A320 engine start
Is it possible to keep one pack on during engine start ?
FCOM says : "Engine start sequence : If the crossbleed valve is closed , the valve located on the Starting engine side immediately closes when the Mode selector is set to IGN
It remains closed on the starting engine side ( provided the crossbleed valve is closed)"
Then further down there is a note : "If the crossbleed valve is open at engine start, both pack flow control valves close."
Crossbleed valves automatically opens with APU bleed ON . Does that mean that If the crossbleed valve is manually shut prior to engine start , only the associated pack will close ?
But then the question , can you start engines with Xbleed closed ?