Pivoting landing gear provided with an immobilization system

A method for locking and unlocking a landing gear provided with a stand and a pivoting assembly carrying a contact member that is configured to be in contact with the ground, the pivoting assembly being able to rotate about a pivot axis in relation to the stand, the landing gear having an immobilization system configured to immobilize the pivoting assembly within a predetermined range of positions in relation to the stand during a locked phase of a locked mode and to authorize unlimited pivoting of the pivoting assembly in relation to the stand during an unlocked phase of an unlocked mode, the immobilization system comprising a movable pin and a control configured to request the application of the locked mode or the unlocked mode, the immobilization system comprising a passage provided in a base secured to the pivoting assembly, the pin being outside the passage in the unlocked phase, the pin being able to move in the passage in azimuth relative to the pivot axis in the locked phase,

• the method comprising:
• when the immobilization system is in the unlocked mode, activating the control in order to switch to the locked mode, then:
• if the pin is in line with the passage, moving the pin into the passage;
• and if the pin is not in line with the passage, pressing the pin against the base with an elastic locking system and moving the pin into the passage as soon as the pin comes into line with the passage;
• and
• when the immobilization system is in the locked mode, activating the control in order to switch to the unlocked mode, then, if the pin is in the passage and in contact with the base, compressing an elastic unlocking system, and:
• keeping the pin in the passage as long as the pin is subject to a shearing force greater than or equal to a threshold, the immobilization system being in a disarmed phase;
• and as soon as the pin is subject to a shearing force less than the threshold, expanding the elastic unlocking system and ejecting the pin out of the passage under the effect of the expansion of the elastic unlocking system of the in order to switch to the unlocked phase.