On 3/3/81 the Douglas A-26B Invader N9417H was on a flight from Edwards Air Force Base, California. While on that flight, the airplane suffered a structural failure of a wing spar causing the left wing to separate in flight. Killed in the accident were the instructor pilot and two Test Pilot School engineering students.
This Douglas A-26B was built as S/N 44-34653 and was modified to a variable stability test bed in the early 1960s by the Air Force Research Lab. The instructor pilot would sit in the left seat with the student in the right with flight controls that could be programmed to simulate the flight characteristics of a variety of airplanes. This airplane and its sister ship the A-26B S/N 44-34165 N9146H were approaching their end of useful service life and were due to be replaced with a Learjet with the next Test Pilot School class.