A little bit of history behind Angel Flights:
If you did not figure out via pictures already, Angel Flights are the U.S. Air Force planes (C-130's) used to fly home our Fallen Soldiers. Angel Flight is also their call sign. In addition, Angel Flights have top priority in U.S. Airspace - as you saw the Towers say "number 1 for landing/takeoff" .... now of course, I know, there are other flights that have an even higher priority ... but in reference to other standard military flights, Angel Flights get number 1 priority.
3rd November 2011