Page:Aviation Accident Report, American Export Airlines Flight 71.pdf/10

- 9 - interested in the effect of flap for take-off, I turned in my seat and looked back and watched the flaps come down. I noticed that the flaps were part way down, a very short distance, it appeared." He further stated that he "thought the flaps were moving at the time." He testified that at this time he turned around and looked forward again and "as the speed picked us, it started to porpoise like. It was very, very small and not particularly noticeable, no more than it had been on other take-offs. It porpoised, I think it was, about three times. I wouldn't say whether three or four times, and I believe it was the third time it left the water very slightly, probably three, four, or six inches, and then came back and slapped the water again, and then jumped some, probably 30 feet in the air, and at this altitude it leveled out, apparently looked like it was going to fly. At least it felt like it to me, it certainly was not stalled. It was hanging there with sufficient flying speed and then it just nosed over and headed for the water."

Flap Control

Examination of the wings immediately after they were recovered from the water revealed all flaps to be fully deflected to 35°, and the conclusion was reached that they must have been in this position at the time of the aircraft's impact with the water. The flap control system on this airplane is on the electrically operated type. The flap selector switch located on the instrument panel is wired to the electrical portion of the system, located within the wing immediately aft of the rear spar, just above the cabin ceiling. This part of the flap mechanism consists of a electric motor, timer, and the up and down relays. This reversible motor operates the flaps through a series of gears, sprockets, chains, and actuating screw-type jack-struts. The latter are considered sufficiently irreversible to preclude the possibility of the flaps being deflected by any means other than the operation of the electric motor. That the flaps were not deflected by external forces at the time of impact was further evidenced by the position of the electric timer which was also found at 35° - flaps fully down.