Helicopter-maker says test of new thruster was a success

Piasecki Aircraft Corp., of Essington, said yesterday that it had successfully completed the first test flight of a new thruster designed to enable helicopters to fly farther and faster at less cost.

Conventional helicopter tail rotors blow air sideways to counter the torque of the whirling main rotors and help control the direction of the aircraft. Piasecki said its new X-49A ducted propeller-vectored tail thruster faced rearward and directed thrust at angles controlled by the pilot. This both controls the lateral torque and adds forward thrust.

The evaluation is managed by the U.S. Army Aviation Applied Technology Directorate, Fort Eustis, Va.

The company said the first phase was using a modified Sikorsky SH-60F Seahawk helicopter to test performance and vibration reduction within existing speed and maneuvering limits of the SH-60F. If further results are positive, a second phase has been proposed to test potential drag-reduction features and other enhancements at higher speeds, the Piasecki announcement said, adding that a decision on the second phase would be made in about 12 months.

The system, called a "ring-tail ducted fan," is designed to enhance the performance of existing helicopters, including the Army's H-60 and AH-64, and the Marine Corps' H-1, as well as become part of future helicopters.

Frank N. Piasecki, founder, chairman and president of Piasecki Aircraft, is the second American after Igor Sikorsky to develop and fly a helicopter. He pioneered the tandem-rotor concept that led to the Army Chinook and Navy Sea Knight helicopters now built by Boeing in the Philadelphia area.