Next, Behnken went to the Air Force Test Pilot School at Edwards Air Force Base. He was assigned to the F-22 Combined Test Force and served as the lead flight test engineer for the fourth F-22, a stealth tactical fighter aircraft that flies at speeds of up to 1,500 mph (2,414 kilometers per hour). Behnken has flown more than 1,500 flight hours and piloted more than 25 different types of aircraft.