What happened
During a repositioning flight intended for air ambulance services, a Citation 550 was performing a manual approach to a 4,801-foot asphalt runway. The crew reported that the aircraft broke out of the cloud layer approximately two miles from the runway threshold while following the localizer and glide slope. While the crew maintained a target approach speed of 106 knots, witnesses noted the aircraft appeared to be traveling fast and at a high altitude as it crossed the threshold.
The aircraft made contact with the runway halfway down its length and failed to stop before the end of the pavement. The excursion continued past the departure end of the runway, where the aircraft struck a wooden localizer antenna platform and the airport perimeter fence. After crossing a nearby road, the aircraft came to a final stop roughly 400 feet from the runway terminus. There were 0 fatalities and no injuries reported.
Findings
Investigation of the flight data from the Enhanced Ground Proximity Warning System (EGPWS) indicated that the aircraft's groundspeed at the moment of touchdown was approximately 140 knots. This significantly exceeded the intended approach speed. The cockpit voice recorder indicated that the pilot failed to deploy the speed brakes upon landing.
At the time of the accident, the runway surface was covered with a layer of loose, fluffy snow, approximately 0.25 to 0.5 inches deep, with braking action rated as fair. While the flight manual indicated a required landing distance of roughly 5,800 feet for a contaminated runway at standard speeds, the high speed of the aircraft necessitated a much longer stopping distance than the available runway could provide.