Goodyear Inflatoplane

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. 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."

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 psi; at full size, it was 19 ft long, with a 22 ft wingspan. A pilot would then hand-start the two-stroke cycle, 40 hp Nelson engine, and takeoff with a maximum load of 240 lb. On 20 US gallons (76 L) of fuel, the aircraft could fly 390 mi, with an endurance of 6.5 hours. Maximum speed was 72 mph, with a cruise speed of 60 mph. Later, a 42 hp engine was used in the aircraft.

Takeoff from turf was in 250 feet with 575 feet needed to clear a 50 foot obstacle. It landed in 350 feet. 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 shorter, but with a 6 ft longer wingspan than the GA-468. A more powerful 60 hp McCulloch 4318 engine could power the 740 lb of plane and passenger to 70 mph, although the range of the plane was limited to 275 mi.

Operational history
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, as was clear from marks on his helmet. Wallace was pitched out over the nose of the aircraft and fell into the shallow lake. His chute never opened. He may have been knocked unconscious and rendered unable to open it. Only 12 Goodyear Inflatoplanes were built, but development continued until the project was cancelled in 1973.

Survivors
Goodyear donated two Inflatoplanes for museum display at the end of the project, one to the Franklin Institute in Philadelphia and one to the Smithsonian Institution in Washington, D.C.

Variants

 * GA-33 Inflatoplane
 * The initial single-seat version, with open cockpit, based on the Taylor McDaniel inflatable rubber glider experiments from the early 1930s. One built.


 * GA-447 Inflatoplane
 * An enclosed cockpit and new wing, used for undercarriage experiments (tricycle, uniwheel, and hydroskid). One built.


 * GA-466 Inflatoplane
 * Company designation for the AO-2 Inflatoplane


 * GA-468 Inflatoplane
 * Company designation for the AO-3 Inflatoplane


 * XAO-2-GI Inflatoplane
 * Military designation for the GA-466. One built.


 * XAO-3-GI Inflatoplane
 * Military designation for the GA-468. Five built.