Finds Manufacturing Anomalies Led To Engine Power Loss Near Bella Coola, British Columbia

In its investigation report (A13P0163) released Wednesday, the Transportation Safety Board of Canada (TSB) found that a Kamov Ka-32 helicopter operated by VIH Helicopters Ltd. suffered an engine power loss due to anomalies in engine components that were not detected by quality control during engine manufacture and assembly.

On 4 August 2013, a Kamov Ka-32 helicopter was carrying out forest fire suppression operations near Bella Coola, British Columbia using a water bucket on a long line. Just as the helicopter lifted a load of water out of a lake, there was a series of unusual sounds and the aircraft began to shake severely. The pilot not flying released the water bucket, and the pilot flying flew towards land for an emergency landing. The crew experienced difficulties controlling the aircraft on the way to the intended landing area. The helicopter touched down while drifting sideways to the right, and subsequently bounced and rolled onto its right side. The crew, who suffered minor injuries, shut down the engines and exited the helicopter without difficulties. There was no fire.

The investigation found that compressor turbine components failed due to manufacturing anomalies, causing the engine to lose power. Quality control during the manufacture and assembly of the engine's compressor turbine section did not identify the anomalies in the components, which were visible to the naked eye. If poor quality control is systemic, helicopters with these engines (Klimov TV3-117) are at risk of failure, which can have serious consequences for aircraft, crew, and passengers.

Following the occurrence, the Russian aviation regulator issued a revised airworthiness directive that increased maintenance requirements for engines installed in Kamov Ka-32 helicopters used for external load operations.

(Image included in final report)

FMI: www.tsb.gc.ca