Answer: landinggear

AnswerCrossword Clue
LANDINGGEAR

It's lowered for a touchdown

LANDINGGEAR

Plane's wheels, etc.

LANDINGGEAR

Plane's undercarriage

LANDINGGEAR
Floats on a seaplane, e.g.
LANDINGGEAR
Part of a plane.
LANDINGGEARAirplane's undercarriage
LANDINGGEARIt makes frequent touchdowns