[fshbbdssbbgdd]

Would you hear it from inside the plane? Even if it’s not as loud as the main engine, if it’s audible at all a lot of people would notice a change in pitch/tone. At least, I notice when the sounds the plane is making change even though I don’t know anything about the reason.

[jszymborski]

It's apparently quite loud

> After starting the descent, the flight crew made an announcement to the passengers; however, unbeknownst to the flight crew, the noise generated by the RAT (because of its high rotation speed) prevented the passengers and the cabin crew from hearing the announcement.

https://asn.flightsafety.org/wikibase/187755

[Filligree]

Oww. Seems they got lucky.

It always surprised me that there aren’t small, local lithium batteries to provide backup power for critical components like the smoke detectors. Is the risk of those catching fire considered too high?

[fphhotchips]

I feel like it's not the RAT you'll notice from inside the plane, it will be the silence from the engines. That combined with at least a momentary flicker of the lighting (I'm not sure if a RAT on a 787 will run cabin lighting but I doubt it), and you'll know.