The Bravo can be ready to fly after less
than 10 hours of assembly time. Its
wing loading is in the light sport
range, at 25.2 ounces
per square foot.
Inverted flight required downelevator,
but this will be
corrected as the CG is moved
back. Inverted handling was as
precise and directional as
upright flight.
RC AIRCRAFT designed for demanding
Aerobatics (Pattern) competition are arguably
the best-performing, most forgiving sport
airplanes available. Many would argue that
modern Pattern aircraft simply fly better than
anything else in the air.
This was not always true; earlier Pattern
aircraft were short-coupled, heavy, and flew
on small, highly swept wings. The pilot had to
be far ahead of these airplanes, which in many
cases were capable of speeds exceeding 130
mph and landing speeds as high as 40 mph,
while making sure they didn’t snap roll into
the ground, which they were prone to do
given any excuse.
The mists of time may have us fondly
remembering those “Good Ol’ Days,” but the
truth is that a modern Pattern airplane
outperforms anything flying then or now.
With 1,000 square inches of wing and
weighing 10.5 pounds, its landing speed is 20
mph or less. That is basic trainer performance.
The top speed for these fixed-gear aircraft
is usually 100 mph, but the best performance
is in the 50-60 mph range; that is slower than
most sport airplanes. A good Pattern airplane
needs little rudder input in vertical climbs or
loops; performs perfect axial rolls; is
forgiving in all attitudes, airspeeds, and flight
regimes; and never offers to snap roll with
elevator input.
But if the pilot does want the model to
snap roll, it will do so with minimal
directional change and stop exactly on
command—immediately. That is a Pattern
aircraft’s greatest asset; it will go exactly
where the pilot commands it to go. Whether
flying inverted, in knife edge, rolling in a
climb, or heading straight down, it will never
deviate from its planned course.
If Pattern models are so easy to fly,
responsive, and capable of exacting flight
performance, why doesn’t every RC pilot fly
one? First, 2-meter ARF Pattern kits are not
readily available.
Second, models that are available range in
price from $500 to $3,200 (airframe only).
Third, building a Pattern airplane is exacting;
the job of properly locating the fuselage holes
for the wing tube is enough to make most of
us quit before we start.
High cost, poor availability, and tight
building tolerances have kept us average RC
pilots away from one of the best flying
experiences we could have. But now things
are changing. Design advances originally
made for 2-meter aircraft are finding their
way into slightly smaller Pattern airplanes that
fly almost as well.
The increasing number of such 60- to 90-
size airplane kits means greater availability
and lower cost. Modern ARF design has
reduced the builder’s workload by
incorporating the required exactness into the
assembly process itself.
How did they do that? Good question, and
that brings us to the subject of this review:
Black Horse Model’s new Bravo 303 Pattern
airplane. One of the “new breed” of 60- to 90-
The Bravo front end looks competitive. It
has a European appearance and a New York
attitude—perfect for competition or
aggressive sport flying.
This is how a modern Pattern aircraft handles on final
approach. Nose up roughly 20° idle at 2,100 rpm, and airspeed
approximately 20 mph. Landing roll is roughly 30 feet on grass.
size precision Aerobatics machines, the Bravo
303 is designed for the beginning Pattern pilot
and the sport flier who wants outstanding
performance without building hassles.
There is some good engineering here; the
way the Bravo incorporates the required
building accuracy into the airplane’s
construction is impressive. Construction is
lightweight and straight. The covering, which
is a form of Oracover, is tight and wrinkle
resistant and the cowling’s paint job is
stunning.
As you read the short building review,
keep in mind that there are a few differences
between building a Pattern airplane and a
good sport aircraft. For instance, Pattern
aircraft are built for durability. If used in
competition, a Pattern airplane will fly 200-
400 flights per season. Structure, control
surfaces, and all moving parts must be able to
survive constant use.
Pattern airplanes must be properly aligned
and balanced; building tolerances approach
1/64 inch. And most important of all, Pattern
airplanes are built as light as possible without
sacrificing durability.
The Design: The Bravo 303 is a midwing
aircraft. This helps make the rolls truly axial.
The 714-square-inch wing supports just 7.81
pounds. The resultant 25.2 ounces per square
foot of wing loading is in the light class for
sport models, providing excellent slow-flight
performance, maneuver accuracy, and slow
landing speeds.
The symmetrical airfoil makes inverted
flight and maneuvers consistent. However, the
stabilizer and vertical fin are flat as opposed
to having an airfoil shape. Airfoil surfaces are
always more effective, but the pilot will notice
the difference most during low-speed
maneuvers.
Most of the new low-cost Pattern airplanes
use this simple tail design. In theory the
performance of these aircraft should suffer,
but in reality the difference is just not that
meaningful.
The Bravo 303 is designed for a .61 twostroke
or .91 four-stroke glow engine, but
most Bravos I’ve seen at contests use a .91
two-stroke engine. This model handles that
engine well and has nearly unlimited vertical
performance operating with this power plant.
The Bravo uses independent servos for
each aileron and elevator half for fine-tuning
trim; few other low-cost Pattern airplanes
have this ability. The wing design permits
further fine tuning since the halves can be set
at individual incidences. But enough theory;
let’s build the thing and see how it flies.
Construction: The kit is complete, with all
the hardware and some extras. There is a
great deal of prefabrication here that is
seldom found in most ARF kits. For instance,
all control surfaces are hinged and pinned.
The wing mounting system and upper
canopy/deck/pilot are preinstalled.The fuel
tank is supplied preassembled, and the engine
mount and landing-gear bolts are factory
installed.
The cutouts for the horizontal stabilizer
The cables that link the rudder to the servo interfere with the
throttle servo. The throttle servo needs to be lowered or
exchanged for a low-profile type.
Each aileron servo mounts to factory-installed hard points. Short
pushrods were made with clevises at both ends, as the
recommended “bend wire” connections enlarge in time.
The vertical fin has extra gluing area for strength. Excess covering
from the slot was used to seal the joint. A metal triangle aids in
alignment.
The rear alignment pin determines attack angles and can be
adjusted by sanding. After test-flying, gluing the wing halves
together is an option.
and vertical fin are preshaped and accurate.
All the servo mounts, including the ailerons,
are completely ready for servo installation and
sized to fit modern standard-case servos.
The wing uses an aluminum tube spar and
dowel-rod alignment pins; there’s no spar glue
and the wing need not be glued together. And
as a bonus, its pull-pull rudder cables are
factory installed.
Wing assembly begins with the aileron
servos, which install directly onto cover plates
in the wing. If you want to employ spoilers,
which allow accurate landing placement and
prevent “bounced” landings, remember
output-arm placement.
JR radios are easier to program in
aileron/spoiler installations if the aileron servo
output shaft points outward toward the
wingtip. Futaba radios are easier to program if
the servo’s output shaft points to the inside,
toward the root of the wing.
Position the servo upright on the wing,
mark the correct side of the output shaft, and
then make sure that side is oriented out the
servo hatch slot when the servo is laid on its
side. Temporarily place a thin cardboard
spacer between the servo and the hatch during
servo installation so that it’s correctly isolated
from vibration. A 12-inch servo extension is
required.
For durability and strength, all the
adjustable control horns mount with three
screws completely through the control surface
and have two lock nuts. Make sure the aileron
control rods run in a straight line from the
servo output arms to the control horns.
Use clear tape or clear plastic model
covering to seal the aileron gaps. This makes
the ailerons more effective, allowing the
proper roll rate without excessive surface
movement that can cause nonaxial rolls.
Sealing also helps equalize each aileron’s
effectiveness.
On most ARFs this is the time to construct
the main spar and glue the wing halves
together, but the Bravo’s main spar is an
aluminum tube for extra rigidity and
durability. The wing alignment is determined
by a thick wooden dowel at the TE. The front
of the wing is held down by equal-size
wooden dowels.
You probably don’t have to glue the wing
halves together. The rear mounting bolts (all
factory drilled and the fuselage blind nuts
installed) and the front dowels hold the wing
in place. The photo-illustrated instruction
manual doesn’t mention gluing the wing
halves.
I took this as a trimming opportunity.
Two-Meter Pattern aircraft wing halves are
individually adjustable for incidence. The
Bravo accomplishes almost the same effect by
allowing a few trim flights and then sanding
the rear pin to adjust the incidence. The idea is
to adjust the wing incidence so that both
ailerons are neutral during level flight.
This Bravo needed no wing adjustment.
After the first two flights I glued the wing
halves together using slow epoxy. Why?
Because the front dowels and the rear
alignment pin will gradually wear, and that
will result in changing wing incidences.
+•
Factory-painted fiberglass cowling,
wheel pants.
• Detachable wing halves secured with
aluminum tubing.
• Prepainted, prefitted pilot and canopy.
• Preglued, pinned hinges on all control
surfaces.
• Preinstalled pull-pull rudder control
cables.
• Terrific flier.
-•
Small fuel tank when equipped
with .91 engine.
• Rudder cables interfere with the
throttle servo.
• Cutouts required for proper engine
cooling.
Pluses and Minuses
The Bravo 303 is a complete kit that has been well engineered for accurate
assembly. The hardware that accompanies this airplane is worth using.
Remember: durability plus more durability.
The centering marks are factory drawn on
the front and rear fuselage formers. Wow, talk
about making things easy! Center the wing
and measure the distance from each wingtip
to a pin located in the center of the rear
fuselage. Both distances must be equal. This
Bravo was equal to within 0.01 inch. That
worked for me!
The stabilizer and vertical fin attach as on
any other ARF, except that there is extra
support for the vertical fin. The extra strength
keeps the fin stiff during rudder-critical
maneuvers such as knife edge, Snap Rolls,
and Stall Turns.
When removing the covering from the
areas that receive epoxy, try using the
Hobbico Hot Knife (part HCAR0770) that has
the blade made dull with a file. The idea is to
use the heat to melt the covering without
Engine used: O.S. Engines .91 FX
Propeller: APC 15 x 8
Fuel: 450cc (13 ounces),
S&W 15% nitromethane
Radio system: JR 8103 transmitter;
R770 PCM receiver; NES 517 servos
on ailerons, elevators, and throttle,
DS8231 on rudder; 1100 mAh 4.8-volt
battery; two 18-inch, two 12-inch, and
two 6-inch extensions
Ready-to-fly weight: 7.81 pounds
Flight duration: 11 minutes
Test-Model Details
Model type: F3A sport Aerobatics ARF
Pilot skill level: Intermediate
Wingspan: 64.4 inches
Wing area: 714 square inches
Length: 65.4 inches
Weight: 7.7 pounds
Wing loading: 24.8 ounces per square foot
Engine: .61 (two-stroke), .91 (four-stroke)
Radio: Four channels (minimum), six servos
Construction: Balsa and plywood
Covering/finish: Covered with hand
iron-on Oracover film
Price: $179.99
Specifications
scoring the wood, and a dull blade works best
for that.
The Bravo uses two elevator servos and
18-inch servo extensions. Their mounts are
cleverly positioned so that a servo reverser is
not required, yet the linkage geometry
remains identical. Equal geometry means that
each elevator half moves exactly the same
amount.
Mixing the two elevator servos allows the
pilot to fine-tune movement for straight loop
segments. Seal the elevator gaps as you did
the aileron gaps. (You did seal the aileron
gaps, right? It makes a difference—I
promise.) Make sure the stabilizer is parallel
to the wing.
The rudder pull-pull cables, required for
precision centering, are factory installed
leading up to the front-mounted rudder servo.
There is a minor problem here. Since rudder
centering is critical, I used a true precision
Pattern servo: the JR DS8231. But that meant
the rudder cable did not clear the standardsize
throttle servo.
The rudder servo could not be raised or it
would hit the wing. An option is to lower the
throttle servo by cutting out the servo tray’s
mounting area and mounting short 1/8 x 1/2
birch beams on the underside of the tray. This
lowers the throttle servo so that the cables
can’t rub. The other option is to use a lowerprofile
servo on the throttle, which is the route
I took.
If this is your first rudder/cable
installation, remember one key point: exact
rudder centering is critical for making straight
maneuvers. Both cables must run in a straight
line from the servo to the rudder, without
deviation, for exact centering.
The Bravo is 1.45 inches wide where the
rudder cables exit the rear fuselage. Therefore,
the twin rudder control horns must be 1.45
inches apart. Use the two-sided Du-Bro Super
Strength Servo Arm, standard size (parts 673
and 675), and hook the cables to the holes
second from the end. Noted Pattern airplane
builder George Asteris taught me this trick. It
works wonders on those sticky rudders.
The engine mount is the two-beam variety
and is installed into the factory blind nuts. The
mount is made from a unique material. It is a
“soft” nylon with unique properties. First, it
seems to reduce sound levels, which is
important since Pattern airplanes must be
quieter than 96 decibels at 3 meters.
Second, the mount cannot be “tapped” in
the usual manner; I tried and nearly broke the
tap. Instead use the machine screws that come
with the Bravo. I know that is heresy, and
maybe worse, but the mount’s material locks
the screws in place and the engine remains
tightly secured, even after 34 flights.
Position the thrust washer 43/8 inches from
the firewall, mount the engine, hook up the
throttle, and then cut all the holes into that
beautifully painted cowling. You don’t want
to make a mistake here.
Mount the cowling first so it clears the
spinner backplate by 1/8 inch. Use the
cardboard-template trick to find out where the
cutouts need to be located. If you are using a
four-stroke engine, cut the inlet area of the top
“air scoop” to allow cool air to enter the
engine’s carburetor for increased power.
There is ample cooling-inlet air, but not
much outlet area. Cut a 2-inch-wide exit hole
in the bottom of the cowl. The manual
instructs to remove the entire cowling over the
gear-leg area. Instead, cut only two slots for
the legs. Make sure to use thread-locking
compound on the gear leg bolts since they
will not be visible once covered.
