Originally Posted by
Check Airman
Interesting story. Two Questions:
What's a speed card?
Is there a RAT CB on the 757?
On the B757 (RB211 version) the engine speed card supplies "Engine Running/Not Running" information to the:
Equipment cooling system
APU fire extinguishing
Fuel boost pumps
Power Transfer Unit
Ram Air Turbine
Angle of Attack probe heat
Pitot-Static probe anti-icing
Total Air Temperature probe heat
Flight Management Computers
Electronic Engine Control
Engine start system
Air cooling pack system.
And probably other functions as well.
Sorry Stilton, but the Speed Card has nothing to do with SPEED TAPE on ADI´s but all to do with engines and their control. Hence why the RAT drops when both CB´s pulled simultaneously, it thinks both engines have quit.