AS I WAS driving to the AMA Nats this
summer, I noticed a billboard advertising
the Combat Air Museum in Topeka,
Kansas. Since it is hard for me to pass any
aviation museum, I stopped at Forbes Field,
where the museum is located, and spent an
enjoyable two hours touring the aircraft and
exhibits with docent Ralph Knehans.
The Combat Air Museum is housed in a
World War II-era hangar and a Cold War
B-47 maintenance hangar on the former Forbes Air Force Base,
located south of Topeka. The museum’s holdings include veteran
aircraft from World War II, Korea, and Vietnam, with enough
Navy airplanes for any Carrier modeler.
There is a Grumman F4F-3 Wildcat that was returned to flying
condition after decades in Lake Michigan, a Korean War-veteran
F9F Panther, a Blue Angels F11F Tiger, and a Douglas F3D
Skyknight. The museum’s Lockheed EC-121 saw service in
Vietnam and is open to allow visitors to view the stations from
which controllers helped manage the air war over the north.
For a much better description than I have the space for here,
visit www.combatairmuseum.org.
Duly Guardian: The photos this month are of Ron Duly’s
prototype Grumman AF-2 Guardian for Class II Nostalgia Navy
Carrier. Ron’s original model won the Nats at Riverside (March
Air Force Base), California, in 1977.
Ron’s original intent was to refurbish the model for the
Nostalgia Carrier event, but after starting the project he decided
that the structural integrity of the wings and fuselage was less than
it should be. At that point he salvaged the tail surfaces, canopy,
cowling, and some control-system components, and he mated them
to a new fuselage and wings.
The result is a beautiful model with outstanding performance.
Power for Ron’s Guardian is a Rossi .65 engine equipped with a
classic Johnson-style exhaust slide and fuel meter. It operates on
crankcase pressure.
Unlike the combined exhaust slide and intake throttle systems I
discussed in earlier columns, the Johnson system uses only the
exhaust slide for speed control. With the intake wide open, even at
low speed, the crankcase pressure remains high and fairly
consistent regardless of engine speed.
As you can see, the entire throttle system is attached to the
engine. That configuration is essential to the consistent operation
of the engine because the components must work together.
Adjustments are made by varying the lengths of the linkages
and the lengths of the various arms. If some of the components
were mounted on the aircraft, the adjustments could not be
maintained with the engine removed, and the engine could not
operate alone, as on a test stand.
The system was a logical development from the Smurthwaite
exhaust slide concept with a unique fuel meter that allowed the
Johnson system to use a pressure fuel system. The fuel meter is the
Topeka, Kansas, Combat Air Museum at Forbes Field
[tailhooker@comcast.net]
Control Line Navy Carrier Dick Perry
Ron Duly’s Class II Nostalgia Carrier Guardian in slow flight during the 2005 Nats.
Ron Duly’s 2005 model (R) used some components from his 1977
Nats winner.
Ron Duly’s Rossi .65 engine in his Grumman AF-2 Guardian uses a
Bill Johnson meter and slide for speed control.
Also included in this column:
• Ron Duly’s Class II Guardian
resurrection
• 2007 Navy Carrier rules
October 2006 141
10sig5.QXD 8/24/06 1:15 PM Page 141device at the top of the backplate in the
photograph. It was constructed from
telescoping brass tubing with a piece of
Tygon fuel line as a seal around the rotating
inner tubing.
This was (and still is) a consistent
system as long as the variables of fuel and
propeller were not changed significantly.
2007 Rules: Final voting on the rules
changes for 2007 has been completed. There
are no significant modifications.
Most of the changes are editorial in
nature, with some minor changes to deck,
circle marking, and timing. Center marking
will do away with the movable plate, which
is rarely used.
Deck specifications will allow the use of
thread laid out on the ground as a means of
identifying late takeoffs and early landings
on decks, and will add visible markers to
make landing areas of ground-based carrier
decks easier to see from the center of the
circle. Timing changes will include the
designation of the two timers who will serve
as the official timers unless their recorded
times vary by more than the record
requirements.
