Plain English Meaning

Bright red ribbons attached to safety pins on the landing gear. They make the pins easy to spot so they get pulled out before flight.

Full Definition

Brightly colored red ribbons or flags attached to landing gear safety pins that hold the gear in the down-and-locked position while the airplane is on the ground. The streamers are clearly visible during preflight so the pins can be removed before flight, preventing the airplane from taking off with the gear pins still installed.

Context Anchor

Seen during preflight inspection, especially near landing gear safety devices and items marked “Remove Before Flight.”

Derivation

A 'streamer' is a long, narrow strip of fabric or ribbon that streams or flutters in the air. Red is used because it is the most visible warning color, designed to catch 's so the pins are not overlooked.