Definition
Hinged or sliding panels on the underside of an airplane that cover the wheel wells when the landing gear is retracted, forming a smooth surface with the surrounding airframe to reduce drag in flight. On most retractable-gear airplanes, the doors open during gear extension and retraction and close again once the cycle is complete.
Plain English
The panels that cover the holes where the wheels fold up into the airplane. They open to let the wheels come down or go up, then close so the bottom of the airplane is smooth again.
Context Anchor
Seen during preflight inspection, landing gear system discussions, and cockpit indications for retractable-gear airplanes.
Why Pilots Care
When the doors fail to close or open properly, the aircraft experiences added drag, reduced performance, and possible gear damage from debris or airflow.
Intuition Check
Do not think of these as doors for people or cargo. Landing gear doors are aircraft skin panels that open and close around the wheel openings.
Example Sentence 1
After raising the gear lever, the pilot heard the landing gear doors close and confirmed three lights out, indicating the gear was up and the doors were sealed.
Example Sentence 2
During the preflight inspection the pilot checked that the landing gear doors moved freely and showed no signs of hydraulic leaks.