A control apparatus for a gas-turbine aeroengine having discriminator that discriminates normality of a low-pressure turbine rotational speed sensor adapted to detect the low-pressure turbine rotational speed and a high-pressure turbine rotational speed controller that establish a first value as an upper limit value of a high-pressure turbine rotational speed and controls the high-pressure turbine rotational speed based on the established upper limit value, and is configured to change the upper limit value to a second value lower than the first value when the low-pressure turbine rotational speed sensor is discriminated not to be normal, whereby engine output (thrust) determined by the low-pressure turbine rotational speed can be controlled to a desired value while restraining the high-pressure turbine rotational speed to not greater than the first value, and low-pressure turbine overspeed at the time of a mishap such as engine fan blade breakage can be reliably prevented.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed by detecting a first period below a lower threshold and a second period above an upper threshold, and detecting a rate of occurrence of the first period and the second period, the oscillation wave having a wave modulation frequency corresponding to the rate of occurrence and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed by detecting a first period below a lower threshold and a second period above an upper threshold, and detecting a rate of occurrence of the first period and the second period, the oscillation wave having a wave modulation frequency corresponding to the rate of occurrence and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

There is described a shaft shear event detection method. The method comprises obtaining a demodulated waveform of a shaft oscillation wave superimposed on a shaft rotational speed signal, comparing the amplitude to an amplitude threshold, detecting oscillation when the amplitude threshold is exceeded for a plurality of samples, and detecting a shaft shear when oscillation continues for a predetermined time limit.

There is described a shaft shear event detection method. The method comprises obtaining a demodulated waveform of a shaft oscillation wave superimposed on a shaft rotational speed signal, comparing the amplitude to an amplitude threshold, detecting oscillation when the amplitude threshold is exceeded for a plurality of samples, and detecting a shaft shear when oscillation continues for a predetermined time limit.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed, the oscillation wave having a wave modulation frequency and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

There is described a shaft shear event detection method. The method comprises storing in memory a shaft oscillation signature determined as a function of known characteristics of the shaft and associated with a shaft shear event; monitoring a rotational speed of the shaft; detecting from the rotational speed an oscillation wave superimposed on the rotational speed, the oscillation wave having a wave modulation frequency and a wave modulation amplitude; comparing the oscillation signature to the oscillation wave; and detecting the shaft shear event when the oscillation wave corresponds to the oscillation signature.

An arrangement for detecting a shaft break, including a shaft and a reference shaft that can be rotated together with the shaft, wherein an opening in the shaft overlaps with an opening in the reference shaft in an operational state of the shaft according to the intended use, and a signal conductor that can be severed extends through the two openings and is operatively connected to an evaluation unit, and the evaluation unit is configured to detect a severing of the signal conductor by applying a signal to the signal conductor to detect a shaft break of the shaft. The invention further relates to a turbomachine and a method.

An arrangement for detecting a shaft break, including a shaft and a reference shaft that can be rotated together with the shaft, wherein an opening in the shaft overlaps with an opening in the reference shaft in an operational state of the shaft according to the intended use, and a signal conductor that can be severed extends through the two openings and is operatively connected to an evaluation unit, and the evaluation unit is configured to detect a severing of the signal conductor by applying a signal to the signal conductor to detect a shaft break of the shaft. The invention further relates to a turbomachine and a method.

A gas turbine engine is provided with a controller configured to detect a spool shaft failure and to initiate an engine shut-down in response to the shaft failure. The controller evaluates the compressor speed probe, the speed probe continuity, P30 pressure and compressor surge to determine whether a shaft failure has occurred.