Originally Posted by
ExplorerWannabe
They can't stage or position it if ground control won't let them. Prep yes but moving it? No.
They're towing planes around between 1 am and 6 am before things get dicey at SFO. Position am planes at the open gates for "cleaning" after MX and pull and park on the west side before the Hawaii and East Coast banks of flights arrive. Also, both FAA ATC as well as UA Ops usually have an idea hours in advance if SFO's am is going to go pear shaped due to WX (at least) as well as volume/flow control issues given what and when FAA posts.
David