B 737 eng bleed
 

Can an engine be started with the engine bleed engine switch in the OFF position?

Why would you be asked this question, because the bleed air valve is signaled closed from the start valve durring engine start anyway.
Any thoughts?
GTM

It does not matter, if bleed SW is ON or OFF.
As you can see in the bleed schematic below, the duct to the starter is upstream of the PRSOV.
At 737NG you are right with closing signal from the (not closed) start VLV.
But at the 737CL the closing signal comes from the start SW when he is in GRD position.

B737CL
http://img209.imageshack.us/img209/8...6eng4ew.th.jpg

Ingo

On the 737 200, the air for the starter passes through the bleed valve, so you need it open.

Not so on the classic and NG.

737-200
 

You does not mentioned it before.
Please do it next time at the beginning.
Then i don´t waste time on things you dont´t want to know. :*

Ingo

Thanks for the replies.
Happy and safe flying,
GTM