August 2007 51
BY ERIC HENDERSON
Plane Talk: ASM P-61 Black Widow Twin ARF
The daydream of a
night-fighter twin
becomes reality
with this wellmannered
model
IT IS EXCITING to put together an
airplane with more than one engine. It is
even more exciting when it is a semiscale
model of a World War II night-fighter.
The instructions read, in bold, red type,
that this RC aircraft is intended for
“experienced pilots” only. I am never sure if
manufacturers mean an experienced builder
or an experienced flier when they include
that. I will touch on this several times
during the review.
The Black Widow by Advanced Scale
Models (ASM) is designed for gas engines
or electric motors. It comes in a small box
despite the fact that it will span an
impressive 79.5 inches. The box is small
because the wing comes in three parts.
The airplane’s design creates a
“fuselage” that is really three relatively
short fuselages. There are two wingmounted
booms and a central fuselage pod.
A central wing panel connects the booms
and the pod.
The wings and stabilizers are
constructed from balsa and plywood. They
are covered with black heat-shrink film.
The center fuselage and the two main
booms are made from an internal laser-cut
plywood framework that is surrounded by
lightweight plastic skin. This moldedplastic-
skin method allows for better scale
shaping and finer detail, while giving a light
weight for better flight performance.
The ASM P-61 ARF is supplied with
fixed gear legs. However, there is an
optional set of ASM retractable landing gear
available with gear-door actuating
mechanisms. There is also a set of sprung
oleo struts, which gives a good scale effect
in the air and on the ground. The ASM
retract set includes a modified unit that will
accommodate the steerable nose-leg strut.
You will need 11 servos to guide this
airplane: two for the ailerons, two for the
flaps, two for the rudders, two for the
throttles, one for nose-gear steering, one for
the elevator, and one for the retract valve.
The radio you choose needs only five
channels. You will then use a load of Y
leads.
For this review I used a JR 10X
transmitter and a nine-channel JR PCM
receiver. I did so because the JR radio
transmitter has terrific mixing features that
will allow many options and some extreme
fine-tuning of the engines and flight/
steering controls.
You can build either a glow- or an
electric-powered version of the Black
Widow. Glow power can be two- or fourstroke
engines. The review model was built
for two Magnum XLS .52A two-strokes.
You will need such tools as a modeling
knife, a screwdriver, hex wrenches,
sandpaper, a sanding block, a couple
airplane stands, paper towels, etc.
It is necessary to study the instructions
before you build the ASM P-61. This is not
just the usual rhetoric about building a
model; you need to do more than familiarize
yourself with all the parts. It is essential to
plan how you are going to transport the
finished item and how you intend to set up
and program your radio. There is a great
deal for you to decide.
For instance, you could use three or four
Y leads to connect the two throttles,
rudders, and flaps, not forgetting the third
“rudder” servo that is connected to the front
steering leg only. You could use four Y
leads and only three channels, but this will
limit you to making mechanical adjustments
only. Then you would need four 12-inch
servo-extension leads to go with the Y leads
in the center panel.
If you decide to use two channels for the
two throttle servos, two channels for the two
rudders, and a third channel for the steering
servo, you will be able to adjust all the
servos from the transmitter. Instead of Y
Left: The ASM P-61 is a fast mover even with gear and flaps down.
Richard Girardo finished his Black
Widow with electric power.
The author’s P-61 uses .52 cu. in. two-stroke engines. The electric- and
glow-powered models weigh roughly the same.
08sig2.QXD 6/22/07 11:31 AM Page 51
52 MODEL AVIATION
ASM’s optional tricycle air-retract kit includes oil-filled struts. Use
Robart disconnects (part 190) at the wing-attach point.
Without the outer wing panels attached, the P-61 does not take
up much room in a vehicle.
The P-61 comes with a comprehensive set of accessories including
spinners and fixed-landing-gear equipment.
A balloon makes a good “tool” to hold the clear plastic in place
while the RC/56 glue dries.
Almost all the parts are night-flier black. Invasion stripes
underneath help distinguish the model’s orientation in flight.
The optional pneumatic retractable landing gear operates in
sequence with the gear doors.
