United Technologies Corporation

Coltec Industries, Inc.

David H Sweet

Nicholas D Lappos

Charles E Greenberg

David M Walsh

Joseph T Driscoll

Charles W Evans

Frederick J Ebert

Robert W Rice

Richard P Meisner

James J Howlett

Mark A Johnston

Gregory P Wright

Byron Graham, Jr

An engine failure monitor 50 for use with a multi-engine aircraft having at least two engines detects conditions indicative of a partial (700) or total (400) engine failure, including turbine shaft failures (600). In response to an engine failure, suitable inputs (134, 138, 712) are provided to an electronic engine control for operating the remaining engine. Additionally, indications indicative of the engine failure (132, 710) are provided to the cockpit.

Engine failure monitor for a multi-engine aircraft having partial engine

A bleed air control system for an aircraft gas turbine engine operates in a fuel saving mode in response to operation of the aircraft in a steady-state cruise condition (215,350) within a threshold flight envelope (202,310) during steady-state engine operation above a threshold range. During operation in the fuel saving mode, a gas turbine engine compressor bleed valve (10) is closed. The rate of bleed valve closure is determined as a function of bleed valve position (12,20) and gas generator speed (26,30) at the instant the fuel savings mode is initiated. The bleed air control system is returned to normal operation in response to actual or commanded engine acceleration above respective threshold magnitudes, in response to aircraft load factor differing from a reference load factor by a threshold magnitude, and in response to the discontinued operation of the aircraft at steady-state cruise conditions, discontinued steady-state operation of the engine above the transient range, or operation of the aircraft outside of the threshold flight envelope.

Automatic turbine engine bleed valve control for enhanced fuel management

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). A limiter (120) limits the magnitude of the fuel compensation signal. The fuel compensation signal is overridden (127,125,103) when it is increasing fuel flow ( 303) during rotor overspeed (128,301), and when it is decreasing fuel flow (311) if rotor acceleration (130,133) is negative (310) during rotor droop (128,301).

Helicopter engine control having lateral cyclic pitch anticipation

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).

Helicopter engine control having yaw input anticipation

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).

Range maximizing, stable, helicopter cruise fuel conservation

The speed 54,56 of the free turbine 40 of a helicopter engine 22 is compared 134,138 with the speed 142,140 of the helicopter rotor 10 to indicate 106,108 a specific magnitude of autorotation and the deceleration 150 of the rotor above either one of two threshold magnitudes 220,222 (dependent on the magnitude of autorotation) is utilized 81,68,69 to increase fuel flow 72 to the engine according to a specific schedule 160,162 determined by the type of autorotation, in anticipation of rotor speed droop which would otherwise occur during recovery from the autorotation maneuver.

Helicopter control with multiple schedule rotor speed decay anticipator

A helicopter engine speed reference (66) is increased (113, 103-105) in response to heavy rotor loading (108). The reference speed is faded up (113, 104) at a rather rapid rate to 107% of rated speed (114). After a fixed time interval (118), reduced rotor loading (119) will cause the reference speed to be faded down slowly (120, 103-105) to rated speed (121). If torque exceeds 111% of rated torque (117), the reference speed is similarly faded down (120, 103-105).

Helicopter, high rotor load speed enhancement

Primary logic (116-128) for engine failure detection in a multi-engine aircraft is based on thresholds for engine torque (Q), gas generator speed (NG), power turbine inner stage temperature (T5), power turbine speed (NF), throttle setting (PLA), and throttle manipulation (PLADOT).

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Tequesta, FL, United States of America

David H Sweet