A dual-loop fire detection system requires how many loops to trigger a fire warning?

Either single loop alone, or both for confirmed fire depending on system logic

Correct

Both loops must trigger simultaneously

Only loop A

Neither — it uses smoke detection

Explanation

Dual-loop systems can be set for single-loop (either triggers warning) or dual-loop (both must agree) modes for fault tolerance.

Test yourself with random questions from Aircraft General Knowledge and all other ATPL subjects.