What happened
On a daylight flight from Wawa, Ontario, to Smiths Falls-Montague, a Cessna 210L, registration C-GPMC, was conducting a visual flight rules operation under flight following from air traffic control. While descending through approximately 7,800 feet above sea level, the aircraft's ground speed increased significantly, reaching up to 203 knots. During this descent, the aircraft performed a left turn followed by a sharp right turn. At approximately 1615 EDT, the aircraft disappeared from radar coverage and radio communications ceased abruptly. The aircraft crashed into Lake Lavieille, leaving two fatalities.
The investigation
Investigators examined the wreckage and analyzed radar and radio data. The investigation established that the aircraft was likely using autopilot during the initial portion of the descent. However, the right turn initiated at 7,600 feet indicated the autopilot had been disconnected. The aircraft's airspeed of approximately 175 knots was noted to be within the cautionary range and exceeded the autopilot's maximum operating speed of 165 KIAS.
Detailed examination of the wreckage revealed that the left wing failed in overload and separated into several pieces. At least one fragment of the left wing struck the vertical stabilizer, causing the entire empennage to detach from the fuselage. The investigation found no evidence of pre-existing structural issues such as fatigue, corrosion, or improper repairs. The engine and propeller were found to be in serviceable condition.
Findings
- The left wing failed in overload and separated from the aircraft, which caused the aircraft to become uncontrollable.
- The separation of the left wing led to the subsequent loss of the empennage after fragments struck the vertical stabilizer.
- There were no signs of structural weakness, flutter, or improper maintenance prior to the accident.
- The aircraft was operating at a high airspeed, which increased the risk of encountering a structurally damaging gust load.
- The destruction of the left wing root caused the immediate loss of power to the VHF communication and navigation radios.