GIV Tried To Stop with Autothrottle Engaged

 - November 16, 2006, 8:46 AM

The NTSB determined that the probable cause of the landing accident involving a Gulfstream IV at Teterboro Airport, N.J., on Dec. 1, 2004, was the ”flight crew’s inadvertent engagement of the autothrottle and their failure to recognize the engagement.” The flight crew told the Safety Board that they had disengaged the autothrottle during the approach, and they did not recall reengaging it; the system is controlled by an unguarded paddle switch on each power lever. After touchdown, as the airplane decelerated, the autothrottle system gradually advanced the power levers. Without the power levers in the idle position, the ground spoilers and thrust reversers would not deploy. While pulling up on the thrust-reverser levers, "the crew might not have used enough aft force to override and disconnect the autothrottle.” As the airplane neared the end of the runway it went off the right side, coming to rest on its belly in trees. The airplane was substantially damaged, but none of the nine occupants was injured.