Radio Control Giants - 2006/12

124 MODEL AVIATION
THE GASOLINE ENGINES we typically use in our larger RC
models generally use some version of the ubiquitous Walbro
carburetor. Used in overwhelming numbers of two-stroke gaspowered
weed whackers, chain saws, and other small landscape and
gardening
equipment, the
Walbro carburetor is
easy to use and
adjust and is
extremely reliable.
The standard
operating
procedures differ
between
landscaping and RC
models. In RC we
usually drain the
fuel tanks of our
Modify your Walbro choke for RC operation
[[email protected]]
Radio Control Giants Sal Calvagna
Also included in this column:
• A 1/4-scale Sperry Messenger
built by Gene Oshrin
• Ed Hirschfeld’s Jalopaplane
makes its maiden flight
• Bill Hofmann builds a Byron
F4U Corsair
The butterfly choke in the Walbro carburetor is held on with only
one screw in the center.
The Walbro carburetor with the modified choke is more effective
for RC and there are no more gas-soaked thumbs.
Gene Oshrin built this 1/4-scale Sperry Messenger that spans a
scant 60 inches and measures 50 inches in length.
Gene, of Bridgehampton, New York, displays his Messenger
modeled after the one based at McCook Field in 1922.
aircraft back into our fuel containers at the end of the flying day.
With landscape equipment, this is rarely done; the remaining fuel
stays in the tank for use on another day.
Another difference is that most small, two-stroke-powered
machines usually have a fuel bulb to prime the engine when it’s
cold. Our model engines lack this fuel bulb to assist in priming.
What we do have in common is the brass butterfly choke. One trait
shared by two-stroke gas engines is that they like to be well primed
for a cold start.
A frequent scenario at the flying field is a modeler with one
hand over the closed butterfly to make a good seal while the other
hand moves the propeller back and forth through the compression
stroke or around and around in order to draw fuel into the
carburetor. Fuel doesn’t easily draw into the carburetor from the
fuel tank because there is a sizable hole manufactured into the
butterfly. This hole is approximately 3/32 inch in diameter and
allows air to be ingested, reducing the amount of draw from the fuel
tank.
12sig4.QXD 10/25/06 11:46 AM Page 124The easiest way I’ve found to remedy this is to remove the
butterfly choke; it’s held on with only one screw in the center. Lay
it down flat on a surface that won’t burn, and fill the hole with a bit
of solder with a hot soldering iron. Now you have a more effective
choke. No more gas-soaked thumbs!
Sperry Messenger: Gene Oshrin of Bridgehampton, New York, is
shown with his 1/4-scale Ikon N’wst Sperry Messenger. The model
spans a scant 60 inches and is 50 inches in length. It’s powered by a
.91 four-stroke glow engine and painted with DuPont automotive
paint. Gene modeled his Messenger after the full-scale airplane that
was based at McCook Field in 1922.
The Sperry Messenger was the smallest manned aircraft ever
used by the United States Army. It was built between 1920 and
1926 and was able to land in small clearings such as the forward
area to pick up and deliver messages from field commanders. It was
structurally simple, easy to maintain, and a minimal cost of $4,000
per airplane made the Messenger practical for its designed task.
The aircraft was built by the Lawrence Sperry Aircraft
Company of Farmingdale, New York. It was called the Messenger,
but reporters watching the first flight coined it the Sperry
Messenger after its builder. The military designated the aircraft as
the M-1, M-1A, or MAT, and orders were issued to not call it the
Sperry Messenger, but the name stuck and it became readily
acceptable as the Sperry M-1 Messenger.
The airplane was powered with a small, 60-horsepower, threecylinder
radial. Lawrence Sperry, who lived in Garden City, New
York, used to take off and land on the road directly in front of his
home. He once landed his Messenger in front of the Capitol
building in Washington DC and later in front of the Jefferson
Memorial.involved with restoring an original
Messenger. He had the opportunity to use
the original drawings to assist in
completing his 1/4-scale model. The kit
may still be available from Ikon N’wst at
3012 N. Altamont, Spokane WA 99207.
The telephone numbers are (509) 533-1649
and (800) 717-4508.
Nice job, Gene!
Jalopaplane: I had the pleasure of being
present at the first flight of one of the
strangest-looking models that I have ever
seen. I’m referring to the Eddie A.
Aircraft 83-inch-wingspan Jalopaplane
built by my friend Ed Hirschfeld of
Selden, New York.
