How does gravity extension operate in practice for gear?

• A. The gear is allowed to drop under gravity after hydraulic pressure is relieved, with doors opening to permit movement.
• B. The gear uses a separate electric motor to extend.
• C. Gravity extension only works on aircraft on ground.
• D. Doors stay closed during gravity extension.

Answer: (A)

Gravity extension relies on the weight of the gear to lower it once hydraulic pressure is relieved. Normally the gear is held up by hydraulic actuators and locked in place. When an emergency or maintenance procedure releases the hydraulic pressure, the gear drops downward under gravity, and the wheel doors open to clear the bay so the legs and wheels can extend properly. The downlock mechanisms then secure the gear in the full down position. This method uses no separate motor; it’s all about gravity working with the mechanical linkages and door action. It can occur in flight if hydraulics fail, not just on the ground. Doors staying closed would block the extension, so that option isn’t correct.