What happened
On 2 March 2009, a BAe RJ8/85, registration EI-RJF, was undergoing pushback from Stand C4 at Dublin Airport in preparation for a flight to London City Airport. During the maneuver, the aircraft's four engines were running at ground idle. As the aircraft reached a position abeam Stand 37, the tug driver attempted to pull the aircraft forward in an arc to realign the nose wheel with the taxi-line.
During this turning movement, the tug driver experienced a loss of control as the weight of the aircraft pushed against the vehicle. The tug jack-knifed, causing the tow bar to break at the tug end. Due to the aircraft's forward inertia, the BAe RJ85 continued moving forward and collided with the tug. The impact forced the tug against the right side of the aircraft's fuselage below the cockpit, resulting in serious structural damage to the aircraft skin and several internal frames. There were no injuries to the 5 crew members or 48 passengers on board.
The investigation
The investigation examined the technical specifications of the equipment and the operational procedures in place at the time. The tug used, a Tracma TD 3500, had a sufficient draw bar pull capacity for the aircraft, though it was specifically marked for "push back only." Investigators found that the tow bar's shear pins had not sheared as intended; instead, the eye end of the bar had broken off. It was also noted that the pushback maneuver was nonstandard, as it proceeded to the left rather than the right, contrary to the established airport manual.
Findings
- The tug driver initiated a forward pulling motion in an arc to realign the aircraft, which led to the jack-knifing of the vehicle.
- The aircraft's forward momentum, maintained by its own inertia while engines were at idle, caused the collision.
- The tow bar failed at the eye end rather than through the shearing of the pins.
- Environmental factors, including a slight downhill slope and recent rain, may have reduced the tug's traction.
Safety action
Following the incident, the aircraft operator introduced new flight crew instructions to limit engine starts to one engine while on the stand, with the remaining engines started only after the pushback is complete and brakes are set. The operator also emphasized the importance of flight crew vigilance and the authority to stop a maneuver if it deviates from the plan. The tug service provider removed the specific vehicle from aircraft pushback service, reassigning it to cargo towing, and reinforced the necessity of adhering to standard operating procedures.