Plane Talk 2010/07

MANY CONSIDER THE Fokker D.VII to
be the finest single-seat fighter of World War
I. Reinhold Platz designed the aircraft, and the
Red Baron—Manfred von Richthofen—flew
the prototype in January 1918. It soon entered
service, in May 1918, and more than 1,700
had been built by the end of the war.
58 MODEL AVIATION
Photos by the author and Michael Ramsey
Before gluing the dummy engine to the
cowl, a piece of 3/32 balsa was added to the
bottom of the engine, to give it more
surface area for better adhesion to the
cowl.
The Saito .82 four-stroke mounted in the D.VII. A 90° adapter is required for
the muffler to fit. A 45° muffler manifold is recommended if you are using a
newer Saito engine, because they are now supplied with a 15° type.
Scale wheels are put together on the
model, to make use of the wheel collar
without it being seen on the outside of
the wheel. Six screws hold the assembly
together.
The included weight box assists in providing
the correct CG. However, the manual does
not recommend an amount needed for
proper balance. The author found 3.5 ounces
to be perfect.
A look inside the fuselage shows the fuel tank
installed with the tank brace to hold it in place.
DS821 servos are a perfect fit, and servo cutouts
even have predrilled holes for servo screws.
Cooling holes and an exit hole for the exhaust deflector need to
be added to the bottom of the cowl. It is thick enough to support
the fuel dot and keep it out of sight. Blue painter’s tape was used
to secure the cowl while drilling mounting holes.
The tail skid is easy to attach with a landing gear strap and two
#4 x 1/2-inch self-tapping screws. This allows the tail skid to be
replaced if it becomes worn from flying from a hard surface.
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July 2010 59
Below: The Fokker is highly visible in the air, with its
colorful scheme. Lozenge camouflage covering on
the bottoms of the wings and tail add to the
model’s appearance.
The D.VII looks great on the ground but shines in the air, with predictable flight
characteristics. This fighter is all bark and no bite.
locations—the front, middle, and rear—so I
removed only the covering where the solid
wood was.
Landing gear legs and tail skid were
installed using white nylon straps. I decided to
color them, using a red Sharpie for the landing
gear and a blue one for the tail skid. This will
work great if your aircraft has electric power,
but it will not last when it comes in contact
with glow fuel. Another option is to dye the
parts.
Once I mounted the scale wheels on the
axle using the supplied wheel collars, I
noticed that the wheels seemed spaced slightly
farther apart than would be scale on the
Fokker D.VII. I thought about shortening the
axle but decided to leave the spacing, to
improve ground handling and lessen the
chances of scraping the wingtips.
O-rings were used to hold the axle in place
and allow for a bungee suspension. They have
Pluses and Minuses
+•
Built-up and sheeted-wood construction
with plastic and fiberglass details.
• Provided pilot with scarf, machine guns,
and engine detail.
• Preapplied decals.
• Bungee-suspension landing gear and
scale wheels.
• Accurate details with lozenge
camouflage on bottom of wings and tail.
• Choice of electric or two- or fourstroke
glow power.
• Excellent flight characteristics with good
manners. -•
Manual contains minor errors.
• Four-stroke setup requires additional
exhaust parts and hardware.
Specifications
Test-Model Details
held up so far, but I recommend checking
them during every outing. The rings do allow
for the axle to shift slightly to one side or the
other, and I check that after every flight.
I employed a test stand to break in the Saito
.82. Even on the first run, it started easily and
ran well.
Following the instructions that came with
the power plant, I kept it below 4,000 rpm and
ran it four times while slightly leaning it out
after the second run. I used Magnum #1 fuel
for running in and flying.
Installing the Saito proved to be the most
challenging part of the D.VII build. Not only
were additional exhaust parts needed, as I
mentioned, but I also had to replace some of
the included mounting hardware because it
was the wrong size.
To install the engine without the 45°
manifold, it needed to be affixed to the mount,
Model type: RC Fun Scale ARF
Skill level: Intermediate builder,
intermediate pilot
Wingspan: 64.6 inches
Wing area: 1,114 square inches
Length: 49.8 inches
Weight: 8.5-9.5 pounds
Wing loading: 17.50-19.65 ounces/
square foot
Engine: .61 two-stroke or .82 four-stroke
Radio: Six channels with five servos
Construction: Balsa, plywood, fiberglass
details
Covering/finish: Hangar 9 UltraCote,
painted plastic and fiberglass
Price: $239.99
Engine used: Saito 82 AAC four-stroke
with muffler
Propeller: Evolution 14 x 8
Fuel: Magnum #1, 17-ounce tank
Radio system: JR 12X transmitter;
Spektrum AR7000 receiver; five JR DS821
servos; 2300 mAh, 6-volt receiver battery;
two 12-inch extensions; two 6-inch
extensions
Ready-to-fly weight: 8 pounds, 9.6
ounces dry
Flight duration: 12-15 minutes
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and then the mount needed to be bolted onto
the firewall. And a bit of work with the
Dremel tool was required to give the muffler
slightly more room on the inside of the
fuselage.