Photos by the author except as noted
08sig2.QXD 6/22/07 11:34 AM Page 52
August 2007 53
Two tachometers provide simultaneous engine rpm readings
while synchronizing.
ASM P-61 Black Widow With Nitro Power
leads you would use four 18-inch extension
leads to reach the servos from the receiver.
The four individual leads would be in the
center wing panel rather than Y leads.
I used two Y leads for this review: one
for the flaps and one for the ailerons. I used
separate channels for the two throttles, two
rudders, and one steering servo. The steering
servo is positioned in the center pod and
does not need a servo-extension lead
because it plugs directly into the receiver.
The elevator servo is all the way back
inside the stabilizer. It needs to have its
wiring routed all the way through one boom
and then has to be connected to an extension
lead in the center wing panel. This extension
lead then has to connect with a short
extension lead coming out of the receiver in
the central fuselage pod. You can use more
Y leads to cut down the number of wires,
but then you lose the programming
capability that comes with each servo
being connected to its own channel.
It took roughly an hour to plan the
extension-and-Y-lead configuration. This
is one area where an experienced pilot’s
knowledge would probably be needed.
Connecting all the servos took 10 6-
inch leads, five 18-inch leads, six 12-inch
leads, one 24-inch lead, and two Y leads. A
6-inch extension was also required to bring
the servo lead out of the end of the
stabilizer.
Field assembly is much easier if you
make sets of labels with something such as
a Brother label maker. You could use color
coding, but there would be many colors
involved. Approximately 40 labels were
needed to code every extension and servo
lead.
If you plan to keep the P-61 stored and/
or transported in a semiassembled state, you
will not need to connect and disconnect these
leads very often. However, they will still need
good and clear identification.
There will also be a pair of air-line tubes
that go to each retract unit. If you use the
Robart in-line quick connect/disconnect units,
you can “polarize” the identity of the up-anddown
air lines. You could use a “male”
connector on each up-line and a “female”
connector on each down-line. That will make
it so you cannot connect any of the retract
units the wrong way.
Assembly: The manual is a series of highquality
photos with notes and basic directions.
It is clear that construction is an area in which
the “builder” should have a good amount of
RC-model construction knowledge.
The Magnum XLS .52A is a .52 cu. in. (8.47cc) two-stroke
aircraft engine with a twin-needle carburetor. It features an ABC
(aluminum-brass-chrome) piston and sleeve, a standard or rearneedle-
valve position option, a high-flow quiet muffler, a dualball-
bearing-supported crankshaft, and a dual-bushing-supported
connecting rod. It weighs 17.4 ounces with the muffler attached.
The .52A has a practical rpm range of 2,200-18,000. The
recommended break-in propeller is an APC 10 x 6.
The engine instructions recommended a break-in fuel with
10% nitromethane and 20% castor-oil content. That may be a
misprint.
A gallon of fuel with some castor content will, for example,
normally have 20% oil content. Within that 20% oil there is a
ratio of synthetic-to-castor oil that should be at least 80:20. The
10% Morgan (pink) fuel that was used had a 70:30 ratio of
synthetic-to-castor oil. It was used for initial break-in, and then
the same brand with 15% nitro was used for flying.
As should any engine, the XLS .52A should be thoroughly
broken in. When running two engines together, it is essential to
obtain reliable idles, sustainable high-end rpm, and consistent/
smooth throttle responses.
The instructions for how to set the engines are clear and easy
to follow. Once the engine can run without overheating, it is a
good idea to run it at full throttle for a whole tank before you try
to adjust the idle and transition.
Both .52As started easily with an electric starter motor. Not
much hand flipping
was done,
especially when
using a three-blade
propeller, because
there is not much
room between the
engines and the
center pod. An
electric starter
motor is a much
safer option.
The engines
were adjusted one
at a time. Both
needed their low
ends leaned out
approximately one-
An O.S. muffler extension on the
Magnum XLS .52A provides better
clearance.
quarter turn to get a good idle. Both idled extremely well and
went through the transition to full throttle “cough free.”
