Failure Analysis and Solution of Aircraft Landing Gear Door Non-command Unlocking

Aircraft hatch is a very important component, which provides the most basic function and security for the use of aircraft. In the process of landing gear’s loading and unloading, the non-command unlocking of the cabin door occurred. This failure was analyzed and checked according to the principle of the lock structure of the door actuating cylinder. Using AMESim modeling and simulation analysis, it was found that the failure was caused by the abnormal pressure of the main return oil line and the low pressure of the lock opening in the actuator cylinder. By increasing the stiffness and the pre-compression of the spring in the lock, the unlocking pressure and the reset ability of the spring seat are increased. The working performance of the door actuator is improved, which is verified experimentally.