N598S

On December 22, 2003, at 1806 eastern standard time, a Sikorsky S-58JT helicopter, N598S, piloted by a commercial pilot, was destroyed when it impacted light poles and the ground during landing at the Willow Run Airport (YIP), Ypsilanti, Michigan. The 14 CFR Part 135 flight was cleared to land at the United States Customs Service ramp. The flight was operating in night visual meteorological conditions on a visual flight rules flight plan. The pilot and passenger received minor injuries. The flight originated from the Windsor International Airport, Ontario, Canada, at 1745.

According to the pilot's statement, he was on a southwest heading on-course to YIP when he contacted YIP tower. He stated that at this time, he was cleared by YIP Tower to land at the U.S. Customs ramp. The pilot reported that approximately 40 knots airspeed and 70 feet above ground level (agl), "there was an abrupt boom and pitch of the aircraft followed by a right forward rapid decent with a very large horizontal one-to-one out of balance oscillation." The pilot stated that he, "attempted to apply all available collective pitch, which was followed by contact with the ground, followed by rolling and flipping of the aircraft." The pilot reported that after he and the passenger exited the helicopter through a window, they noticed inoperative light poles which stood 70 to 80 feet in height.

The pilot had made a full-stop landing at YIP earlier on the day of the accident.

According to the YIP airport manager, the light pole that was struck was 45 feet tall and was located at the southwest cargo ramp area near the south end of taxiway D. The light pole is located 4,542 feet south-southwest of the U.S. Customs circle. The light pole is located to the south of runway 09R/27L. The U.S. Customs ramp is located on the west ramp between runways 09R/27L and 09L/27R.