Engines Auxiliary Power Unit (APU) Practice Exam 2026 - Free APU Practice Questions and Study Guide

The green REV indicator is telling you the thrust reversers are deployed. That light appears above the N1 gauges to confirm that the reverser system has moved from stowed to an active, providing reverse thrust to help slow the aircraft after touchdown. The color green signals normal, active status.

If the reversers weren’t deployed, or if there were a fault, you’d see a different indication (no green REV, or an amber/red warning), and the light would not be indicating deployed.