Landing Gear and Brakes Practice Test 2026 - Free Landing Gear and Brakes Practice Questions and Study Guide

The DN LOCK RLS button serves as a manual release for the downlock mechanism on the landing gear. When the gear is lowered, a downlock keeps it securely in the extended position and prevents unintended retraction. If the gear will not retract during takeoff and terrain is imminent, this button provides a manual override to release that lock, allowing the gear to come up again so you can complete the retraction sequence.

This is why it’s the best answer: it describes a deliberate, manual action to unlock the gear’s downlock so retraction can proceed in a critical situation. The other options describe actions that aren’t what this button does—locking the lever, triggering a warning light, or retracting gears automatically—whereas the DN LOCK RLS is specifically about releasing the downlock to enable retraction.