For many years I had seen this model
on its display stand at the annual
Westchester Radio Aeromodelers Show in
Westchester, New York; however, I have
never heard about or seen one of these
models fly. I’m happy and surprised to say
that it flew extremely well.
Ed used the recommended Zenoah G-23
gas engine for power and covered the
model in Solartex material. The aircraft is
unique, and at first glance it looks sort of
like the platypus of Australia. I guess the
next step for Ed is to find a suitable pilot
figure for such an unusual model.
Good luck, Ed!
For readers interested in this model, I
believe you can purchase one from Eddie
A. Aircraft at 917 Marie Ct., Franklin
Lakes NJ 07417. The telephone number is
(201) 337-6159.
Bill Hofmann’s F4U: Bill Hofmann of
Port Jefferson Station, New York, built a
beautiful Byron Originals F4U Corsair. It
is shown on approach after its first flight.
The model spans 85 inches, has a length of
68.5 inches, and weighs approximately 25
pounds.
Bill installed a Zenoah G-62 gas engine
to power a Bolly 20 x 12 propeller. The
model has Robart retracts, and Bill even
added a retractable tailhook for carrier
operation.
The actual development of the Corsair
started in 1938 when the US Navy issued a
request for a new single-seat fighter. The
prototype first flew in May 1940, and after
many design changes the first production
model was finally delivered in July 1942.
Further changes were made for carrieroperations
approval.
More than 12,000 of the airplanes were
eventually built by Chance-Vought,
Goodyear, and Brewster. Production of the
F4U Corsair ended in 1952.
Although the Corsair acquired many
nicknames including “Whistling Death”
and “Bent-Wing Bird,” the most
unfavorable was “Ensign Eliminator.” This
name was given to the Corsair because the
cockpit, which was placed farther back
than on most carrier-based aircraft, made
carrier landings extremely difficult. This
resulted in many inexperienced pilots
crashing their airplanes on landing.
In its defense, some who have flown the
Corsair and the P-51 Mustang state without
hesitation that the P-51 exhibited a greater
propensity to roll on its back than did the
F4U. Moreover, the Corsair was a far more
forgiving aircraft when entering a stall.
Although it would drop its right wing
abruptly, the aircraft gave plenty of
advanced warning of an impending stall by
entering a pronounced buffeting roughly 6-
7 mph before the wing dropped.
The question is still asked today—more
than 60 years later—what the best fighter
aircraft of World War II was. There’s
evidence to support the argument that the
Chance Vought F4U-4 Corsair was the
finest all-around fighter of the war. It
certainly qualifies as the best fighter/
bomber.
The F4U-4 arrived in combat late in
World War II—in early 1945. This meant
that it had only approximately six months
to establish its combat record against the
Japanese. It did remain in service
throughout the Korean War, where, along
with the F4U-5, it gained an outstanding
reputation for delivering ordnance with
great accuracy.
The P-51, given the moniker “Cadillac
of the Skies” for its outstanding service
mainly in Europe during World War II, has
many stalwart supporters for the best
overall fighter. There are others who stand
behind the P-38, Spitfire, and P-47. Before
you get embroiled in yet another argument
about the finest fighter of World War II,
take heed of these points.
The F4U-4 had a 30 mph speed
advantage over the P-51D. The F4U-4 had
a 20% better climb rate than the P-51D.
The F4U-4 was the premier load-carrying,
single-seat fighter of the war.
The United States Army Air Force
admitted that the F4U could absorb more
battle damage than the tanklike P-47. The
F4U could also outturn the P-51 at slower
speeds. In fact, the F4U could fly 30 mph
slower than the speed at which the
Mustang stalled. The Mustang did have
better pilot visibility and certainly
maintained a large edge in flight
endurance.
So there you have it! The next time
someone brings up the subject, you have
more ammunition. Fire away!
Although Byron Originals is no longer
in business, you can purchase many of the
company’s designs from the Iron Bay
Model Company, including the Corsair.
You can visit its Web site at www.ironbay
modelcompany.com or call (304) 232-
7511. The mailing address is Box 6383,
Wheeling WV 26003.
I want to take this opportunity to wish all
of you a happy and healthy holiday season.
Now is the time to start your next
winter project. Let me know if you need a hand, and please send me some photos of
your current project. I’m sure that all my
readers would like to see what’s on your building board.
In 1923 Lawrence made a forced landing in the English Channel
and apparently drowned trying to swim ashore. In all, 42 Sperry M-
1 Messenger aircraft were built.
Gene became interested in completing the kit when he was