apologies i may have mis-read/INTERRUPTED the post, thanks for the replies,
THE OP states
ie when to start apu on etops...?
my response was surely an in-op APU is part of the MEL for ETOPS and you cannot depart without it serviceable prior to departure (it can fail later?)
but you state that you CAN depart with an APU u/s on various types now,
i am very surprised but my ETOPS exp ended in 1993 so am out of the latest loop!
thanks