A METHOD FOR ANALYZING FLIGHT DATA RECORDED BY AN AIRCRAFT IN ORDER TO CUT THEM UP INTO FLIGHT PHASES

1 . A method for analyzing flight data recorded during at least one flight of an aircraft, the flight data comprising data relating to characteristic parameters of the flight, the method comprising a step for:

determining ( 10 ) a state model of a flight comprising several states (E 0 -E 16 , E 0 ′), each state corresponding to a possible flight phase of the aircraft, the state model comprising transitions (T 1 -T 19 ) defining switchings between these so-called states and at least one criterion (T 0 -T 0 ′) for initialization of the state model, said initialization criterion (T 0 , T 0 ′) corresponding to an initial state (E 0 , E 0 ′) of the state model, each transition and each initialization criterion depending on at least one characteristic parameter which may be recorded during the flight of the aircraft;

the method further successively comprising the following steps:

extracting ( 20 ) from recorded flight data, flight data relating to characteristic parameters of the aircraft;

calculating ( 30 ) an initialization criterion from flight data relating to the characteristic parameters of the aircraft in order to detect an initial instant from which the flight data correspond to an initial state of the state model;

calculating ( 40 ) a plurality of transitions of the state model from flight data relating to characteristic parameters recorded before the initial instant in order to detect instants from which the flight data relating to characteristic parameters of the aircraft correspond to a change of state of the state model;

cutting up ( 50 ) the flight data depending on the thereby determined instants in order to match the recorded flight data with flight phases.

2 . The method according to claim 1 , wherein the calculation of the transitions comprises after detection of the initial state, at least one calculation of a transition of the state model giving the possibility of passing from the initial state to a state,

a so-called current state, corresponding to a flight phase.

3 . The method according to claim 2 , wherein the calculation of the transitions comprises at least one calculation of a transition giving the possibility of passing from the current state to a state posterior to said current state.

4 . The method according to claim 1 , wherein the time interval between two transitions is determined in order to determine the duration during which the flight data correspond to a state of the state model.

5 . The method according to claim 1 , wherein the initial state of the state model is the cruising aircraft or the aircraft at the end of the flight.

6 . The method according to claim 1 , wherein the calculation of a transition consists of calculating a decision criterion depending on flight data, relating to at least one characteristic parameter of the aircraft.

7 . The method according to claim 1 , wherein the flight data before the instant from which the flight data correspond to an initial state, are suppressed.

8 . The method according to claim 1 , wherein the characteristic parameters are: vertical acceleration, horizontal acceleration, longitudinal acceleration, horizontal acceleration, longitudinal acceleration, pitch, configuration of the flaps, vertical speed and horizontal speed, barometric altitude, radio altitude, condition of the landing gear, heading.

9 . The method according to claim 1 , wherein the states of the state model are: end of flight, engine start, taxi out, take off, rejected take off, second segment, initial climb, climb, descent, cruise, approach, go around, final approach, landing, touch and go, taxi in.

10 . A system for analyzing flight data, comprising a processing unit adapted for applying a method according to claim 1 and a storage unit for storing the state model.