Incident Overview
An aircraft was being pushed back from the gate with both engines operating because the auxiliary power unit (APU) was inoperative. The pushback was conducted by a tug driver assisted by two wing walkers. However, no signalman was positioned in front of the aircraft, as required by Delta Airlines pushback procedures.
Sequence of Events
The aircraft was initially pushed straight back and then turned to the left, positioning the tail in that direction. After this maneuver, the tug was repositioned to the right front of the aircraft. As the tug moved forward to straighten the nose gear, the safety pin on the tug end of the tow bar sheared.
Disconnection and Collision
With the tow bar pin sheared, the aircraft became disconnected from the tug. The aircraft then rolled forward and struck the tug with its right front area. During the forward roll, the tug driver's headset became disconnected from the aircraft, resulting in a loss of communication with the cockpit crew.
Procedural Deviation
The pushback was performed without a signalman in front of the aircraft, a requirement of Delta Airlines pushback procedures. The presence of two wing walkers was noted, but their roles did not substitute for the missing signalman.
Damage and Aftermath
The collision caused damage to the aircraft and tug. The tug driver lost communication with the cockpit when the headset disconnected. No further details were provided regarding the extent of damage or any injuries.