What happened
On 10 January 2011, an Airbus A300-B4-622R, registration TF-ELK, was performing a cargo flight from Belfast to East Midlands Airport. During the approach, the crew encountered gusty crosswind conditions. Upon touchdown, the commander selected reverse thrust; however, the aircraft experienced a heavy bounce. The pilot subsequently decided to execute a go-around.
During the climb, the No 2 engine thrust reverser failed to return to its stowed position. Because the sleeves were in transit, the FADEC system automatically limited the No 2 engine thrust to idle. This loss of power, combined with the aircraft's high-drag configuration, severely compromised climb performance. As the aircraft attempted to rotate for the go-around, the pitch attitude increased excessively, resulting in a tailstrike that caused damage to the tailskid and fuselage skin. The crew diverted to Stansted Airport, where they performed a single-engine landing.
The investigation
The AAIB examined the aircraft's flight recorders and the thrust reverser mechanical and electrical systems. Investigators found that the No 2 engine thrust remained at idle due to the FADEC logic responding to the unlatched reverser. While the crew believed reverse thrust had not been selected, flight data confirmed the reversers had indeed deployed.
Technical inspections of the No 2 engine revealed that the flexible driveshafts were twisted, and the secondary locks were not engaged. Furthermore, electrical testing identified a loose wire in the auto-restow circuit. This intermittent connection was found to be the primary reason the pneumatic system failed to complete the stowage cycle during the high-stress maneuvers of the go-around.
Findings
- The most likely cause of the No 2 thrust reverser failing to stow was an intermittent loose connection in the auto-restow circuit.
- The aircraft's climb performance was significantly degraded because the FADEC system maintained No 2 engine thrust at idle while the reverser was in transit.
- The tailstrike occurred because the aircraft's pitch exceeded safe limits during a low-speed rotation in a high-drag configuration.
- The crew's awareness of the reverse thrust selection was likely hindered by the distractions of the difficult landing conditions.