History of the Flight
The aircraft, a turbine-powered de Havilland DHC-3 Otter (registration C-GMCW, serial number 108) owned by Black Sheep Aviation and Cattle Co. Ltd., departed Mayo, Yukon, at 1448 Pacific Daylight Time on a day visual flight rules flight to Rackla Airstrip, 94 statute miles northeast. The flight was in support of mineral exploration, transporting twelve 6x6-inch wood timbers (16 feet long each) and two barrels of jet fuel. At 1507, approximately 19 minutes after departure, the Canadian Mission Control Centre received a 406-MHz emergency locator transmitter alert. The Joint Rescue Co-ordination Centre Victoria was notified, and a commercial helicopter was dispatched from Ross River, Yukon. Wreckage was located at 1833 on a remote, snow-covered hillside 38 nautical miles northeast of Mayo, at about 4,300 feet above sea level. The aircraft had experienced a catastrophic in-flight breakup; both wings, the empennage, and all flight controls had separated during flight. There was no post-impact fire.
Injuries and Damage
The pilot, the sole occupant, sustained fatal injuries. No persons on the ground were injured. The aircraft was substantially damaged due to the in-flight breakup and ground impact. The fuel tanks and two barrels of Jet A fuel ruptured, releasing approximately 770 litres of jet fuel into the environment; damage was confined to the main impact site.
Personnel Information
The pilot held a valid commercial pilot licence endorsed for single- and multi-engine land and seaplanes, with previous instrument and instructor ratings. Although personal logbooks were not found, other sources indicated approximately 5,000 total flying hours, with an estimated 3,000 hours on turbine-powered DHC-3 Otters. The pilot also held an E-category aircraft maintenance engineer licence. He had flown for Black Sheep Aviation during the 2010 float season and winter operations from January to February 2011, returning for a second winter campaign starting 21 March 2011. The pilot was paid on a per-mile-flown basis; flight records from 21 to 31 March showed regular flights of 6 to 7 trips (12 to 14 flights) and 1,200 to 1,400 miles per day.
The pilot's accommodation was a shared motel room in Mayo; the quality of sleep could not be determined. Restaurant facilities were limited; the pilot normally ate a light breakfast in the room, but lunch and dinner routines were not determined.
Flight Duty Time and Regulatory Context
Canadian Aviation Regulations (CARs) define flight duty time and minimum rest periods. The operator held an Operations Specification permitting extension of flight duty time to 15 consecutive hours under certain conditions. The investigation determined that the pilot's actual flight times exceeded 8 hours in any 24 consecutive hours for the 8 days before the accident, and on days when flight duty time exceeded 14 hours and flight time exceeded 8 hours, the minimum rest periods had not been extended as required. A system to monitor flight time, duty time, and rest periods was required; the operator's tracking was based on pilot journey log entries, and records were reconciled monthly. Company records completed after the accident indicated pilot flight duty times of 122.2 hours from 21 to 30 March and 92.6 hours for 24 to 30 March, but examination with other sources showed actual times of 132.6 hours and 99.6 hours respectively. The pilot had a 9.5-hour rest period before the accident flight, including travel, meals, and sleep.