1. Method of analysing flight data recorded during N flights of at least one aircraft, by means of a flight data recorder of an aircraft, the data being grouped together (E2) by flight i in a signature vector of the flight X i of size d, the components of which correspond to data recorded during said flight i of the aircraft, a flight i being thus defined by the signature vector X i , the method comprising the following steps: Gaussian kernel entropy component analysis (E4) of the flight signatures X i to obtain a zone of normal flights (E) and classifying the flight signatures X i with respect to their distance to said zone; determining (E5), for each flight i, an abnormality score z i defined by the distance of a flight signature X i with respect to the zone of normal flights (E); detecting (E6), as a function of the abnormality score z i , at least one abnormal flight.