What happened
On 19 April 2001, an Airbus A3/21-211, registration G-JSJX, was undergoing a standard pushback procedure at Birmingham International Airport. During the maneuver, which involved towing the aircraft forward and to the left, the aircraft suddenly halted with a noticeable judder. The ground handler reported that the forward right edge of the tug had become wedged beneath the aircraft. The tug driver noted that the nose of the aircraft appeared to have descended onto the top of the vehicle's cab.
Upon inspection by an engineer, it was determined that the aircraft's fuselage had been punctured. To facilitate the removal of the stuck tug, several of the 167 passengers on board had to be relocated from the front of the cabin to the rear. There were no injuries to the crew or passengers during the incident.
The investigation
The investigation examined the configuration of the pushback equipment and the positioning of the vehicles. The tug used was a Mercury Standard, a four-wheel vehicle with a cab positioned at the front. Under standard pushback procedures, the tow bar is attached to the cab end of the tug, placing the higher part of the vehicle closer to the aircraft.
Measurements revealed that the distance from the aircraft's nose gear to the tug attachment point was approximately 2.5 meters, while the distance from the nose gear to the aircraft's nose was 5 meters. This confirmed that the tug's cab was positioned directly under the aircraft's fuselage. While a straight tow provides sufficient clearance, the investigation found that the tow bar was angled to the right while the tug was turning left, significantly reducing the safety margin. Although the ground-handling organization had previously conducted risk assessments for these procedures, the specific risk of contact between the tug cab and the fuselage had not been identified.
Findings
- The primary cause of the incident was the reduced clearance between the tug cab and the aircraft fuselage caused by the specific angles of the tow bar and the tug during the turn.
- The height of the aircraft's fuselage varies based on weight and center of gravity, creating a potential for contact when using this specific tug and tow-bar combination.
- Existing risk assessments had failed to identify the potential for collision during angled maneuvers.
Safety action
Following the incident, the ground-handling company implemented short-term guidance to increase personnel awareness regarding the risks identified. Additionally, the organization began seeking physical solutions to increase the separation distance between the tug and the aircraft.