Incident Overview
A scheduled domestic passenger flight sustained substantial damage when the airplane collided with a food service truck during pushback from the gate. The impact caused the food service truck to tip onto its side.
Pre-Pushback Events
The operator reported that an additional provisioning (provo) truck was parked behind the aircraft to allow a second driver to assist the driver of the assigned provisioning truck. The captain was informed by the pushback driver about the "provo truck" located at the rear galley. The captain then instructed the pushback driver to proceed with the push at his discretion.
After the assigned truck completed its service, it was marshaled away from the aircraft and departed. The pushback driver, unaware of the second truck positioned behind the aircraft, began to push the airplane out.
Pushback Sequence
During the pushback, as the flight crew initiated the engine start, the APU stopped running. The engine start was subsequently terminated, and the push sequence was halted. The pushback driver reported experiencing "difficulty with going forward" and therefore stopped the push.
The pushback driver stated that he "did not see anyone telling me to stop pushing that my zone was not clear." Meanwhile, the wing walker had taken his position at the taxiway to walk out the flight and was aware of the truck behind the aircraft. The wing walker said, "I put up the stop signal and yelled stop but the plane kept on being pushed."
Procedures and Communications
The operator's ground operations manual stated that the pushback driver "is ultimately responsible for ensuring that the aircraft has been secured, all personnel involved in the push are in proper position, and the pushback is conducted in a safe manner." However, the manual did not list, note, caution, or warn the pushback driver to stop the pushback when the driver's visual contact with the guide agent (wing walker) is not maintained. Instead, the manual instructed the guide agent to "always be in visual range of the pushback driver."
When asked whether a backup aural signal existed for visual stop signals, the operator indicated that there was none and stated, "since this event we are testing headset communication systems." Regarding supervisor involvement, the operator responded that "the supervisor was within visual range but his attempts to stop the push were not heard or seen."