Instead of cutting holes in the outside of
the wheel pants, shorten the axles by 5/16 inch.
Cut away the thin cowling post that would
otherwise cover the engine’s air intake area
for maximum airflow.
The listed CG is 0.5 inch (14mm) in from
the LE at the fuselage—way too far forward.
The diagram is confusing and the 14mm may
refer to the wingtip. The best starting CG is at
47/8 inches back from the LE at the fuselage.
The first flights may be made with the CG
farther forward, but only knife-edge flight will
suffer. No weights were needed to obtain this
CG with the O.S. .91 FX up front.
Lateral balance is an extremely important
but often overlooked step. Since the wing has
no true dihedral, level flight and concentric
loops are impossible without good lateral
balance. Run nylon fishing line under the
bottom rudder hinge and under the crankshaft
(remove the propeller), and lift the aircraft.
One wingtip, usually on the muffler side, will
drop. Drive thin finishing nails into the lighter
wingtip until the aircraft remains level.
Control-surface movement was set on the
elevators at 7/8 inch of travel up and down. If
possible, mix the two elevator servos
instead of using a Y harness. This permits
the elevator movement to be fine-tuned for
precision loops.
Set the ailerons for 1/2 inch of
movement; no differential was needed on
the Bravo. Spoilers worked best when the
ailerons were raised 1/4 inch.
The book lists rudder movement as 3/4
inch, but that didn’t seem to be enough.
There is enough between the elevator halves
for 2 inches of rudder movement, so use it.
There are two schools of thought about
low/high rates vs. high rate with
exponential. I think IMAC (International
Miniature Aerobatic Club) pilots have
proven that the latter works best.
There is less to remember during the
stress of aerobatic flying using only one
rate. I tried many different exponential rates
(remember that these are JR settings) and
found the following to work best: elevator at
25%, ailerons at 30%, and rudder at 50%.
After trying many propellers ranging
from 14 to 16 inches, I picked the APC 15 x
8 Sport. While allowing slower flight speeds
(great for precision Aerobatics), the 16-inch
propellers produced too much torque for the
Bravo’s vertical side area, resulting in
excess rudder input. The 14-inch propellers
were too fast.
The 15 x 8 propeller produces nearly
unlimited vertical, is quieter, reduces engine
torque, and provides good “downhill”
braking. Braking is important as picking up
speed when pointed toward the ground
hastens maneuvers, giving the pilot less
time to prepare for the next segment. The
best idle speed I could get was 2,100 rpm.
Except for the rudder, this Bravo uses
standard sport servos (except on the
throttle?). If you intend to compete, use the
newer digital sport servos for more positive
control. The Bravo does not need $100
“Gee Whiz” servos, except on the rudder.
Flying: With the engine ticking over just
right, the Bravo 303 could be taxied out to
the runway and stopped approximately 120
feet from the midpoint. Ground steering was
positive and immediately effective. The
takeoff was initiated with the Bravo rolling
on the grass runway as throttle was applied.
The ground roll was straight and the
model lifted off at 80% throttle at midpoint
down the runway. Good for a “10,” maybe?
Initial climbout was straight, with no aileron
trim required and gentle with a 45° climb
angle.
The Bravo quickly climbed upstairs with
apparently no lack of vertical performance.
A few clicks of up-trim settled the Bravo
and the flying commenced.
The Bravo flew the procedure turn
without trying to gain altitude and steadied
up for the first rolling pass. Throw the
aileron stick all the way over and the Bravo
rolled at the correct speed—roughly three
rolls in five seconds. The nose never varied
from the flight path.
The model went into a full-power
vertical climb, a tall turn at the top, a half
roll down, and back into center, inverted. It
needed some down-elevator for this. The
Bravo pushed vertical at center without
dropping a wing and started rolling all the
way up. The nose remained straight—no
need for aileron differential on this airplane.
At approximately 500 feet high I stopped
the climb and threw all the controls into the
right corner. The Bravo did several “snaps”
and began to spin down. The spin rate was
moderate at approximately 11/2 turns per
second. Reversing the spin yielded roughly
the same rotational speed. Centering the
ailerons slowed the rotation to roughly one
turn per second.
Centering the rudder and elevator
immediately stopped the spin. I added
throttle and headed for the other corner. It
doesn’t look like quarter-roll Humpty
Bumps will be a problem either. But coming
back, the Four Point Roll proved the need
for some elevator trim as the airplane pulled
to the canopy on both knife edges and the
slow roll was sloppy.
It was time for some photo passes
anyway, so the Bravo and I quit our sky
games and went back to work. Flying photo
passes with this aircraft is like driving a
NASCAR racer in commuter traffic; it just
isn’t natural.
After the passes it was time to land.
Two-meter Pattern airplanes land like
feathers. They float down, nose high,
without needing to flare to a three-point
landing. The Bravo did exactly that.
It needed 12% (again, JR settings) of
down-elevator for left-rudder knife edge and
9% for right. There was also minor rudder/
bank coupling. Just 7% opposite aileron was
needed to eliminate coupling on both sides.
The CG was moved backward by adding
small tail weights. Not much—just a little—
but please make your first Bravo flights at
the CG I gave in the preceding. Adjust it
later, in small steps, if you think it’s
necessary.
Moving the CG rearward reduced
inverted down-elevator but quickened the
roll rate, so an extra 5% exponential was
added. Complete trimming how-to
information is posted on the National
Society of Radio Controlled Aerobatics
Web site: www.nsrca.org.
At this point the Bravo was ready to
light up the sky. And it did!
Snap Rolls remained on line and stopped
at the right point; there was no wandering
and no drifting. Slow Rolls ate up the sky
horizon to horizon. Concentric Inside and
Outside Loops were so easy they became
boring. Repeated Avalanches, inside and
outside, drew comments, as did the repeated
alternate Snap Rolls during the low passes.
Four Point, Eight Point, and opposite
Slow Rolls started to remind me of my
Temptation 2-meter Pattern airplane (one of
those $1,800 models I mentioned earlier).
That hurt some since the Bravo’s all-up cost
was less than 15% of the Temptation’s.
The second landing was identical to the
first but slower since I knew the aircraft
better. Final ground roll was less than 20
feet. It was time to refuel, which was the
Bravo’s one weak point.
The stock tank was almost all that could
fit into the fuselage, along with the battery
up front, without major surgery. The O.S.
.91 FX will run approximately 11 minutes
on a tank. Although that is time enough to
fly even the full FAI pattern and some
maneuvers, 15 minutes would be better; it
would allow a pilot to fly through the
maneuver sequence twice during practice.
There are now 34 flights on my Bravo,
including several trips through the Masters
pattern and the Sportsman and
Intermediate sequences. The Bravo flies
the latter two great, but the workload is
higher for Masters than with a 2-meter
airplane. (That’s why the big boys pay the
money.)
Still, I plan to practice with the Bravo
during the winter, even using skis if
needed. The airplane is that good.
I suspect that most Bravo 303s built
will never see competition, and that is fine.
It would do well in the Sportsman and
Intermediate classes, but it is also one of
the best sport airplanes I have ever flown.
If you do want to try competing, I
suggest a few changes. Use a Lithium-Ion
battery with a Mil Spec resistor switch.
Install a lightweight aluminum spinner,
carbon-fiber aileron linkages with ball
bearings, sport digital servos, and a larger
fuel tank. These modifications lighten the
Bravo while increasing control response.
Considering all the engineering, the
precision construction, the enormous
amount of prefabrication, and the model’s
excellent flying abilities, the $180 price tag
seems on the low side. This is a chance for
every RC pilot to experience what a
precision aircraft can do without having to
see a loan shark first.
Take this opportunity. You might not
fly any better, but you will definitely enjoy
flying more. MA
Frank Granelli
[email protected]
Manufacturer/Distributor:
Black Horse Model
Distributed exclusively by American Pioneer
Hobbies Inc.
7 Dana St.
Springfield MA 01104
(413) 781-2036
www.americanpioneerhobbies.com
Products Used in Review:
.91 FX engine
www.osengines.com
JR Propo radio:
www.horizonhobby.com
Hobbico Hot Knife:
www.hobbico.com
Du-Bro
http://dubro.com/hobby/
Edition: Model Aviation - 2007/02
Page Numbers: 55,56,57,58,62
Edition: Model Aviation - 2007/02
Page Numbers: 55,56,57,58,62
The Bravo can be ready to fly after less
than 10 hours of assembly time. Its
wing loading is in the light sport
range, at 25.2 ounces
per square foot.
Inverted flight required downelevator,
but this will be
corrected as the CG is moved
back. Inverted handling was as
precise and directional as
upright flight.
RC AIRCRAFT designed for demanding
Aerobatics (Pattern) competition are arguably
the best-performing, most forgiving sport
airplanes available. Many would argue that
modern Pattern aircraft simply fly better than
anything else in the air.
This was not always true; earlier Pattern
aircraft were short-coupled, heavy, and flew
on small, highly swept wings. The pilot had to
be far ahead of these airplanes, which in many
cases were capable of speeds exceeding 130
mph and landing speeds as high as 40 mph,
while making sure they didn’t snap roll into
the ground, which they were prone to do
given any excuse.
The mists of time may have us fondly
remembering those “Good Ol’ Days,” but the
truth is that a modern Pattern airplane
outperforms anything flying then or now.
With 1,000 square inches of wing and
weighing 10.5 pounds, its landing speed is 20
mph or less. That is basic trainer performance.
The top speed for these fixed-gear aircraft
is usually 100 mph, but the best performance
is in the 50-60 mph range; that is slower than
most sport airplanes. A good Pattern airplane
needs little rudder input in vertical climbs or
loops; performs perfect axial rolls; is
forgiving in all attitudes, airspeeds, and flight
regimes; and never offers to snap roll with
elevator input.
But if the pilot does want the model to
snap roll, it will do so with minimal
directional change and stop exactly on
command—immediately. That is a Pattern
aircraft’s greatest asset; it will go exactly
where the pilot commands it to go. Whether
flying inverted, in knife edge, rolling in a
climb, or heading straight down, it will never
deviate from its planned course.
If Pattern models are so easy to fly,
responsive, and capable of exacting flight
performance, why doesn’t every RC pilot fly
one? First, 2-meter ARF Pattern kits are not
readily available.
Second, models that are available range in
price from $500 to $3,200 (airframe only).
Third, building a Pattern airplane is exacting;
the job of properly locating the fuselage holes
for the wing tube is enough to make most of
us quit before we start.
High cost, poor availability, and tight
building tolerances have kept us average RC
pilots away from one of the best flying
experiences we could have. But now things
are changing. Design advances originally
made for 2-meter aircraft are finding their
way into slightly smaller Pattern airplanes that
fly almost as well.
The increasing number of such 60- to 90-
size airplane kits means greater availability
and lower cost. Modern ARF design has
reduced the builder’s workload by
incorporating the required exactness into the
assembly process itself.
How did they do that? Good question, and
that brings us to the subject of this review:
Black Horse Model’s new Bravo 303 Pattern
airplane. One of the “new breed” of 60- to 90-
The Bravo front end looks competitive. It
has a European appearance and a New York
attitude—perfect for competition or
aggressive sport flying.
This is how a modern Pattern aircraft handles on final
approach. Nose up roughly 20° idle at 2,100 rpm, and airspeed
approximately 20 mph. Landing roll is roughly 30 feet on grass.
size precision Aerobatics machines, the Bravo
303 is designed for the beginning Pattern pilot
and the sport flier who wants outstanding
performance without building hassles.
There is some good engineering here; the
way the Bravo incorporates the required
building accuracy into the airplane’s
construction is impressive. Construction is
lightweight and straight. The covering, which
is a form of Oracover, is tight and wrinkle
resistant and the cowling’s paint job is
stunning.
As you read the short building review,
keep in mind that there are a few differences
between building a Pattern airplane and a
good sport aircraft. For instance, Pattern
aircraft are built for durability. If used in
competition, a Pattern airplane will fly 200-
400 flights per season. Structure, control
surfaces, and all moving parts must be able to
survive constant use.
Pattern airplanes must be properly aligned
and balanced; building tolerances approach
1/64 inch. And most important of all, Pattern
airplanes are built as light as possible without
sacrificing durability.
The Design: The Bravo 303 is a midwing
aircraft. This helps make the rolls truly axial.
The 714-square-inch wing supports just 7.81
pounds. The resultant 25.2 ounces per square
foot of wing loading is in the light class for
sport models, providing excellent slow-flight
performance, maneuver accuracy, and slow
landing speeds.
The symmetrical airfoil makes inverted
flight and maneuvers consistent. However, the
stabilizer and vertical fin are flat as opposed
to having an airfoil shape. Airfoil surfaces are
always more effective, but the pilot will notice
the difference most during low-speed
maneuvers.
Most of the new low-cost Pattern airplanes
use this simple tail design. In theory the
performance of these aircraft should suffer,
but in reality the difference is just not that
meaningful.
The Bravo 303 is designed for a .61 twostroke
or .91 four-stroke glow engine, but
most Bravos I’ve seen at contests use a .91
two-stroke engine. This model handles that
engine well and has nearly unlimited vertical
performance operating with this power plant.
The Bravo uses independent servos for
each aileron and elevator half for fine-tuning
trim; few other low-cost Pattern airplanes
have this ability. The wing design permits
further fine tuning since the halves can be set
at individual incidences. But enough theory;
let’s build the thing and see how it flies.
Construction: The kit is complete, with all
the hardware and some extras. There is a
great deal of prefabrication here that is
seldom found in most ARF kits. For instance,
all control surfaces are hinged and pinned.
The wing mounting system and upper
canopy/deck/pilot are preinstalled.The fuel
tank is supplied preassembled, and the engine
mount and landing-gear bolts are factory
installed.
