What happened
On May 23, 2008, an Airbus A300-B4-203 cargo aircraft was performing a takeoff roll on runway 14L at Cologne-Bonn Airport. As the aircraft reached a speed of approximately 110 knots, the crew heard a loud noise originating from the left side of the aircraft. In response to this event, the crew initiated an aborted takeoff, and the aircraft returned to its parking position without further incident.
The investigation
The BFU investigation focused on the structural failure of the left engine's core cowling. The investigation examined the engine's cowlings, which consist of fan and core components. The core cowling is secured by hinges at the top and three fasteners at the bottom, utilizing a system of eyes on the left side and hooks on the right side.
Investigators found significant damage to the left engine's core cowling, noting that both halves were bent backward and torn in several locations. The inspection of the fastening mechanism revealed that while the eye on the right side remained intact, the hooks on the two rear fasteners (No. 2 and No. 3) had broken due to force. Specifically, the spring mechanism for fastener No. 3 was found to be incomplete and bent at a 90-degree angle, and the retaining pins for the securing bracket on this fastener were heavily worn, having decreased in diameter from 3.2 mm to 2.6 mm.