Accident Sequence
The aircraft, a Piper PA-31-350 Chieftain (registration C-GRNK), was departing Matheson Island, Manitoba, on a visual flight rules flight to Poplar River, Manitoba, with one pilot and seven passengers. Shortly after lift-off from Runway 03, the right engine lost power and trailed black smoke. The pilot initially attributed the changing control forces to windshear, but after the aircraft cleared the trees, identified the power loss, shut down the engine, and feathered the propeller. The aircraft attained an airspeed of 90 to 100 knots but did not accelerate or climb above approximately 200 feet above ground level. The pilot made a brief radio transmission and turned left to initiate a race track circuit to return to Runway 03. During the turn from downwind to base leg, the aircraft lost altitude. The pilot prepared for a forced landing and instructed passengers to brace. The aircraft landed in a marshy area with shallow water and tall reeds, with the landing gear retracted and flaps up. After coming to rest, water entered the passenger compartment, and the pilot initiated an evacuation onto the wings.
Aircraft and Modification
The aircraft was equipped with a Boundary Layer Research, Inc. Super Chieftain I gross weight increase kit installed in 1995, which included engine nacelle strakes and 88 vortex generator tabs. The modification increased the maximum approved gross take-off weight from 7,000 to 7,368 pounds and revised center of gravity limits. At take-off, the calculated gross weight was 6,978 pounds with a center of gravity between 133 and 134.2 inches aft of datum. The aircraft's approved flight manual specified take-off power settings of 2,575 rpm and approximately 43 inches of manifold pressure at sea level standard temperature. The operator was using an unapproved quick reference handbook that listed a take-off power setting of 37 to 42 inches manifold pressure. The aircraft was not equipped with flight data or cockpit voice recorders, nor were they required.
Pilot Information
The pilot held a commercial pilot licence endorsed for single- and multi-engine land and sea aeroplanes, with a valid medical certificate through December 2007. The last pilot proficiency check was completed on June 1, 2007, valid to July 2009.
Weather Conditions
At 1800 central daylight time, observed weather at Winnipeg, Manitoba (110 nautical miles south of Matheson Island) reported wind 320° true at 12 knots gusting to 18 knots, visibility 15 statute miles, with a few towering cumulus clouds at 5,100 feet. At Berens River (38 nautical miles north), wind was north-northeast at 4 knots, temperature 18°C. Winds at Matheson Island were estimated as northwest at 10 knots gusting to 18 knots.
Injuries and Evacuation
Several Wamair Service & Outfitting Inc. staff members responded with vehicles and boats to transport the occupants to the nearest road, about 0.3 nautical miles from the aircraft. The passengers were taken by ambulance for medical attention. One passenger suffered serious injuries. The pilot and three passengers sustained minor injuries. Three passengers were not injured. Most passengers, including one who did not use a seat belt, were mobile and left the aircraft unassisted.
Post-Accident Examination
The aircraft was recovered and examined by Transportation Safety Board investigators. No structural or control anomalies were noted. The right engine could not be run due to internal corrosion from submersion. Fuel tanks contained sufficient fuel, and no anomalies were found in the fuel delivery system aside from damage during the forced landing. The engine's spark plugs were black and sooty. The turbocharger system's differential pressure controller was found to have a poppet valve that turned easily on its shaft, indicating insecure adjustment.