The cutouts for the horizontal stabilizer
The cables that link the rudder to the servo interfere with the
throttle servo. The throttle servo needs to be lowered or
exchanged for a low-profile type.
Each aileron servo mounts to factory-installed hard points. Short
pushrods were made with clevises at both ends, as the
recommended “bend wire” connections enlarge in time.
The vertical fin has extra gluing area for strength. Excess covering
from the slot was used to seal the joint. A metal triangle aids in
alignment.
The rear alignment pin determines attack angles and can be
adjusted by sanding. After test-flying, gluing the wing halves
together is an option.
and vertical fin are preshaped and accurate.
All the servo mounts, including the ailerons,
are completely ready for servo installation and
sized to fit modern standard-case servos.
The wing uses an aluminum tube spar and
dowel-rod alignment pins; there’s no spar glue
and the wing need not be glued together. And
as a bonus, its pull-pull rudder cables are
factory installed.
Wing assembly begins with the aileron
servos, which install directly onto cover plates
in the wing. If you want to employ spoilers,
which allow accurate landing placement and
prevent “bounced” landings, remember
output-arm placement.
JR radios are easier to program in
aileron/spoiler installations if the aileron servo
output shaft points outward toward the
wingtip. Futaba radios are easier to program if
the servo’s output shaft points to the inside,
toward the root of the wing.
Position the servo upright on the wing,
mark the correct side of the output shaft, and
then make sure that side is oriented out the
servo hatch slot when the servo is laid on its
side. Temporarily place a thin cardboard
spacer between the servo and the hatch during
servo installation so that it’s correctly isolated
from vibration. A 12-inch servo extension is
required.
For durability and strength, all the
adjustable control horns mount with three
screws completely through the control surface
and have two lock nuts. Make sure the aileron
control rods run in a straight line from the
servo output arms to the control horns.
Use clear tape or clear plastic model
covering to seal the aileron gaps. This makes
the ailerons more effective, allowing the
proper roll rate without excessive surface
movement that can cause nonaxial rolls.
Sealing also helps equalize each aileron’s
effectiveness.
On most ARFs this is the time to construct
the main spar and glue the wing halves
together, but the Bravo’s main spar is an
aluminum tube for extra rigidity and
durability. The wing alignment is determined
by a thick wooden dowel at the TE. The front
of the wing is held down by equal-size
wooden dowels.
You probably don’t have to glue the wing
halves together. The rear mounting bolts (all
factory drilled and the fuselage blind nuts
installed) and the front dowels hold the wing
in place. The photo-illustrated instruction
manual doesn’t mention gluing the wing
halves.
I took this as a trimming opportunity.
Two-Meter Pattern aircraft wing halves are
individually adjustable for incidence. The
Bravo accomplishes almost the same effect by
allowing a few trim flights and then sanding
the rear pin to adjust the incidence. The idea is
to adjust the wing incidence so that both
ailerons are neutral during level flight.
This Bravo needed no wing adjustment.
After the first two flights I glued the wing
halves together using slow epoxy. Why?
Because the front dowels and the rear
alignment pin will gradually wear, and that
will result in changing wing incidences.
+•
Factory-painted fiberglass cowling,
wheel pants.
• Detachable wing halves secured with
aluminum tubing.
• Prepainted, prefitted pilot and canopy.
• Preglued, pinned hinges on all control
surfaces.
• Preinstalled pull-pull rudder control
cables.
• Terrific flier.
-•
Small fuel tank when equipped
with .91 engine.
• Rudder cables interfere with the
throttle servo.
• Cutouts required for proper engine
cooling.
Pluses and Minuses
The Bravo 303 is a complete kit that has been well engineered for accurate
assembly. The hardware that accompanies this airplane is worth using.
Remember: durability plus more durability.
The centering marks are factory drawn on
the front and rear fuselage formers. Wow, talk
about making things easy! Center the wing
and measure the distance from each wingtip
to a pin located in the center of the rear
fuselage. Both distances must be equal. This
Bravo was equal to within 0.01 inch. That
worked for me!
The stabilizer and vertical fin attach as on
any other ARF, except that there is extra
support for the vertical fin. The extra strength
keeps the fin stiff during rudder-critical
maneuvers such as knife edge, Snap Rolls,
and Stall Turns.
When removing the covering from the
areas that receive epoxy, try using the
Hobbico Hot Knife (part HCAR0770) that has
the blade made dull with a file. The idea is to
use the heat to melt the covering without
Engine used: O.S. Engines .91 FX
Propeller: APC 15 x 8
Fuel: 450cc (13 ounces),
S&W 15% nitromethane
Radio system: JR 8103 transmitter;
R770 PCM receiver; NES 517 servos
on ailerons, elevators, and throttle,
DS8231 on rudder; 1100 mAh 4.8-volt
battery; two 18-inch, two 12-inch, and
two 6-inch extensions
Ready-to-fly weight: 7.81 pounds
Flight duration: 11 minutes
Test-Model Details
Model type: F3A sport Aerobatics ARF
Pilot skill level: Intermediate
Wingspan: 64.4 inches
Wing area: 714 square inches
Length: 65.4 inches
Weight: 7.7 pounds
Wing loading: 24.8 ounces per square foot
Engine: .61 (two-stroke), .91 (four-stroke)
Radio: Four channels (minimum), six servos
Construction: Balsa and plywood
Covering/finish: Covered with hand
iron-on Oracover film
Price: $179.99
Specifications
scoring the wood, and a dull blade works best
for that.
The Bravo uses two elevator servos and
18-inch servo extensions. Their mounts are
cleverly positioned so that a servo reverser is
not required, yet the linkage geometry
remains identical. Equal geometry means that
each elevator half moves exactly the same
amount.
Mixing the two elevator servos allows the
pilot to fine-tune movement for straight loop
segments. Seal the elevator gaps as you did
the aileron gaps. (You did seal the aileron
gaps, right? It makes a difference—I
promise.) Make sure the stabilizer is parallel
to the wing.
The rudder pull-pull cables, required for
precision centering, are factory installed
leading up to the front-mounted rudder servo.
There is a minor problem here. Since rudder
centering is critical, I used a true precision
Pattern servo: the JR DS8231. But that meant
the rudder cable did not clear the standardsize
throttle servo.
The rudder servo could not be raised or it
would hit the wing. An option is to lower the
throttle servo by cutting out the servo tray’s
mounting area and mounting short 1/8 x 1/2
birch beams on the underside of the tray. This
lowers the throttle servo so that the cables
can’t rub. The other option is to use a lowerprofile
servo on the throttle, which is the route
I took.
If this is your first rudder/cable
installation, remember one key point: exact
rudder centering is critical for making straight
maneuvers. Both cables must run in a straight
line from the servo to the rudder, without
deviation, for exact centering.
The Bravo is 1.45 inches wide where the
rudder cables exit the rear fuselage. Therefore,
the twin rudder control horns must be 1.45
inches apart. Use the two-sided Du-Bro Super
Strength Servo Arm, standard size (parts 673
and 675), and hook the cables to the holes
second from the end. Noted Pattern airplane
builder George Asteris taught me this trick. It
works wonders on those sticky rudders.
The engine mount is the two-beam variety
and is installed into the factory blind nuts. The
mount is made from a unique material. It is a
“soft” nylon with unique properties. First, it
seems to reduce sound levels, which is
important since Pattern airplanes must be
quieter than 96 decibels at 3 meters.
Second, the mount cannot be “tapped” in
the usual manner; I tried and nearly broke the
tap. Instead use the machine screws that come
with the Bravo. I know that is heresy, and
maybe worse, but the mount’s material locks
the screws in place and the engine remains
tightly secured, even after 34 flights.
Position the thrust washer 43/8 inches from
the firewall, mount the engine, hook up the
throttle, and then cut all the holes into that
beautifully painted cowling. You don’t want
to make a mistake here.
Mount the cowling first so it clears the
spinner backplate by 1/8 inch. Use the
cardboard-template trick to find out where the
cutouts need to be located. If you are using a
four-stroke engine, cut the inlet area of the top
“air scoop” to allow cool air to enter the
engine’s carburetor for increased power.
There is ample cooling-inlet air, but not
much outlet area. Cut a 2-inch-wide exit hole
in the bottom of the cowl. The manual
instructs to remove the entire cowling over the
gear-leg area. Instead, cut only two slots for
the legs. Make sure to use thread-locking
compound on the gear leg bolts since they
will not be visible once covered.
Instead of cutting holes in the outside of
the wheel pants, shorten the axles by 5/16 inch.
Cut away the thin cowling post that would
otherwise cover the engine’s air intake area
for maximum airflow.
The listed CG is 0.5 inch (14mm) in from
the LE at the fuselage—way too far forward.
The diagram is confusing and the 14mm may
refer to the wingtip. The best starting CG is at
47/8 inches back from the LE at the fuselage.
The first flights may be made with the CG
farther forward, but only knife-edge flight will
suffer. No weights were needed to obtain this
CG with the O.S. .91 FX up front.
Lateral balance is an extremely important
but often overlooked step. Since the wing has
no true dihedral, level flight and concentric
loops are impossible without good lateral
balance. Run nylon fishing line under the
bottom rudder hinge and under the crankshaft
(remove the propeller), and lift the aircraft.
One wingtip, usually on the muffler side, will
drop. Drive thin finishing nails into the lighter
wingtip until the aircraft remains level.
Control-surface movement was set on the
elevators at 7/8 inch of travel up and down. If
possible, mix the two elevator servos
instead of using a Y harness. This permits
the elevator movement to be fine-tuned for
precision loops.
Set the ailerons for 1/2 inch of
movement; no differential was needed on
the Bravo. Spoilers worked best when the
ailerons were raised 1/4 inch.
The book lists rudder movement as 3/4
inch, but that didn’t seem to be enough.
There is enough between the elevator halves
for 2 inches of rudder movement, so use it.
There are two schools of thought about
low/high rates vs. high rate with
exponential. I think IMAC (International
Miniature Aerobatic Club) pilots have
proven that the latter works best.
There is less to remember during the
stress of aerobatic flying using only one
rate. I tried many different exponential rates
(remember that these are JR settings) and
found the following to work best: elevator at
25%, ailerons at 30%, and rudder at 50%.
After trying many propellers ranging
from 14 to 16 inches, I picked the APC 15 x
8 Sport. While allowing slower flight speeds
(great for precision Aerobatics), the 16-inch
propellers produced too much torque for the
Bravo’s vertical side area, resulting in
excess rudder input. The 14-inch propellers
were too fast.
The 15 x 8 propeller produces nearly
unlimited vertical, is quieter, reduces engine
torque, and provides good “downhill”
braking. Braking is important as picking up
speed when pointed toward the ground
hastens maneuvers, giving the pilot less
time to prepare for the next segment. The
best idle speed I could get was 2,100 rpm.
Except for the rudder, this Bravo uses
standard sport servos (except on the
throttle?). If you intend to compete, use the
newer digital sport servos for more positive
control. The Bravo does not need $100
“Gee Whiz” servos, except on the rudder.
Flying: With the engine ticking over just
right, the Bravo 303 could be taxied out to
the runway and stopped approximately 120
feet from the midpoint. Ground steering was
positive and immediately effective. The
takeoff was initiated with the Bravo rolling
on the grass runway as throttle was applied.
The ground roll was straight and the
model lifted off at 80% throttle at midpoint
down the runway. Good for a “10,” maybe?
Initial climbout was straight, with no aileron
trim required and gentle with a 45° climb
angle.
The Bravo quickly climbed upstairs with
apparently no lack of vertical performance.
A few clicks of up-trim settled the Bravo
and the flying commenced.
The Bravo flew the procedure turn
without trying to gain altitude and steadied
up for the first rolling pass. Throw the
aileron stick all the way over and the Bravo
rolled at the correct speed—roughly three
rolls in five seconds. The nose never varied
from the flight path.
The model went into a full-power
vertical climb, a tall turn at the top, a half
roll down, and back into center, inverted. It
needed some down-elevator for this. The
Bravo pushed vertical at center without
dropping a wing and started rolling all the
way up. The nose remained straight—no
need for aileron differential on this airplane.
At approximately 500 feet high I stopped
the climb and threw all the controls into the
right corner. The Bravo did several “snaps”
and began to spin down. The spin rate was
moderate at approximately 11/2 turns per
second. Reversing the spin yielded roughly
the same rotational speed. Centering the
ailerons slowed the rotation to roughly one
turn per second.
Centering the rudder and elevator
immediately stopped the spin. I added
throttle and headed for the other corner. It
doesn’t look like quarter-roll Humpty
Bumps will be a problem either. But coming
back, the Four Point Roll proved the need
for some elevator trim as the airplane pulled
to the canopy on both knife edges and the
slow roll was sloppy.
It was time for some photo passes
anyway, so the Bravo and I quit our sky
games and went back to work. Flying photo
passes with this aircraft is like driving a
NASCAR racer in commuter traffic; it just
isn’t natural.
After the passes it was time to land.
Two-meter Pattern airplanes land like
feathers. They float down, nose high,
without needing to flare to a three-point
landing. The Bravo did exactly that.
It needed 12% (again, JR settings) of
down-elevator for left-rudder knife edge and
9% for right. There was also minor rudder/
bank coupling. Just 7% opposite aileron was
needed to eliminate coupling on both sides.
The CG was moved backward by adding
small tail weights. Not much—just a little—
but please make your first Bravo flights at
the CG I gave in the preceding. Adjust it
later, in small steps, if you think it’s
necessary.
Moving the CG rearward reduced
inverted down-elevator but quickened the
roll rate, so an extra 5% exponential was
added. Complete trimming how-to
information is posted on the National
Society of Radio Controlled Aerobatics
Web site: www.nsrca.org.
