Definition
In aviation, describing a landing gear system that can be mechanically drawn up into the airframe (fuselage or wings) after takeoff and extended back down before landing, as opposed to fixed gear that remains in the slipstream at all times.
Plain English
The wheels can be pulled up into the airplane after takeoff and lowered again for landing, instead of staying out in the wind the whole flight.
Context Anchor
Seen in takeoff, initial climb, landing gear, and aircraft configuration discussions.
Derivation
From the Latin 'retrahere,' meaning 'to draw back.' The same root gives us 'retract' (to pull back) and 'tractor' (something that pulls). In aviation, the gear is literally drawn back into the airplane after takeoff.
Why Pilots Care
Knowing whether an aircraft has retractable gear affects performance calculations and requires specific procedures after takeoff.
Intuition Check
Do not read retractable as just “movable.” Here it means the part can be drawn back into a stored position, such as landing gear being raised after takeoff.
Example Sentence 1
After a positive rate of climb was confirmed, the pilot raised the retractable landing gear to reduce drag.
Example Sentence 2
Pilots transitioning to retractable gear airplanes must learn the proper sequence for raising the gear after liftoff.