What happened
The pilot in command was cleared for takeoff from runway 36. As the Boeing 737 reached V1 speed of 128 knots and VR speed of 134 knots, the pilot attempted to rotate the aircraft. However, the control column would not move aft from the neutral position, though forward movement remained normal. The pilot felt as if the column was locked against a stop. At approximately 4,000 feet down the runway, while traveling between 140 and 145 knots, no enunciation lights were illuminated.
The pilot commanded an abort, extending the spoilers and applying maximum braking and maximum reverse thrust while maintaining the centerline. Despite these efforts, the aircraft went off the end of the runway, causing the nose wheel to collapse in the mud. There were no injuries reported.
The investigation
An examination of the aircraft revealed that a Dual Baker M1045 Cockpit Audio System had been installed in 1984 under Supplemental Type Certificate Number SA 4900SW. Investigators found that when the control column was pulled aft, a handheld microphone audio jack assembly attached to the co-pilot's control column was bent downward. This assembly made contact with the control column cover, which prevented the aft movement of the control column.
Findings
A new Airworthiness Directive was issued following the investigation. The directive requires the modification of the microphone jack assembly and a revision to the airplane flight manual to mandate repetitive visual checks of the microphone jack assemblies on both control columns to detect any damage that could interfere with control column movement.