At this point the Bravo was ready to
light up the sky. And it did!
Snap Rolls remained on line and stopped
at the right point; there was no wandering
and no drifting. Slow Rolls ate up the sky
horizon to horizon. Concentric Inside and
Outside Loops were so easy they became
boring. Repeated Avalanches, inside and
outside, drew comments, as did the repeated
alternate Snap Rolls during the low passes.
Four Point, Eight Point, and opposite
Slow Rolls started to remind me of my
Temptation 2-meter Pattern airplane (one of
those $1,800 models I mentioned earlier).
That hurt some since the Bravo’s all-up cost
was less than 15% of the Temptation’s.
The second landing was identical to the
first but slower since I knew the aircraft
better. Final ground roll was less than 20
feet. It was time to refuel, which was the
Bravo’s one weak point.
The stock tank was almost all that could
fit into the fuselage, along with the battery
up front, without major surgery. The O.S.
.91 FX will run approximately 11 minutes
on a tank. Although that is time enough to
fly even the full FAI pattern and some
maneuvers, 15 minutes would be better; it
would allow a pilot to fly through the
maneuver sequence twice during practice.
There are now 34 flights on my Bravo,
including several trips through the Masters
pattern and the Sportsman and
Intermediate sequences. The Bravo flies
the latter two great, but the workload is
higher for Masters than with a 2-meter
airplane. (That’s why the big boys pay the
money.)
Still, I plan to practice with the Bravo
during the winter, even using skis if
needed. The airplane is that good.
I suspect that most Bravo 303s built
will never see competition, and that is fine.
It would do well in the Sportsman and
Intermediate classes, but it is also one of
the best sport airplanes I have ever flown.
If you do want to try competing, I
suggest a few changes. Use a Lithium-Ion
battery with a Mil Spec resistor switch.
Install a lightweight aluminum spinner,
carbon-fiber aileron linkages with ball
bearings, sport digital servos, and a larger
fuel tank. These modifications lighten the
Bravo while increasing control response.
Considering all the engineering, the
precision construction, the enormous
amount of prefabrication, and the model’s
excellent flying abilities, the $180 price tag
seems on the low side. This is a chance for
every RC pilot to experience what a
precision aircraft can do without having to
see a loan shark first.
Take this opportunity. You might not
fly any better, but you will definitely enjoy
flying more. MA
Frank Granelli
[email protected]
Manufacturer/Distributor:
Black Horse Model
Distributed exclusively by American Pioneer
Hobbies Inc.
7 Dana St.
Springfield MA 01104
(413) 781-2036
www.americanpioneerhobbies.com
Products Used in Review:
.91 FX engine
www.osengines.com
JR Propo radio:
www.horizonhobby.com
Hobbico Hot Knife:
www.hobbico.com
Du-Bro
http://dubro.com/hobby/
Edition: Model Aviation - 2007/02
Page Numbers: 55,56,57,58,62
The Bravo can be ready to fly after less
than 10 hours of assembly time. Its
wing loading is in the light sport
range, at 25.2 ounces
per square foot.
Inverted flight required downelevator,
but this will be
corrected as the CG is moved
back. Inverted handling was as
precise and directional as
upright flight.
RC AIRCRAFT designed for demanding
Aerobatics (Pattern) competition are arguably
the best-performing, most forgiving sport
airplanes available. Many would argue that
modern Pattern aircraft simply fly better than
anything else in the air.
This was not always true; earlier Pattern
aircraft were short-coupled, heavy, and flew
on small, highly swept wings. The pilot had to
be far ahead of these airplanes, which in many
cases were capable of speeds exceeding 130
mph and landing speeds as high as 40 mph,
while making sure they didn’t snap roll into
the ground, which they were prone to do
given any excuse.
The mists of time may have us fondly
remembering those “Good Ol’ Days,” but the
truth is that a modern Pattern airplane
outperforms anything flying then or now.
With 1,000 square inches of wing and
weighing 10.5 pounds, its landing speed is 20
mph or less. That is basic trainer performance.
The top speed for these fixed-gear aircraft
is usually 100 mph, but the best performance
is in the 50-60 mph range; that is slower than
most sport airplanes. A good Pattern airplane
needs little rudder input in vertical climbs or
loops; performs perfect axial rolls; is
forgiving in all attitudes, airspeeds, and flight
regimes; and never offers to snap roll with
elevator input.
But if the pilot does want the model to
snap roll, it will do so with minimal
directional change and stop exactly on
command—immediately. That is a Pattern
aircraft’s greatest asset; it will go exactly
where the pilot commands it to go. Whether
flying inverted, in knife edge, rolling in a
climb, or heading straight down, it will never
deviate from its planned course.
If Pattern models are so easy to fly,
responsive, and capable of exacting flight
performance, why doesn’t every RC pilot fly
one? First, 2-meter ARF Pattern kits are not
readily available.
Second, models that are available range in
price from $500 to $3,200 (airframe only).
Third, building a Pattern airplane is exacting;
the job of properly locating the fuselage holes
for the wing tube is enough to make most of
us quit before we start.
High cost, poor availability, and tight
building tolerances have kept us average RC
pilots away from one of the best flying
experiences we could have. But now things
are changing. Design advances originally
made for 2-meter aircraft are finding their
way into slightly smaller Pattern airplanes that
fly almost as well.
The increasing number of such 60- to 90-
size airplane kits means greater availability
and lower cost. Modern ARF design has
reduced the builder’s workload by
incorporating the required exactness into the
assembly process itself.
How did they do that? Good question, and
that brings us to the subject of this review:
Black Horse Model’s new Bravo 303 Pattern
airplane. One of the “new breed” of 60- to 90-
The Bravo front end looks competitive. It
has a European appearance and a New York
attitude—perfect for competition or
aggressive sport flying.
This is how a modern Pattern aircraft handles on final
approach. Nose up roughly 20° idle at 2,100 rpm, and airspeed
approximately 20 mph. Landing roll is roughly 30 feet on grass.
size precision Aerobatics machines, the Bravo
303 is designed for the beginning Pattern pilot
and the sport flier who wants outstanding
performance without building hassles.
There is some good engineering here; the
way the Bravo incorporates the required
building accuracy into the airplane’s
construction is impressive. Construction is
lightweight and straight. The covering, which
is a form of Oracover, is tight and wrinkle
resistant and the cowling’s paint job is
stunning.
As you read the short building review,
keep in mind that there are a few differences
between building a Pattern airplane and a
good sport aircraft. For instance, Pattern
aircraft are built for durability. If used in
competition, a Pattern airplane will fly 200-
400 flights per season. Structure, control
surfaces, and all moving parts must be able to
survive constant use.
Pattern airplanes must be properly aligned
and balanced; building tolerances approach
1/64 inch. And most important of all, Pattern
airplanes are built as light as possible without
sacrificing durability.
The Design: The Bravo 303 is a midwing
aircraft. This helps make the rolls truly axial.
The 714-square-inch wing supports just 7.81
pounds. The resultant 25.2 ounces per square
foot of wing loading is in the light class for
sport models, providing excellent slow-flight
performance, maneuver accuracy, and slow
landing speeds.
The symmetrical airfoil makes inverted
flight and maneuvers consistent. However, the
stabilizer and vertical fin are flat as opposed
to having an airfoil shape. Airfoil surfaces are
always more effective, but the pilot will notice
the difference most during low-speed
maneuvers.
Most of the new low-cost Pattern airplanes
use this simple tail design. In theory the
performance of these aircraft should suffer,
but in reality the difference is just not that
meaningful.
The Bravo 303 is designed for a .61 twostroke
or .91 four-stroke glow engine, but
most Bravos I’ve seen at contests use a .91
two-stroke engine. This model handles that
engine well and has nearly unlimited vertical
performance operating with this power plant.
The Bravo uses independent servos for
each aileron and elevator half for fine-tuning
trim; few other low-cost Pattern airplanes
have this ability. The wing design permits
further fine tuning since the halves can be set
at individual incidences. But enough theory;
let’s build the thing and see how it flies.
Construction: The kit is complete, with all
the hardware and some extras. There is a
great deal of prefabrication here that is
seldom found in most ARF kits. For instance,
all control surfaces are hinged and pinned.
The wing mounting system and upper
canopy/deck/pilot are preinstalled.The fuel
tank is supplied preassembled, and the engine
mount and landing-gear bolts are factory
installed.
The cutouts for the horizontal stabilizer
The cables that link the rudder to the servo interfere with the
throttle servo. The throttle servo needs to be lowered or
exchanged for a low-profile type.
Each aileron servo mounts to factory-installed hard points. Short
pushrods were made with clevises at both ends, as the
recommended “bend wire” connections enlarge in time.
The vertical fin has extra gluing area for strength. Excess covering
from the slot was used to seal the joint. A metal triangle aids in
alignment.
The rear alignment pin determines attack angles and can be
adjusted by sanding. After test-flying, gluing the wing halves
together is an option.
and vertical fin are preshaped and accurate.
All the servo mounts, including the ailerons,
are completely ready for servo installation and
sized to fit modern standard-case servos.
The wing uses an aluminum tube spar and
dowel-rod alignment pins; there’s no spar glue
and the wing need not be glued together. And
as a bonus, its pull-pull rudder cables are
factory installed.
Wing assembly begins with the aileron
servos, which install directly onto cover plates
in the wing. If you want to employ spoilers,
which allow accurate landing placement and
prevent “bounced” landings, remember
output-arm placement.
JR radios are easier to program in
aileron/spoiler installations if the aileron servo
output shaft points outward toward the
wingtip. Futaba radios are easier to program if
the servo’s output shaft points to the inside,
toward the root of the wing.
Position the servo upright on the wing,
mark the correct side of the output shaft, and
then make sure that side is oriented out the
servo hatch slot when the servo is laid on its
side. Temporarily place a thin cardboard
spacer between the servo and the hatch during
servo installation so that it’s correctly isolated
from vibration. A 12-inch servo extension is
required.
For durability and strength, all the
adjustable control horns mount with three
screws completely through the control surface
and have two lock nuts. Make sure the aileron
control rods run in a straight line from the
servo output arms to the control horns.
Use clear tape or clear plastic model
covering to seal the aileron gaps. This makes
the ailerons more effective, allowing the
proper roll rate without excessive surface
movement that can cause nonaxial rolls.
Sealing also helps equalize each aileron’s
effectiveness.
On most ARFs this is the time to construct
the main spar and glue the wing halves
together, but the Bravo’s main spar is an
aluminum tube for extra rigidity and
durability. The wing alignment is determined
by a thick wooden dowel at the TE. The front
of the wing is held down by equal-size
wooden dowels.
You probably don’t have to glue the wing
halves together. The rear mounting bolts (all
factory drilled and the fuselage blind nuts
installed) and the front dowels hold the wing
in place. The photo-illustrated instruction
manual doesn’t mention gluing the wing
halves.
I took this as a trimming opportunity.
Two-Meter Pattern aircraft wing halves are
individually adjustable for incidence. The
Bravo accomplishes almost the same effect by
allowing a few trim flights and then sanding
the rear pin to adjust the incidence. The idea is
to adjust the wing incidence so that both
ailerons are neutral during level flight.
This Bravo needed no wing adjustment.
After the first two flights I glued the wing
halves together using slow epoxy. Why?
Because the front dowels and the rear
alignment pin will gradually wear, and that
will result in changing wing incidences.
+•
Factory-painted fiberglass cowling,
wheel pants.
• Detachable wing halves secured with
aluminum tubing.
• Prepainted, prefitted pilot and canopy.
• Preglued, pinned hinges on all control
surfaces.
• Preinstalled pull-pull rudder control
cables.
• Terrific flier.
-•
Small fuel tank when equipped
with .91 engine.
• Rudder cables interfere with the
throttle servo.
• Cutouts required for proper engine
cooling.
Pluses and Minuses
The Bravo 303 is a complete kit that has been well engineered for accurate
assembly. The hardware that accompanies this airplane is worth using.
Remember: durability plus more durability.
The centering marks are factory drawn on
the front and rear fuselage formers. Wow, talk
about making things easy! Center the wing
and measure the distance from each wingtip
to a pin located in the center of the rear
fuselage. Both distances must be equal. This
Bravo was equal to within 0.01 inch. That
worked for me!
The stabilizer and vertical fin attach as on
any other ARF, except that there is extra
support for the vertical fin. The extra strength
keeps the fin stiff during rudder-critical
maneuvers such as knife edge, Snap Rolls,
and Stall Turns.
When removing the covering from the
areas that receive epoxy, try using the
Hobbico Hot Knife (part HCAR0770) that has
the blade made dull with a file. The idea is to
use the heat to melt the covering without
Engine used: O.S. Engines .91 FX
Propeller: APC 15 x 8
Fuel: 450cc (13 ounces),
S&W 15% nitromethane
Radio system: JR 8103 transmitter;
R770 PCM receiver; NES 517 servos
on ailerons, elevators, and throttle,
DS8231 on rudder; 1100 mAh 4.8-volt
battery; two 18-inch, two 12-inch, and
two 6-inch extensions
Ready-to-fly weight: 7.81 pounds
Flight duration: 11 minutes
Test-Model Details
Model type: F3A sport Aerobatics ARF
Pilot skill level: Intermediate
Wingspan: 64.4 inches
Wing area: 714 square inches
Length: 65.4 inches
Weight: 7.7 pounds
Wing loading: 24.8 ounces per square foot
Engine: .61 (two-stroke), .91 (four-stroke)
Radio: Four channels (minimum), six servos
Construction: Balsa and plywood
Covering/finish: Covered with hand
iron-on Oracover film
Price: $179.99
Specifications
scoring the wood, and a dull blade works best
for that.
