What happened
On September 1, 2009, at approximately 21:00 local time, an incident occurred on the apron at Bremen Airport during a pushback operation. An Embraer ERJ 190-200 LR, which was preparing for a scheduled flight to Munich, was being moved by a Schopf tug. During the maneuver, the tug positioned itself at an angle of 80 to 90 degrees relative to the longitudinal axis of the aircraft. This movement caused the upper right side of the tug's driver cabin to strike the underside of the aircraft, tearing a hole in the lower fuselage skin forward of the avionics bay access door. There were no injuries to the 56 passengers or five crew members on board, but the aircraft sustained heavy damage, and the tug also sustained damage to its cabin.
The investigation
The BFU examined the physical dimensions and clearances of the pushback assembly. The investigation noted that the tug's cabin height was set to its minimum level of 1,620 mm. The distance between the nose gear and the tug's coupling point was measured at 3,750 mm, while the distance from the nose gear to the aircraft nose was 4,200 mm. This configuration provided a clearance of 420 mm between the aircraft nose and the tug's roof when aligned straight. However, as the tug turned relative to the aircraft's longitudinal axis, this clearance decreased until the collision occurred. The investigation also reviewed the equipment specifications, noting that the Cavotec-Fladung towbar in use had a total length of 3,805 mm.
Findings
- The primary cause of the collision was the reduction in clearance between the aircraft nose and the tug's cabin roof as the tug turned at an angle of 80 to 90 degrees.
- The towbar length used in this operation was significantly shorter than the 5,032 mm length listed in the Illustrated Tool and Equipment Manual for the GS80 towbar.
- It was noted that some airlines recommend a minimum towbar length of at least 5,000 mm for this specific aircraft type to maintain safe separation during maneuvering.