Abstract: A method of adaptive engine acceleration for accessory loads includes receiving an accessory load indicator corresponding to an accessory load of an engine. The accessory load indicator is compared to an adjustment threshold. An acceleration rate of the engine is increased based on determining that the accessory load indicator is below the adjustment threshold. The acceleration rate of the engine is decreased based on determining that the accessory load indicator is above the adjustment threshold.

Abstract: A gas turbine engine control system according to an exemplary aspect of the present disclosure includes, among other things, an automatic control operable to control a gas turbine engine. The gas turbine engine control system further comprises a module operable to fail-fix the gas turbine engine to one of a multiple of pre-determined modes in response to failure of the automatic control. The exemplary gas turbine engine control system may further comprise a fuel flow meter to sense a fuel flow to the engine, a fuel control to control the fuel flow to the engine, and the module in electrical communication with the fuel flow meter to fix the fuel control in response to one of the multiple of pre-determined modes.

Abstract: A method of adaptive engine acceleration for accessory loads includes receiving an accessory load indicator corresponding to an accessory load of an engine. The accessory load indicator is compared to an adjustment threshold. An acceleration rate of the engine is increased based on determining that the accessory load indicator is below the adjustment threshold. The acceleration rate of the engine is decreased based on determining that the accessory load indicator is above the adjustment threshold.

Abstract: A method of aircraft engine thermal threat mitigation includes detecting an airflow thermal profile at a location on the aircraft forward of an aircraft engine inlet and transmitting the thermal profile to an aircraft control system. The thermal profile is compared to a catalog of thermal threat profiles at the aircraft control system and a determination is made if a thermal threat is present based on the comparison. A thermal threat mitigation measure is initiated to reduce an effect of the thermal threat on aircraft engine performance.

Abstract: A method of aircraft engine thermal threat mitigation includes detecting an airflow thermal profile at a location on the aircraft forward of an aircraft engine inlet and transmitting the thermal profile to an aircraft control system. The thermal profile is compared to a catalog of thermal threat profiles at the aircraft control system and a determination is made if a thermal threat is present based on the comparison. A thermal threat mitigation measure is initiated to reduce an effect of the thermal threat on aircraft engine performance.

Abstract: A gas turbine engine control system includes a module operable to fail-fix the gas turbine engine to one of a multiple of pre-determined modes in response to failure of an automatic control.

Abstract: 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.

Abstract: 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.

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).

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).

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).

Abstract: 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.

Abstract: 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).

Abstract: 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).Subroutines for return to dual engine operation (110), backup of the primary logic (200,300) and remaining engine failure (200) are disclosed.