Hmm i must be an idiot because i cannot figure out the thing about cross-electric power systems in the hydraulics A and B.

I have Angle of Attacks videos and must have seen it 3-4 times but still cannot get it why the electric is cross-over to the pumps,

 

In my mind i think that if the engine is lost then the otherside must have lost its supply so why bother with crossover ?

 

Does the above make sense? i sometimes wright baad english :-)

 

Michael

 

PS! And i might understand the videos wrong because i have tested the emergency FS2CREW add-on and i dont lose anything across

 

Michael 

IIRC: Each system (A & B) have two sources of power: Engine driven and Electric. The engine-driven hydraulic pumps have much more capacity than the electric. So, if you lost Eng #1, you'd lose the A sys eng pump, but not the A elec pump. You'd lose the B sys elec pump, but you don't need it at all since you've already got more than enough from the B sys eng driven pump.

 

Also, you get the A elec pump back if you start the APU gen.

 

Basically, you're not going to lose all of A or B with an engine failure.

Thanks ahh got it now :-)

 

Michael

The system A electric pump is powered by transfer bus #2 and the system B pump is powered by transfer bus #1.  That way if you lose an engine and the bus tie contractors failed to connect both transfer buses you would still have both hydraulic systems.  If they were powered by the transfer bus on the same side you would lose one entire hydraulic system if the buses didn't connect after an engine failure.  It's all about redundancy.