Could someone help with this?
(737 Classic) In the ops manual I looked up, it states that when using External Air and GPU for engine start, you MUST start Eng 1 first.
In some airports, the GPU cable is coming from the airbridge and it is not long enough to reach the receptacle without being within less than 3 meters from Eng 1 inlet. The ground crew asks for Eng 2 to start first.
I looked in the books and I could not find any serious implications from starting 2, push back and x-bleed 1. The only obvious implication is the black and white EADI & EHSI (they loose the colours due to reduced equipment cooling I think.)
Two start-push-xbleeds occured the last few weeks with 2 then 1 sequence with no problems.
Why the manual (at least the one I saw) says MUST? It does not even say should or "recomended".
Any ideas?
Thanks a lot.