Accident Description
During a pushback operation of a B737, a two-person ground crew was performing the procedure. The tug driver was seated on the left side of the tug, while the walker was positioned forward of the tug on the left side of the airplane. The walker was using a 15-foot headset cord, which restricted his ability to stay clear of the nosewheel, tug, and towbar.
According to the tug driver, he saw the walker fall in his peripheral vision and stopped the tug immediately. However, the tug was not stopped prior to striking the fallen walker, who was fatally injured. No witnesses were found who could explain why the walker fell.
Company Procedures
Examination of company procedures revealed that a maintenance training bulletin had been issued in December 1989. The bulletin referenced a requirement to stay clear of the airplane nosewheel. Although the bulletin was sent to all stations, it was not mandatory reading, and it was not determined if the walker was aware of its content. Additionally, the requirements of the bulletin were not implemented into the general maintenance manual.
Investigation Findings
The investigation did not establish a probable cause for the accident. The reason the walker fell remains unknown. The non-mandatory nature of the training bulletin and the lack of formal incorporation into the maintenance manual were noted as part of the procedural review.