Incident
On a visual flight rules flight from Four Mile Lake, Alberta, to the Taltson River, Northwest Territories, a Cessna A185F seaplane (registration C-GVYE, serial number 18503778) operated by Big River Air Ltd. was transporting three passengers to a site known as Ferguson's Cabin. At approximately 1700 mountain daylight time, during landing on the water near the cabin, the left float dug in and the left wing struck the water. The aircraft immediately cartwheeled and came to rest floating inverted in the river, with only the bottoms of the floats visible at the surface.
Occupants
The pilot and the front seat passenger sustained serious injuries but managed to exit the submerged and damaged aircraft through a broken window in the left cabin door. Four fishermen in boats responded, removed the survivors from the cold water, and transported them to a warm shelter. The rear seat occupants drowned; one was found inside the aircraft, and the second was found two days later outside the aircraft, near the crash position, in 55 feet of water.
Aircraft and Operator
The aircraft was a Cessna A185F seaplane equipped with a Robertson STOL kit and Canadian Aircraft Products 3000E floats. Big River Air Ltd., based at Fort Smith Airport, Northwest Territories, operated eight types of small aircraft under Canadian Aviation Regulations 702 and 703. The pilot held a commercial pilot licence with a sea rating and had approximately 447 hours of flight experience, including an estimated 220 hours on float-equipped aircraft. He had 12.4 hours of float experience in the 2004 season.
Investigation
The wreckage was recovered and examined; no pre-impact discrepancies were identified. There was no indication of a strike against a floating or submerged object at touchdown. Both wing rear spars failed adjacent to the fuselage attachment fittings at impact. The aircraft was at or near gross weight; a weight and balance calculation showed it was under maximum gross weight with the center of gravity near the aft limit but within limits. The weather was suitable for VFR, with nearly clear skies, unlimited visibility, and surface winds estimated from the west at 15 to 20 knots, variable with a tendency to swirl within the bay.
The pilot circled three times before landing and observed what he considered shallow water in a murky area. He landed in the bay, where the available landing distance was approximately 1800 feet. The final approach was at about 80 knots indicated airspeed with 20 degrees of flap. The prescribed way to arrive at Ferguson's Cabin was to land on the main channel and taxi; landing in the bay was not advised due to limited area and strong cross-current. Two days after the accident, investigators observed minimal current in the centre of the bay where the accident is believed to have occurred.
Safety Issues
Life preservers were inflatable type, packaged and stored in the extended baggage compartment, not easily accessible. None of the occupants were wearing life preservers. The main cabin doors were the only emergency exits; after the accident, the interior door handles were found in the LOCKED position. Both survivors could not locate the handles initially. The pilot exited through the broken left cabin window. The opening was 13 inches by 30 inches. The rear occupants had lap belts only; they released them but their egress actions could not be determined. The aircraft flight manual specified maximum cargo loads of 120 pounds in baggage area 1 and 50 pounds in area 2; the total cargo was 250 pounds, likely exceeding area 1's limit. However, there was no indication that loose cargo impeded egress.