Overview
A Fairchild F-27, registration N2712, was destroyed when it crashed on the northwest slope of Stukel Mountain. The aircraft was on a scheduled flight from Klamath Falls, Oregon, to Seattle, Washington, with intermediate stops at Medford, North Bend, and Portland. All four occupants were killed.
Flight Details
Due to falling snow at Klamath Falls, the aircraft was loaded inside a hangar instead of on the ramp. A delay occurred while pushing the aircraft out because the tow tractor lost traction in the snow. The F-27 was exposed to the falling snow for approximately 11 minutes before taxiing to runway 14. At 05:01, the aircraft began its takeoff roll.
Takeoff and Climb
During the takeoff roll, after about 1,000 feet, the aircraft gradually veered to the left. The nose wheel lifted off the ground 600 feet before the main gear, at a point approximately midway between the runway centerline and the left row of runway lights. The left main gear was about 12 feet off the left runway edge for 250 feet prior to lift-off. Immediately after becoming airborne, the aircraft swerved sharply to the right and then back to the left. During the climb, the aircraft tended to the left despite multiple course corrections. After reaching an altitude of 5,250 feet, it descended to 4,700 feet before resuming a climb.
Crash
The aircraft continued climbing until it struck a steep ridge on the northwest slope of Stukel Mountain at an elevation of 5,049 feet (1,539 meters). The F-27 was in a right-wing-low attitude when the wing contacted the mountain. The aircraft then cartwheeled up the 30-degree uphill slope. The aircraft was destroyed.
Probable Cause
The official probable cause was loss of control due to ice accretion on airframe surfaces. The Board further determined that the pilot should have required that deicing fluid be applied to the aircraft to remove the accumulation of ice and snow prior to takeoff. This had not been done by the appropriate maintenance personnel.