Science: Straight-UpJet

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An odd aircraft has been flying, rather tentatively, at Niagara Falls, N.Y. over the past few weeks. It looks like a light private plane with a bulky ashcan suspended under each wing, and helicopter skids instead of wheels. Last week Bell Aircraft Corp. told how it works. It is a jet-powered VTOL (vertical take-off and landing), and Bell believes that from it will develop jet fighters and transports that can rise like helicopters from a small patch of ground, then turn themselves into normal-flying airplanes.

Bell's VTOL has a glider's fuselage and the wing of a light commercial airplane. Hung under the wings on swivels are two small jet. engines made by Fairchild for use in drone targets and guided missiles. Each weighs 300 Ibs. and has 1,000 Ibs. of static thrust. Since the whole airplane, engines and all, weighs only about 2,000 Ibs., the twin jets, directed downward, can lift it vertically off the ground. Controlling a craft that rises in this manner is a tricky business. Even more tricky is converting it to horizontal flight.

Air Blasts. Bell's VTOL has conventional controls (ailerons and tail surfaces) for use when flying horizontally. These do not work when the craft has no forward speed, so tubes of compressed air from the engines' compressors are carried out to the tail and the wingtips. The pilot controls the plane's attitude on the rise or descent by varying the strength of the air blast from the ends of the tubes.

Pilot David W. Howe trained for his job of testing the vertically rising jet by learning how to fly a helicopter.* With this experience behind him, he says, he had no trouble at all. The little VTOL, with its engines turned downward, rises easily off the ground. Speed of ascent is controlled by varying the speed of the engines, and the plane is kept on an even keel by juggling the air jets. When it is clear of obstacles, Pilot Howe gets his nose down and picks up flying speed. Then he swivels the engines so that their thrust is directed backward. This maneuver takes about 15 seconds, and when it is complete, the VTOL is flying horizontally like a normal jet plane.

At Home in the Air. Pilot Howe makes landing sound just as easy. "The pilot," he says, "merely selects the spot where he wants to land. He brings the VTOL to a hovering position—and lands." According to him, the VTOL is as at home in the air as a dragonfly. It can hover indefinitely, its engines blasting downward. It can fly backward and sideways and spin like a waltzing mouse.

Bell does not say much about the VTOL's speed and cargo capacity. The present model, the company explains, was put together from existing components to prove that a jet plane can really rise like a helicopter. A more advanced model is being designed, and Bell believes that the swiveled-engine principle will eventually be used in both military and commercial airplanes.