Patent ID: 8374735

Claim:
A method for reducing actual loads generated on an airplane by an aerodynamic disturbance, the airplane comprising control surfaces arranged on wings, a flight envelope of the airplane being defined by couples of altitude and speed values available to the airplane, and the method comprising: in a preliminary step, a load exceeding envelope is determined, defined by couples of values of altitude and speed available to the airplane, for which the actual loads applied on the airplane are able to be at least equal to a predefined load threshold, wherein determining the load exceeding envelope further includes the following steps (a)-(c) performed in succession automatically: (a) at least one parameter of the airplane is selected having its value being able to vary during the flight of the airplane; (b) for at least one given value of the selected parameter, theoretical loads are determined, applied on the airplane for all couples of the flight envelope with which theoretical aerodynamic disturbances of a given intensity are respectively associated; (c) for each couple of the flight envelope associated with a theoretical disturbance of a given intensity, the determined theoretical loads, associated with the couple, are compared to the predefined load threshold, so that the load exceeding envelope is determined by the set of couples of the flight envelope for which the associated determined theoretical loads are at least equal to the load threshold; and during a flight of the airplane, the following steps are repeatedly and automatically performed: (i) a monitoring is achieved for the current altitude and speed of the airplane for detecting whether the latter flies in the load exceeding envelope; (ii) when the airplane flies in the load exceeding envelope, deflection orders are determined of at least some of the control surfaces for reducing the actual loads applied on the airplane, the deflection orders being such that they generate a deflection of the control surfaces respectively according to a particular deflection angle; and (iii) the determined deflection orders are applied to the control surfaces.