The 8-32 hardware provided with the kit
proved to be too large to fit through the
mounting lugs. Not wanting to enlarge the
holes, I replaced the supplied items with
3.5mm hardware.
In addition, the 8-32 x 1-inch bolts used
to attach the power plant mount to the
firewall were too long and protruded past the
blind nuts. This was not acceptable, because
they would come in contact with the fuel
tank. The bolts could have been shortened,
but I replaced them with a set that was 3/4
inch in length.
A weight box was supplied to add the
necessary nose weight to get the Fokker to
balance. I attached the box behind the engine
using two 4-40 screws.
The manual gave no recommendation for
the amount of weight needed. I used 3.5
ounces as a starting point, which worked out
to be right on the money.
The instructions showed installing the
dummy engine before installing the cowl,
but I highly recommend that you install the
cowl first. The dummy engine was made
from brittle plastic that I had to trim with a
nibbler tool, because my hobby scissors
were making small cracks. Installing the
exhaust stack on the dummy engine was
made easiest by gluing one attachment at a
time.
The hardest part of aligning the cowl was
getting the rear onto the 1/16-inch support on
the fuselage. I used a couple pieces of scrap
balsa to make 45° ramps with which to guide
it, which worked great.
Before gluing the dummy engine to the
cowl, I cut a piece of 3/32 balsa and added it
to the bottom of the engine, to give it more
surface area for better adhesion to the cowl.
Flying the Fokker: I established all control
throws and exponential setting per the manual.
The CG was exactly 35/8 inches behind the LE
of the top wing near the cabane struts.
I set up an aileron/rudder mix that could be
switched on and off via the transmitter. That
way, if I was unhappy with my left finger’s
ability to make coordinated turns, I could use
the radio to help.
I chose a grass runway since a tail skid was
used. The model taxied reasonably well with
full up-elevator to keep the tail down.
However, a 180° turn proved to be a bit
difficult.
With the D.VII facing into the wind, I took
a moment to admire the colorful aircraft and
the sound of the four-stroke purring gently. I
knew it was ready to leap into the air and
didn’t disappoint when the coals were poured
on smoothly.
As did the full-scale WW I airplanes, the
Hangar 9 version needed slight up-elevator
and rudder work to stay straight down the
runway on takeoff. Within 30 feet, the
German fighter was in the air and, after a few
clicks of trim, ready to show what it was
capable of doing.
The low rate settings allowed the aircraft to
be flown in a scale manner and feel
comfortable. Lazy aerobatics could also be
performed at this setting. Being familiar with
more aerobatic models, I found the high rates
to be enjoyable and manageable.
The aileron/rudder mix did help with
making perfect turns but is not required. The
model was fully capable of turning on ailerons
alone without a noticeable loss of altitude.
Approximately half throttle was the only
thing required to pilot the fighter around the
sky. I used brief bursts of power when setting
up for vertical maneuvers.
After a few low camera passes, it was time
to fly the Fokker like an Allied fighter was on
its tail. Keeping in mind I was piloting a WW
I biplane, it did not disappoint.
60 MODEL AVIATION
This model was highly capable of
performing any aerobatics or maneuvers that
were flown during the Great War. Loops,
rolls, and stall turns were easy to complete,
because the D.VII tracked well and was
responsive to control inputs.
One of this aircraft’s most impressive
characteristics was its stall performance. With
the throttle cut back and full up-elevator
applied, it was able to keep the nose up for a
respectable amount of time.
The Fokker provided me with a warning
when it finally did stall: a gentle break to the
left before falling off. Even then, it was easy
to recover.
Landing the D.VII was best done into the
wind. Don’t worry if you find yourself in a
light crosswind with this model, because the
rudder is effective. The airplane slowed nicely
and had good glide performance—so good
that a pilot might overshoot his or her first
landing approach.
To ensure that this doesn’t happen,
maintain a bit of throttle on landing to keep
air flowing over the control surfaces. Once
the Fokker touches down, pull back smoothly
on the elevator to plant the tail and use the
ailerons, if needed, to keep the wings level
until the rollout is complete.
The whole time I was flying the model, I
was impressed with its predictable flight
characteristics. It had the realistic look and
sound of a WW I fighter, with the manners of
a sport aircraft.
The Saito .82 was a great match for this
model. Not only did the engine provide
enough power to comfortably haul the D.VII
around the sky, but the unmistakable sound
was close to that of the Mercedes and BMW
engines found in the full-scale Fokkers.
That along with this fighter’s cool factor
made it worthy of all the money spent on the
cleaning supplies necessary to fly it! MA
Jay Smith
[email protected]
Manufacturer/Distributor:
Hangar 9/Horizon Hobby
4105 Fieldstone Rd.
Champaign IL 61822
(800) 338-4639
www.hangar-9.com
Sources:
Saito
(800) 338-4639
www.saitoengines.com
JR
(800) 338-4639
www.jrradios.com
Spektrum
(800) 338-4639
www.spektrumrc.com
Other Published Reviews:
R/C Report: December 2008
Model Airplane News: February 2009
Fly RC: May 2009
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