What happened
At approximately 1100 MST, an Aerospatiale AS 350BA helicopter departed from Kimberley, British Columbia, bound for an alpine hut in the Purcell Mountains. The flight, intended for visual flight rules operations, carried the pilot, four passengers, and a dog. The mission involved transporting groups for avalanche training.
After the aircraft failed to return to Kimberley as scheduled, a search operation was launched at 1600. The wreckage was located near Boulder Pass, approximately 10 miles west of Kimberley, at an elevation of 7,900 feet. The impact occurred 60 feet below the summit of an obstructing peak. All five occupants sustained fatal injuries upon impact, and the aircraft suffered substantial damage.
The investigation
Investigators examined the wreckage and the Turbomeca Arriel 1B engine. Analysis of the engine's muffcoupling nut and the torsional deformation of the drive train confirmed that the engine was producing power and driving the rotor systems at the moment of impact. No mechanical failures or technical malfunctions were identified in the airframe, flight controls, or engine components prior to the crash.
Calculations regarding the aircraft's weight and balance indicated that the gross weight and center of gravity were within allowable limits. Evidence from a slash in the snow near the wreckage showed the helicopter was in a 40-degree nose-down attitude at the time of impact. The impact speed was estimated between 50 and 70 knots.
Findings
- The pilot was properly certified and qualified for the flight.
- The aircraft's weight and balance were within normal operational limits.
- There was no evidence of any mechanical or system failure prior to the accident.
- Adverse weather conditions, including heavy snow showers and strong winds, were reported in the vicinity, which may have created whiteout conditions and obscured terrain features.
- The pilot may have encountered visibility restrictions that hindered the ability to maintain visual contact with the ground, potentially leading to a loss of control.