Samuel Wyatt Ferguson

US Patent:

43043755, Dec 8, 1981

Filed:

May 17, 1979

Appl. No.:

6/039943

Inventors:

Kenneth E. Builta - Euless TX
Samuel W. Ferguson - Fort Worth TX

Assignee:

Textron Inc. - Providence RI

International Classification:

B64C 1144

US Classification:

244 1713

Abstract:

A helicopter elevator (12, 13) is driven by an electrical actuator (20) to position the elevator (12, 13) to an optimum angle of incidence for given flight conditions. The actuator (20) is included within a servo loop which responds to a command signal derived from an electronics module (69). Transducers which measure longitudinal cyclic position (40), collective pitch position (41) and air speed (42) generate signals which are summed in a summation unit (43). The output of the summation unit (43) is passed through a signal multiplier (45) which has the gain thereof set inversely proportional to air speed. A trigger unit (56) activates the signal multiplier (45) at an air speed above a preset threshold. An integrator (54) integrates the sum of the outputs of the longitudinal cyclic position transducer (40) and air speed transducer (42) to compensate for different center of gravity aircraft loadings. Duplicate electronic systems are provided to drive a pair of servo motors (36a, 36b) with brakes provided to lock the actuator (20) when an electronic failure is detected.