The Bravo uses two elevator servos and
18-inch servo extensions. Their mounts are
cleverly positioned so that a servo reverser is
not required, yet the linkage geometry
remains identical. Equal geometry means that
each elevator half moves exactly the same
amount.
Mixing the two elevator servos allows the
pilot to fine-tune movement for straight loop
segments. Seal the elevator gaps as you did
the aileron gaps. (You did seal the aileron
gaps, right? It makes a difference—I
promise.) Make sure the stabilizer is parallel
to the wing.
The rudder pull-pull cables, required for
precision centering, are factory installed
leading up to the front-mounted rudder servo.
There is a minor problem here. Since rudder
centering is critical, I used a true precision
Pattern servo: the JR DS8231. But that meant
the rudder cable did not clear the standardsize
throttle servo.
The rudder servo could not be raised or it
would hit the wing. An option is to lower the
throttle servo by cutting out the servo tray’s
mounting area and mounting short 1/8 x 1/2
birch beams on the underside of the tray. This
lowers the throttle servo so that the cables
can’t rub. The other option is to use a lowerprofile
servo on the throttle, which is the route
I took.
If this is your first rudder/cable
installation, remember one key point: exact
rudder centering is critical for making straight
maneuvers. Both cables must run in a straight
line from the servo to the rudder, without
deviation, for exact centering.
The Bravo is 1.45 inches wide where the
rudder cables exit the rear fuselage. Therefore,
the twin rudder control horns must be 1.45
inches apart. Use the two-sided Du-Bro Super
Strength Servo Arm, standard size (parts 673
and 675), and hook the cables to the holes
second from the end. Noted Pattern airplane
builder George Asteris taught me this trick. It
works wonders on those sticky rudders.
The engine mount is the two-beam variety
and is installed into the factory blind nuts. The
mount is made from a unique material. It is a
“soft” nylon with unique properties. First, it
seems to reduce sound levels, which is
important since Pattern airplanes must be
quieter than 96 decibels at 3 meters.
Second, the mount cannot be “tapped” in
the usual manner; I tried and nearly broke the
tap. Instead use the machine screws that come
with the Bravo. I know that is heresy, and
maybe worse, but the mount’s material locks
the screws in place and the engine remains
tightly secured, even after 34 flights.
Position the thrust washer 43/8 inches from
the firewall, mount the engine, hook up the
throttle, and then cut all the holes into that
beautifully painted cowling. You don’t want
to make a mistake here.
Mount the cowling first so it clears the
spinner backplate by 1/8 inch. Use the
cardboard-template trick to find out where the
cutouts need to be located. If you are using a
four-stroke engine, cut the inlet area of the top
“air scoop” to allow cool air to enter the
engine’s carburetor for increased power.
There is ample cooling-inlet air, but not
much outlet area. Cut a 2-inch-wide exit hole
in the bottom of the cowl. The manual
instructs to remove the entire cowling over the
gear-leg area. Instead, cut only two slots for
the legs. Make sure to use thread-locking
compound on the gear leg bolts since they
will not be visible once covered.
Instead of cutting holes in the outside of
the wheel pants, shorten the axles by 5/16 inch.
Cut away the thin cowling post that would
otherwise cover the engine’s air intake area
for maximum airflow.
The listed CG is 0.5 inch (14mm) in from
the LE at the fuselage—way too far forward.
The diagram is confusing and the 14mm may
refer to the wingtip. The best starting CG is at
47/8 inches back from the LE at the fuselage.
The first flights may be made with the CG
farther forward, but only knife-edge flight will
suffer. No weights were needed to obtain this
CG with the O.S. .91 FX up front.
Lateral balance is an extremely important
but often overlooked step. Since the wing has
no true dihedral, level flight and concentric
loops are impossible without good lateral
balance. Run nylon fishing line under the
bottom rudder hinge and under the crankshaft
(remove the propeller), and lift the aircraft.
One wingtip, usually on the muffler side, will
drop. Drive thin finishing nails into the lighter
wingtip until the aircraft remains level.
Control-surface movement was set on the
elevators at 7/8 inch of travel up and down. If
possible, mix the two elevator servos
instead of using a Y harness. This permits
the elevator movement to be fine-tuned for
precision loops.
Set the ailerons for 1/2 inch of
movement; no differential was needed on
the Bravo. Spoilers worked best when the
ailerons were raised 1/4 inch.
The book lists rudder movement as 3/4
inch, but that didn’t seem to be enough.
There is enough between the elevator halves
for 2 inches of rudder movement, so use it.
There are two schools of thought about
low/high rates vs. high rate with
exponential. I think IMAC (International
Miniature Aerobatic Club) pilots have
proven that the latter works best.
There is less to remember during the
stress of aerobatic flying using only one
rate. I tried many different exponential rates
(remember that these are JR settings) and
found the following to work best: elevator at
25%, ailerons at 30%, and rudder at 50%.
After trying many propellers ranging
from 14 to 16 inches, I picked the APC 15 x
8 Sport. While allowing slower flight speeds
(great for precision Aerobatics), the 16-inch
propellers produced too much torque for the
Bravo’s vertical side area, resulting in
excess rudder input. The 14-inch propellers
were too fast.
The 15 x 8 propeller produces nearly
unlimited vertical, is quieter, reduces engine
torque, and provides good “downhill”
braking. Braking is important as picking up
speed when pointed toward the ground
hastens maneuvers, giving the pilot less
time to prepare for the next segment. The
best idle speed I could get was 2,100 rpm.
Except for the rudder, this Bravo uses
standard sport servos (except on the
throttle?). If you intend to compete, use the
newer digital sport servos for more positive
control. The Bravo does not need $100
“Gee Whiz” servos, except on the rudder.
Flying: With the engine ticking over just
right, the Bravo 303 could be taxied out to
the runway and stopped approximately 120
feet from the midpoint. Ground steering was
positive and immediately effective. The
takeoff was initiated with the Bravo rolling
on the grass runway as throttle was applied.
The ground roll was straight and the
model lifted off at 80% throttle at midpoint
down the runway. Good for a “10,” maybe?
Initial climbout was straight, with no aileron
trim required and gentle with a 45° climb
angle.
The Bravo quickly climbed upstairs with
apparently no lack of vertical performance.
A few clicks of up-trim settled the Bravo
and the flying commenced.
The Bravo flew the procedure turn
without trying to gain altitude and steadied
up for the first rolling pass. Throw the
aileron stick all the way over and the Bravo
rolled at the correct speed—roughly three
rolls in five seconds. The nose never varied
from the flight path.
The model went into a full-power
vertical climb, a tall turn at the top, a half
roll down, and back into center, inverted. It
needed some down-elevator for this. The
Bravo pushed vertical at center without
dropping a wing and started rolling all the
way up. The nose remained straight—no
need for aileron differential on this airplane.
At approximately 500 feet high I stopped
the climb and threw all the controls into the
right corner. The Bravo did several “snaps”
and began to spin down. The spin rate was
moderate at approximately 11/2 turns per
second. Reversing the spin yielded roughly
the same rotational speed. Centering the
ailerons slowed the rotation to roughly one
turn per second.
Centering the rudder and elevator
immediately stopped the spin. I added
throttle and headed for the other corner. It
doesn’t look like quarter-roll Humpty
Bumps will be a problem either. But coming
back, the Four Point Roll proved the need
for some elevator trim as the airplane pulled
to the canopy on both knife edges and the
slow roll was sloppy.
It was time for some photo passes
anyway, so the Bravo and I quit our sky
games and went back to work. Flying photo
passes with this aircraft is like driving a
NASCAR racer in commuter traffic; it just
isn’t natural.
After the passes it was time to land.
Two-meter Pattern airplanes land like
feathers. They float down, nose high,
without needing to flare to a three-point
landing. The Bravo did exactly that.
It needed 12% (again, JR settings) of
down-elevator for left-rudder knife edge and
9% for right. There was also minor rudder/
bank coupling. Just 7% opposite aileron was
needed to eliminate coupling on both sides.
The CG was moved backward by adding
small tail weights. Not much—just a little—
but please make your first Bravo flights at
the CG I gave in the preceding. Adjust it
later, in small steps, if you think it’s
necessary.
Moving the CG rearward reduced
inverted down-elevator but quickened the
roll rate, so an extra 5% exponential was
added. Complete trimming how-to
information is posted on the National
Society of Radio Controlled Aerobatics
Web site: www.nsrca.org.
At this point the Bravo was ready to
light up the sky. And it did!
Snap Rolls remained on line and stopped
at the right point; there was no wandering
and no drifting. Slow Rolls ate up the sky
horizon to horizon. Concentric Inside and
Outside Loops were so easy they became
boring. Repeated Avalanches, inside and
outside, drew comments, as did the repeated
alternate Snap Rolls during the low passes.
Four Point, Eight Point, and opposite
Slow Rolls started to remind me of my
Temptation 2-meter Pattern airplane (one of
those $1,800 models I mentioned earlier).
That hurt some since the Bravo’s all-up cost
was less than 15% of the Temptation’s.
The second landing was identical to the
first but slower since I knew the aircraft
better. Final ground roll was less than 20
feet. It was time to refuel, which was the
Bravo’s one weak point.
The stock tank was almost all that could
fit into the fuselage, along with the battery
up front, without major surgery. The O.S.
.91 FX will run approximately 11 minutes
on a tank. Although that is time enough to
fly even the full FAI pattern and some
maneuvers, 15 minutes would be better; it
would allow a pilot to fly through the
maneuver sequence twice during practice.
There are now 34 flights on my Bravo,
including several trips through the Masters
pattern and the Sportsman and
Intermediate sequences. The Bravo flies
the latter two great, but the workload is
higher for Masters than with a 2-meter
airplane. (That’s why the big boys pay the
money.)
Still, I plan to practice with the Bravo
during the winter, even using skis if
needed. The airplane is that good.
I suspect that most Bravo 303s built
will never see competition, and that is fine.
It would do well in the Sportsman and
Intermediate classes, but it is also one of
the best sport airplanes I have ever flown.
If you do want to try competing, I
suggest a few changes. Use a Lithium-Ion
battery with a Mil Spec resistor switch.
Install a lightweight aluminum spinner,
carbon-fiber aileron linkages with ball
bearings, sport digital servos, and a larger
fuel tank. These modifications lighten the
Bravo while increasing control response.
Considering all the engineering, the
precision construction, the enormous
amount of prefabrication, and the model’s
excellent flying abilities, the $180 price tag
seems on the low side. This is a chance for
every RC pilot to experience what a
precision aircraft can do without having to
see a loan shark first.
Take this opportunity. You might not
fly any better, but you will definitely enjoy
flying more. MA
Frank Granelli
[email protected]
Manufacturer/Distributor:
Black Horse Model
Distributed exclusively by American Pioneer
Hobbies Inc.
7 Dana St.
Springfield MA 01104
(413) 781-2036
www.americanpioneerhobbies.com
Products Used in Review:
.91 FX engine
www.osengines.com
JR Propo radio:
www.horizonhobby.com
Hobbico Hot Knife:
www.hobbico.com
Du-Bro
http://dubro.com/hobby/
Edition: Model Aviation - 2007/02
Page Numbers: 55,56,57,58,62
The Bravo can be ready to fly after less
than 10 hours of assembly time. Its
wing loading is in the light sport
range, at 25.2 ounces
per square foot.
Inverted flight required downelevator,
but this will be
corrected as the CG is moved
back. Inverted handling was as
precise and directional as
upright flight.
RC AIRCRAFT designed for demanding
Aerobatics (Pattern) competition are arguably
the best-performing, most forgiving sport
airplanes available. Many would argue that
modern Pattern aircraft simply fly better than
anything else in the air.
This was not always true; earlier Pattern
aircraft were short-coupled, heavy, and flew
on small, highly swept wings. The pilot had to
be far ahead of these airplanes, which in many
cases were capable of speeds exceeding 130
mph and landing speeds as high as 40 mph,
while making sure they didn’t snap roll into
the ground, which they were prone to do
given any excuse.
The mists of time may have us fondly
remembering those “Good Ol’ Days,” but the
truth is that a modern Pattern airplane
outperforms anything flying then or now.
With 1,000 square inches of wing and
weighing 10.5 pounds, its landing speed is 20
mph or less. That is basic trainer performance.
The top speed for these fixed-gear aircraft
is usually 100 mph, but the best performance
is in the 50-60 mph range; that is slower than
most sport airplanes. A good Pattern airplane
needs little rudder input in vertical climbs or
loops; performs perfect axial rolls; is
forgiving in all attitudes, airspeeds, and flight
regimes; and never offers to snap roll with
elevator input.
But if the pilot does want the model to
snap roll, it will do so with minimal
directional change and stop exactly on
command—immediately. That is a Pattern
aircraft’s greatest asset; it will go exactly
where the pilot commands it to go. Whether
flying inverted, in knife edge, rolling in a
climb, or heading straight down, it will never
deviate from its planned course.
If Pattern models are so easy to fly,
responsive, and capable of exacting flight
performance, why doesn’t every RC pilot fly
one? First, 2-meter ARF Pattern kits are not
readily available.
Second, models that are available range in
price from $500 to $3,200 (airframe only).
Third, building a Pattern airplane is exacting;
the job of properly locating the fuselage holes
for the wing tube is enough to make most of
us quit before we start.
High cost, poor availability, and tight
building tolerances have kept us average RC
pilots away from one of the best flying
experiences we could have. But now things
are changing. Design advances originally
made for 2-meter aircraft are finding their
way into slightly smaller Pattern airplanes that
fly almost as well.
The increasing number of such 60- to 90-
size airplane kits means greater availability
and lower cost. Modern ARF design has
reduced the builder’s workload by
incorporating the required exactness into the
assembly process itself.
