British Royal Air Force Senior Aircraftsman Chris Mather, a 2nd Army Cooperation Squadron avionics technician, watches aircraft taxi and launch on the flight line during Red Flag 12-3 March 5, 2012, at Nellis Air Force Base, Nev. Red Flag is an advanced aerial combat training exercise held four to six times a year to train pilots from the U.S., NATO and other allied countries for real combat situations.