What happened
During a routine return to the Cline River heliport in Alberta, a Bell 206B Jet Ranger, registration C-GFQZ, experienced a sudden loss of engine power. While on final approach at approximately 1420 mountain daylight time, the Rolls-Royce/Allison 250-C20B engine decelerated and subsequently flamed out.
As the engine failed, the pilot initiated an autorotation and executed a 90-degree turn to avoid steep, high terrain. The helicopter descended into Abraham Lake, striking the water approximately 20 feet from the shore. The impact caused the aircraft to roll onto its right side and sink in roughly eight feet of water. While the pilot and one passenger evacuated the wreckage immediately, the second passenger required assistance to escape as the cabin became submerged. All three occupants sustained minor injuries, and while the aircraft suffered substantial damage, no fire occurred.
The investigation
The TSB examined the wreckage after it was recovered from the lake two days later. Investigators analyzed the engine components, including the fuel control unit and various valves, and reviewed the operator's maintenance history. The investigation also looked into the maintenance practices of Kananaskis Mountain Helicopters Ltd. and the parts procurement process at Eagle Copters Maintenance Ltd.
Findings
- The engine lost power and flamed out for undetermined reasons.
- The pilot's approach over the water, necessitated by wind conditions and terrain avoidance, placed the aircraft in an adverse environment for a forced landing.
- Maintenance deficiencies were identified, including the installation of an incorrect power turbine governor (PTG) and the absence of proper engine technical records.
- Small amounts of unidentified solid contamination were discovered within several engine fuel system components.
- Several mechanical anomalies were noted, such as a leaking compressor discharge pressure tube and a cracked fuel line flare, though these were not proven to be the direct cause of the flame-out.