Comment by Filligree
1 year ago
APU failure maybe? That would be troublesome indeed; with no engines and no APU you'd lose most instrumentation and a lot of the hydraulics.
1 year ago
APU failure maybe? That would be troublesome indeed; with no engines and no APU you'd lose most instrumentation and a lot of the hydraulics.
There is also a RAT at the back that can be deployed to generate some power(~5-10 minutes max) in case of severe emergency in Air. It is what you hear sometimes, when the aircraft is making a very shrill noise flying over your head.
However, if it is not a test flight, a RAT deployment should make you very uncomfortable and worried…
> RAT … It is what you hear sometimes, when the aircraft is making a very shrill noise flying over your head.
I’ve been around a lot of airplanes and I can’t say I’ve seen or heard a ram air turbine deployed in flight. There was a recent incident involving a Frontier Airlines flight in which the RAT was deployed when the aircraft was put in emergency electrical configuration. The deployment of the RAT would be quite rare.
https://en.wikipedia.org/wiki/Ram_air_turbine
I find it hard to believe that anyone reading this was within earshot of a plane in a severe emergency and heard this particular sound and since turbine engines are already quite shrill I am basically just sorta confused who your audience is for this suggestion.
The RAT makes an extremely distinctive sound. You'd recognize it nearly instantly. However the RAT will not power everything.
https://www.youtube.com/watch?v=KzejbxNj1hY
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Usually, when the RAT is really deployed because of an emergency, the jet engines will be a lot more silent (because they're not producing any power). Although I'm not really sure how loud a windmilling jet engine really is, and I somehow doubt there is a YouTube video of a plane landing with both engines disabled - but you never know...
Indeed unlikely to hear RAT deployed due to emergency. But they do deploy it sometimes on test flights after maintenance.
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.
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Username does not check out.
Jokes aside... I'm certainly part of the intended audience: point me at an interesting rabbit hole, and there I gooo.
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The chances of you being on multiple commercial flights where the Ram Air Turbine are deployed is infinitesimal, no?
Also, RAT can power limited systems indefinitely on most models, not all or limited systems for a limited amount of time.
Why would the Ran Air Turbine be time restricted? As long as the plane is moving there’s power.
> Why would the Ran Air Turbine be time restricted?
Gravity?
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By definition, when you are using the RAT, you don't have any electrical power and you probably don't have thrust.
You are constrained by battery, airspeed, and altitude.
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If the RAT could keep the plane flying indefinitely we would just be using RAT instead of fuel I suppose.
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The RAT is a generator, not a device that can provide thrust. If anything it will minutely slow the plane down.
I thought the guy I was speaking mentioned something about instrumentation but I wasn't 100% sure and that sounded more serious so didn't mention it - but if the aux engine failing would do that - I guess that lines up!