David T Sweet

US Patent:

50237977, Jun 11, 1991

Filed:

Sep 20, 1990

Appl. No.:

7/587495

Inventors:

Nicholas D. Lappos - Orange CT
David M. Walsh - Jupiter FL
David H. Sweet - Tequesta FL
Charles E. Greenberg - Jupiter FL

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

F02L 908

US Classification:

364442

Abstract:

The reference speed for a helicopter engine is incremented or decremented (237, 239) in dependence upon whether a specific range (miles per unit of fuel) has increased or decreased (236a) in a current period of time compared to the next preceding period of time, separated therefrom by at least 20 seconds (243, 244) to thereby set engine speed for minimizing use of fuel over distance traveled. Fuel is sampled only during steady flight (250-255).

US Patent:

52658252, Nov 30, 1993

Filed:

Aug 26, 1992

Appl. No.:

7/936187

Inventors:

Frederick J. Ebert - Westport CT
Joseph T. Driscoll - Cheshire CT
David H. Sweet - Tequesta FL

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B64C 1144
B64C 2754
G05D 108

US Classification:

244 1713

Abstract:

A helicopter engine fuel control anticipates sudden changes in engine power demand during yaw inputs to thereby minimize engine and main rotor speed droop and overspeed during yaw maneuvers. The rate (121,123) of yaw control (107) position change generates (110) a yaw component (104) of a helicopter fuel control (52) fuel command signal (70). The magnitude of the yaw component is also dependant upon the rate of yaw control position change (703). The fuel command signal yaw component (104) is overridden (113,115) when rotor decay rate (209,217) has been arrested during a sharp left hover turn (216); when the yaw component is removing fuel (239) during rotor droop (238); and when the yaw component is adding fuel (228) during rotor overspeed (227).

US Patent:

52658260, Nov 30, 1993

Filed:

Aug 26, 1992

Appl. No.:

7/935764

Inventors:

Frederick J. Ebert - Westport CT
Joseph T. Driscoll - Cheshire CT
Byron Graham - Easton CT
David H. Sweet - Tequesta FL

Assignee:

United Technologies Corporation - Hartford CT

International Classification:

B64C 1134
B64C 2757
G05D 108

US Classification:

244 1713

Abstract:

A helicopter engine fuel control anticipates changes in main rotor torque in response to lateral cyclic pitch commands, to thereby minimize engine and main rotor speed droop and overspeed during left and right roll maneuvers. A fuel compensation signal (100,101) is summed with a helicopter fuel control (52) fuel command signal (67) in response both to a lateral cyclic pitch command signal (LCP) (107) from a pilot operated cyclic pitch control exceeding a left or right threshold magnitude (201,210) and a total lateral cyclic pitch command signal (TCP) (108) from a lateral cyclic pitch control system exceeding a left or right threshold magnitude (202,207,215,220). The magnitude of the fuel compensation signal is dependant upon the direction of TCP and LCP, e. g. , left or right, and helicopter roll acceleration (115). Alternatively, the magnitude and duration of the fuel compensation signal is dependant upon the rate of change in commanded lateral cyclic pitch (107,400,407).