What happened
At 0645 UTC, an Air Transat Airbus A310-308 departed Varadero, Cuba, bound for Québec, Canada. The flight was carrying 262 passengers and 9 crew members. While cruising at flight level 350, approximately 90 nautical miles south of Miami, the crew experienced a loud bang and intense vibrations. This was immediately followed by the onset of a Dutch roll.
To manage the instability, the captain disconnected the autopilot and took manual control. The aircraft climbed nearly 1,000 feet during the struggle to stabilize the lateral axis. The crew eventually initiated a descent, which caused the Dutch roll to subside as the aircraft passed through flight level 280. Although the crew considered diverting to Fort Lauderdale, they ultimately decided to return to Varadero.
During the landing flare at Varadero, the crew noted that rudder inputs were ineffective at correcting a slight crab. Upon reaching the gate and shutting down the engines, a visual inspection revealed that the rudder was missing, with only small fragments remaining attached to the vertical stabilizer. One flight attendant sustained a minor injury during the in-flight event.
The investigation
The investigation focused on the structural failure of the rudder and the crew's response to the instability. Investigators examined the aircraft's maintenance history and found that while the aircraft was maintained according to approved programs, the existing inspection methods were limited. Specifically, visual inspections from the ground and the five-year tap tests were unable to detect internal damage such as skin disbonds or fluid ingress.
Regarding the flight crew, the investigation looked into why an emergency was not declared and how the crew managed the Dutch roll. It was noted that there were no specific procedures in the Quick Reference Handbook (QRH) or the Electronic Centralized Aircraft Monitor (ECAM) for recovering from a Dutch roll. Furthermore, the investigation found that critical information from the cabin crew regarding the severity of the vibrations was not communicated to the flight deck.
Findings
- The structural failure of the rudder was the primary cause of the flight control difficulties.
- The existing maintenance inspection program was inadequate to detect internal rudder damage in a timely manner.
- The crew faced flight control difficulties of unknown origin with no established emergency procedure for a Dutch roll.
- A lack of effective communication between the cabin crew and the flight crew prevented the pilots from having a full understanding of the event's intensity.