History of the Flight
The aircraft was scheduled to fly from Liverpool International Airport, Merseyside to Dublin International Airport, Ireland. Air traffic control cleared the aircraft to push back from Stand 3 onto Stand 33, directly behind the aircraft, due to airport congestion. The pushback crew consisted of a tug driver and a headset operator positioned to the right of the aircraft's nose. An Airside Safety Officer (ASO) was also present at the rear of Stand 33. Just before the pushback was completed, ATC informed the pilots that the aircraft had hit a lighting stanchion at the rear of Stand 33. The aircraft was towed back onto Stand 3, where an engineer inspected it and found minor damage to the left horizontal stabiliser tip cap. Passengers were transferred to another aircraft.
Airport Information
Airport Operational Instruction (AOI) 13 stated that Stands 33 to 37 are similar to Stands 2-10 and can accommodate all Code C aircraft except those longer than 34 m. The Boeing 737-800 is 39.48 m long. The AOI also noted that all stands are designed for taxi-in pushback operations; aircraft should not be pushed back into these stands. No separate night-time procedures existed.
Airside Safety Officer's Comments
The ASO received a call from ATC asking if EI-DCN could push from Stand 3 and hold on Stand 33. She approved and went to inspect Stand 33 before parking her vehicle on an adjacent stand to control airside traffic. She did not expect the pushback crew to position the tug and aircraft onto Stand 33. When the aircraft's tail approached the rear of the stand, she looked for a banksman but could not see one. The aircraft then collided with the lighting stanchion. She requested ATC to stop the pushback and signalled the tug driver to stop.
ATCO's Comments
The ATCO was not aware of the limitations on the use of Stand 33 published in AOI 13. He decided to clear EI-DCN for a pushback due to apron congestion. As the ASO had approved the pushback and was present, he assumed it was appropriate, noting he had issued such clearances before without incident. He did not require the aircraft to park on the stand, only to push back far enough to clear the taxiway.
Pushback Crew's Comments
The headset operator was unaware of the requirement for a banksman. The tug driver believed the ASO was acting as a banksman and concentrated on guiding the aircraft along the centreline, watching the headset operator.
Airport Operator's Comments
Liverpool International Airport commented that it was not common practice to push back aircraft to a remote stand; it was done to facilitate ground movements. The controller acted within procedures that allow pushback onto vacant remote stands. The procedure required a banksman, but one was not provided. The pushback crew attempted to push the aircraft onto the stand, but the tug and aircraft combination exceeded the stand's depth by 5 m. The position of the light stanchion within the stand and the fact that the aircraft was pushed tail first were also factors.
Safety Actions
Liverpool International Airport suspended similar pushback instructions and will review AOI 13 to ensure clarity and understanding.