Patent ID: 8896329

Claim:
A method for detecting an irregularity in a structure of an aircraft, the method comprising: providing a transponder stimulated by a radio signal at a resonance frequency of a resonant circuit of said transponder, wherein a probe is connected to the resonant circuit so that, when probe is not damaged, said resonance frequency is significantly modified from a second resonance frequency to a first resonance frequency, and the probe is sensitively attached to a surface of the structure, said probe being damaged in case of a structure change due to formation of an irregularity; deducing that the structure has an irregularity if a return signal is received from the transponder and an ID number of an RFID tag, in which the resonant circuit is comprised, is readable when stimulating the transponder using a stimulating signal at the second resonance frequency of the resonant circuit; and deducing that the probe is not damaged and the structures has no irregularity if the transponder returns a signal and the ID number of the RFID tag, in which the resonant circuit is comprised, is not readable when stimulated using a stimulating signal at the first resonance frequency.