A method for detecting damages to a rotor of an aircraft, where the aircraft comprises actuators for active vibration reduction, may comprising one or more of the following steps: determining actuator variables in a reference flight of the aircraft; plotting the actuator variables of respective data range tiles determined in the reference flight of the aircraft in first coordinates of a coordinate system, wherein the coordinate system contains numerous data range tiles; obtaining the number of actuator variables in the reference flight of the aircraft that are located in each data range tile; eliminating the data range tiles that have a number of actuator variables lying below a limit value for this in the reference flight of the aircraft, by means of which a reference flight signature is created; and determining actuator variables for a flight-specific signature.

A method for detecting damages to a rotor of an aircraft, where the aircraft comprises actuators for active vibration reduction, may comprising one or more of the following steps: determining actuator variables in a reference flight of the aircraft; plotting the actuator variables of respective data range tiles determined in the reference flight of the aircraft in first coordinates of a coordinate system, wherein the coordinate system contains numerous data range tiles; obtaining the number of actuator variables in the reference flight of the aircraft that are located in each data range tile; eliminating the data range tiles that have a number of actuator variables lying below a limit value for this in the reference flight of the aircraft, by means of which a reference flight signature is created; and determining actuator variables for a flight-specific signature.

A fan blade containment system is arranged to surround a fan including a plurality of fan blades in a gas turbine engine for an aircraft. The fan blade containment system includes a fan case arranged to surround the fan and two debris retainers. The first debris retainer extends inwardly from the fan case and is arranged to prevent forward debris release should all or part of a fan blade become detached from the fan, the first debris retainer being located near and forward of the fan. The second debris retainer extends inwardly from the fan case and is arranged to prevent forward debris release should all or part of a fan blade become detached from the fan, the second debris retainer being located forward of the first debris retainer.

Sensorless propeller damage detection systems and methods may receive and process motor quadrature-axis currents to extract current ripples and fast average current values. In addition, the current ripples and fast average current values may be further processed to generated normalized rms (root-mean-square) values of the current ripples. Further, the calculated values may be compared to one or more threshold values over a time duration to determine whether a propeller is damaged. In this manner, the sensorless propeller damage detection systems and methods may quickly, reliably, and accurately detect propeller damage without any additional sensors or dedicated hardware and with low computational cost, while also minimizing false positive determinations of propeller damage.