Extension of the High-Speed Flight Envelope of the XH-51A Compound Helicopter

摘要

This report presents the results of a speed extension program conducted by the Lockheed-California Company on the compound version of the rigidrotor XH-51A helicopter (under a supplement to contract DA 44-177-AMC150 (T), Modification l). The principle objective of this program was to investigate the flight characteristics of the compound helicopter vith special emphasis on the areas of flying qualities, performance, structural loads, vibration, and maneuverability in the speed range of 200 to 230 knots true airspeed. All contract objectives were net or exceeded. The maximum level flight true airspeeds demonstrated, during this program, were 236 knots at sea level and 228 knots at a density altitude of 12,000 feet.