Method for diagnosing a state of deterioration of an uplock

A method for diagnosing a state of deterioration of an uplock for the retention of a tapped nut of a movable element, the uplock comprising:

• a hook pivoting between a release position and a retaining position that retains the tapped nut;
• a locking member pivoting between a locking position, in which the hook is immobilised immobilized in the retaining position by the locking member, and an unlocking position, in which the hook is free to be moved under a thrust of the tapped nut of the movable element;
• and
• an unlocking actuator comprising a hydraulic cylinder configured to act on the locking member in view of pushing it back to the unlocking position;
• the method comprising, during a release sequence of the hook immobilized in the retaining position by the locking member, the following steps:
• a) supplying the cylinder with pressurized fluid with an evolution law according to which the pressure of the fluid is, for a predetermined period, lower than a full pressure, then equal to the full pressure;
• b) determining a release time of the hook and comparing the release time with a time when the predetermined time period ends;
• and
• c) deducing, from the comparison performed in step b), a state of deterioration of the uplock.