How did they do that? Good question, and
that brings us to the subject of this review:
Black Horse Model’s new Bravo 303 Pattern
airplane. One of the “new breed” of 60- to 90-
The Bravo front end looks competitive. It
has a European appearance and a New York
attitude—perfect for competition or
aggressive sport flying.
This is how a modern Pattern aircraft handles on final
approach. Nose up roughly 20° idle at 2,100 rpm, and airspeed
approximately 20 mph. Landing roll is roughly 30 feet on grass.
size precision Aerobatics machines, the Bravo
303 is designed for the beginning Pattern pilot
and the sport flier who wants outstanding
performance without building hassles.
There is some good engineering here; the
way the Bravo incorporates the required
building accuracy into the airplane’s
construction is impressive. Construction is
lightweight and straight. The covering, which
is a form of Oracover, is tight and wrinkle
resistant and the cowling’s paint job is
stunning.
As you read the short building review,
keep in mind that there are a few differences
between building a Pattern airplane and a
good sport aircraft. For instance, Pattern
aircraft are built for durability. If used in
competition, a Pattern airplane will fly 200-
400 flights per season. Structure, control
surfaces, and all moving parts must be able to
survive constant use.
Pattern airplanes must be properly aligned
and balanced; building tolerances approach
1/64 inch. And most important of all, Pattern
airplanes are built as light as possible without
sacrificing durability.
The Design: The Bravo 303 is a midwing
aircraft. This helps make the rolls truly axial.
The 714-square-inch wing supports just 7.81
pounds. The resultant 25.2 ounces per square
foot of wing loading is in the light class for
sport models, providing excellent slow-flight
performance, maneuver accuracy, and slow
landing speeds.
The symmetrical airfoil makes inverted
flight and maneuvers consistent. However, the
stabilizer and vertical fin are flat as opposed
to having an airfoil shape. Airfoil surfaces are
always more effective, but the pilot will notice
the difference most during low-speed
maneuvers.
Most of the new low-cost Pattern airplanes
use this simple tail design. In theory the
performance of these aircraft should suffer,
but in reality the difference is just not that
meaningful.
The Bravo 303 is designed for a .61 twostroke
or .91 four-stroke glow engine, but
most Bravos I’ve seen at contests use a .91
two-stroke engine. This model handles that
engine well and has nearly unlimited vertical
performance operating with this power plant.
The Bravo uses independent servos for
each aileron and elevator half for fine-tuning
trim; few other low-cost Pattern airplanes
have this ability. The wing design permits
further fine tuning since the halves can be set
at individual incidences. But enough theory;
let’s build the thing and see how it flies.
Construction: The kit is complete, with all
the hardware and some extras. There is a
great deal of prefabrication here that is
seldom found in most ARF kits. For instance,
all control surfaces are hinged and pinned.
The wing mounting system and upper
canopy/deck/pilot are preinstalled.The fuel
tank is supplied preassembled, and the engine
mount and landing-gear bolts are factory
installed.
The cutouts for the horizontal stabilizer
The cables that link the rudder to the servo interfere with the
throttle servo. The throttle servo needs to be lowered or
exchanged for a low-profile type.
Each aileron servo mounts to factory-installed hard points. Short
pushrods were made with clevises at both ends, as the
recommended “bend wire” connections enlarge in time.
The vertical fin has extra gluing area for strength. Excess covering
from the slot was used to seal the joint. A metal triangle aids in
alignment.
The rear alignment pin determines attack angles and can be
adjusted by sanding. After test-flying, gluing the wing halves
together is an option.
and vertical fin are preshaped and accurate.
All the servo mounts, including the ailerons,
are completely ready for servo installation and
sized to fit modern standard-case servos.
The wing uses an aluminum tube spar and
dowel-rod alignment pins; there’s no spar glue
and the wing need not be glued together. And
as a bonus, its pull-pull rudder cables are
factory installed.
Wing assembly begins with the aileron
servos, which install directly onto cover plates
in the wing. If you want to employ spoilers,
which allow accurate landing placement and
prevent “bounced” landings, remember
output-arm placement.
JR radios are easier to program in
aileron/spoiler installations if the aileron servo
output shaft points outward toward the
wingtip. Futaba radios are easier to program if
the servo’s output shaft points to the inside,
toward the root of the wing.
Position the servo upright on the wing,
mark the correct side of the output shaft, and
then make sure that side is oriented out the
servo hatch slot when the servo is laid on its
side. Temporarily place a thin cardboard
spacer between the servo and the hatch during
servo installation so that it’s correctly isolated
from vibration. A 12-inch servo extension is
required.
For durability and strength, all the
adjustable control horns mount with three
screws completely through the control surface
and have two lock nuts. Make sure the aileron
control rods run in a straight line from the
servo output arms to the control horns.
Use clear tape or clear plastic model
covering to seal the aileron gaps. This makes
the ailerons more effective, allowing the
proper roll rate without excessive surface
movement that can cause nonaxial rolls.
Sealing also helps equalize each aileron’s
effectiveness.
On most ARFs this is the time to construct
the main spar and glue the wing halves
together, but the Bravo’s main spar is an
aluminum tube for extra rigidity and
durability. The wing alignment is determined
by a thick wooden dowel at the TE. The front
of the wing is held down by equal-size
wooden dowels.
You probably don’t have to glue the wing
halves together. The rear mounting bolts (all
factory drilled and the fuselage blind nuts
installed) and the front dowels hold the wing
in place. The photo-illustrated instruction
manual doesn’t mention gluing the wing
halves.
I took this as a trimming opportunity.
Two-Meter Pattern aircraft wing halves are
individually adjustable for incidence. The
Bravo accomplishes almost the same effect by
allowing a few trim flights and then sanding
the rear pin to adjust the incidence. The idea is
to adjust the wing incidence so that both
ailerons are neutral during level flight.
This Bravo needed no wing adjustment.
After the first two flights I glued the wing
halves together using slow epoxy. Why?
Because the front dowels and the rear
alignment pin will gradually wear, and that
will result in changing wing incidences.
+•
Factory-painted fiberglass cowling,
wheel pants.
• Detachable wing halves secured with
aluminum tubing.
• Prepainted, prefitted pilot and canopy.
• Preglued, pinned hinges on all control
surfaces.
• Preinstalled pull-pull rudder control
cables.
• Terrific flier.
-•
Small fuel tank when equipped
with .91 engine.
• Rudder cables interfere with the
throttle servo.
• Cutouts required for proper engine
cooling.
Pluses and Minuses
The Bravo 303 is a complete kit that has been well engineered for accurate
assembly. The hardware that accompanies this airplane is worth using.
Remember: durability plus more durability.
The centering marks are factory drawn on
the front and rear fuselage formers. Wow, talk
about making things easy! Center the wing
and measure the distance from each wingtip
to a pin located in the center of the rear
fuselage. Both distances must be equal. This
Bravo was equal to within 0.01 inch. That
worked for me!
The stabilizer and vertical fin attach as on
any other ARF, except that there is extra
support for the vertical fin. The extra strength
keeps the fin stiff during rudder-critical
maneuvers such as knife edge, Snap Rolls,
and Stall Turns.
When removing the covering from the
areas that receive epoxy, try using the
Hobbico Hot Knife (part HCAR0770) that has
the blade made dull with a file. The idea is to
use the heat to melt the covering without
Engine used: O.S. Engines .91 FX
Propeller: APC 15 x 8
Fuel: 450cc (13 ounces),
S&W 15% nitromethane
Radio system: JR 8103 transmitter;
R770 PCM receiver; NES 517 servos
on ailerons, elevators, and throttle,
DS8231 on rudder; 1100 mAh 4.8-volt
battery; two 18-inch, two 12-inch, and
two 6-inch extensions
Ready-to-fly weight: 7.81 pounds
Flight duration: 11 minutes
Test-Model Details
Model type: F3A sport Aerobatics ARF
Pilot skill level: Intermediate
Wingspan: 64.4 inches
Wing area: 714 square inches
Length: 65.4 inches
Weight: 7.7 pounds
Wing loading: 24.8 ounces per square foot
Engine: .61 (two-stroke), .91 (four-stroke)
Radio: Four channels (minimum), six servos
Construction: Balsa and plywood
Covering/finish: Covered with hand
iron-on Oracover film
Price: $179.99
Specifications
scoring the wood, and a dull blade works best
for that.
The Bravo uses two elevator servos and
18-inch servo extensions. Their mounts are
cleverly positioned so that a servo reverser is
not required, yet the linkage geometry
remains identical. Equal geometry means that
each elevator half moves exactly the same
amount.
Mixing the two elevator servos allows the
pilot to fine-tune movement for straight loop
segments. Seal the elevator gaps as you did
the aileron gaps. (You did seal the aileron
gaps, right? It makes a difference—I
promise.) Make sure the stabilizer is parallel
to the wing.
The rudder pull-pull cables, required for
precision centering, are factory installed
leading up to the front-mounted rudder servo.
There is a minor problem here. Since rudder
centering is critical, I used a true precision
Pattern servo: the JR DS8231. But that meant
the rudder cable did not clear the standardsize
throttle servo.
The rudder servo could not be raised or it
would hit the wing. An option is to lower the
throttle servo by cutting out the servo tray’s
mounting area and mounting short 1/8 x 1/2
birch beams on the underside of the tray. This
lowers the throttle servo so that the cables
can’t rub. The other option is to use a lowerprofile
servo on the throttle, which is the route
I took.
If this is your first rudder/cable
installation, remember one key point: exact
rudder centering is critical for making straight
maneuvers. Both cables must run in a straight
line from the servo to the rudder, without
deviation, for exact centering.
The Bravo is 1.45 inches wide where the
rudder cables exit the rear fuselage. Therefore,
the twin rudder control horns must be 1.45
inches apart. Use the two-sided Du-Bro Super
Strength Servo Arm, standard size (parts 673
and 675), and hook the cables to the holes
second from the end. Noted Pattern airplane
builder George Asteris taught me this trick. It
works wonders on those sticky rudders.
The engine mount is the two-beam variety
and is installed into the factory blind nuts. The
mount is made from a unique material. It is a
“soft” nylon with unique properties. First, it
seems to reduce sound levels, which is
important since Pattern airplanes must be
quieter than 96 decibels at 3 meters.
Second, the mount cannot be “tapped” in
the usual manner; I tried and nearly broke the
tap. Instead use the machine screws that come
with the Bravo. I know that is heresy, and
maybe worse, but the mount’s material locks
the screws in place and the engine remains
tightly secured, even after 34 flights.
Position the thrust washer 43/8 inches from
the firewall, mount the engine, hook up the
throttle, and then cut all the holes into that
beautifully painted cowling. You don’t want
to make a mistake here.
Mount the cowling first so it clears the
spinner backplate by 1/8 inch. Use the
cardboard-template trick to find out where the
cutouts need to be located. If you are using a
four-stroke engine, cut the inlet area of the top
“air scoop” to allow cool air to enter the
engine’s carburetor for increased power.
There is ample cooling-inlet air, but not
much outlet area. Cut a 2-inch-wide exit hole
in the bottom of the cowl. The manual
instructs to remove the entire cowling over the
gear-leg area. Instead, cut only two slots for
the legs. Make sure to use thread-locking
compound on the gear leg bolts since they
will not be visible once covered.
Instead of cutting holes in the outside of
the wheel pants, shorten the axles by 5/16 inch.
Cut away the thin cowling post that would
otherwise cover the engine’s air intake area
for maximum airflow.
The listed CG is 0.5 inch (14mm) in from
the LE at the fuselage—way too far forward.
The diagram is confusing and the 14mm may
refer to the wingtip. The best starting CG is at
47/8 inches back from the LE at the fuselage.
The first flights may be made with the CG
farther forward, but only knife-edge flight will
suffer. No weights were needed to obtain this
CG with the O.S. .91 FX up front.
Lateral balance is an extremely important
but often overlooked step. Since the wing has
no true dihedral, level flight and concentric
loops are impossible without good lateral
balance. Run nylon fishing line under the
bottom rudder hinge and under the crankshaft
(remove the propeller), and lift the aircraft.
One wingtip, usually on the muffler side, will
drop. Drive thin finishing nails into the lighter
wingtip until the aircraft remains level.
Control-surface movement was set on the
elevators at 7/8 inch of travel up and down. If
possible, mix the two elevator servos
instead of using a Y harness. This permits
the elevator movement to be fine-tuned for
precision loops.
Set the ailerons for 1/2 inch of
movement; no differential was needed on
the Bravo. Spoilers worked best when the
ailerons were raised 1/4 inch.
The book lists rudder movement as 3/4
inch, but that didn’t seem to be enough.
There is enough between the elevator halves
for 2 inches of rudder movement, so use it.
There are two schools of thought about
low/high rates vs. high rate with
exponential. I think IMAC (International
Miniature Aerobatic Club) pilots have
proven that the latter works best.
There is less to remember during the
stress of aerobatic flying using only one
rate. I tried many different exponential rates
(remember that these are JR settings) and
found the following to work best: elevator at
25%, ailerons at 30%, and rudder at 50%.
After trying many propellers ranging
from 14 to 16 inches, I picked the APC 15 x
8 Sport. While allowing slower flight speeds
(great for precision Aerobatics), the 16-inch
propellers produced too much torque for the
Bravo’s vertical side area, resulting in
excess rudder input. The 14-inch propellers
were too fast.
The 15 x 8 propeller produces nearly
unlimited vertical, is quieter, reduces engine
torque, and provides good “downhill”
braking. Braking is important as picking up
speed when pointed toward the ground
hastens maneuvers, giving the pilot less
time to prepare for the next segment. The
best idle speed I could get was 2,100 rpm.
Except for the rudder, this Bravo uses
standard sport servos (except on the
throttle?). If you intend to compete, use the
newer digital sport servos for more positive
control. The Bravo does not need $100
“Gee Whiz” servos, except on the rudder.
