What happened
On 6 November 2010, a Boeing 737-8AS, registration EI-DCN, was preparing for a scheduled passenger flight from Liverpool International Airport to Dublin. During the pushback process, which involved a tug driver and a headset operator, the aircraft was directed by Air Traffic Control (ATC) to push back from Stand 3 into Stand 33. This maneuver was intended to clear the taxiway due to apron congestion.
As the aircraft moved into the position, the left horizontal stabiliser tip cap struck a lighting stanchion located at the rear of the stand. Following the impact, the aircraft was towed back to Stand 3, where an engineering inspection confirmed minor damage to the stabiliser. There were no injuries to the 6 crew members or 139 passengers on board, and the passengers were transferred to a different aircraft to complete their journey.
The investigation
The investigation examined the procedures used during the pushback and the suitability of the stand. It was established that the pushback crew attempted to position the aircraft and the tug into a space that exceeded the depth of the stand by 5 metres. The investigation found that the headset operator was unaware that a banksman was required for such a maneuver, and the tug driver believed the Airside Safety Officer (ASO) was performing that role.
Furthermore, the investigation reviewed the Airside Operational Instruction (AOI) 13, which specifies that stands 33 to 37 are designed for taxi-in operations and are not intended for pushback maneuvers. The Airside Safety Officer noted that while she had approved the pushback to the remote stand, she could not locate a dedicated banksman to monitor the aircraft's tail as it approached the rear of the stand.
Findings
- The primary cause of the collision was the pushback crew attempting to position the aircraft and tug into a space that exceeded the available depth of the stand.
- The aircraft was being pushed tail-first into a position where the lighting stanchion was located within the stand area.
- The pushback crew failed to provide a banksman to monitor the aircraft's tail or wingtips during the maneuver.
- The Airside Safety Officer was focused on monitoring road traffic and was not expecting the crew to attempt to occupy the stand in that manner.
- The ATCO issued the clearance based on the assumption that the presence of an ASO made the maneuver appropriate, unaware of the specific limitations regarding Stand 33.