Couple of points about 737NG...
1/ yes they can pressurize the water system with a small electric compressor, but only if AC power is available.
2/ no, there is no way the aircon system can supply only the flight deck and not both flt deck and cabin. (but both flight deck side windows are openable!)
3/ if they were awaiting a time slot for departure, without an APU or ground power, just how was the navigation system going to be ready for departure? That would be around 10 minutes worth of delay, after AC power was available.
4/ how were they planning to start the first engine after they got the OK to depart, without an APU or GPU?
5/ that MEL regarding departing with no operating APU is good if both IDGs are operating, and the airplane battery(s) are fully charged, which would not have been the case if the pilots were operating on standby power to drive the VHF-1 radio (amongst other stuff) for ATC comms during this extended delay, with no AC power available.
All this doesn't make sense, as reported.
Last edited by EW73; 18th Jun 2011 at 11:08.