A de Havilland Canada DHC-3T Turbo Otter was destroyed in an accident 56 km northeast of Mayo, YT, Canada. The pilot, who was the sole occupant, sustained fatal injuries. The wheel-ski equipped aircraft was being utilized in support of mineral exploration activities, to transport building materials, fuel, and winter camp supplies from Mayo, Yukon, to winter airstrips located at Withers Lake and Rackla River, Yukon. On the accident flight, the aircraft was transporting a load of twelve 6-inch by 6-inch wood timbers, each 16 feet long, and 2 barrels of jet fuel. The accident flight departed Mayo at 14:48 under visual flight rules (VFR). Some nineteen minutes later the aircraft experienced a catastrophic in-flight breakup. Aircraft wreckage came down on a remote, snow-covered hillside at about 4300 feet above sea level. Findings as to causes and contributing factors: “The aircraft departed controlled flight for reasons which could not be determined, and broke up due to high speed.”