I tried several propellers during flight-testing. The break-in
APC 10 x 6 also did the job during the early test flights. The final
propeller I chose was the APC 11 x 6; it gave the best speed and
climb rate.
A pair of rare Zingali 10 x 8 three-blade propellers was just
right for scale-looking flight. However, they did not match the
pulling power of the 11 x 6, which the .52A, set slightly rich,
would turn comfortably at 12,400 rpm.
Both throttle arms had been set to the same angle, so each
servo-to-arm geometry relationship in the final installation was
closely matched. This helped when matching and synchronizing
the engines with the computer radio.
The pair of Magnum XLS .52As is a wonderful match for the
ASM P-61. They fit the cowl installation well but require a 1/2- to
5/8-inch muffler spacer to clear the firewall if you don’t want to
cut at the firewall. MA
—Eric Henderson
08sig2.QXD 6/22/07 11:34 AM Page 53
54 MODEL AVIATION
The outer wing panels attach easily. Extension-lead labels help
during field assembly.
The dummy wing tank comes assembled and is removable to
allow service access to the flap servo.
It proved to be helpful to study the pictures and then make
assembly lists. It helps to break down the construction into
segments such as booms, center pod, wing, etc.
The wing is made from a center panel and two outer panels.
The outer panels are host to the ailerons, flaps, and their servos.
The center-section is the hub of this airplane and contains all
the servo extensions to the outer wing panels, the booms, and the
lead to the elevator servo. It also supports the retract control
valve, associated servo, and main-gear air lines. In addition to
being attached to the main pod, the center wing panel supports
the two booms that contain the engines, throttle, rudder servos,
and main landing-gear retracts.
The three wing sections use a total of five servos. Two operate
the ailerons, two operate the flaps, and one operates the retract air
valve. As I mentioned, before assembly begins you should have
decided how you are going to connect and operate all these
servos.
I began building by fitting the aileron and flap hinges. The
instructions showed Mylar hinges for the ailerons, but the ARF
came with pin hinges. Both types work fine, so I fitted the control
surfaces with those supplied.
I stained the Mylar hinges black with a marker to keep them
from showing. You will learn that a black finish makes any white
items really stand out.
I had to add servo extension leads so the servos would reach
the wing joint. The wing panels use aluminum joiner tubes. This
lets you take the wing apart for transport and storage.
I applied thin cyanoacrylate to the antirotation dowels. This
will stop them from swelling in the humidity and assures that
they are glued firmly in place.
The center wing panel is where you mount the air valve and
servo for the retractable landing-gear control. The air tank is
fitted inside the fuselage pod and requires a line connector to the
air-control valve.
The wing hatch/gun mount is a removable hatch that covers
the valve. This means that if there is any compressed air in the
tank, you can operate the gear without having to turn on the radio.
The instructions suggest that you leave the wing tubes bolted
in the outer wing panels for easier reassembly and lining up the
wing-tube retention bolts. This was good advice!
It’s time to construct the fuselage pod. The front and rear
cockpit areas use gray prepainted plywood plates as cabin floors.
The front plate was made removable to allow maintenance access
to the nose gear and steering mechanism.
Each throttle was programmed to have its own low-end trim control. Not only were the top and bottom ends matched, but
seven other positions on the throttle mix were matched in rpm. Both engines could be “killed” at low idle using the snap-roll
momentary switch.
A separate steering servo channel was mixed with the rudders, but it was not controlled by the rudder trim lever. The steering
could be adjusted using a trim knob independent of the rudder trim action. Similarly, the rudder could be trimmed in flight without
affecting the nose wheel’s position.
The steering servo was activated only by the landing-gear-down position. That means when the gear was up the steering servo
would not move unnecessarily and possibly tangle the pull-pull wires.
The flap servo was set to move at approximately half the normal speed using the JR 10X servo-slow option. That helps prevent
a sudden change in flight attitude when the flaps are deployed. To allow flap-related elevator trim to be set during test flights, an
extra channel mix was linked to a rotary knob.
The beauty of this is that the mix allows the settings to be dialed in during flight, and relating it to the flap switch allows the
trim to be disengaged when the flap is raised. After landing the “in-flight” setting can be measured and coded directly into the
radio’s landing/flap switch options.
