What happened
On February 6, 2010, a Scandinavian Airlines System (SAS) McDonnell Douglas MD-81, registration OY-KHP, was performing an unscheduled international night flight from Copenhagen to Grenoble-Isère. The flight arrived under Visual Flight Rules (VFR) in dark conditions with significant cloud cover.
During the ILS approach to runway 09, the crew was operating with landing lights set to a dim intensity. At approximately 1,000 feet, the pilot flying disengaged the autopilot. As the aircraft descended to 200 feet, the co-pilot also disengaged the auto-throttle. Following this manual thrust management, the aircraft's airspeed began to drop below the target Vapp, and the rate of descent increased.
At 15 feet above the ground, the pilot flying executed a sharp nose-up input, likely due to a sudden realization of the aircraft's proximity to the ground. This maneuver caused the pitch attitude to exceed the safety limits for touchdown. Consequently, the rear of the fuselage struck the runway 166 meters before the touchdown zone, resulting in serious damage to the aircraft's structure.
The investigation
The BEA examined flight data recorder (FDR) information, interviews with the crew, and aerodrome lighting configurations. The investigation revealed that the crew was navigating a "black-hole effect," where the lack of visual references and dim runway lighting made it difficult to perceive height and distance.
Investigators also found that the crew's aeronautical charts were inconsistent; the Navtech AERODROME chart incorrectly indicated a much longer approach lighting system than what was actually present at the aerodrome. Furthermore, the investigation noted that the cockpit voice recorder (CVR) data for the landing phase was lost because the aircraft's electrical system was switched on after the accident without pulling the CVR circuit breaker.
Findings
- The primary cause of the accident was the crew continuing the landing despite a significant deterioration in situational awareness.
- The pilot flying's perception of height and distance relative to the runway was erroneous due to the black-hole effect.
- The crew failed to use the maximum brightness for landing lights, which could have improved visual references.
- Manual thrust management was inappropriate, leading to a loss of airspeed and an increased descent rate.
- The absence of a visual approach slope indicator system at the aerodrome contributed to the difficulty in transitioning from instrument to visual references.
- The co-pilot's recent notification of redundancy may have caused emotional distress, potentially impacting mental availability.