What happened
A privately owned Beech UC4ps-J departed from a clay-and-gravel airstrip near Swan Lake, Yukon Territory, carrying a pilot, two passengers, and approximately 800 pounds of meat. During the takeoff roll, the aircraft initially performed normally, with the tail lifting first. However, after leaving the runway surface, the aircraft entered a steep climb, followed by a leftward yaw and bank. The aircraft then entered the Pleasant Creek valley in a near-vertical, nose-down attitude. The impact resulted in an explosion and fire, and there were no survivors.
The investigation
The investigation examined the aircraft's weight and balance, the loading configuration, and the physical evidence at the crash site. The aircraft was found to have a takeoff weight of approximately 9,000 pounds. While the aircraft was certified for a gross takeoff weight of 10,100 pounds, the center of gravity (C of G) was a critical factor. The investigation noted that the meat was loaded onto a plastic tarpaulin over a plywood sheet, and while straps were used, the aircraft lacked dedicated cargo tie-down rings in that area.
Physical evidence at the scene showed the aircraft struck the ground 500 feet from the end of the runway. The damage to the propellers indicated that the engines were producing significant power at the moment of impact. Because the wreckage was largely destroyed by the impact and subsequent fire, investigators could not confirm specific mechanical failures, though no system malfunctions were identified.
Findings
- The meat was placed on a potentially slippery plastic surface and was not sufficiently restrained.
- The uneven surface of the airstrip likely caused the 800-pound load to shift rearward during the takeoff roll.
- This shift moved the center of gravity well beyond the allowable aft limit, causing an uncontrollable pitch-up and an aerodynamic stall.
- The low altitude of the occurrence prevented the pilot from recovering from the resulting dive.