Accident Overview
On the morning of the accident, the pilot departed Nimpo Lake, British Columbia, at about 1020 Pacific daylight saving time in a float-equipped Cessna 180J. The intended destination was Knot Lake, approximately 35 nautical miles southwest, with a flight duration of 25 minutes. This was the pilot's second flight of the day. When the aircraft did not return by 1330 PDT, the company owner initiated an aerial search from Nimpo Lake in a Beaver aircraft. He detected an emergency locator transmitter (ELT) signal near Knot Lake but could not locate the source. The Rescue Coordination Centre (RCC) was notified, and the missing aircraft was found later that day on Knot Lake, partially afloat and sinking.
Sequence of Events
The flight's purpose was to pre-position a client's personal belongings and equipment at Knot Lake. The aircraft carried 175 pounds of belongings, a 70-pound outboard motor, 40 pounds of outboard motor gasoline, and the 190-pound pilot. Estimated fuel weight was 200 pounds, bringing the takeoff weight to an estimated 2,600 pounds, below the maximum allowable 2,950 pounds. A cargo net was available but it is not known if it was used. Persons fishing at the north end of Knot Lake, about a mile from the accident site, observed the aircraft flying overhead from north to south, approximately five seconds from landing, before losing sight behind a spit of land. They reported the lake surface was very rough with whitecaps. No witnesses saw the accident.
Aircraft Information
The Cessna 180J (registration not specified in source) was equipped with floats. The RCMP divers reported that upon recovery the next day, both floats were separated from the aircraft, the left wing had separated and was missing, and the propeller and engine mounts were bent. This damage is consistent with a cartwheeling impact. The aircraft sank in about 35 feet of water on the east side of the lake. Due to winter freeze-up, the aircraft was not recovered. Maintenance log-books showed no relevant deficiencies; total airframe time was 6,965.5 hours, and the engine had been overhauled at 1,470.4 hours.
Pilot Information
The pilot began employment as an office manager with Wayco Aviation in June 1996, transitioning to pilot-in-command duties on 23 August 1996. He held a commercial licence with multi-engine and float endorsements, a class one instrument rating, and a valid medical certificate. At the time of the accident, he had about 850 total flying hours, including 212 hours on floatplanes. He had flown about 20 hours with the company and had landed at Knot Lake at least seven times previously. His employer and colleagues considered him competent. Colleagues reported he appeared rested and behaved normally before the flight. It is not known if he obtained an area weather forecast, but he had first-hand knowledge from an earlier flight that day.
Weather Conditions
The Wayco Aviation company owner, who arrived at the accident site about two hours after the accident, reported that cloud base and visibility were suitable for operations. He described the landing location as being at the confluence of two airflows: a prevailing south wind and air flowing down a glacial ravine from the west. This mixing often created hazardous turbulence. He noted turbulent air and rough water, requiring caution even in the better-suited Beaver aircraft. Another pilot who arrived about three hours after the accident observed water spouts up to 60 feet high and stated he would not have landed had he not seen the missing aircraft.
Damage and Injury
The pilot sustained a severe head laceration and drowned. Toxicology tests excluded alcohol and drugs. RCMP divers reported the pilot was wearing only the lap belt, not the available shoulder harness. It was not determined if the head injury resulted from striking the aircraft or being struck by loose cargo, or if a shoulder harness would have mitigated the injury. The aircraft's damage patterns were typical of a cartwheeling water impact after a wing tip strike.
Probable Cause
The aircraft struck the water and crashed, probably because the pilot encountered turbulence and lost control of the aircraft during an attempted landing.