Preliminary Reports: Trim woes precede 1900D crash

 - October 9, 2007, 5:01 AM

BEECH 1900D, HYANNIS, MASS., AUG. 26, 2003–At approximately 7:38 p.m. EDT Beech N240CJ, operated by Colgan Air, crashed after takeoff from Runway 24 at Barnstable Municipal Airport (HYA) in Hyannis. Both pilots–captain Scott Knabe, 39, and first officer Steven Dean, 38–the only occupants, were killed and the aircraft was destroyed.

Shortly after takeoff the crew declared an emergency and was cleared to return and land on Runway 33. While attempting to return to HYA, the aircraft crashed into Nantucket Sound approximately three miles south of Hyannis. It came to rest in approximately 18 feet of water about 100 yards from shore.

Witnesses saw the airplane in a left turn with a nose-up attitude. The airplane then pitched nose down, and hit the water at an approximate 30-degree angle. According to preliminary data from the flight data recorder (FDR), the airplane began the flight at a pitch trim control position of approximately two degrees nose down. Shortly after takeoff, the pitch trim control moved to approximately three degrees nose down, where it remained for a period of about 10 seconds. The pitch trim control then moved to an approximate seven-degree nose-down position, where it remained for the duration of the flight. The data also revealed that after takeoff the airspeed continued to increase to approximately 250 knots.

The majority of the wreckage, including both engines, was recovered two days later. NTSB investigators examined wreckage, operational and maintenance records and FDR data on scene. On both engines, the shroud and guide vane inner and outer drums were circumferentially scored at the second-stage power turbine. The first-stage compressor blades were bent forward and opposite the direction of rotation, and the shroud exhibited circumferential scoring.

Portions of both wings, the cockpit and fuselage were recovered. The empennage was recovered partially intact. Eight feet of the right elevator was found with the inboard portion still attached to the horizontal stabilizer at two hinge points. Five feet of the left elevator was recovered and was still attached at the inboard hinge. Both elevator balance weights were recovered. A seven-foot section of the left horizontal stabilizer was recovered, and a five-foot section of right stabilizer spar was visible. The rudder was attached to the vertical stabilizer.

The right and left elevator trim tabs were found attached to the elevator. The right and left elevator trim actuators were also recovered. The electric elevator trim servo was found attached to the base of the horizontal stabilizer. The left and right trim cables remained wrapped around their respective drums. Elevator trim continuity was confirmed from the elevator trim tabs to the cargo door area. Due to fragmentation forward of the cargo door area, trim cable continuity could not be confirmed from the elevator to the cockpit pedestal. However, the cockpit pedestal with elevator trim drum and manual trim wheel was recovered. The cockpit pedestal, elevator electric trim system, elevator trim actuators, both control yokes and CVR are being examined.

According to NTSB investigator Bob Gretz, the Colgan Air pilot told the control tower he was experiencing runaway trim just before the crash. He told AIN that just before the Colgan Air flight the company’s in-house mechanics replaced two elevator trim actuators and a forward elevator trim cable. He said the aircraft has both electric and manual trim, but the exact nature of the problem has yet to be determined. The trim components have been sent to the NTSB’s Washington headquarters for examination. He said he is treating this as an individual aircraft problem and not an issue that might affect the entire fleet.