What happened
On 22 November 1999, an air ambulance flight operated by SOS Flygambulans AB was conducting a non-scheduled mission from Luleå/Kallax airport to Gällivare airport. The flight, involving a Beech 200 with registration SE-INI, was transporting a patient when the crew encountered deteriorating weather, including snowfall, low clouds, and moderate icing.
During the approach to runway 12, the crew initially failed to establish the aircraft on the centerline, necessitating a missed approach. On the subsequent attempt, the aircraft drifted right due to crosswinds. As the aircraft descended, the co-pilot attempted to correct the glide path by raising the nose, which led to a reduction in airspeed. Just before reaching the runway threshold, the commander selected full landing flaps. This sudden configuration change caused a significant trim shift. In an attempt to compensate for the resulting pitch change, the co-post lowered the aircraft's nose abruptly. Despite the commander increasing engine thrust to counteract a rising sink rate, the aircraft struck the runway with excessive force.
The investigation
The Swedish Accident Investigation Authority (SHK) examined the aircraft wreckage and the flight circumstances. The investigation focused on the crew's performance during the approach, the impact of the weather, and the aircraft's configuration. Investigators found that a 6-7 mm layer of ice had accumulated on the wing leading edges prior to landing. The investigation also reviewed the experience levels of the crew, noting that while the commander was highly experienced, the co-pilot had very limited experience with night operations.
Findings
- The landing was characterized by improper speed control during a period of difficult weather.
- The aircraft was not in a stabilized approach configuration, evidenced by the late selection of full landing flaps.
- The co-pilot's limited night flying experience contributed to an incorrect judgment of height above the runway.
- The commander failed to provide adequate supervision of the co-pilot's performance during the difficult approach.
- The accumulation of ice on the wing leading edges likely increased the stall speed, reducing the margin for error during the high sink rate event.