M4.2-plus - Edwards, Eglin combine testing on next-generation F-16

OVER CALIFORNIA—Six F-16 Fighting Falcons fly in formation during combined developmental and operational testing of the M4.2-plus core avionics suite upgrade to the aircraft. The formation consists of operational test aircraft from Eglin Air Force Base, Fla., and developmental test aircraft from Edwards AFB, Calif. (U.S. Air Force photo by Tom Reynolds)