STBYRUD,
First of all thank you very much for your reply.
I think that you didn't understand me because my English and I'm sorry about that.
Well, I know that the pressure will drop to 15-20 PSI duct air in the isolation system, the question is why ?
Why after starting engine #1 the PSI drops and why do I need to disconnect the ASU external source ?
So, if I understand you, the ASU disconnected automatically when engine #1 starts and because the engine is on idle thrust, the engine needs more bleed air and that's why I need to raise the thrust - for providing more bleed air.
More thrust - more bleed air.
am I right ?
But why the ASU automatically disconnected ?
Again,
Thank you very much,
I'm really appreciate your help !
P.S: it is a flight simulator issue, but the aircraft's behavior is the same like the reality.