Method for alleviating and protecting loads for an aircraft

A method for alleviating and protecting loads of a lifting surface of an aircraft comprising a control unit in which is stored an acceptable interval of tolerance of shapes for the lifting surface, the lifting surface comprising a fixed proximal end and a free distal end and being equipped with at least one control surface and a maneuvering system provided to displace the control surface relative to the lifting surface, the lifting surface also comprising a distal sensor fixed to a structure of the lifting surface in a vicinity of its distal end and a proximal sensor fixed to the structure of the lifting surface in the vicinity of its proximal end, each sensor being connected to a control unit and configured to measure a dimensional characteristic linked to distortion of the lifting surface, the method for alleviating and protecting loads comprising:

• a first process and a second process, wherein the first process comprises, for the control unit, assigning a first value to a strain attribute if the lifting surface is not placed under controlled strain or a second value to the strain attribute if the lifting surface is placed under controlled strain, and wherein the second process comprises at least:
• an acquisition step during which each sensor acquires characteristic data linked to the distortion to which the lifting surface is subjected and transmits these data to the control unit;
• a computation step during which the control unit determines, from the duly transmitted data, a set of values characterizing a shape of the lifting surface;
• a first comparison step during which the control unit analyzes the value of the strain attribute;
• if the value of the strain attribute is equal to the second value, the process is continued by a second comparison step during which the control unit compares the set of values characterizing shape of the lifting surface to values of the tolerance interval associated with the lifting surface;
• if the set of values characterizing the shape lies within the interval, the process loops to the acquisition step;
• and
• if the set of values characterizing the shape is outside of the interval, the process comprises an alleviation step during which the control unit triggers an activation of the maneuvering system to displace the control surface from an initial position, in order to alleviate the loads on the lifting surface.