Options_SLAVE
Well-known member
- Joined
- Jul 20, 2007
- Posts
- 192
RAT drops with the failure of both engines, or if manually deployed. It provides hydraulic pressure down to 130 KIAS. It can be used to power not only hydraulic systems, but also a hydraulic driven generator installed on the ER and ETOPS aircraft. The HDG is activated when AC1 and AC2 busses are not powered.
The center demand pump uses bleed air to power center system hydraulics during periods of high demand. On the 767 the big items are on the center system.
The Center Isolation Switch is maintained open, guarded with break away wire. It is a QRH item to isolate the center pneumatic duct from the cross over manifold. If a bleed leak can not be isolated in the center duct, the airplane is designed for 6 hours of operation before structural damage occurs. Because of sensor position, most of the crossover duct is displayed as a left duct leak message.
I've got no idea what the penalty is, we'd be in the MDM to double check what dispatch comes up with. The gear and flap retration would be significantly slower without the demand pump, so I'm guessing that the aircraft would be climb limited in the second stage.
You ask good questions. Missed two out of approximately 140 questions on the systems test for my type rating. I like this stuff.
What do I win? How about the name of your buddy so we can ensure he is provided with accurate information.
Correct answers. The RAT is to supply hydraulic power to the flight controls. The weight penalty is 45,000 lbs. ;-)
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