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Old 01-25-2008, 07:15 AM   #66
C-Rex
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Join Date: Oct 2007
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Default Re: Breaking News - Heathrow Shutdown, BA772 landed short of the runway.

Quote:
Originally Posted by Dork View Post
Not positive on the 777, but on the 767 and 757 the RAT provides hydraulic power only for the essential flight controls. Backup electrical power is provided by a hydraulically driven generator. If the APU is off and all generators fail, essential power would be provided by batteries for at least a half an hour or so, depending on the aircraft model. The APU is generally only left on if an engine driven generator is inoperative or when conducting a CAT II or III approach.
I have misinterpreted the APU and RAT wrong on what they can do and not do. Blimey, My mistake on mixing the two up of what powers what. Thanks for the info and correction, Dork.
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