Method for controlling an unmanned aircraft

A method for controlling an unmanned aircraft (A), implemented by an electronic control unit, comprising determining a maximum flying altitude (Ap) for a ground position (P0) of the aircraft, said method comprising:

• i. for each point from a plurality of ground points (P0, P1, P2, P3, P′1, P′2, P′3) situated within a perimeter around the ground position (P0) of the aircraft, referred to as “surrounding points”, determining one or more intersections (I1, I′1) between firstly a circle (C1, C′1), the centre of which is said point and the radius of which is the maximum authorized ground distance (H) at this point, referred to as the “determination circle”, and secondly a vertical (Δ) related to the ground position (P0) of the aircraft, the circle (C1, C′1) being contained in a vertical plane comprising said vertical (Δ) related to the ground position (P0) of the aircraft, and
• ii. for all of the intersections (I1, I′1) thus obtained, selecting the greatest altitude as the maximum flying altitude (Ap).