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The Transportation Safety Board of Canada (TSB) has released its investigation report (A12P0134) into the August 13, 2012 engine power loss and ditching of a Sikorsky S-76 helicopter in the water off Langara Island, B.C.
The Sikorsky S-76 operated by Helijet International was flying to a fishing lodge on Langara Island from Massett Airport, B.C., with one pilot and one passenger aboard. Shortly before landing, the number 2 engine lost power. As the helicopter could not land safely on the fishing lodge’s floating helipad, the pilot elected to ditch the helicopter in the water using the emergency flotation system. After a successful ditching, the pilot and passenger escaped the helicopter without injury. The helicopter rolled inverted into the water 4 minutes later.
The investigation found that a metal fatigue crack in the engine casing caused the engine to fail in flight. This crack was not detected by the engine manufacturer’s recommended inspection procedures. Additionally, a seam joint on one of the flotation cells was found to be degraded and when subjected to the ditching forces, it failed, causing the cell to deflate; this caused the helicopter to roll inverted after ditching.
Following the occurrence, Rolls-Royce, the engine manufacturer, amended its inspection procedures for this type of engine, and released a newer, stronger design for the engine casing. Helijet International initiated more frequent and enhanced engine inspections and replaced all emergency floats that were more than 14 years old.
