An engine control system includes a first user control lever configured for rotational movement between a first control position and a second control position and a second user control lever configured for rotational movement between a third control position and a fourth control position. The first user control lever is configured for operational control of an engine in a first control mode and the second user control lever is configured for operational control of the engine in a second control mode, such as a backup mode. A mechanical link couples the first user control lever to the second user control lever with at least one angular offset. As a result of the angular offset, the second user control lever can be maintained in a safe operating position relative to the first user control lever position.

Herein provided are methods and systems for reducing an acoustic signature of a gas turbine engine. An acceleration command for the engine is received. In response to receiving the acceleration command: a fuel flow to the engine is increased for a first predetermined time period; subsequent to the first predetermined time period, the fuel flow to the engine is reduced for a second predetermined time period; and subsequent to the second predetermined time period, the fuel flow to the engine is increased for a third time period.

An apparatus for controlling a gas-turbine aeroengine is configured to calculate a fuel command to supply fuel based on a calculated desired rotational speed of a low-pressure turbine calculated from an operation angle of a thrust lever installed at an aircraft cockpit pilot's seat, determines whether it is a time point for outputting a command to open/close a bleed-off valve equipped at a high-pressure compressor connected to a high-pressure turbine and to supply the fuel command based on the time point when it is determined to be the time point for outputting the command to open/close the bleed-off valve.

The invention relates to a method for detecting a fuel leakage in the fuel distribution system between a fuel control valve and at least one burner of a gas turbine during the operation of the gas turbine. In order to detect a fuel leakage, the fuel consumption is approximated in accordance with the mechanical power of the gas turbine, the fuel amount fed to the fuel distribution system is determined, and the leakage flow is determined from the difference between the fed fuel amount and the fuel consumption. The invention further relates to a gas turbine for performing such a method.

A propulsion system is disclosed comprising a gas turbine engine and an acceleration schedule which determines the rate of acceleration of the gas turbine engine from an idle condition in response to a demand for increased thrust off-idle. The acceleration schedule determines the rate of acceleration in dependence upon the value of an engine parameter of the engine the value of which is substantially unaltered by variation in the magnitude of an electrical load drawn from the engine while it is operating in the idle condition.