NTSB: Elevator jammed on UM plane that slid off runway
The National Transportation Safety Board’s investigative update released Wednesday does not indicate probable cause for the Michigan basketball team’s charter plane incident on March 8 beyond that it was an aborted takeoff, but it does share some new information.
A preliminary report from the NTSB on Tuesday said the Michigan charter “rejected takeoff” at Willow Run Airport. The report said wind speeds at the time were 35 knots (about 40 mph) with gusts of 50 knots (about 56 mph).
In the latest update, the NTSB indicates the right elevator — there is a left and a right and they are the primary means of controlling the airplane’s pitch — was jammed in a “trailing edge-down position (airplane nose down).”
The NTSB update makes clear it does not provide “probable cause” for the incident and does not offer analysis of the information collected so far. The investigation is ongoing and “no conclusions regarding the cause of the incident should be made from this preliminary investigation.” An investigation generally takes 12-18 months to complete.
All 109 passengers and seven crewmembers evacuated the Ameristar Air Cargo Inc., using escape slides after the Boeing MD-83 came to a rest about 1,000 feet past the end of runway 23L at Willow Run, according to the report. One person sustained a minor injury during the evacuation, presumably Michigan guard Derrick Walton Jr.
Both pilots held certificates with DC-9-series ratings that includes the MD-83, according to the report. The pilot in command, the Ameristar chief pilot, was in the right seat and “providing differences training to the captain” who was in the left seat and was the pilot flying the plane. The Ameristar chief pilot had 9,660 total flight hours, including 2,462 hours in DC 9-series planes, and the captain (flying pilot) had 15,518 total flight hours with 8,495 in DC-9-series planes.
Regarding the right elevator, the NTSB said in the report movement of the control column in the cockpit appeared normal.
“The control columns were free to move, and the elevator control tabs moved as commanded,” the report reads. “However, when investigators tried to move the elevator surfaces by hand, the left elevator moved normally, but the right elevator was jammed in a trailing edge-down position (airplane nose down). Upon further inspection, the right elevator geared tab inboard pushrod linkage was found damaged which restricted movement of the right elevator surface but allowed movement of the control tab. After the damaged components were removed, the elevator could be moved by hand.
“Examination of the flight data recorder data indicates that during the taxi and take-off roll, the left elevator moved normally, but the right elevator did not move. During takeoff roll, the left elevator began a large airplane nose-up movement (consistent with rotation) at an irspeed of about 152 knots and continued for five seconds to about 166 knots. There was no change in the airplane pitch attitude during this time. The airplane data then are consistent with the takeoff being rejected. The maximum recorded airspeed was about 173 knots.”
Review of flight date from two days earlier when the plane flew to Willow Run in Ypsilanti, showed normal movement in both the left and right elevator.
Also, flight and cabin crewmembers said in post-accident statements that all slides except the forward right door deployed correctly. The slide was removed from the airplane and will be examined by investigators at a future date.