Hybrid Aircraft

The dream aircraft that takes off vertically like a helicopter, but flies horizontally like a proper airplane, is gradually coming true. Last week, at Fort Worth, Bell Aircraft Corp. showed a prototype convertiplane. It looks like an airplane, but it has two helicopter rotors projecting from nacelles on the tips of its stubby wings.

The convertiplane takes off with the rotor shafts vertical, and the rotors lift it into the air helicopter-fashion. Then the pilot tilts the rotors forward so that they begin to act like oversized airplane propellers. As the aircraft gains forward speed, its wing begins to contribute lift. When the rotors have been turned through 90DEG and are facing fully forward, all the lift comes from the wing, as in a standard airplane. The conversion in the Bell takes about 15 seconds and is said to be smooth and easy. Top speed in horizontal flight: more than 175 m.p.h.

Deputy to the Under Secretary of the Army Frank H. Higgins hailed Bell's convertiplane, the XV-3,* as a possible answer to the Army's air requirements. For use in rugged country, the Army needs an aircraft that can land and take off anywhere like a helicopter. But helicopters are notoriously slow, and their flailing rotors waste fuel because they are comparatively inefficient sources of lift. A convertiplane on the general plan of the XV3 mav prove to have the speed and economy of the fixed-wing airplane without sacrificing the special advantages of the rotary wing helicopter.

*Much further advanced than Bell's jet-propelled convertiplane (TIME, Feb. 14).

This file is automatically generated by a robot program, so reader's discretion is required.