What happened
On the evening of 06 November 2009, a Cessna 310R, registration C-GFIT, departed Sioux Lookout, Ontario, for a scheduled night flight to Cat Lake. The aircraft, operated by Lockhart Air Services Limited, was carrying a pilot and two passengers on a company itinerary. After takeoff, the pilot reported climbing to 5500 feet above sea level.
As the aircraft approached Cat Lake, the pilot flew over the airport and turned southwest to establish a downwind leg for the final approach to Runway 11. During this maneuver, the aircraft struck rising terrain in a densely wooded area approximately eight nautical miles southwest of the runway. The impact caused the fuel cells to rupture and explode. The aircraft was destroyed, and the three fatalities were confirmed upon impact.
Following the aircraft's failure to arrive, a search was initiated by the operator. The wreckage was discovered two days later. An investigation revealed that the aircraft's emergency locator transmitter failed to signal because its antenna was torn off during the crash.
The investigation
Investigators examined the aircraft's mechanical state, the pilot's credentials, and the environmental conditions. The pilot was fully qualified with a commercial license and an instrument rating. The Cessna 310R was found to be well-maintained, within weight and balance limits, and carrying sufficient fuel for the flight.
Analysis of the wreckage indicated the aircraft was in a level flight attitude and under control at the moment of impact, with engines producing power. However, investigators discovered a critical discrepancy in the altimeter settings. The right altimeter subscale was set to 30.40 inches, which was approximately one inch higher than the actual barometric pressure of 29.41 inches. Because the aircraft's three-pointer altimeters were used, the pilot likely failed to notice that the setting was incorrect.
Findings
- The aircraft's altimeters were likely set incorrectly, providing a reading approximately 1000 feet higher than the actual altitude.
- This error led the pilot to believe the aircraft was at a safe altitude while descending to join the approach.
- The pilot descended into rising terrain while maneuvering for the final approach in total darkness.
- The lack of visual cues and lights in the area, combined with the aircraft's position away from the lighted community, increased the risk of terrain collision.