What happened
On 27 June 2000, an Airbus A300B4-605R, registration N14065, was operating a scheduled public transport flight from London Heathrow to New York JFK. During the climb through FL220, approximately 10 nautical miles northeast of Filton, the aircraft encountered a sudden disturbance. The flight crew, who were flying the aircraft manually, perceived an abrupt yawing motion which they initially believed was caused by uncommanded rudder input. This event was accompanied by a loud bang heard by both the flight crew and cabin attendants.
Following the disturbance, the aircraft's flight path remained stable, though the commander elected to abort the transatlantic mission and return to London Heathrow. The aircraft landed safely at Heathrow without any zero injuries or damage to the airframe.
The investigation
Investigators examined the aircraft's flight data recorder, which captured the precise mechanics of the event. The data revealed that while the crew perceived a significant yaw, the actual rudder deflection was minimal, and the aircraft primarily experienced a slight roll. The investigation also included a thorough engineering inspection of the flight control systems, including the ailerons, spoilers, and rudder. No mechanical failures, structural damage, or defects in the electrical flying control units were found to be responsible for the movement.
To identify the source of the loud noise, investigators searched the cargo holds for unsecured items, but no shifting of freight was detected. Meteorological analysis was also conducted to determine if atmospheric conditions like clear air turbulence or convective activity were responsible. Radar data revealed that a heavy Boeing 777 had passed through the exact same airspace only about four minutes prior to the incident.
Findings
- The aircraft was flying in a stable atmosphere with no evidence of convective activity or significant wind shear.
- Extensive engineering checks and test flights confirmed that all primary and secondary flight controls were functioning normally.
- The most likely cause of the localized turbulence was an encounter with the wake vortex generated by the preceding Boeing 777.
- The loud noise reported by the crew may have been a result of the aircraft's fuselage intercepting the low-pressure core of the vortex.