Originally Posted by
herbert23
of course it is possible that the APU was running. Aircraft was heavy (150 pax) and it was cold. So it makes sense to perform the takeoff with packs on APU for performance reasons. In this case you still have the packs running for passenger comfort and you can increase your flex temp.
150 pax - not quite heavy, also applicable w/rgds to sector length.
cold - good for performance, time delay between RWY lineup and re-selecting a pack is irrelevant with regards of cabin cooling to affect comfort
flex increase - good for money saving, should you decide to keep APU on the fuel consumption offsets the savings.
I see no reason why would they need to keep APU on for departure, certainly not in based on the above. Let's wait for the report.
FD (the un-real)