Flying: With the engine ticking over just
right, the Bravo 303 could be taxied out to
the runway and stopped approximately 120
feet from the midpoint. Ground steering was
positive and immediately effective. The
takeoff was initiated with the Bravo rolling
on the grass runway as throttle was applied.
The ground roll was straight and the
model lifted off at 80% throttle at midpoint
down the runway. Good for a “10,” maybe?
Initial climbout was straight, with no aileron
trim required and gentle with a 45° climb
angle.
The Bravo quickly climbed upstairs with
apparently no lack of vertical performance.
A few clicks of up-trim settled the Bravo
and the flying commenced.
The Bravo flew the procedure turn
without trying to gain altitude and steadied
up for the first rolling pass. Throw the
aileron stick all the way over and the Bravo
rolled at the correct speed—roughly three
rolls in five seconds. The nose never varied
from the flight path.
The model went into a full-power
vertical climb, a tall turn at the top, a half
roll down, and back into center, inverted. It
needed some down-elevator for this. The
Bravo pushed vertical at center without
dropping a wing and started rolling all the
way up. The nose remained straight—no
need for aileron differential on this airplane.
At approximately 500 feet high I stopped
the climb and threw all the controls into the
right corner. The Bravo did several “snaps”
and began to spin down. The spin rate was
moderate at approximately 11/2 turns per
second. Reversing the spin yielded roughly
the same rotational speed. Centering the
ailerons slowed the rotation to roughly one
turn per second.
Centering the rudder and elevator
immediately stopped the spin. I added
throttle and headed for the other corner. It
doesn’t look like quarter-roll Humpty
Bumps will be a problem either. But coming
back, the Four Point Roll proved the need
for some elevator trim as the airplane pulled
to the canopy on both knife edges and the
slow roll was sloppy.
It was time for some photo passes
anyway, so the Bravo and I quit our sky
games and went back to work. Flying photo
passes with this aircraft is like driving a
NASCAR racer in commuter traffic; it just
isn’t natural.
After the passes it was time to land.
Two-meter Pattern airplanes land like
feathers. They float down, nose high,
without needing to flare to a three-point
landing. The Bravo did exactly that.
It needed 12% (again, JR settings) of
down-elevator for left-rudder knife edge and
9% for right. There was also minor rudder/
bank coupling. Just 7% opposite aileron was
needed to eliminate coupling on both sides.
The CG was moved backward by adding
small tail weights. Not much—just a little—
but please make your first Bravo flights at
the CG I gave in the preceding. Adjust it
later, in small steps, if you think it’s
necessary.
Moving the CG rearward reduced
inverted down-elevator but quickened the
roll rate, so an extra 5% exponential was
added. Complete trimming how-to
information is posted on the National
Society of Radio Controlled Aerobatics
Web site: www.nsrca.org.
At this point the Bravo was ready to
light up the sky. And it did!
Snap Rolls remained on line and stopped
at the right point; there was no wandering
and no drifting. Slow Rolls ate up the sky
horizon to horizon. Concentric Inside and
Outside Loops were so easy they became
boring. Repeated Avalanches, inside and
outside, drew comments, as did the repeated
alternate Snap Rolls during the low passes.
Four Point, Eight Point, and opposite
Slow Rolls started to remind me of my
Temptation 2-meter Pattern airplane (one of
those $1,800 models I mentioned earlier).
That hurt some since the Bravo’s all-up cost
was less than 15% of the Temptation’s.
The second landing was identical to the
first but slower since I knew the aircraft
better. Final ground roll was less than 20
feet. It was time to refuel, which was the
Bravo’s one weak point.
The stock tank was almost all that could
fit into the fuselage, along with the battery
up front, without major surgery. The O.S.
.91 FX will run approximately 11 minutes
on a tank. Although that is time enough to
fly even the full FAI pattern and some
maneuvers, 15 minutes would be better; it
would allow a pilot to fly through the
maneuver sequence twice during practice.
There are now 34 flights on my Bravo,
including several trips through the Masters
pattern and the Sportsman and
Intermediate sequences. The Bravo flies
the latter two great, but the workload is
higher for Masters than with a 2-meter
airplane. (That’s why the big boys pay the
money.)
Still, I plan to practice with the Bravo
during the winter, even using skis if
needed. The airplane is that good.
I suspect that most Bravo 303s built
will never see competition, and that is fine.
It would do well in the Sportsman and
Intermediate classes, but it is also one of
the best sport airplanes I have ever flown.
If you do want to try competing, I
suggest a few changes. Use a Lithium-Ion
battery with a Mil Spec resistor switch.
Install a lightweight aluminum spinner,
carbon-fiber aileron linkages with ball
bearings, sport digital servos, and a larger
fuel tank. These modifications lighten the
Bravo while increasing control response.
Considering all the engineering, the
precision construction, the enormous
amount of prefabrication, and the model’s
excellent flying abilities, the $180 price tag
seems on the low side. This is a chance for
every RC pilot to experience what a
precision aircraft can do without having to
see a loan shark first.
Take this opportunity. You might not
fly any better, but you will definitely enjoy
flying more. MA
Frank Granelli
[email protected]
Manufacturer/Distributor:
Black Horse Model
Distributed exclusively by American Pioneer
Hobbies Inc.
7 Dana St.
Springfield MA 01104
(413) 781-2036
www.americanpioneerhobbies.com
Products Used in Review:
.91 FX engine
www.osengines.com
JR Propo radio:
www.horizonhobby.com
Hobbico Hot Knife:
www.hobbico.com
Du-Bro
http://dubro.com/hobby/
Edition: Model Aviation - 2007/02
Page Numbers: 55,56,57,58,62
The Bravo can be ready to fly after less
than 10 hours of assembly time. Its
wing loading is in the light sport
range, at 25.2 ounces
per square foot.
Inverted flight required downelevator,
but this will be
corrected as the CG is moved
back. Inverted handling was as
precise and directional as
upright flight.
RC AIRCRAFT designed for demanding
Aerobatics (Pattern) competition are arguably
the best-performing, most forgiving sport
airplanes available. Many would argue that
modern Pattern aircraft simply fly better than
anything else in the air.
This was not always true; earlier Pattern
aircraft were short-coupled, heavy, and flew
on small, highly swept wings. The pilot had to
be far ahead of these airplanes, which in many
cases were capable of speeds exceeding 130
mph and landing speeds as high as 40 mph,
while making sure they didn’t snap roll into
the ground, which they were prone to do
given any excuse.
The mists of time may have us fondly
remembering those “Good Ol’ Days,” but the
truth is that a modern Pattern airplane
outperforms anything flying then or now.
With 1,000 square inches of wing and
weighing 10.5 pounds, its landing speed is 20
mph or less. That is basic trainer performance.
The top speed for these fixed-gear aircraft
is usually 100 mph, but the best performance
is in the 50-60 mph range; that is slower than
most sport airplanes. A good Pattern airplane
needs little rudder input in vertical climbs or
loops; performs perfect axial rolls; is
forgiving in all attitudes, airspeeds, and flight
regimes; and never offers to snap roll with
elevator input.
But if the pilot does want the model to
snap roll, it will do so with minimal
directional change and stop exactly on
command—immediately. That is a Pattern
aircraft’s greatest asset; it will go exactly
where the pilot commands it to go. Whether
flying inverted, in knife edge, rolling in a
climb, or heading straight down, it will never
deviate from its planned course.
If Pattern models are so easy to fly,
responsive, and capable of exacting flight
performance, why doesn’t every RC pilot fly
one? First, 2-meter ARF Pattern kits are not
readily available.
Second, models that are available range in
price from $500 to $3,200 (airframe only).
Third, building a Pattern airplane is exacting;
the job of properly locating the fuselage holes
for the wing tube is enough to make most of
us quit before we start.
High cost, poor availability, and tight
building tolerances have kept us average RC
pilots away from one of the best flying
experiences we could have. But now things
are changing. Design advances originally
made for 2-meter aircraft are finding their
way into slightly smaller Pattern airplanes that
fly almost as well.
The increasing number of such 60- to 90-
size airplane kits means greater availability
and lower cost. Modern ARF design has
reduced the builder’s workload by
incorporating the required exactness into the
assembly process itself.
How did they do that? Good question, and
that brings us to the subject of this review:
Black Horse Model’s new Bravo 303 Pattern
airplane. One of the “new breed” of 60- to 90-
The Bravo front end looks competitive. It
has a European appearance and a New York
attitude—perfect for competition or
aggressive sport flying.
This is how a modern Pattern aircraft handles on final
approach. Nose up roughly 20° idle at 2,100 rpm, and airspeed
approximately 20 mph. Landing roll is roughly 30 feet on grass.
size precision Aerobatics machines, the Bravo
303 is designed for the beginning Pattern pilot
and the sport flier who wants outstanding
performance without building hassles.
There is some good engineering here; the
way the Bravo incorporates the required
building accuracy into the airplane’s
construction is impressive. Construction is
lightweight and straight. The covering, which
is a form of Oracover, is tight and wrinkle
resistant and the cowling’s paint job is
stunning.
As you read the short building review,
keep in mind that there are a few differences
between building a Pattern airplane and a
good sport aircraft. For instance, Pattern
aircraft are built for durability. If used in
competition, a Pattern airplane will fly 200-
400 flights per season. Structure, control
surfaces, and all moving parts must be able to
survive constant use.
Pattern airplanes must be properly aligned
and balanced; building tolerances approach
1/64 inch. And most important of all, Pattern
airplanes are built as light as possible without
sacrificing durability.
The Design: The Bravo 303 is a midwing
aircraft. This helps make the rolls truly axial.
The 714-square-inch wing supports just 7.81
pounds. The resultant 25.2 ounces per square
foot of wing loading is in the light class for
sport models, providing excellent slow-flight
performance, maneuver accuracy, and slow
landing speeds.
The symmetrical airfoil makes inverted
flight and maneuvers consistent. However, the
stabilizer and vertical fin are flat as opposed
to having an airfoil shape. Airfoil surfaces are
always more effective, but the pilot will notice
the difference most during low-speed
maneuvers.
Most of the new low-cost Pattern airplanes
use this simple tail design. In theory the
performance of these aircraft should suffer,
but in reality the difference is just not that
meaningful.
The Bravo 303 is designed for a .61 twostroke
or .91 four-stroke glow engine, but
most Bravos I’ve seen at contests use a .91
two-stroke engine. This model handles that
engine well and has nearly unlimited vertical
performance operating with this power plant.
The Bravo uses independent servos for
each aileron and elevator half for fine-tuning
trim; few other low-cost Pattern airplanes
have this ability. The wing design permits
further fine tuning since the halves can be set
at individual incidences. But enough theory;
let’s build the thing and see how it flies.
Construction: The kit is complete, with all
the hardware and some extras. There is a
great deal of prefabrication here that is
seldom found in most ARF kits. For instance,
all control surfaces are hinged and pinned.
The wing mounting system and upper
canopy/deck/pilot are preinstalled.The fuel
tank is supplied preassembled, and the engine
mount and landing-gear bolts are factory
installed.
The cutouts for the horizontal stabilizer
The cables that link the rudder to the servo interfere with the
throttle servo. The throttle servo needs to be lowered or
exchanged for a low-profile type.
Each aileron servo mounts to factory-installed hard points. Short
pushrods were made with clevises at both ends, as the
recommended “bend wire” connections enlarge in time.
The vertical fin has extra gluing area for strength. Excess covering
from the slot was used to seal the joint. A metal triangle aids in
alignment.
The rear alignment pin determines attack angles and can be
adjusted by sanding. After test-flying, gluing the wing halves
together is an option.
and vertical fin are preshaped and accurate.
All the servo mounts, including the ailerons,
are completely ready for servo installation and
sized to fit modern standard-case servos.
The wing uses an aluminum tube spar and
dowel-rod alignment pins; there’s no spar glue
and the wing need not be glued together. And
as a bonus, its pull-pull rudder cables are
factory installed.
Wing assembly begins with the aileron
servos, which install directly onto cover plates
in the wing. If you want to employ spoilers,
which allow accurate landing placement and
prevent “bounced” landings, remember
output-arm placement.
JR radios are easier to program in
aileron/spoiler installations if the aileron servo
output shaft points outward toward the
wingtip. Futaba radios are easier to program if
the servo’s output shaft points to the inside,
toward the root of the wing.
Position the servo upright on the wing,
mark the correct side of the output shaft, and
then make sure that side is oriented out the
servo hatch slot when the servo is laid on its
side. Temporarily place a thin cardboard
spacer between the servo and the hatch during
servo installation so that it’s correctly isolated
from vibration. A 12-inch servo extension is
required.
For durability and strength, all the
adjustable control horns mount with three
screws completely through the control surface
and have two lock nuts. Make sure the aileron
control rods run in a straight line from the
servo output arms to the control horns.
Use clear tape or clear plastic model
covering to seal the aileron gaps. This makes
the ailerons more effective, allowing the
proper roll rate without excessive surface
movement that can cause nonaxial rolls.
Sealing also helps equalize each aileron’s
effectiveness.
On most ARFs this is the time to construct
the main spar and glue the wing halves
together, but the Bravo’s main spar is an
aluminum tube for extra rigidity and
durability. The wing alignment is determined
by a thick wooden dowel at the TE. The front
of the wing is held down by equal-size
wooden dowels.
You probably don’t have to glue the wing
halves together. The rear mounting bolts (all
factory drilled and the fuselage blind nuts
installed) and the front dowels hold the wing
in place. The photo-illustrated instruction
manual doesn’t mention gluing the wing
halves.
I took this as a trimming opportunity.
