What happened
While conducting an IFR charter flight from Lourdes-de-Blanc-Sablon, Quebec, to Mont-Joli Airport, a Piper Navajo experienced a power loss in its left engine. The incident occurred at 6,000 feet above sea level, approximately 50 nautical miles west of Port-Meunier, Quebec. Upon noticing the loss of power, the pilot applied full throttle to both engines and continued along the planned route, though the aircraft began descending at a rate of 400 to 500 feet per minute.
Two minutes later, as the aircraft descended to 4,800 feet, the pilot diverted toward Sept-Îles Airport. Approximately 25 nautical miles south of the destination, the pilot declared an emergency and announced an intention to ditch in the St. Lawrence River. The pilot did not feather the left engine propeller until the aircraft reached 1,000 feet. Following the ditching, all seven occupants successfully evacuated through the aft door before the aircraft sank in 85 and 850 feet of water. The crew and passengers, who were not wearing life jackets, were rescued by a civilian helicopter after treading water for approximately forty minutes.
The investigation
Investigators examined the aircraft's maintenance history and found the left engine had been installed only one week prior, having flown for 12 hours. While the engine was equipped with a turbocharger, the pilot interpreted a drop in intake pressure as a partial failure rather than a total loss of power. Because the pilot believed sufficient power remained, he bypassed the standard emergency procedures, which include feathering the propeller to reduce drag.
Radar analysis revealed that if the propeller had been feathered immediately following the power loss, the aircraft could have maintained enough altitude to reach Sept-Îles. The investigation also noted that the aircraft was not required to carry life jackets under existing regulations for its specific flight parameters, though the operator has since equipped all aircraft with them.
Findings
- The specific cause of the left engine power loss remains undetermined because the wreckage was not recovered.
- The pilot's failure to feather the propeller immediately significantly increased drag, preventing the aircraft from maintaining altitude.
- The pilot's decision-making was impacted by the stress of the emergency, leading him to focus on limited information and conclude that the engine was still producing sufficient power to reach the diversion airport.
- The aircraft was operating at maximum allowable weight at the time of takeoff.