History of the Flight
On 18 July 2011, at approximately 1448 Eastern Daylight Time, a Cessna A185E floatplane (registration C-FZNK, serial number 18501822) operated by Air Tamarac Inc. departed the La Tuque, Quebec, seaplane base for a 20-minute sightseeing flight. The aircraft took off northward and climbed to about 1600 feet above sea level. This was the third flight of the day for the same pilot and aircraft.
Before the first flight, the pilot performed an external inspection and drained the fuel system to check for contaminants. The first flight, to Lac aux Trois Caribous, lasted about 30 minutes. After returning, the pilot measured fuel with a dipstick, indicating approximately 15 gallons per tank. The second sightseeing flight lasted about 20 minutes and ended at around 1439.
Before the accident flight, the pilot did not measure the fuel but estimated 10 gallons in the left tank and 15 in the right. At approximately 1443, the pilot boarded four passengers. The pilot provided safety briefings in two parts: during boarding and while taxiing. The fuel selector was in the BOTH position for takeoff at about 1449.
Approximately 5 minutes after takeoff, the pilot moved the fuel selector to the LEFT position. The aircraft turned right toward the Croche River and then flew over the Bostonnais River.
Engine Failure and Ditching
At about 1501, 12 minutes after takeoff, the engine stopped. The propeller began windmilling, and the aircraft lost altitude. The pilot attempted emergency procedures from memory, returning the selector to BOTH and trying various combinations of power, mixture, and fuel tank selections, but the engine would not restart. The pilot twice attempted radio communication with the company but received no response.
The pilot directed the aircraft toward the Bostonnais River for an emergency ditching. The river was narrow and winding, with an elevation of about 620 feet asl. At approximately 1502, witnesses observed the aircraft making a sharp left turn over trees along the riverbank. The aircraft then nose-dived, struck the water, tumbled, and came to rest inverted with its floats on the surface.
Local residents called emergency services and offered assistance. Of the five occupants, the pilot and three passengers survived; one passenger died. The emergency locator transmitter activated on impact, but no transmission was received.
Investigation Findings
The pilot held the required licence and qualifications and was familiar with the Cessna 185. The investigation found no evidence that fatigue, weather, or aircraft airworthiness contributed. No anomalies were found in the engine or fuel supply system.
Fuel management was a key area of focus. The fuel quantity indicators were serviceable but known to be unreliable below one-quarter tank. The pilot relied on dipstick measurements rather than panel gauges. After the previous flight, the pilot estimated fuel distribution but did not re-measure before the accident flight. The company operations manual and aircraft operating manual recommend supplying the engine primarily from both tanks, with no restriction on other selections in cruise. The pilot had selected the left tank to facilitate refueling at the dock. The fuel recovered from the left tank was about 1 gallon above unusable levels. The engine experienced momentary fuel starvation in the left tank, causing it to stop.
During engine stoppage management, the pilot had limited time—about 60 seconds—to execute emergency procedures, select a landing site, and communicate. Examination of the cockpit showed that several steps in the emergency ditching checklist were not completed. The pilot did not activate the auxiliary electric fuel pump, which could have helped purge air from the mechanical pump and possibly restart the engine. The laminated emergency checklist was onboard but the pilot did not refer to it; moreover, that checklist did not include the auxiliary pump step (which was in section 7 of the aircraft operating manual).
The pilot's stress may have contributed to forgetting the pump activation. The engine failure occurred earlier than expected given the estimated fuel remaining.
Safety briefings were provided in two parts and may have been incomplete; passengers were distracted by engine noise and excitement. No passenger safety guide was offered, and the briefing did not cover procedures for using personal flotation devices or evacuating a submerged, inverted aircraft.
Conclusion
The investigation determined that the engine failure was caused by momentary fuel starvation of the left fuel tank, and the pilot's failure to activate the auxiliary electric fuel pump prevented a restart. The resulting forced landing, terrain constraints, and subsequent stall led to the fatal accident.