What happened
On a night medical evacuation flight from Gods Lake Narrows to Shamatta and, a Fairchild SA226TC (registration C-GYPA) struck trees approximately 2600 feet from the end of Runway 01. The flight, operated by Perimeter Airlines, was carrying two pilots and a flight nurse.
As the crew approached Shamattawa, they were flying too high and too fast for a landing. The crew elected to execute a missed approach, increasing power to the engines. However, during the transition, the aircraft failed to climb away from the terrain. The aircraft struck trees with a left bank, causing the airframe to break apart along an 850-foot wreckage trail. The impact resulted in two fatalities (the captain and first officer) and one serious injury (the flight nurse).
The investigation
Investigators examined the wreckage, the cockpit voice recorder (CVR), and the aircraft's systems. The CVR confirmed the crew was in control and expressed no immediate concern prior to the impact. The engines were found to be operating at high power at the time of the crash, and all flight control surfaces were intact before the collision.
Technical analysis revealed that the crew had used an incorrect, lower altimeter setting, which caused the aircraft to be approximately 70 feet higher than intended. The investigation also noted the absence of a visual approach slope indicator (VASIS) at the airport, which would have assisted in maintaining the correct glide path. Additionally, while the first officer's toxicology showed the presence of cannabinoids, investigators could not definitively link this to his performance during the flight.
Findings
- The aircraft struck terrain because the pilot flying failed to establish and maintain the necessary pitch attitude to ensure a positive rate of climb.
- The captain likely experienced a somatogravic illusion, a vestibular error where rapid acceleration during a night overshoot is perceived as a nose-up attitude, leading to a loss of situational awareness.
- The first officer failed to monitor the flight instruments effectively, potentially due to distraction by the non-directional beacon (NDB) or the same sensory illusion.
- The lack of ground-based approach aids and the company's less stringent standard operating procedures (SOPs) regarding missed approaches contributed to the accident.