Investigation Summary
During the departure of Delta Air Lines Flight 82, the Lockheed L-1011 was pushed back from gate 23 by a three-person ground crew consisting of a tug operator and two wing walkers. The accident occurred during dusk conditions with 10 miles visibility and winds from 240 degrees at 13 knots. After the aircraft reached the vicinity of the Lima and Alpha taxi lines, the right wing walker, who was the designated Dispatch Agent (DA), signaled the tug operator to start the engines. The tug operator then began pulling the aircraft forward to align it with the taxiway centerline. During this forward movement, the two wing walkers began to converge toward the tow bar in anticipation of the disconnect. The left wing walker observed the DA near the tow bar, apparently attempting to retrieve the tug operator's headset cord which had become disconnected and fallen to the ground. When the left wing walker looked back after a brief glance at his wing tip, he found the DA under the aircraft's nose wheel. Investigators found the plug end of the headset cord under the nose wheel. The investigation revealed that while headset disconnects were a known occurrence during sharp turns, the company's Ground Operations Manual (GOM) did not provide specific safety positioning for pull-forward maneuvers or identify danger zones around moving aircraft and operating engines.
Final Conclusions
The National Transportation Safety Board determined the probable cause to be the failure of the right wing walker (Dispatch Agent) to identify and avoid a hazardous condition, resulting in his presence near the nose wheel during tow operations. A contributing factor was the inadequacy of the Delta Ground Operations Manual in providing safety information and differentiating between pushback and pull-forward procedures. The investigation concluded with the NTSB Aviation Investigation Final Report published on April 10, 1998.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Age 57, Male. Held ATP and Commercial certificates. Last medical exam Jan 13, 1997. Had 173 hours in the last 90 days.
Systems & Failure Modes
Ground Communication System
A wired headset system connecting the tug operator and ground crew to the flight deck. The cord frequently disconnected during sharp towing maneuvers.
Nose Landing Gear
A retractable tricycle gear system; the dual-wheel nose gear struck the ground crew member during the pull-forward maneuver.
Interesting Facts
- 01The aircraft was being moved forward to align with the taxiway centerline when the accident occurred.
- 02The ground crew consisted of one tug operator and two wing walkers.
- 03The headset cord plug was found under the nose wheel of the aircraft.
- 04The Delta Ground Operations Manual did not specify safe positioning for ground crew during pull-forward maneuvers.
- 05Ground crew supervisors were aware that headset cords frequently disconnected during sharp turns but had no specific training for the event.
- 06The aircraft involved was serial number 193Y-1210.
Safety Actions & Advisories
Revision of Ground Operations Manual
Delta Air Lines revised its GOM to establish 'danger zones' for ground crew, create 'Wing Walker Alleyways,' and implement formal 'pull forward' procedures.
Crew Complement Increase
The airline implemented a recommended pushback/pull forward crew consisting of four personnel instead of three.
Enhanced Tow Procedures
The revised manual included expanded tow bar disconnect procedures and illustrations depicting preferred locations for ramp personnel.