The day an F-105 went down on takeoff. I think it was Spring of 1967. If I remember, pilots would set the "Up" switch for the landing gear at the end of the runway before rolling and the gear would fold up as soon as the pressure was off on liftoff. We heard the Air Force sent down a TWIXT after this that they would get court martialed if they continued as it cost planes. I don't recall if the pilot(s) bailed.