Patent ID: 7792614

Claim:
An aircraft including an apparatus for measuring an operational load on an aircraft component, the apparatus including a processing unit and a plurality of pairs of electromagnetic radiation devices, wherein each electromagnetic radiation device comprises an emitter paired to at least one detector, the emitter being an emitter of electromagnetic radiation, and the detector being able to detect radiation from the emitter, wherein either the emitter or the detector is mounted to the aircraft component and the paired electromagnetic radiation device mounted independently to the aircraft, the separation of the emitter and the detector is altered upon application of the operational load, the emitter and the detector each include a signal generating component, and wherein the processing unit receives a signal from the signal generating component of the emitter and the detector from which an indication of a deformation of the aircraft component may be ascertained and provides an output signal which provides an indication of the load sustained by the aircraft component, the output signal being ascertained by the processing unit by means of a calculation involving the signals received by the processing unit and load model data.