When Colgan Air flight 9446 left Barnstable Municipal Airport in Hyannis, Mass., on a repositioning flight to Albany, N.Y., maintenance had just been performed on the plane. But that could have been what killed the two pilots on board and wrecked the plane.
The Federal Aviation Administration released an airworthiness directive today to order changes in the maintenance manual of the Beech-1900 series, the model of a Raytheon Company-built plane that crashed into the water near Yarmouth, Mass., on Aug. 26, 2003 at 3:40 p.m.
Colgan Air, based at Manassas Regional Airport, declined to comment during the ongoing investigation.
According to a preliminary report released by the National Transportation Safety Board, the elevator trim actuator and the forward elevator trim cable had been replaced before the flight. But no statement has been made that this was the cause of the crash.
“The elevator trim system uses a trim wheel in the cockpit and cables and drums within the fuselage, or the body of the aircraft, to move small panels on the rear edge of the aircraft’s elevators,” said Jim Peters, an FAA spokesperson. “This causes small up and down forces on the airplane.”
The directive was published in the Federal Register, and will take effect Oct. 15. It said an illustration in the plane’s manual shows the elevator trim cable drum backwards. But the worded instruction process articulates correct installment.
“If only the picture is used to install the control cables, it could produce a reversal of elevator trim system movement,” Peters said. “If the pilot wanted to apply nose-up, he’d get nose-down.”
Tim Travis, a Raytheon spokesperson said the Beech-1900 series has been flying safely for 20 years using this maintenance manual.
“It has accumulated over 12 million hours flying all over the world,” Travis said.
Travis said the maintenance manual, made by Raytheon at the time of the aircraft’s conception, is constantly updated. But only in light of the recent accident did mechanics find the flawed drawing. The backwards illustration was a pullout from a larger set, where the part was represented correctly, according to Travis.
But Raytheon won’t assign blame to any one person, and the company issued a notice that clarified the mistake about two weeks ago.
“It’s not a matter of pointing fingers,” Travis said. “It’s a matter of making sure you have the most accurate, up to date information.”
Although Peters said he could make no link between the incorrect drawing, the maintenance prior to the crash and the crash itself, the NTSB’s statement of flight communications suggests the possibility of a link.
“Shortly after takeoff, the flight crew declared an emergency and reported a runaway trim,” the report said. “The airplane flew in a left turn and reached an altitude of approximately 1,100 feet. The flight crew subsequently requested to land on runway 33, and air traffic control cleared the flight to land on any runway. No further transmissions were received from the flight crew.”
“Witnesses observed the airplane in a left turn, with a nose-up altitude,” the report said. “The airplane then pitched nose-down and impacted the water at an approximate 30-degree angle.”
The pilots were alone on board, and were certified airline transport and commercial pilots.
Staff writer Sari Krieger can be reached at (703) 369-6751