This method allows the flap auto trim to be set up quickly and accurately without having to guess on the ground and go through
a tedious trial-and-error process. The result is that the ASM P-61 Black Widow needs approximately 1/4 inch of up-elevator trim
for full flap deployment. Then the rotary-knob control mix should be deleted to avoid mistakes in future operation. MA
—Eric Henderson
Scale Programming Secrets
08sig2.QXD 6/22/07 11:58 AM Page 54
August 2007 55
STORM 42-50-600 brushless outrunners by Hurricane Flight
Systems provide 730 watts of power each on a 4S pack.
Richard Girardo photo.
The nose gear is controlled via pull-pull wires and a third servo for
ground steering. Notice the gear-door-sequence hardware.
These reasonably priced Cirrus servos are used to guide the P-61.
The microservo is for the retract air valve.
ASM’s P-61 heads for the runway. The grass was a bit long, but
the engines and landing gear handled it well.
ASM P-61 Black
Widow–Electric
The heavily armed Black Widow was the USA’s first aircraft
that was specifically designed to be a night-fighter. It carried
radar equipment that enabled its two- or three-man crew to
locate enemy aircraft in darkness and fly into attack position.
The Advanced Scale Models P-61 is perfectly suited for
electric power. Richard Girardo of Vision Hobbies designed a
power system to make this scale model even stealthier.
Richard selected two STORM 42-50-600 brushless
outrunner motors by Hurricane Flight Systems. They are 42mm
in diameter, measure 50mm in length, and have a kilovolt rating
of 600.
Vision Hobbies recommends a larger-capacity ESC than
required, so Rich went with two 70-amp Hurricane Flight
Systems brushless ESCs that would operate their individual
3700 mAh 4S Li-Poly battery packs. The BECs would be
disconnected so the radio system could operate on its own 2700
mAh, 4.8-volt receiver pack.
Each motor turned an APC 13 x 6.5E propeller at 7,975 rpm.
Static testing showed that each motor drew 33.34 amps and had
an output of 730 watts.
Richard selected Robart retracts and a Futaba radio system
for guidance. The model’s all-up weight came to 14 pounds with
the batteries and an ounce of lead buried in the nose.
Flight performance proved to be impressive, with flight times
of eight-10 minutes. Throttle management is important for this
aircraft to keep it from flying too fast. Acceleration is quick, so
the takeoffs are short. On landing be sure to carry a bit of power
just to keep a good flow of air over the control surfaces. MA
—Michael Ramsey
Sources:
Hurricane Flight Systems:
5723 Golden Owl Loop
Land O’ Lakes FL 34638
(813) 996-6997
www.flyhurricane.com
Vision Hobbies
18635 N. 35th Ave. #110-402
Phoenix AZ 85027
(623) 572-8655
www.visionhobbies.com
08sig2.QXD 6/22/07 11:58 AM Page 55
The center pod is molded, and the front
and rear cockpit frames are cut as part of
the fuselage. That means you have to glue
the clear plastic “windows” inside the
existing frame.
The one-piece plastic canopy part is a
bit hard to hold inside the fuselage while
the glue dries. I glued both canopies in
place with RC/56 adhesive and then held
them there with small balloons.
Your air compressor (for the retracts)
will inflate the balloons until you can see
that they are just the right size. Then you
can clamp each balloon off to retain the air
pressure. I used two for the front cockpit.
A former is already in place to accept
the air tank. A second frame is glued in to
keep it from moving. The plastic fuselage
material works well with cyanoacrylate.
The air fill valve needs some kind of
support to handle the forces when it is
operated. I epoxied a 1/4 plywood plate in
place to do the job.
The instructions show a four-stroke
engine installation. In deciding how to
position the Magnum XLS .52As, my first
goal was to aim the muffler down low and
point the exhaust gases away from the
booms.
The best option was to mount the
engines on their side, which put the
carburetor in perfect alignment with the
fuel tank. The bonus was that the existing
blind nuts lined up just right with the
engine mounts.
