What happened
On a scheduled flight from Sioux Lookout to Big Trout Lake, Ontario, a Beechcraft A1/100, registration C-GYQT, encountered severe weather while attempting to land. The flight, operated by Bearskin Lake Air Services Ltd., was carrying two crew members and nine passengers. While flying under visual flight rules near the airport, the crew encountered whiteout conditions and significantly reduced visibility.
During the approach, the captain attempted to reference approach charts held in a binder on his lap. While focused on these documents, the aircraft's descent rate increased sharply. The aircraft struck the frozen surface of the lake approximately three miles northwest of Big Trout Lake Airport. The initial impact caused the aircraft to bounce, after which the crew attempted a recovery, but the aircraft subsequently crashed a second time further along the lake surface. All eleven people on board survived, though the crew and seven passengers sustained serious injuries.
The investigation
The investigation examined the aircraft's descent profile, which radar data showed had dropped to approximately 150 feet above ground level before a final descent at over 1,200 feet per minute just before impact. Investigators also reviewed the aircraft's maintenance records, noting that the radar altimeter was unserviceable and had not been properly placarded in the cockpit. Additionally, the crew's workload was analyzed, specifically the captain's use of approach charts during the descent.
Findings
- The crew's workload was too high as they attempted to maintain visual flight conditions while simultaneously managing navigation and approach documentation.
- The captain's attention was diverted by reviewing approach charts in a binder, causing him to miss or disregard critical altitude and vertical speed information.
- The decision to continue a visual approach in an area with minimal visual cues and deteriorating visibility contributed to the accident.
- Localized whiteout conditions significantly reduced visibility to less than half a mile.
- The aircraft's radar altimeter was unserviceable and not properly marked for the crew.