What happened
On 6 February 2009, a Bombardier BD-700-1A10, registration N906JW, was performing an approach to Samedan Airport in Switzerland. During the final phase of the flight, the aircraft's approach became unstable. The crew noted the runway was visible, but the aircraft subsequently touched down on runway 03 significantly late and at an excessive speed. Due to the combination of the late touchdown and the presence of snow and ice on the runway surface, the aircraft could not be brought to a halt within the remaining runway distance, resulting in a runway excursion.
The investigation
The investigation examined the flight path, meteorological conditions, and runway maintenance protocols. Investigators reviewed the flight data and cockpit voice recordings, which captured the crew's observations of the terrain and the Flight Information Service Officer's (FISO) warning regarding the wet snow and ice on the runway. The inquiry also scrutinized the airport's snow clearance procedures and the management of the runway environment. It was noted that the runway surface was covered with snow and partially covered in ice at the time of the accident.
Findings
- The primary cause of the accident was the aircraft's late and high-speed touchdown following an unstabilized approach.
- The runway surface was covered in snow and contained patches of ice, which significantly reduced braking effectiveness.
- Inadequate flight preparation contributed to the crew's inability to manage the approach under critical meteorological conditions at a mountain airport.
- The aircraft's inability to stop was exacerbated by the remaining runway distance being insufficient given the high speed and slippery conditions.