The firewall is round, so the large
muffler touched the firewall when it was
trial-fit regardless of the angle at which the
56 MODEL AVIATION
Type: Semiscale ARF
Pilot skill level: Advanced
Wingspan: 79.5 inches
Wing area: 1,010 square inches
Length: 59.5 inches
Weight: 13.75 pounds
Wing loading: 31 ounces/square foot
Engines: .45-.52 two-stroke, .52-.61
four-stroke
Radio: Five, six, or more channels
Construction: Conventional wood
wing and tail surfaces, plastic center pod
and booms with internal plywood frame,
fiberglass cowling, film-covered wood
parts
Covering/finish: Fuelproof paint, ironon
fabric covering
Price: $419.99
Specifications
+
• High-quality, well-constructed kit.
• Easy to build; includes assembly guide
with more than 50 color photos.
• Ease of transport with plug-in outer
wing-panels.
• Scale detail on molded components.
• Well-built fiberglass molded engine
cowlings.
• Good ground handling with realistic,
sturdy optional sprung leg struts.
-• Supplied fuel tanks did not clear main
retract units.
• Gear actuator door springs missing.
Will be in future releases.
• Steering servo plate missing. Will be in
future releases.
• Cries out for more front and rear
cockpit detail.
• Air retracts’ action proved to be too
fast in up and down directions. Robart
in-line pressure restrictors were
added.
Pluses and Minuses
Engines used: Magnum XLS .52A
Propellers: APC 11 x 6
Fuel: 10-ounce tanks, 15%-nitromethane
fuel
Radio system: JR nine-channel receiver;
four-cell, 2500 mAh NiMH battery; 10
Cirrus CS-601BB servos; one Cirrus CS-
401MG miniservo; one MPi charge
switch; 10 6-inch, six 12-inch, five-18
inch, one 24-inch servo extension lead;
two Y harnesses
Ready-to-fly weight: 14 pounds, 2.4
ounces
Flight duration: Exceeds 10 minutes
Test-Model Details
engines were placed. This is mainly because
the current Magnum XLS .52 two-stroke
mufflers include quieting sections that make
them longer. Quieter operation is desirable,
so the mufflers were left as supplied and a
pair of 1/2-inch O.S. muffler extensions were
fitted to solve the problem.
The well-built fiberglass engine cowlings
felt extremely sturdy once the three
attachment bolts were fitted. To make
mounting the cowlings much easier, I
removed the cylinder head and muffler from
one engine. Then I simply slid the cowl over
the engine.
I fashioned a plywood ring and bolted it
to the front of the engine. This “tool” aided
greatly in accurately lining up both cowls.
To find out where the cylinder head
would exit the cowl, I cut a pilot hole that
exposed the top of the piston. A red dot had
previously been put on the center of the
piston. I lined up the cylinder head using the
glow-plug hole with the dot and the outline
of the head drawn on the cowl. This is quick,
easy, and accurate, especially when you have
two to do.
I fitted the muffler bolts in a similar
manner and then used them to position where
the muffler would exit the cowl. I made a
square opening at the bottom of the cowl to
let cooling air pass through and over the
engine.
When the main retract units were fitted, I
found that the supplied fuel tanks were too
long and interfered with the installation of
the main-gear retract-unit cylinders. I
swapped in two new 270cc tanks to replace
the supplied 290cc versions. The new tanks
give 10-minute flights.
Both rudder servos needed to be moved
over to clear the retracted main legs. I
enlarged the opening in the rudder-servo
plate to allow the servo to be moved more
toward the side of the boom.
It is a good idea to fit the rudder push
wire and sleeve last. Then you can make
sure it does not hit the wheel of the main
retract leg.
The nose-gear steering is controlled by a
separate servo that is mixed with the rudder.
To give good high- and low-speed handling,
I mixed in exponential around the center
position. The more extreme throws, needed
for slow-speed taxiing, were limited to near
maximum and beyond stick deflection only.
I programmed the steering servo not to
operate when the wheels are retracted.
One of the ASM P-61’s attractions is the
three retracting undercarriage legs and their
associated opening and closing gear doors.
You can go with fixed gear, but there is
really no substitute for a scale warbird with
fully operating landing gear.
