 These were the only Starfighters built by Lockheed specifically for NASA; all other NASA aircraft were transferred from the USAF.The third of these F-104Ns, number 013, was destroyed on 8 June 1966 in a mid-air collision with a North American XB-70 during a publicity photo flight for General Electric.One NASA F-104G, registration N826NA, was equipped with a flight test fixture (FTF) consisting of a pylon mounted on the fuselage centerline.