of any water that
might find its way in. The hatch itself is
factory assembled and fits well. Thin foam
sealing material is provided to keep the
water out, but I found that the hatch didn’t
fit exactly right unless I omitted the front
piece of foam.
For safety’s sake I added a couple extra
plywood hard points inside the front lip of
the fuselage opening and used two screws
instead of just one to hold the hatch on. I do
get a few drops of water in the fuselage
during a flight, but it is far too small an
amount to cause a problem. I could
eliminate even that by taping over the
canopy and wing joints as the manual
suggests.
What about the self-bailer? I assembled
and installed it as instructed and tested it in
my neighbor’s pool. It seems to be just as
good at letting water in as it is at letting
water out. I plugged it with a piece of dowel.
I wanted my Seawind to be as simple and
light as possible, so I installed an O.S. 61FX
two-stroke engine. The engine-mount blind
nuts are factory installed, but I had to run an
8-32 tap through them to clean out the paint
that had run into the threads.
The manual instructs you to position the
engine on the mount so that the propellerdrive
washer is 51/8 inches from the firewall.
This will result in a 3/16- to 1/4-inch gap
between the back of the spinner and the
cowl. Making it so the drive washer is 415/16-
5 inches from the firewall will bring that gap
down to a much better-looking 1/16 inch.
Installing a two-stroke engine will
require that the throttle pushrod be installed
on the opposite side of the engine pod from
that shown in the manual. The supplied
pushrod is not long enough to reach the
front-mounted carburetor on a two-stroke, so
you will have to purchase a longer one. The
throttle servo and its mount will also have to
be reversed.
Installing the throttle servo in accordance
with the manual would make it difficult to
remove. For ease of maintenance I used a
larger servo retainer than the one provided
and used the supplied servo mounting tape
to attach the servo to the retainer rather than
the tray.
The provided fuel tank is large and
almost fills the engine pod. The tank’s neck
fits in a hole in the firewall, but the rear of
the tank passes through a former that
touches the sides but not the top or bottom.
Vibration can make the fuel in tanks that
touch the airplane’s hard structure froth and
cause the engine to run inconsistently. I
sanded 1/8 inch off both sides of the former
to allow some room and then padded the
rear of the tank to isolate it and support it
within the former.
Mounting a two-stroke engine inverted
can cause fuel to siphon out of the tank
through the carburetor, because the
carburetor is usually lower than the tank. I
solved this problem by installing a Great
Planes fuel-filler valve at the top of the
cowl.
After filling the tank and after each
flight, I open the valve to air by inserting
the probe with a short section of open fuel
line attached. This breaks the suction in
the fuel line, and even after removing the
probe the fuel will not siphon out.
The O.S. 61FX’s stock muffler is
extraordinarily efficient. It allows the
engine to make plenty of horsepower
without a lot of noise. Unfortunately it is
heavy and looks bad on the Seawind. I
used a Bisson O.S. .61 inverted muffler,
which is just as quiet, makes almost as
much power, and fits mostly inside the
cowl.
As delivered, the Bisson muffler would
not clear the Seawind’s engine mount and
required a 5/8-inch O.S. 744B exhaust
extension. It pushed the muffler almost 1/2
inch farther from the engine than it needed
to be, but I don’t have the equipment to cut
it down and the Bisson still looks much
nicer than the stock muffler would.
Bisson informed me that all new O.S.
.61 Inverted mufflers will be made with
longer mounting flanges, so extensions
will not be needed. That will allow the
muffler to fit closer to the engine and be
hidden even better within the cowl than
mine.
Fitting and installing the cowl and the
pod hatch are straightforward and
relatively easy tasks using the methods the
manual describes. Most of the important
cooling air comes in through the bottom of
the cowl, so I sealed off the right-side airinlet
opening to give the hotter bottom air
a chance to reach the built-in exits. It is a
tight cowl and most of the hot muffler is
inside it, but I have had no cooling
problems, even in 90° weather.
The Seawind has comfortable clearance
for a 12-inch propeller. Although the
recommended four-stroke engine needs a
three-blade propeller to keep its diameter
down to 12 inches, my O.S. 61FX is happy
with a 12 x 6 APC two-blade.
Two-blade propellers are more efficient
than the three-blade types, but that meant I
had to replace the nice three-blade spinner
that came in the kit. I used Tru-Turn’s
21/2-inch two-blade spinner and its 5/16-24
adapter kit. These are top-quality, madein-
America products.
The manual calls for the CG to be set at
11/32 inches behind the LE; there is no
acceptable range. Setting the airplane a bit
nose-heavy for the first flight would be a
bad idea. Even though the recommended
position sounds too far forward, that’s
where I set it.
It took 15 ounces of lead shot/epoxy
poured into the tip of the nose and a fourcell,
sub-C-size battery right behind it to
get the CG to that point. I set the control
throws exactly as recommended in the
manual. My flaps are operated by a threeposition
switch, giving no flap, 50% flap
(1/2 inch), and 100% flap (1 inch).
The clear coat on the fuselage will
absorb the color dye from your fuel. Be
sure to give the fuselage and canopy a
good, heavy coat of car wax before you
put fuel in the tank.
