Method and system for analyzing aircraft data, including multiple selected
flight parameters for a selected phase of a selected flight, and for determining
when the selected phase of the selected flight is atypical, when compared with
corresponding data for the same phase for other similar flights. A flight signature
is computed using continuous-valued and discrete-valued flight parameters for the
selected flight parameters and is optionally compared with a statistical distribution
of other observed flight signatures, yielding atypicality scores for the same phase
for other similar flights. A cluster analysis is optionally applied to the flight
signatures to define an optimal collection of clusters. A level of atypicality
for a selected flight is estimated, based upon an index associated with the cluster analysis.