A turbofan engine has an engine core including in flow series a compressor, a combustor and a turbine. The engine further has a fan located upstream of the engine core, has a supersonic intake for slowing down incoming air to subsonic velocities at an inlet to the fan formed by the intake, has a bypass duct surrounding the engine core, wherein the fan generates a core airflow to the engine core and a bypass airflow through the bypass duct, and has a mixer for mixing an exhaust gas flow exiting the engine core and bypass airflow exiting bypass duct. The engine further has a thrust nozzle rearwards of the mixer for discharging mixed flows, the thrust nozzle having a variable area throat. The engine further has a controller controlling the thrust produced by the engine over a range of flight operations including on-the-ground subsonic take-off and subsequent off-the-ground subsonic climb.

Propulsion system (8) for a single-engine helicopter (1), comprising: a main engine (9) connected to a front drive shaft (5) and a rear drive shaft (7), respectively, suitable for driving a main gearbox (4) referred to as MGB (4) and a tail gearbox (6) referred to as TGB (6); an assistance device (10) attached to the main engine (9); characterised in that said propulsion system (8) is designed in order that the assistance device (10) can mechanically drive the TGB and MGB (6, 4) by introducing power to the rear drive shaft (7).

A starter air valve comprising: a housing comprising an inlet at a first end, an outlet at a second end opposite the first end, and a center portion between the first and second end, the outlet being fluidly connected to the inlet through a fluid passage; a first piston located within the housing between first end and center portion, the first piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; a second piston located within the housing between second end and center portion, the second piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; and a manual override system configured to move from closed to open position at least one of the first and second pistons.

A method of thrust reversal operation according to an example of the present disclosure includes, among other things, permitting an increase in engine power when at least one criterion is not met and a thrust reverser is deployed, and denying the increase in engine power when the at least one criterion is met. A system for thrust reversal is also disclosed.

A blocking device for preventing an inappropriate shut-off of an engine of an aircraft. The blocking device enables by default the actuation of the shut-off unit and receives information representative of an activated or inactivated state of a fuel shut-off lever, of a reduced or non-reduced speed state of a throttle lever, and a correct or incorrect operating state of the engine. The blocking device blocks the actuation of the shut-off unit when the throttle lever is in an inactivated state, when the engine is in a correct operating state, and when, in addition, the throttle lever is in a non-reduced speed state or the throttle lever is in a reduced speed state and, in addition, the opposite propulsion engine is in a failed state or in an incorrect operating state.

The invention relates to an overspeed protection device of an aircraft engine.

A method of controlling a combustor of a gas turbine engine, the method comprising the steps supplying a total fuel quantity to the combustor dependent on a load of the gas turbine engine, the total fuel quantity is split into a pilot fuel quantity and a main fuel quantity via a scheduled pilot fuel split, the pilot fuel split is the percentage of the pilot fuel quantity of the total fuel quantity, monitoring combustion instability, applying a steady state active pilot split offset to the scheduled pilot fuel split when a predetermined temperature of the combustor is exceeded and/or a predetermined value of combustion instability is exceeded to create a steady state pilot fuel split, monitoring a condition of the gas turbine engine that influences an air/fuel ratio in the combustor, disabling the steady state active pilot split offset when the condition of the gas turbine engine is indicative of a transient condition and when a threshold value of combustion instability is exceeded, and applying a transient active pilot split offset to the steady state pilot fuel split while maintaining the total fuel quantity being supplied at any point in time, the transient active pilot split offset and the steady state active pilot split offset result in a total split offset, the total split offset being greater than the steady state active pilot split offset and the rate of change of the transient active pilot split offset is faster than the rate of change of the steady state active pilot split offset.

A starter air valve comprising: a housing comprising an inlet at a first end, an outlet at a second end opposite the first end, and a center portion between the first and second end, the outlet being fluidly connected to the inlet through a fluid passage; a first piston located within the housing between first end and center portion, the first piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; a second piston located within the housing between second end and center portion, the second piston configured to block airflow through the fluid passage when in a closed position and allow airflow through the fluid passage when in an open position; and a manual override system configured to move from closed to open position at least one of the first and second pistons.

A system and method of detecting an uncontrolled high thrust (UHT) condition in a turbofan gas turbine engine includes processing data to determine when a current commanded fan speed value is greater than a predetermined speed value. A current UHT commanded fan speed value is processed to determine if it will cause a target fan speed value to increase, remain steady, or decrease. The target fan speed value is set equal to the current UHT commanded fan speed value when the current UHT commanded fan speed value will cause the target fan speed value to increase or remain steady, and to a deceleration threshold value when the current UHT commanded fan speed value will cause the target fan speed value to decrease. An uncontrolled high thrust alert signal is generated when actual engine fan speed exceeds the target fan speed value by a predetermined amount for a preset time period.

A method of controlling a combustor of a gas turbine engine, the method comprising the steps supplying a total fuel quantity to the combustor dependent on a load of the gas turbine engine, the total fuel quantity is split into a pilot fuel quantity and a main fuel quantity via a scheduled pilot fuel split, the pilot fuel split is the percentage of the pilot fuel quantity of the total fuel quantity, monitoring combustion instability, applying a steady state active pilot split offset to the scheduled pilot fuel split when a predetermined temperature of the combustor is exceeded and/or a predetermined value of combustion instability is exceeded to create a steady state pilot fuel split, monitoring a condition of the gas turbine engine that influences an air/fuel ratio in the combustor, disabling the steady state active pilot split offset when the condition of the gas turbine engine is indicative of a transient condition and when a threshold value of combustion instability is exceeded, and applying a transient active pilot split offset to the steady state pilot fuel split while maintaining the total fuel quantity being supplied at any point in time, the transient active pilot split offset and the steady state active pilot split offset result in a total split offset, the total split offset being greater than the steady state active pilot split offset and the rate of change of the transient active pilot split offset is faster than the rate of change of the steady state active pilot split offset.