The new rules will be published on the
AMA Web site (www.modelaircraft.org) in
January 2007. MA
Edition: Model Aviation - 2006/10
Page Numbers: 141,142
Edition: Model Aviation - 2006/10
Page Numbers: 141,142
AS I WAS driving to the AMA Nats this
summer, I noticed a billboard advertising
the Combat Air Museum in Topeka,
Kansas. Since it is hard for me to pass any
aviation museum, I stopped at Forbes Field,
where the museum is located, and spent an
enjoyable two hours touring the aircraft and
exhibits with docent Ralph Knehans.
The Combat Air Museum is housed in a
World War II-era hangar and a Cold War
B-47 maintenance hangar on the former Forbes Air Force Base,
located south of Topeka. The museum’s holdings include veteran
aircraft from World War II, Korea, and Vietnam, with enough
Navy airplanes for any Carrier modeler.
There is a Grumman F4F-3 Wildcat that was returned to flying
condition after decades in Lake Michigan, a Korean War-veteran
F9F Panther, a Blue Angels F11F Tiger, and a Douglas F3D
Skyknight. The museum’s Lockheed EC-121 saw service in
Vietnam and is open to allow visitors to view the stations from
which controllers helped manage the air war over the north.
For a much better description than I have the space for here,
visit www.combatairmuseum.org.
Duly Guardian: The photos this month are of Ron Duly’s
prototype Grumman AF-2 Guardian for Class II Nostalgia Navy
Carrier. Ron’s original model won the Nats at Riverside (March
Air Force Base), California, in 1977.
Ron’s original intent was to refurbish the model for the
Nostalgia Carrier event, but after starting the project he decided
that the structural integrity of the wings and fuselage was less than
it should be. At that point he salvaged the tail surfaces, canopy,
cowling, and some control-system components, and he mated them
to a new fuselage and wings.
The result is a beautiful model with outstanding performance.
Power for Ron’s Guardian is a Rossi .65 engine equipped with a
classic Johnson-style exhaust slide and fuel meter. It operates on
crankcase pressure.
Unlike the combined exhaust slide and intake throttle systems I
discussed in earlier columns, the Johnson system uses only the
exhaust slide for speed control. With the intake wide open, even at
low speed, the crankcase pressure remains high and fairly
consistent regardless of engine speed.
As you can see, the entire throttle system is attached to the
engine. That configuration is essential to the consistent operation
of the engine because the components must work together.
Adjustments are made by varying the lengths of the linkages
and the lengths of the various arms. If some of the components
were mounted on the aircraft, the adjustments could not be
maintained with the engine removed, and the engine could not
operate alone, as on a test stand.
The system was a logical development from the Smurthwaite
exhaust slide concept with a unique fuel meter that allowed the
Johnson system to use a pressure fuel system. The fuel meter is the
Topeka, Kansas, Combat Air Museum at Forbes Field
[tailhooker@comcast.net]
Control Line Navy Carrier Dick Perry
Ron Duly’s Class II Nostalgia Carrier Guardian in slow flight during the 2005 Nats.
Ron Duly’s 2005 model (R) used some components from his 1977
Nats winner.
Ron Duly’s Rossi .65 engine in his Grumman AF-2 Guardian uses a
Bill Johnson meter and slide for speed control.
Also included in this column:
• Ron Duly’s Class II Guardian
resurrection
• 2007 Navy Carrier rules
October 2006 141
10sig5.QXD 8/24/06 1:15 PM Page 141device at the top of the backplate in the
photograph. It was constructed from
telescoping brass tubing with a piece of
Tygon fuel line as a seal around the rotating
inner tubing.
This was (and still is) a consistent
system as long as the variables of fuel and
propeller were not changed significantly.
2007 Rules: Final voting on the rules
changes for 2007 has been completed. There
are no significant modifications.
Most of the changes are editorial in
nature, with some minor changes to deck,
circle marking, and timing. Center marking
will do away with the movable plate, which
is rarely used.
Deck specifications will allow the use of
thread laid out on the ground as a means of
identifying late takeoffs and early landings
on decks, and will add visible markers to
make landing areas of ground-based carrier
decks easier to see from the center of the
circle. Timing changes will include the
designation of the two timers who will serve
as the official timers unless their recorded
times vary by more than the record
requirements.
The new rules will be published on the
AMA Web site (www.modelaircraft.org) in
January 2007. MA