Retracts with operating gear doors do
add a higher degree of complexity and are
probably best tackled by an experienced
builder. However, it is possible to do and the
instructions can get you there. The extra
effort is well worth the reward of a gear-up
fast pass followed by a landing with
“everything hanging down.”
A useful “tool” to make while you are
installing the air retracts is to temporarily
assemble the air tank and valve. You can
operate the valve, hence each leg
“manually.” You can also use the same
connect and disconnect setup for each leg as
in your final installation.
This “tool” will allow you to work the
legs up and down individually. This is
especially useful when installing and
adjusting the gear doors.
The holes in the nose-gear plate did not
line up with the factory-drilled and -fitted
landing-gear blocks. They were correct for
08sig2.QXD 6/22/07 11:35 AM Page 56
the fixed-gear plate, so I used it as a guide to
drill two new holes to get the nose leg to fit.
The nose gear has to be fitted in the
forward bolt holes’ position to clear the
nose wheel during retraction. I sanded the
nose-gear area smooth so nothing could
snag the pull-pull steering wires.
The compressed-air operation of all the
legs proved to be too fast. They made a
resounding “whack!” each time the retract
units were operated. I cured this by fitting
Robart restrictors in the up and down air
lines to slow the operation.
The hinges are glued to the inner surface
of the retract doors. As insurance I laid
small squares of 20-ounce fiberglass cloth
over the epoxy, while wet, to hold the
hinges in place.
When the door hinges are glued to the
gear openings, be sure to leave at least a
1/16-inch gap to allow the doors to open fully
later. The doors are operated by a hinged
plate that is loaded to spring the doors open.
They go back when the wheel strikes the
plate during retraction and eventually pulls
them all the way closed.
The instructions give accurate positions
for the door-actuating horns. Even so,
mainly because of the Z bends I experienced
some difficulty getting the doors to close
equally. Fortunately the Internet, and RC
Universe in particular, has a construction
thread running on this model.
Jimmy Bonanno of Urbandale, Iowa,
came up with a great solution. He soldered
threaded connectors onto the ends of the
door-actuator wires. Then he fitted
adjustable clevises. This allowed him to
adjust the lengths of the wires perfectly.
Now the doors are easy to set. It does not
matter how far they open as long as the
wheels and legs do not touch them on the
way back up.
This is an easy airplane to align. The fins
are a part of the fiberglass molded fuselage
booms. The wings’, booms/fins’ and
stabilizer’s alignment has been done for
you.
The center pod is attached to the wing
center panel with two bolts. The two booms
attach to the same panel with one bolt each.
The stabilizer is inserted between the
fins and tightened in place with a bolt at
each end. Clip the wing hatch in place and
you are finished. There is nothing to adjust
or glue.
My airplane was going to be stored and
transported fully assembled minus the outer
wing panels. This caused one small
problem: the bolt that was intended to hold
the outer wing panels to the center panel
was completely covered by the boom that
was already bolted to the wing. The wing
tube could have been left in the center panel
instead of the outer panel, but it was almost
guaranteed to be sticking out at the wrong
moment during transport, handling, or
storage.
Closer inspection of the center wing
revealed that the manufacturer had installed
a hardwood block inside the lower wing
skin to guide and hold the wing-tube
retaining bolt. I reproduced this block and
glued it in place inside the top wing
surface. Then it was easy to drill a new
hole to allow the wing to be bolted in place
from the top. Field assembly takes
approximately 30 seconds, and best of all
the airplane does not need to be flipped
over.
The P-61’s overall length is 61 inches.
Without the outer wing panels fitted it is
only 27 inches wide. In this configuration
the airplane will fit in most small
hatchbacks, minivans, and SUVs. It travels
nicely sitting on the tricycle undercarriage
or you could keep the gear retracted for
less height.
The scale plastic-trim bits went on
easily. I cut them to fit with a small pair of
“car body” scissors. I used a black felt-tip
pen to hide the white edges that were
exposed by the scissor cut.
I glued the trim in place with a thin
bead of medium cyanoacrylate. Use
masking tape for quick alignment if you are
using cyanoacrylate glue.
