Boeing designed and built the BRAVE 200 in the early 1980s to seek out and attack radars that control anti-aircraft artillery and surface-to-air missiles. Launched from the ground with rocket assistance, the BRAVE 200 UAV was powered by a two-cylinder, two-stroke engine mounted on the rear fuselage to drive a pusher propeller. Using instructions programmed into its computer, the BRAVE 200 flew to a designated target area, where it loitered or circled until its sensors detected the enemy radar signal. The vehicle then followed the radar beam to its source and destroyed the site. The BRAVE 200 underwent testing for a number of years with promising results but never became operational. The program was canceled in 1989.