Abstract: A control apparatus 50 for a gas turbine engine for an aircraft includes engine control means 52 forming part of an outer fuel control loop and fuel control means/overthrust protector 76 forming part of an inner fuel control loop. Overthrust protection is provided within each of the engine control means 52 and the fuel control means/overthrust protector 76, which are powered and housed separately. Thus, a failure within one of these systems could not result in overthrust and demonstrably reliable overthrust protection is provided within a single channel.

Abstract: An apparatus and method for controlling a gas turbine engine involves calculating a simple corrected speed value for the engine using values of compressor speed and inlet stagnation temperature of the compressor. This simple corrected speed value is then adjusted to take into account the water vapour concentration at the inlet to the compressor. This results in a more accurate value of corrected speed for the compressor, which may be used to modulate the fuel supply to a combustor of the engine or to control the geometry of one or more variable compressors in the engine.

Abstract: A control apparatus 50 for a gas turbine engine for an aircraft includes engine control means 52 forming part of an outer fuel control loop and fuel control means/overthrust protector 76 forming part of an inner fuel control loop. Overthrust protection is provided within each of the engine control means 52 and the fuel control means/overthrust protector 76, which are powered and housed separately. Thus, a failure within one of these systems could not result in overthrust and demonstrably reliable overthrust protection is provided within a single channel.

Abstract: A gas turbine engine (10) comprises a fan rotor (26) having a plurality of fan blades (24) and an apparatus (34) for detecting damage to the fan blades (24). The apparatus (34) comprises a transducer (36) arranged to detect the pressure in the gas flow around the fan blades (34) and to produce a pressure signal. A speed sensor (48) is arranged to measure the speed of rotation of the fan rotor (26) and to produce a speed signal. A processor unit (40) analyses the pressure signal and the speed signal to detect changes in the amplitude of the pressure signal, which occur at multiples of the rotational frequency of the fan rotor (24). The changes indicate differences in pressure between the gas flow around a damaged fan blade (24) and the gas flow around the remainder of the fan blades (24). The processor unit (40) sends a signal indicative of damage to a fan blade (24), if the difference in pressure is above the predetermined level, to an indicator device (44, 46).

Abstract: An apparatus and method for controlling a gas turbine engine involves calculating a simple corrected speed value for the engine using values of compressor speed and inlet stagnation temperature of the compressor. This simple corrected speed value is then adjusted to take into account the water vapour concentration at the inlet to the compressor. This results in a more accurate value of corrected speed for the compressor, which may be used to modulate the fuel supply to a combustor of the engine or to control the geometry of one or more variable compressors in the engine.

Abstract: A gas turbine engine (10) comprises a fan rotor (26) having a plurality of fan blades (24) and an apparatus (34) for detecting damage to the fan blades (24). The apparatus (34) comprises a transducer (36) arranged to detect the pressure in the gas flow around the fan blades (34) and to produce a pressure signal. A speed sensor (48) is arranged to measure the speed of rotation of the fan rotor (26) and to produce a speed signal. A processor unit (40) analyses the pressure signal and the speed signal to detect changes in the amplitude of the pressure signal, which occur at multiples of the rotational frequency of the fan rotor (24). The changes indicate differences in pressure between the gas flow around a damaged fan blade (24) and the gas flow around the remainder of the fan blades (24). The processor unit (40) sends a signal indicative of damage to a fan blade (24), if the difference in pressure is above the predetermined level, to an indicator device (44, 46).