My Seawind weighs 11 pounds and has
a wing loading of almost 38 ounces per
square foot. If you know that most 60-size
models tend to weigh roughly 8 pounds
and have wing loadings of 28 ounces or
less per square foot, those numbers will
give you pause.
And the stories you see on the Internet
about botched takeoffs and broken
airplanes ... Let’s give it a try.
Flying: Opinion on the street is unanimous
that the hardest part of flying the Seawind
is the water takeoff. It will supposedly
ground loop violently or bounce until it
sticks its nose in the water. I had six
takeoffs at the Seawind’s first float-fly,
and none of that happened.
Given the Seawind’s high wing
loading, I reasoned that it would need to
reach a stable high speed on the water
before even attempting to rotate.
Following is the technique I used and why.
1) Taxi out to the takeoff area, throttle
back, and let the airplane weather-vane
into the wind. A crosswind takeoff will
make it much harder to get the wingtip out
of the water and level the wings.
2) Lower the flaps to 50% and then
throttle up to approximately one-third to
get the hull and wingtip onto the step. The
wingtip is actually in the water at the
beginning of this stage, and you will have
to use a great deal of rudder to overcome
its drag.
3) When the hull and wingtip are
skimming on top of the water, raise the
throttle to two-thirds to build up enough
speed to allow the ailerons to level the
wings. During this stage the water rudder
will become tremendously sensitive.
Perhaps the best all-around rudder solution
will be to install the water rudder, add a
bunch of exponential on the rudder
channel, and train yourself to be gentle
with necessary rudder inputs until the
wings are level.
4) When both wingtips are out of the
water and the wings are level, advance the
throttle to full. Do not touch the rudder
during this stage. No elevator input is
generally needed during the takeoff
process. The Seawind will usually take off
by itself shortly after the wings are level. I
needed to add up-elevator only on glasssmooth
water.
5) After you reach a safe altitude, raise
the flaps.
I would guess that most of the reported
water-takeoff problems result from either
using the rudder at high speed (groundloop) or trying to use the full-throttle and
full-up takeoff technique (bouncing). Taking
off from land should be easier, but I didn’t
try it.
Once in the air, the Seawind turns into a
great-flying sport model. It is fast, nicely
stable at both high and low speeds, and
reasonably aerobatic.
Stall tests showed that the wing is
forgiving. I could not get the Seawind to tip
stall in normal flight. Stalled from level flight
at idle power, holding full up-elevator (low
rate), the nose will drop barely below the
horizon before it starts flying again, although
the sink rate at low speeds is high because of
the high wing loading. I couldn’t get the
model to spin either.
Although the recommended CG breaks
all the established rules of thumb, it seemed
to be ideal in flight. It takes a lot of downelevator
to fly the Seawind inverted, but no
more than for some conventional sport
models with similar semisymmetrical
airfoils.
I prefer the high rate throws on aileron
and rudder. The elevator seemed slightly
slow on low rates also, but the low rate
worked so well on takeoff and landing that I
left it there.
The Seawind tracks well for such a shortcoupled
airplane. Loops can be big or tight,
with no rollout or wandering off track. Rolls
are not linear but are reasonably fast with
minimal altitude loss.
Stall turns are easy and look great. I was
even able to do a decent knife edge with not
too much coupling, but the model wouldn’t
hold altitude in knife edge—even in a 30°
nose-high attitude.
Scale flybys are the most fun. With or
without flaps, they are slow, stable, and
impressive.
Landing the Seawind on water is slightly
more demanding than landing the average
sport seaplane. Full (100%) flaps are
required. Dropping the flaps at approach
speeds requires no elevator trim change, but
it slows the airplane noticeably and you will
need to use throttle to keep the airspeed up.
A flat approach works best, and the speed
needs to be approximately halfway between
a wheel landing and a three point. If it’s too
slow, the airplane will bounce; if it’s too fast,
the model will either skip or hit the water
nose-low and stop fast. Again, landing on
land should be easier.
The Great Planes Seawind is a beautiful
scale model of a beautiful full-scale seaplane.
It is not an everyday sport aircraft. The
design is unconventional in many ways, and
some might even say, “That thing will never
fly.” It does fly—very well.
The Seawind’s unusual design and high
wing loading make it unforgiving of careless
or improper takeoff and landing techniques.
Takeoffs and landings that are done correctly
are a thing of beauty, and the Seawind is one
of the best-flying seaplanes you can buy. The
“wow” factor is high; this model always
draws a crowd.
The included fixed gear or optional
retracts allow the Seawind to be flown from
land, but either will add significantly to the
weight and wing loading. I didn’t try flying
the model with landing gear, so I can’t say
what effect that would have on the flight
characteristics. Flying from land would
obviously eliminate any water takeoff and
landing difficulties. The choice is for you to
make.
Despite a few minor issues, the kit is
quick and easy to put together. If you have
assembled a few ARFs, you should have no
trouble getting this one together properly.
The flier should be comfortable with lowwing
aerobatic sport models and, if flying
from water, have some seaplane experience.
The price is reasonable for what you get, and
having the backing of a major company such
as Great Planes is a good thing. MA
Jim Feldmann
[email protected]
Manufacturer/Distributor:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
(217) 398-8970
www.greatplanes.com
Other Review Articles:
Fly RC: April 2006
Flying Models: January 2007
Model Airplane News: May 2006
R/C Report: September 2006