The supplied clevises and horns were
white. They will work fine, but later I
substituted them with black Du-Bro
clevises as a bit of personalization.
I sprayed the horns for the elevator,
rudders, and gear doors with LustreKote
fuelproof, flat-black paint. It takes only a
few minutes and is well worth the result.
The wing tanks are held in place with
screws to allow future access to the flap
servos. The four-gun unit on the top of the
wing fairing/hatch adds a realistic look. It is
well worth taking the time to get all the guns
parallel.
It was pleasing to find that the CG came
out extremely close to the 33/4 inches from
the LE specified in the instruction manual.
The receiver ended up just behind the
steering servo, with the battery under the
front canopy deck plate. The final CG was
set at the forward position to allow for the
slight reward gravity shift when the landing
gear is retracted.
The completed ARF weighs 14 pounds,
2.4 ounces, probably because the retract
units are heavier than the fixed-gear options.
The wing loading with fixed gear would be
31.36 ounces per square foot. The wing
loading with retractable landing gear is 32.2
ounces per square foot. That proved to be
practical for this P-61.
The last thing to do was iron down all
the covering. You must do this for black
iron-on material, and it is a great idea to
subsequently keep it out of direct sunlight.
Preflight: With the engines broken in and
synchronized, the nose-wheel servo
alignment needs to be tested and set under
taxi conditions. The last thing you want is a
nose wheel fighting the action of the twin
rudders.
The Black Widow taxis with good
authority. Mixing in a rotary-knob channel
to make steering trim adjustments separate
from the rudder trim lever proved to be a
satisfying asset.
A few short taxi runs were all it took to
get the front wheel pointing straight. These
runs can also help make sure the engines
keep running under “moving” conditions.
This airplane has one main color: black.
The white invasion stripes on the booms and
the wings are underneath. Orientation while
airborne was going to require a good runtime
memory of what attitude the airplane
was holding at all times.
Time to Fly: With clean sunglasses and an
empty sky I taxied the Black Widow to the
center of the runway and aimed it into the
wind. The seven-minute countdown timer
on the radio was activated.
The engines were slowly opened up and
began to roar happily in harmony. As the
throttle reached the half-stick position, the
airplane twitched slightly on some rough
grass and made as if to turn but
immediately proceeded to advance quickly
in a straight line.
With the P-61 traveling fast on all three
wheels I added full power and gently fed in
roughly one-quarter up-elevator, and then
the nose came up swiftly approximately 10°.
The main wheels left the ground and the P-
61 was airborne.
At first the climb was getting steeper—
too steep for comfort. There was too much
up-trim in the elevator. (Later it was
determined that there had been too much upelevator
mix for the gear-down condition—a
bad guess on my part.)
Down-trim was feverishly “beeped in”
and in place before the P-61 entered the first
turn. I also input a small amount of left
aileron trim. (I later removed that after the
outer wing-panel flaps and ailerons were
better aligned with the center wing panel.) I
left the landing gear down for a few passes.
The first rule of flying twin-engine models
is to gain height as quickly as possible after
takeoff. The Magnums were running
beautifully and would almost pull the P-61
vertical. Once trimmed, it was time to look at
how the airplane was actually flying.
The trim-setting adjustments were the
only things needed to achieve a good, steady
flight. The controls could be released and the
P-61 would fly hands-off if put in straight and
level flight. The fuselage stayed pleasantly
level when entering a turn.
Later, 1/4 inch of rudder throw either way
was coupled to the ailerons to automatically
help the turn entry at low speeds. Once
banked over, applying elevator only kept the
turn going and there was no climbing or
diving in left- or right-hand turns.
Different throttle settings showed stable
The clock was ticking, so a landing was
next on the agenda. The gear was lowered
and the correct elevator trim was reengaged.
At a safe altitude the flaps were
fully deployed and the preset flap auto
down-elevator engaged itself.
The ASM P-61 dives a bit when the flaps
are down. They are positioned outboard of
the main engines, which may be why they
have that effect. I brought the flaps back up
to level and planned a no-flap landing
approach.
