Boeing 737NG crossbleed engine start
Hey folks,
After starting engine #1 from external power (GPU and ASU) there is no enough bleed air at the isolation system for starting engine #2
(something around 15 PSI).
So, according the pocedures I need to raise the engine #1 thrust for rasing the duct air for allowing to start the engine #2.
and my question is: Why there is no enough bleed air at the isolation system after engine #1 starts, why the pressure reduced only because the engine start ?
a schematic chart will be very helpful too.
Thank you very much,
Avi.