The U.S. Air Force has ordered 126 QF-16 remotely controlled F-16 fighters. These will be used as aerial targets. The QF-16s will be converted from existing F-16s that have been retired from service. This first order of QF-16s will be delivered over the next four years.
The QF-16 replaces the older QF-4 drone aircraft. Nearly 250 F-4 Phantom fighters were modified to fly by remote control. The mods cost about $1.4 million per aircraft. The QF-4 first appeared when the U.S. Air Force retired it's F-4 fighters in the 1980s.
Training operations destroy up to 25 remotely controlled fighters a year. The existing supply of decommissioned F-4s will keep the air force going until about 2011. Before that, QF-16s will enter service.
Before the QF-4, the air force had converted 218 F-100s (for use from 1983-92), 136 F-102s (from 1974-85) and 210 F-106s (1990-98) to act as full scale target aircraft. There are smaller UAVs that are used as small scale targets. The full scale models were needed to fully test the capabilities of new, and existing, missiles. Nothing like using real missiles against real targets to build pilot confidence, and be sure the damn things work.
The QF type aircraft can be flown with, or without, a pilot on board. The aircraft use GPS to help with navigation, and to insure that QFs flying in formation don't collide with one another. The aircraft also carry sensors to detect near misses by missiles.
The UAV version of an aircraft is superior, in some ways, to one with a pilot in it. This is mainly because pilots black out when the aircraft makes turns too sharply, at high speed. The air force discovered how effective this capability was during the 1970s, when they rigged some jet fighters to fly without a pilot, and had them go up against manned aircraft.