Radio Control Giants - 2006/01

DEPENDING ON the type of model you’re
constructing, there are times when access
behind the firewall may be troublesome.
Multiengine models can be more problematic
since space or access to the interior of each
nacelle can make it a challenge to install
landing gear, fuel tank, throttle servo, etc.
One solution is to fabricate a removable
firewall assembly. This is what I did on my
Mitsubishi A5M4 Claude. With the help of a
few photos, I will explain how you can do the
same.
It doesn’t matter what kit or plans you are
working with, all models call for some sort of
firewall. In the case of my A5M4, the firewall
has a round shape.
square as I did on the Claude or you can cut a
circle, leaving a small portion of the first
firewall. Since the Claude needed weight up
front, I decided to leave as much of the
original firewall as possible.
The photo shows the original firewall with
a center square cut out. You can see the
mounting holes around the outer edge.
Then I installed the blind nuts on the first
firewall. I used 10-24 socket-head bolts and
blind nuts to attach the removable firewall.
When it was installed, I installed the engine: a
Zenoah G-62. I made a spacer block to have
the correct propeller clearance. I used 10-24
socket-head bolts and blind nuts to attach the
engine to the firewall.
firewall with 1/4 x 1/4 stock.
After the tank was installed I was able to
attach the throttle servo on the outside of the
box. As you can see, it is a straight run to the
bellcrank on the front of the firewall. In this
fuel-tank setup I used a three-line system: one
line for vent, one for the carburetor, and one
for filling and defueling the tank.
A photo shows the removable firewall in
place. The other holes in the firewall are used
to attach the cowling. If you look to the right
of the engine, you will see a nice chunk of
lead that I had to use to balance the model.
Some of my friends refer to it as an asteroid.
Those darn short-nosed Japanese airplanes!
There you have it: easy access to your tank
and throttle servo.
Curtiss Headless Pusher: Included are a
couple great shots of Ed Hirschfeld and his
Curtiss D-III Headless Pusher. The model,
built from George Marsden plans, is 1/4
scale with a wingspan of 96 inches.
The Pusher is powered by the same SR
Batteries electric-power system that was
used on the SR Batteries Eindecker E1. It
uses an AXI 4130 brushless Outrunner
motor and 24 2000 Max cells powering a
Zinger 18 x 8 wood propeller.
Although the model resembles a fancy
UHF antenna with all those sticks and
wires, Ed is able to assemble it at the field
in approximately 20 minutes. A neat
feature is that the receiver, servos, and
receiver battery pack are hidden within the
pilot figure.
It is a thing of beauty on the ground and
in the air. As I watched the model make
slow passes at the field, I couldn’t help but
think about the pilot of the full-scale
aircraft just sitting out there with nothing
in front of him. What real courage it must
have taken to fly this early aircraft.
An interesting story is how the aircraft
became known as the Headless Pusher.
The name resulted from an accident that
involved a Curtiss exhibition pilot named
Lincoln Beachey.
Upon landing the Pusher, Beachey hit a
fence and damaged the forward elevator
assembly. The assembly could not be repaired
in time for the aerial performance, and under
pressure to fly the machine Beachey removed
the forward elevator assembly and took to the
air. To his surprise the Pusher performed
better than before, thus was born the 1912
Curtiss D-III Headless Pusher.
A Fokker’s Untimely End: This column
includes a picture of Mike Gross’s 1/3-scale
Fokker D.VIII built from Ron Weiss plans.
The airplane spanned 111 inches and was
powered by a Zenoah G-62 gas engine.
The model looked and flew great. Mike is
a consummate builder, flier, and Top Gun
competitor. Unfortunately the Fokker met an
untimely end by means of a midair collision at
the Warbirds Over Delaware event in July
2005.
Certainly, accidents of all kinds can
happen while flying models. It’s a risk that we
take once our pride and joy has left the safety
of terra firma. It’s what separates us from the
model-railroad enthusiasts!
However, this accident was a bit more
personal because I was the other guy involved
in the midair! Yes, that’s right. It was me at
the controls of my 82-inch Me 163 Komet
when the midair occurred.
Mike was experiencing some radio
problems and declared an emergency. I was
flying a racetrack pattern with the Komet.
When the D.VIII came into view, I did not
believe we were on a collision course.
Perhaps the diminutive size of the Komet and
the larger profile of the Fokker had something
to do with depth perception.
The Komet cut the Fokker clean in half.
The Me 163 lost half an outer wing panel and
flew right through the debris field. It flew for
another few hundred feet before it lost
airspeed and spun in. The D.VIII spun in
immediately.
What’s ironic is that Mike and I fly at the
same club field on Long Island. There, Mike
would chase my 1/3-scale Pup in mock
dogfights with his Fokker D.VIII. He would
always emerge the victor because my Pup had
a smoke system installed. I would turn on the
smoke as he maneuvered the D.VIII into
firing position behind my Pup.
Of course, Mike would tell me that it had
nothing to do with the smoke system; he
explained that he was simply the better pilot.
Just before that fateful flight in Delaware,
Mike looked over at me and made some sort
of comment about the Komet. I distinctly
remember my response to him: “Forget about
it; you’ll never get anywhere close to me.”
Famous last words!
That’s a wrap for this column. I’ll be back
next month.
Oh, by the way, get your hobby list ready;
the holidays are nearly upon us. MA
It was time to build a box to house the fuel
tank and throttle servo. I carefully measured
the length and width of the fuel tank that I
was going to use and made a box from light
When I cut out the parts for the model, I
simply made two identical firewalls. The first
was installed as the plans indicated. Then I
placed the second (removable) firewall
directly over the first and drilled eight holes