20-Nov-2023 Source: TSB
Today, the Transportation Safety Board of Canada (TSB) released its investigation report (A22P0023) into the fatal April 2022 helicopter accident involving a Hughes Helicopters, Inc. 369D near Port McNeill Aerodrome, British Columbia (BC).
On 06 April 2022, the occurrence helicopter was conducting slinging operations near Port McNeill Aerodrome, BC, with only the pilot on board. Shortly after releasing a bundle of cedar blocks, the aircraft experienced an engine failure. The pilot broadcasted a distress call and, within a few seconds, the helicopter collided with terrain. The pilot was fatally injured. The helicopter was substantially damaged.
The investigation determined that shrinkage voids developed near the inner circumference of the engine’s sixth stage compressor wheel during the manufacturing process and went undetected using the existing inspection methods. The affected compressor wheel eventually failed when two separate fractures, one due to fatigue caused by shrinkage voids and the other due to overstress, occurred. This resulted in a catastrophic engine failure, and the subsequent impact with the ground.
The investigation also found that the engine failure occurred shortly after the helicopter had released a load of cedar blocks from a 180-foot longline. Therefore, the helicopter likely had insufficient height and forward speed to conduct a successful autorotation. As a result, the helicopter impacted the terrain with significant vertical speed, causing substantial damage to the helicopter. If single-engine helicopters routinely operate with unsafe height and airspeed combinations, the likelihood of a successful landing after an engine failure is significantly reduced.
Following this occurrence, the engine manufacturer re-issued a Commercial Service Letter, which includes a recommendation that its customers convert the compressor to the new wheel design during the next overhaul.
See the investigation page for more information.