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.
Plain English
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.
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 the pilot's attention so the pins are not overlooked.
Why Pilots Care
Leaving the pins in place can lock the gear down, preventing retraction after takeoff and forcing an emergency landing with the gear extended.
Intuition Check
Do not treat red streamers as decoration or as a warning label only. In this context, a red streamer usually points to a temporary safety item that must be checked and often removed before flight.
Example Sentence 1
During preflight, the pilot pulled the landing gear safety pins and confirmed all three red streamers were stowed in the cockpit before engine start.
Example Sentence 2
With the red streamers still attached, the gear would not retract after takeoff.