Aircraft maintenance and repair work is facilitated, especially for a commercial aircraft, by a diagnostic system and method, wherein an aircraft component or assembly of components is monitored by at least one sensor which produces and preferably also stores component status information. Respective status information signals are transmitted, preferably in a wireless manner, from a transmitter of the sensor to a receiver of a signal processing unit which provides status information on a display screen. The status information signals are preferably processed and evaluated with reference to rated maintenance and repair reference information to provide instructions as to what needs to be done where and when for a maintenance or repair. The sensor or sensors may operate during flight and the respective stored information is then processed and used on the ground.