Investigation Summary
The accident occurred during a scheduled multi-stop flight from Klamath Falls to Seattle, with planned intermediate stops at Medford, North Bend, and Portland. Due to snowy conditions, the aircraft was boarded inside a maintenance hangar. During the transition to the ramp, the tug tractor lost traction, leaving the Fairchild F-27 exposed to active precipitation for 11 minutes. Investigators found that despite this exposure, no de-icing fluid was applied, and no attempt was made to clear the surfaces. Evidence from the runway showed the aircraft began swerving left early in the takeoff roll, with the left main gear departing the runway surface before lift-off. Flight data indicated the aircraft struggled to maintain altitude and heading, oscillating between 5,250 and 4,700 feet. The cockpit voice recorder captured the crew reporting a total loss of control and an inability to see the terrain before the aircraft struck Stukel Mountain in a right-wing-low attitude and cartwheeled.
Final Conclusions
The NTSB determined the probable cause was the loss of control resulting from ice accretion on the airframe surfaces. The Board specifically cited the pilot's failure to require de-icing fluid application prior to takeoff, noting that maintenance personnel had also not performed this task. Fatigue was suggested as a possible contributing factor due to the crew's demanding turnaround schedule.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
First Officer
Systems & Failure Modes
Airframe De-icing
The aircraft was not treated with de-icing fluid despite 11 minutes of exposure to freezing precipitation, leading to aerodynamic degradation.
Flight Data Recorder (FDR)
Though damaged, the FDR provided critical data showing the aircraft's heading deviations and altitude fluctuations prior to impact.
Interesting Facts
- 01The aircraft was exposed to snow and rain for 11 minutes without de-icing before takeoff.
- 02The left main gear was 12 feet off the runway edge for 250 feet prior to lift-off.
- 03The aircraft reached a maximum altitude of 5,250 feet before descending to 4,700 feet and then climbing again into the mountain.
- 04The CVR recorded the crew stating they could not see the mountain and had lost control of the aircraft.
- 05The aircraft cartwheeled up a 30-degree slope upon impact.
Safety Actions & Advisories
Operational De-icing Procedures
The investigation emphasized the pilot's responsibility to ensure airframe cleanliness in icing conditions, reinforcing that de-icing is a mandatory pre-flight requirement when frozen contamination is present.