During annunciator light check via the GTC, how many lights are seen in the overhead light switch area?

• A. 10 lights
• B. 4 lights
• C. 6 lights
• D. 2 lights

Answer: (A)

During this test, you’re confirming that every status indicator on the overhead light switch panel will illuminate when the annunciator system is commanded. The GTC triggers a sequence that lights all the available annunciator indicators, and there are ten of these lights on that panel. Seeing all ten lights glow verifies that each lamp and its wiring, fuses, and circuits are functioning properly. If any one of them fails to illuminate, it points to a fault that should be addressed before flight. The other counts would mean some indicators aren’t being tested or aren’t present, which wouldn’t give you a full, reliable check.