The Main Landing Gear (MLG) is held in the up and locked position by which component?

• A. A mechanical uplock
• B. An electric latch
• C. A hydraulic lock
• D. A pneumatic pin

Answer: (A)

The main idea is that the MLG is secured in the stowed position by a mechanical uplock. As the gear retracts, a spring-loaded latch on the uplock engages a strike on the gear leg, physically locking the leg and preventing it from dropping back down under load. This mechanical connection provides a robust, fail-safe hold that doesn’t depend on hydraulic pressure or electrical power, which is crucial for keeping the gear safely retracted in flight. When the gear is commanded to extend, the release mechanism disengages the uplock so the hydraulic actuators can lower the gear. Electric latches and hydraulic locks aren’t the primary means of keeping the gear up in most systems, and pneumatic pins aren’t the typical method for locking the MLG in the up position.