Accident Summary
On a Visual Flight Rules (VFR) flight from Tofino, British Columbia, to Ahousat, a float-equipped Cessna 185F (registration C-GIYQ) operated by Atleo River Air Service departed at 1200 Pacific Daylight Time with a pilot and three passengers. The aircraft was cruising at about 500 feet above sea level when, approximately 2 nautical miles from Ahousat, it entered a steep nose-down descent and struck the water in Millar Channel. The aircraft overturned and sank despite recovery attempts. There were no survivors. The emergency locator transmitter functioned, but its signal was not received until the wreckage was raised two days later.
Investigation Findings
Weather conditions at Tofino were suitable for VFR flight: wind 270° true at 9 knots, visibility 8 statute miles, scattered clouds at 1000 feet and overcast at 1400 feet above ground level, temperature 11°C, dew point 8°C. No reports of glassy water or downdrafts along the route. The investigation found no evidence of mechanical or environmental issues. The aircraft struck the water at an angle and speed consistent with a deliberate dive or loss of control. The pilot had no operational reason to dive, and based on his demeanor, intentional diving to impact was discounted. The aircraft was trimmed for level cruise; a sustained 45° descent would require high forward control column pressure.
Evidence indicated passenger interference: the three passengers were intoxicated upon boarding and had been argumentative. Beer cans and fragments were located near the passengers just before impact. Seat belts of the right front passenger (beside the pilot) and the left rear passenger (behind the pilot) were not fastened at impact. The pilot's right wrist was broken, and the V brace was bent, suggesting he braced against a force from behind. The rear passenger's broken ankles were consistent with bracing or pushing forward. It is possible that passenger kicked the pilot's seatback forward, pushing the pilot into the instrument panel and the controls forward, inducing the dive. The pilot's seatback had no locking mechanism, and the pilot was not wearing his shoulder strap, preventing him from resisting the forward force.
Probable Cause and Contributing Factors
The investigation concluded that it is likely passenger interference caused the pilot to lose control of the aircraft, resulting in a steep nose-down descent until impact. Contributing factors included the passengers' intoxication, which may have impaired their ability to stop the interference; the lack of a locking mechanism on the pilot's seatback; and the pilot not wearing his shoulder strap, which left him unable to prevent being forced onto the controls. The investigation also noted that when aircraft controls are accessible to passengers, there is a risk of inadvertent manipulation and loss of control.