Plain English Meaning

Built-in locks that keep the landing gear firmly in the down position so it can't fold up while the airplane is on the ground.

Full Definition

Mechanical devices, typically over-center linkages or locking pins, that physically hold the landing gear in the extended (down) position so it cannot collapse under the weight of the airplane during landing, taxi, and takeoff roll.

Context Anchor

Encountered when studying retractable landing gear, landing gear safety devices, gear indication systems, and abnormal gear-extension procedures.