Executive summary
The helicopter was departing for the first heliski trip of the day with a guide and four clients on board. It had reached a height of about 200 feet, and airspeed was increasing above 35 knots, when the engine failed. The pilot lowered collective, maintained forward speed and set up an autorotative descent to the large snow covered paddock below. The helicopter contacted the ground heavily, collapsing the skids, and slid some 60m in the soft snow before coming to rest upright. The occupants were uninjured. The helicopter had been parked in the open for some days prior to the accident and had accumulated a heavy covering of snow. Before flight the pilot had removed snow from the cabin roof and the vicinity of the engine intake and had checked the intake duct was clear. The possibility existed that a layer of snow had remained on the rotor head cover, which had been ingested during the departure, resulting in engine flame-out.
Related Recommendations
Operators of the AS 350B helicopter be advised of the circumstances of the accident involving ZK-HWW.
In addition to the precautions already outlined by Aerospatiale in Service Letters relating to "preparation for flight after parking in falling snow" it is recommended that before flight pilots ensure that the whole upper area of the AS 350B cabin and engine cowling assembly, including the rotor head cover, are cleared of all deposits of snow or ice which could constitute a hazard to engine operation if ingested.