Factual Report: Lack Of Control Movement Implicated In Challenger Accident

 - October 24, 2006, 10:56 AM

Bombardier Challenger 600, Tupelo, Miss., March 9, 2005–The pilots of Romeo Mike Aviation’s Challenger 600 aborted the takeoff from Runway 36 of Tupelo Regional Airport and the nosegear collapsed. The airplane went off the departure end of the runway and was substantially damaged. The ATP-rated pilot and copilot and five passengers were not injured. A bent microphone jack receptacle on the copilot’s control column may have interfered with control movement.

On takeoff, with the flaps set at 20 degrees and the trim set for takeoff, the captain advanced the thrust levers to 93 percent N1 and started the takeoff roll. The takeoff run and acceleration were normal. The airplane reached V1 (128 knots) and Vr (134 knots), and the pilot tried o rotate, but the control column would not move back. Forward movement was normal. The captain reported that the control column felt as if it were locked against a stop when he tried to move it aft.

The airplane was about 4,000 feet down the runway traveling at between 140 and 145 knots. No annunciator lights were illuminated. The PIC called for an abort, extended the spoilers, applied maximum braking and maximum reverse thrust and maintained centerline down the runway. After starting to abort, the PIC continued to apply rearward pressure on the control column and he was not sure if he felt or heard a “crunch.” He said something might have given and the control column might have moved aft of the neutral position. He added that he heard or felt the “crunch” after or at the abort and that it might have come from below the flight deck.

The microphone plugs were under the control columns. On the pilot’s side, it was found in a vertical position, while the copilot’s was about 90 degrees to the control column. The copilot’s plug was found o be extended three-eighths of an inch from the fully plugged position. It was missing paint, while the jack on the pilot’s side was not.

The FAA issued AD 2005-11-04 for certain Bombardiers modified under STC4900SW, requiring repetitive visual checks of the microphone jack assemblies on both control columns to detect damage that might interfere with movement of the control column. Bombardier also sent an advisory to operators calling for preflight inspection of similar installations that were not supplied by the OEM.

Weather was not a factor, and the flight, en route to Teterboro, was 790 pounds below the maximum ramp weight.

The PIC, who held an A&P certificate, was type-rated in the Cessna 500 and 525S, the CL-600, the Dassault Falcon 10 and 20, the Hawker 125 and Learjet. He had 6,157 hours, of which 98.7 were in the CL-600. The copilot was not type-rated in the CL-600; he had 3,600 hours, of which 10.2 were in the CL-600.