Definition
A landing gear arrangement with two main wheels positioned aft of the airplane's center of gravity and a single nose wheel forward of it. The nose wheel may be steerable, free-castering, or fixed, and supports the forward fuselage on the ground.
Plain English
A landing gear setup with two wheels under the middle of the airplane and one wheel under the nose, so the airplane sits level on the ground.
Context Anchor
Seen when learning about airplane landing gear types, especially how an airplane sits, steers, taxis, takes off, and lands on the ground.
Derivation
From the Greek 'tri' (three) plus 'cycle' (wheel) -- literally 'three-wheeler.' The name comes from the child's tricycle, which has the same wheel layout: one in front, two in back.
Why Pilots Care
Tricycle gear improves forward visibility during taxi and is more forgiving on landing than conventional tailwheel gear, reducing the chance of a ground loop.
Intuition Check
Do not read “tricycle gear” as meaning the airplane works like a child’s tricycle. Here it means a specific landing gear layout: two main wheels and one nose wheel.
Example Sentence 1
The Cessna 172 has tricycle gear, so the airplane sits level on the ramp and offers a clear view over the nose during taxi.
Example Sentence 2
During the landing rollout the pilot kept the nose wheel lightly on the runway to maintain directional control with the tricycle gear.