Lighten our darkness, oh Lord! The lighting thread

[Juud]

Lights off inflight?

Quick question, if somebody has time & the inclination to answer, I'd be obliged.

Flew home the other day as pax on a 737. Halfway the flight, suddenly most of the cabin lights switched off. Apart from me, it didn't seem to alarm anybody at all, the CC carried on serving food until the cockpit call bell chimed. The lights came back on a while later.

Purser later mumbled something about a generator having given up the ghost and the pilots having had to switch on the APU.

How does that work?
Do the engines drive a generator that powers the lights?
Never knew the APU could be switched on inflight, always see it get switched off before?

Any light to shed?