Last I saw the AC has the final say on 781 times and most of the time that poor loadmaster has a watch running 5-10 mins off the gps clock so yes there are times when I have added 2 - 12 mins to what my misinformed youth downstairs has put on paper. So if I'm told to land and wait for parking, no thanks I'll just burn another turn in the pattern or hold at frank until it gets worked out.