Originally Posted by
galaxy flyer
FADEC has its own Permanent Magnet Alternator to power it, so it runs if there’s NO other power available, it’s all internal to the FADEC. tdracer has covered this several times.
IF the RAT was deployed, flight controls are powered, there is no appreciable switchover time from the normal hydraulics. It deploys in a second. I’ve done in-flight RAT checks on three types and the transition is imperceptible. Note, much older designs, so it’s likely to be better in the 787.
What powers (turns) the alternator?? If the generator(s) go off line, and the emergency batteries (Thales) are inop, how does the APU start? The batteries were destroyed when two generators failed in the United incident. Panel? EICAS??
Isn't the RAT intended to support descent and safe landing??
Not save a TO?
How resilient is the RAT to overload when in flow with arcing and shorting in the Main Generation system??
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Thanks GF