Method of activating protection means for protecting an occupant of an aircraft, and an aircraft implementing said method

A method of activating protection means via activator means in order to protect the physical integrity of an occupant of an aircraft during an accident, the aircraft being associated with a rectangular coordinate system comprising a longitudinal axis (X), a transverse axis (Y), and an elevation axis (Z), the method comprising the following steps:

• determining a longitudinal acceleration of the aircraft along said longitudinal axis (X), a transverse acceleration of the aircraft along said transverse axis (Y), and an elevation acceleration of the aircraft along said elevation axis (Z);
• determining a longitudinal variation of a longitudinal speed of the aircraft along said longitudinal axis (X), a transverse variation of a transverse speed of the aircraft along said transverse axis (Y), and an elevation variation of an elevation speed of the aircraft along said elevation axis (Z);
• and
• activating said protection means when, firstly the acceleration of said aircraft along a particular axis (X, Y, Z) of the system of axes of the aircraft is greater than a first variable threshold, and secondly the speed variation of the aircraft along said particular axis (X, Y, Z) is greater than a second variable threshold, the first and second variable thresholds each varying as a function of the stage of flight of the aircraft so as to be minimized during predetermined accident-prone stages of flight.