What happened
On March 21, 2004, at 01:20 UTC, an MD-83, registration SU-BMF, operated by Luxor Air, was performing a night approach to runway 21 at Nantes Atlantique Airport under instrument meteorological conditions (IMC). The flight, LXO615, was an unscheduled international service arriving from Luxor via Brussels.
During the approach, the crew was cleared for a direct route to the ABLAN waypoint. While attempting to intercept the VOR/LOC radial for the approach, the crew noted a lateral deviation from the radio axis. The captain requested a heading change to bypass what the crew believed to be a thunderstorm area identified on the weather radar. This maneuver caused the aircraft to deviate from the published approach procedure.
As the aircraft descended, the crew experienced significant turbulence. At approximately 01:27 UTC, the air traffic controller notified the crew that the aircraft appeared too low. The crew attempted to maintain 500 feet and initiated a left turn to return to the approach axis. During this maneuver, the aircraft descended through the cloud layer, and the captain initiated a go-around at an altitude of approximately 400 feet while over a populated area. The crew subsequently climbed to 3,000 feet and elected to perform a new approach.
The investigation
The BEA examined the flight data, cockpit voice recorder, and radar information to reconstruct the aircraft's trajectory. The investigation focused on the flight crew's navigation techniques, the interaction between the crew and the air traffic controller, and the operational procedures used by both the airline and the Nantes approach control.
Findings
Several contributing factors were identified in the incident:
- The flight crew performed an unstabilized approach and voluntarily exited the protected envelope of the published procedure.
- There was a lack of Crew Resource Management (CRM) training and a weak safety feedback structure within the operator, Luxor Air.
- The crew's perception of weather radar data was erroneous, leading to an unnecessary deviation, and they failed to account for wind effects on the descent profile.
- A discrepancy existed between established air traffic control procedures and actual practice, where controllers had become accustomed to using shorter, unpublished approach trajectories.
- There was a lack of synergy between the flight crew and the controller, compounded by probable hypovigilance from the controller, who was working alone at night.
- The aircraft's autopilot performance limitations regarding radial interception were not clearly documented in the flight manual.