Goodyear Inflatoplane

Infobox Aircraft
name=Goodyear Inflatoplane


caption= Goodyear inflatoplane on display at the Smithsonian Institution
type=experimental aircraft
manufacturer=Goodyear Aircraft Company
designer=
first flight=13 February 1956
introduced=
retired=
status=Retired
primary user=United States Army
produced=1955-1962
number built=12
unit cost=
variants with their own articles=The Goodyear Inflatoplane was an experimental aircraft made by the Goodyear Aircraft Company, a subsidiary of Goodyear Tire and Rubber Company, well known for the Goodyear blimp. The Inflatoplane was roughly equivalent to the Piper Cub. Although it seemed an improbable project, the finished aircraft proved to be capable of meeting its design objectives although its sponsor, the United States Army ultimately cancelled the project when it could not find a "valid military use for an aircraft that could be brought down by a well-aimed bow and arrow."Winchester 2005, p. 126.]

Design and development

The original concept of an all-fabric inflatable aircraft was based on Taylor McDaniel inflatable rubber glider experiments in 1931. Designed and built in only 12 weeks, the Goodyear Inflatoplane was built in 1956, with the idea that it could be used by the military as a rescue plane to be dropped in a hardened container behind enemy lines. The 44 cubic ft (1.25 cubic meter) container could also be transported by truck, jeep trailer or aircraft.The inflatable surface of this aircraft was actually a sandwich of two rubber-type materials connected by a mesh of nylon threads, forming an I-beam. When the nylon was exposed to air, it absorbed and repelled water as it stiffened, giving the aircraft its shape and rigidity. Structural integrity was retained in flight with forced air being continually circulated by the aircraft's motor.

There were at least two versions:The GA-468 was a single-seater. It took about five minutes to inflate to about 25 lbf/in² (170 kPa); at full size, it was 19 ft 7 in (5.97 m) long, with a 22 ft (6.7 m) wingspan. A pilot would then hand-start the two-stroke cycle, Winchester 2005, p. 127. ] 40 hp (30 kW) Nelson engine, and takeoff with a maximum load of 240 lb (109 kg). On 20 US gallons (76 L) of fuel, the aircraft could fly 390 miles (630 km), with an endurance of 6.5 hours. Maximum speed was 72 mph (116 km/h), with a cruise speed of 60 mph. Later, a 42 hp (31 kW) engine was used in the aircraft.

Takeoff on sod was in 250 feet with 575 feet needed to clear a 50 foot obstacle. It landed in 350 feet on sod. Rate of climb was 550 feet per minute. Its service ceiling was estimated at 10,000 ft.

The GA-466 was the two-seater version, 2 in (50 mm) shorter, but with a 6 ft (1.8 m) longer wingspan than the GA-468. A more powerful 60 hp (45 kW) McCulloch 4318 engine could power the 740 lb (336 kg) of plane and passenger to 70 mph (113 km/h), although the range of the plane was limited to 275 miles (440 km).

Testing

The test program at Goodyear's facilities near Wingfoot Lake, Akron, Ohio showed that the inflation could be accomplished with as little as 8 psi (544 mbar), less than a car tire. The flight test program had a fatal crash when Army aviator Lt. "Pug" Wallace was killed. The aircraft was in a descending turn when one of the control cables under the wing came off the pulley and was wedged in the pulley bracket, locking the stick. The turn tightened until one of the wings folded up over the prop and was chopped up. With the wings flapping because of loss of air, one of the aluminum wing tip skids hit the pilot alongside the head (marks on his helmet proved that). Wallace was pitched out over the nose of the aircraft and fell into the shallow lake. His chute never opened. [ [http://aeroweb.brooklyn.cuny.edu/specs/goodyear/xao-3g1.htm] Note: Comment left on the Aviation Enthusiast Corner: Goodyear XAO-3G1 "Inflatoplane" website. Access date: 17 February 2007.] Only 12 Goodyear Inflatoplanes were built, but development continued until the project was cancelled in 1973.

urvivors

Goodyear donated two Inflatoplanes, one to the Franklin Institute in Philadelphia and one to the Smithsonian Institution in Washington, D.C.

pecifications (Goodyear GA-466 Inflatoplane)

aircraft specifications

plane or copter?=plane
jet or prop?=prop
crew=1
capacity=1 passenger
length main=19 ft 2 in
length alt= m
span main=28 ft
span alt= 8.53 m
height main=4 ft
height alt=1.22 m
area main=
area alt=
empty weight main=
empty weight alt=
loaded weight main=740 lb
loaded weight alt=336 kg
max takeoff weight main=
max takeoff weight alt=
engine (prop)= McCulloch 4318
type of prop=air-cooled
number of props=1
power main=60 hp
power alt= 45 kW
max speed main=70 mph
max speed alt= 113 km/h
cruise speed= 55 mph
stall speed= 43 mph
range main=275 mi
range alt= 440 km
ceiling main=6,500 ft
ceiling alt=1,981 m
climb rate main=500 ft/min
climb rate alt= m/s
loading main=
loading alt=
power/mass main=
power/mass alt=

References

Notes

Bibliography

* Winchester, Jim. "The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters". London: Amber Books Ltd., 2005. ISBN 1-904687-34-2.

External links

* [http://davidszondy.com/future/Flight/rubber_plane.htm Inflatoplane]
* [http://www.aero-web.org/locator/manufact/goodyear/ao-3.htm Aircraft Finder for Goodyear AO (Inflatoplane)]
* [http://www.nasm.si.edu/research/aero/aircraft/goodyear_xao.htm Goodyear XAO-3 Inflatoplane]