I selected half throttle and made a
landing circuit. Once the airplane was over
the runway threshold, roughly one-third
throttle made the P-61 slow down visibly.
The wings stayed level, and at
approximately a foot above the grass the
engines were brought back to a high idle.
The Black Widow “floated” steadily 10
yards or so and settled into a smooth
landing. The first flight was good, but it
definitely fell into the category of needing
an experienced pilot.
It took only a few moments to correct the
elevator mixes. I set the gear up-and-down
mix at barely 1/16 inch up-elevator trim
when the landing gear was down. The flap
auto elevator-trim dial mix was reversed so
flap-related up-elevator trim could be dialed
while in flight.
The takeoff was picture-perfect, and the
gear was retracted halfway around the field.
Long, big scale rolls with positive “G,”
often called barrel rolls, were performed
with ease. Axial rolls were pleasant to do to
the left or the right.
The instructions guide you to put in
more up than down aileron throw. That
definitely made the ailerons roll the airplane
better into the turns.
A huge loop could be pulled with
Magnum XLS .52As willingly doing their
job. The engines sounded great as they came
on “song” for the climb and then “purred”
contently down the back half of the loop.
Low passes at full throttle were
impressive. The most interesting pass may
well be when you throttle back to roughly
one-quarter power, add the flaps, and then
lower the landing gear as you do a slow
flyby for the cameras.
With full flap engaged you can do a
much steeper final approach with no
appreciable gain in airspeed. A short
skimming of the grass and a small flare of
the elevator lets the wheels settle into a
smooth rollout. You can see the gear legs
compressing their springs as the Black
Widow rolls slowly to a stop.
Landings using the flap were
predictable and straightforward. Takeoffs
did not like having the flaps down. The
nose came up much quicker and easier
without the flaps.
Once dialed in the ASM P-61 Black
Widow was a delight to fly and throw
around the sky. There was no need to worry
about potential drag from the wing tanks
because this airplane will fly fast with them
attached. It loops majestically. Cruisingspeed
turns and rolls show no adverse yaw.
Slow-speed aileron turns liked a bit of
top rudder to be added going into the turn.
This can be done manually or mixed in all
the time. One practical way of switching
aileron-to-rudder mix on and off could be
to use the throttle position as a switch.
As far as whether or not the instructions
mean an experienced builder or flier,
advanced building and setup skills are most
likely required, as the supplier advises.
However, it is fair to claim that, once
trimmed, the ASM P-61 is as easy to fly as
any low-wing sport model. If you can get
some help putting one together and setting
it up, this twin could do a lot early in your
RC flying life.
The Magnum XLS .52As are more than
adequate for this airplane. They run well
and sound wonderful when synchronized.
You can do full-bore passes that feel
“locked” all the way.
The ASM P-61 Black Widow’s pedigree
will let you look like a Scale pilot before it
even takes off. It is not designed to be a
pure Scale Masters competition aircraft, but
it does look real in the sky and in the pits.
This P-61 flies as easily as most 60-size
sport models, with no nasty habits. It is
great to fly just for fun! MA
Eric Henderson
[email protected]
Manufacturer/Distributor:
ASM/Global Hobby Distributors
18480 Bandilier Cir.
Fountain Valley CA 92708
(800) 854-8471
www.hobbypeople.net
Sources:
11 x 6 APC sport propellers:
Landing Products
1222 Harter
Woodland CA 95776
(530) 661-0399
www.apcprop.com
Magnum XLS .52A engines:
Global Hobby Distributors
http://magnum.globalhobby.com
JR radios and accessories:
Horizon Hobby, Inc.
4105 Fieldstone Rd.
Champaign IL 61822
(800) 338-4639
www.jrradios.com
Morgan 15%-nitro fuel
www.morganfuel.com
Retracts and accessories:
Robart Manufacturing
Box 1247
Saint Charles IL 60174
(630) 584-7616
www.robart.com
O.S. muffler extensions:
Great Planes Model Distributors
Box 9021
Champaign IL 61826
www.osengines.com
TopFlite LustreKote paint
Great Planes Model Distributors
Other Resources:
Model Airplane News: May 2007