Two-Meter Pattern aircraft wing halves are
individually adjustable for incidence. The
Bravo accomplishes almost the same effect by
allowing a few trim flights and then sanding
the rear pin to adjust the incidence. The idea is
to adjust the wing incidence so that both
ailerons are neutral during level flight.
This Bravo needed no wing adjustment.
After the first two flights I glued the wing
halves together using slow epoxy. Why?
Because the front dowels and the rear
alignment pin will gradually wear, and that
will result in changing wing incidences.
+•
Factory-painted fiberglass cowling,
wheel pants.
• Detachable wing halves secured with
aluminum tubing.
• Prepainted, prefitted pilot and canopy.
• Preglued, pinned hinges on all control
surfaces.
• Preinstalled pull-pull rudder control
cables.
• Terrific flier.
-•
Small fuel tank when equipped
with .91 engine.
• Rudder cables interfere with the
throttle servo.
• Cutouts required for proper engine
cooling.
Pluses and Minuses
The Bravo 303 is a complete kit that has been well engineered for accurate
assembly. The hardware that accompanies this airplane is worth using.
Remember: durability plus more durability.
The centering marks are factory drawn on
the front and rear fuselage formers. Wow, talk
about making things easy! Center the wing
and measure the distance from each wingtip
to a pin located in the center of the rear
fuselage. Both distances must be equal. This
Bravo was equal to within 0.01 inch. That
worked for me!
The stabilizer and vertical fin attach as on
any other ARF, except that there is extra
support for the vertical fin. The extra strength
keeps the fin stiff during rudder-critical
maneuvers such as knife edge, Snap Rolls,
and Stall Turns.
When removing the covering from the
areas that receive epoxy, try using the
Hobbico Hot Knife (part HCAR0770) that has
the blade made dull with a file. The idea is to
use the heat to melt the covering without
Engine used: O.S. Engines .91 FX
Propeller: APC 15 x 8
Fuel: 450cc (13 ounces),
S&W 15% nitromethane
Radio system: JR 8103 transmitter;
R770 PCM receiver; NES 517 servos
on ailerons, elevators, and throttle,
DS8231 on rudder; 1100 mAh 4.8-volt
battery; two 18-inch, two 12-inch, and
two 6-inch extensions
Ready-to-fly weight: 7.81 pounds
Flight duration: 11 minutes
Test-Model Details
Model type: F3A sport Aerobatics ARF
Pilot skill level: Intermediate
Wingspan: 64.4 inches
Wing area: 714 square inches
Length: 65.4 inches
Weight: 7.7 pounds
Wing loading: 24.8 ounces per square foot
Engine: .61 (two-stroke), .91 (four-stroke)
Radio: Four channels (minimum), six servos
Construction: Balsa and plywood
Covering/finish: Covered with hand
iron-on Oracover film
Price: $179.99
Specifications
scoring the wood, and a dull blade works best
for that.
The Bravo uses two elevator servos and
18-inch servo extensions. Their mounts are
cleverly positioned so that a servo reverser is
not required, yet the linkage geometry
remains identical. Equal geometry means that
each elevator half moves exactly the same
amount.
Mixing the two elevator servos allows the
pilot to fine-tune movement for straight loop
segments. Seal the elevator gaps as you did
the aileron gaps. (You did seal the aileron
gaps, right? It makes a difference—I
promise.) Make sure the stabilizer is parallel
to the wing.
The rudder pull-pull cables, required for
precision centering, are factory installed
leading up to the front-mounted rudder servo.
There is a minor problem here. Since rudder
centering is critical, I used a true precision
Pattern servo: the JR DS8231. But that meant
the rudder cable did not clear the standardsize
throttle servo.
The rudder servo could not be raised or it
would hit the wing. An option is to lower the
throttle servo by cutting out the servo tray’s
mounting area and mounting short 1/8 x 1/2
birch beams on the underside of the tray. This
lowers the throttle servo so that the cables
can’t rub. The other option is to use a lowerprofile
servo on the throttle, which is the route
I took.
If this is your first rudder/cable
installation, remember one key point: exact
rudder centering is critical for making straight
maneuvers. Both cables must run in a straight
line from the servo to the rudder, without
deviation, for exact centering.
The Bravo is 1.45 inches wide where the
rudder cables exit the rear fuselage. Therefore,
the twin rudder control horns must be 1.45
inches apart. Use the two-sided Du-Bro Super
Strength Servo Arm, standard size (parts 673
and 675), and hook the cables to the holes
second from the end. Noted Pattern airplane
builder George Asteris taught me this trick. It
works wonders on those sticky rudders.
The engine mount is the two-beam variety
and is installed into the factory blind nuts. The
mount is made from a unique material. It is a
“soft” nylon with unique properties. First, it
seems to reduce sound levels, which is
important since Pattern airplanes must be
quieter than 96 decibels at 3 meters.
Second, the mount cannot be “tapped” in
the usual manner; I tried and nearly broke the
tap. Instead use the machine screws that come
with the Bravo. I know that is heresy, and
maybe worse, but the mount’s material locks
the screws in place and the engine remains
tightly secured, even after 34 flights.
Position the thrust washer 43/8 inches from
the firewall, mount the engine, hook up the
throttle, and then cut all the holes into that
beautifully painted cowling. You don’t want
to make a mistake here.
Mount the cowling first so it clears the
spinner backplate by 1/8 inch. Use the
cardboard-template trick to find out where the
cutouts need to be located. If you are using a
four-stroke engine, cut the inlet area of the top
“air scoop” to allow cool air to enter the
engine’s carburetor for increased power.
There is ample cooling-inlet air, but not
much outlet area. Cut a 2-inch-wide exit hole
in the bottom of the cowl. The manual
instructs to remove the entire cowling over the
gear-leg area. Instead, cut only two slots for
the legs. Make sure to use thread-locking
compound on the gear leg bolts since they
will not be visible once covered.
Instead of cutting holes in the outside of
the wheel pants, shorten the axles by 5/16 inch.
Cut away the thin cowling post that would
otherwise cover the engine’s air intake area
for maximum airflow.
The listed CG is 0.5 inch (14mm) in from
the LE at the fuselage—way too far forward.
The diagram is confusing and the 14mm may
refer to the wingtip. The best starting CG is at
47/8 inches back from the LE at the fuselage.
The first flights may be made with the CG
farther forward, but only knife-edge flight will
suffer. No weights were needed to obtain this
CG with the O.S. .91 FX up front.
Lateral balance is an extremely important
but often overlooked step. Since the wing has
no true dihedral, level flight and concentric
loops are impossible without good lateral
balance. Run nylon fishing line under the
bottom rudder hinge and under the crankshaft
(remove the propeller), and lift the aircraft.
One wingtip, usually on the muffler side, will
drop. Drive thin finishing nails into the lighter
wingtip until the aircraft remains level.
Control-surface movement was set on the
elevators at 7/8 inch of travel up and down. If
possible, mix the two elevator servos
instead of using a Y harness. This permits
the elevator movement to be fine-tuned for
precision loops.
Set the ailerons for 1/2 inch of
movement; no differential was needed on
the Bravo. Spoilers worked best when the
ailerons were raised 1/4 inch.
The book lists rudder movement as 3/4
inch, but that didn’t seem to be enough.
There is enough between the elevator halves
for 2 inches of rudder movement, so use it.
There are two schools of thought about
low/high rates vs. high rate with
exponential. I think IMAC (International
Miniature Aerobatic Club) pilots have
proven that the latter works best.
There is less to remember during the
stress of aerobatic flying using only one
rate. I tried many different exponential rates
(remember that these are JR settings) and
found the following to work best: elevator at
25%, ailerons at 30%, and rudder at 50%.
After trying many propellers ranging
from 14 to 16 inches, I picked the APC 15 x
8 Sport. While allowing slower flight speeds
(great for precision Aerobatics), the 16-inch
propellers produced too much torque for the
Bravo’s vertical side area, resulting in
excess rudder input. The 14-inch propellers
were too fast.
The 15 x 8 propeller produces nearly
unlimited vertical, is quieter, reduces engine
torque, and provides good “downhill”
braking. Braking is important as picking up
speed when pointed toward the ground
hastens maneuvers, giving the pilot less
time to prepare for the next segment. The
best idle speed I could get was 2,100 rpm.
Except for the rudder, this Bravo uses
standard sport servos (except on the
throttle?). If you intend to compete, use the
newer digital sport servos for more positive
control. The Bravo does not need $100
“Gee Whiz” servos, except on the rudder.
Flying: With the engine ticking over just
right, the Bravo 303 could be taxied out to
the runway and stopped approximately 120
feet from the midpoint. Ground steering was
positive and immediately effective. The
takeoff was initiated with the Bravo rolling
on the grass runway as throttle was applied.
The ground roll was straight and the
model lifted off at 80% throttle at midpoint
down the runway. Good for a “10,” maybe?
Initial climbout was straight, with no aileron
trim required and gentle with a 45° climb
angle.
The Bravo quickly climbed upstairs with
apparently no lack of vertical performance.
A few clicks of up-trim settled the Bravo
and the flying commenced.
The Bravo flew the procedure turn
without trying to gain altitude and steadied
up for the first rolling pass. Throw the
aileron stick all the way over and the Bravo
rolled at the correct speed—roughly three
rolls in five seconds. The nose never varied
from the flight path.
The model went into a full-power
vertical climb, a tall turn at the top, a half
roll down, and back into center, inverted. It
needed some down-elevator for this. The
Bravo pushed vertical at center without
dropping a wing and started rolling all the
way up. The nose remained straight—no
need for aileron differential on this airplane.
At approximately 500 feet high I stopped
the climb and threw all the controls into the
right corner. The Bravo did several “snaps”
and began to spin down. The spin rate was
moderate at approximately 11/2 turns per
second. Reversing the spin yielded roughly
the same rotational speed. Centering the
ailerons slowed the rotation to roughly one
turn per second.
Centering the rudder and elevator
immediately stopped the spin. I added
throttle and headed for the other corner. It
doesn’t look like quarter-roll Humpty
Bumps will be a problem either. But coming
back, the Four Point Roll proved the need
for some elevator trim as the airplane pulled
to the canopy on both knife edges and the
slow roll was sloppy.
It was time for some photo passes
anyway, so the Bravo and I quit our sky
games and went back to work. Flying photo
passes with this aircraft is like driving a
NASCAR racer in commuter traffic; it just
isn’t natural.
After the passes it was time to land.
Two-meter Pattern airplanes land like
feathers. They float down, nose high,
without needing to flare to a three-point
landing. The Bravo did exactly that.
It needed 12% (again, JR settings) of
down-elevator for left-rudder knife edge and
9% for right. There was also minor rudder/
bank coupling. Just 7% opposite aileron was
needed to eliminate coupling on both sides.
The CG was moved backward by adding
small tail weights. Not much—just a little—
but please make your first Bravo flights at
the CG I gave in the preceding. Adjust it
later, in small steps, if you think it’s
necessary.
Moving the CG rearward reduced
inverted down-elevator but quickened the
roll rate, so an extra 5% exponential was
added. Complete trimming how-to
information is posted on the National
Society of Radio Controlled Aerobatics
Web site: www.nsrca.org.
At this point the Bravo was ready to
light up the sky. And it did!
Snap Rolls remained on line and stopped
at the right point; there was no wandering
and no drifting. Slow Rolls ate up the sky
horizon to horizon. Concentric Inside and
Outside Loops were so easy they became
boring. Repeated Avalanches, inside and
outside, drew comments, as did the repeated
alternate Snap Rolls during the low passes.
Four Point, Eight Point, and opposite
Slow Rolls started to remind me of my
Temptation 2-meter Pattern airplane (one of
those $1,800 models I mentioned earlier).
That hurt some since the Bravo’s all-up cost
was less than 15% of the Temptation’s.
The second landing was identical to the
first but slower since I knew the aircraft
better. Final ground roll was less than 20
feet. It was time to refuel, which was the
Bravo’s one weak point.
The stock tank was almost all that could
fit into the fuselage, along with the battery
up front, without major surgery. The O.S.
.91 FX will run approximately 11 minutes
on a tank. Although that is time enough to
fly even the full FAI pattern and some
maneuvers, 15 minutes would be better; it
would allow a pilot to fly through the
maneuver sequence twice during practice.
There are now 34 flights on my Bravo,
including several trips through the Masters
pattern and the Sportsman and
Intermediate sequences. The Bravo flies
the latter two great, but the workload is
higher for Masters than with a 2-meter
airplane. (That’s why the big boys pay the
money.)
Still, I plan to practice with the Bravo
during the winter, even using skis if
needed. The airplane is that good.
I suspect that most Bravo 303s built
will never see competition, and that is fine.
It would do well in the Sportsman and
Intermediate classes, but it is also one of
the best sport airplanes I have ever flown.
If you do want to try competing, I
suggest a few changes. Use a Lithium-Ion
battery with a Mil Spec resistor switch.
Install a lightweight aluminum spinner,
carbon-fiber aileron linkages with ball
bearings, sport digital servos, and a larger
fuel tank. These modifications lighten the
Bravo while increasing control response.
Considering all the engineering, the
precision construction, the enormous
amount of prefabrication, and the model’s
excellent flying abilities, the $180 price tag
seems on the low side. This is a chance for
every RC pilot to experience what a
precision aircraft can do without having to
see a loan shark first.
Take this opportunity. You might not
fly any better, but you will definitely enjoy
flying more. MA
Frank Granelli
[email protected]
Manufacturer/Distributor:
Black Horse Model
Distributed exclusively by American Pioneer
Hobbies Inc.
7 Dana St.
Springfield MA 01104
(413) 781-2036
www.americanpioneerhobbies.com
Products Used in Review:
.91 FX engine
www.osengines.com
JR Propo radio:
www.horizonhobby.com
Hobbico Hot Knife:
www.hobbico.com
Du-Bro
http://dubro.com/hobby/