Thanks for your inputs . I was just wondering whether it is possible because the FCOM notes say: If the Xbleed valve is closed the valve located on the starting engine side immediately closes " . So I don t understand why they are stating this case , if its not considered feasible or would give an abnormal start .
Then FCOM says : "If the crossbleed valve is open at engine start, both pack flow control valves close."
SO they are considering 2 cases : One where You would start with Xbleed closed which would result in the closure of only the associated pack .
Second case : Xbleed Open , and close both packs during start .
They put the accent on the Xbleed valve position during start, which give 2 different results . Please Refer to FCOM 1 Air Conditioning System , Packs