NH-3A (Sikorsky S-61F) Flight Test Program
UNITED TECHNOLOGIES CORP STRATFORD CT SIKORSKY AIRCRAFT DIV
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This report summarizes a flight test evaluation of the effects of auxiliary propulsion, wings, rotor solidity, and blade twist on a modified SH-3A helicopter airframe with standard S-61 dynamic components. A total of 88 hours of tests explored performance, handling qualities, stresses, vibrations and control loads for eight different configurations. The primary objective of the program, to extend tests of the compound configuration to a maximum safe speed of not less than 200 knots, was achieved. Level flight and dive speeds of 211 and 230 knots, respectively, were reached. At 200 knots, rotor lift was varied from 25 to 75 of gross weight. Throughout the expanded flight envelope, handling qualities and structural loads confirmed predictions with few exceptions. The tests confirmed the ability of the articulated rotor system to operate satisfactorily in this flight regime and provided a basis for future aircraft design and for extrapolation to higher speed.