What happened
During a pushback operation involving a Boeing 737, a two-man ground crew was maneuvering the aircraft. The tug driver was positioned on the left side of the tug, while the walker was located forward of the tug on the left side of the airplane. The walker was using a 15-foot headset cord, which limited his ability to maintain a safe distance from the towbar, the tug, and the nosewheel.
The tug driver observed the walker fall through his peripheral vision and attempted to stop the vehicle immediately. However, the tug struck the fallen worker before it could come to a complete halt. The incident resulted in one fatality.
The investigation
Investigators were unable to determine why the walker fell, as no witnesses were available to provide information regarding the cause of the fall. An examination of company procedures identified that a maintenance training bulletin had been issued in December 1989. This bulletin included a requirement for personnel to stay clear of the aircraft nosewheel. While this bulletin was distributed to all stations, it was not a mandatory reading requirement, and investigators could not confirm if the walker had been aware of its contents. Furthermore, the instructions contained within that bulletin had not been integrated into the company's general maintenance manual.