What happened
A S-76A was conducting a positioning flight with two pilots and two medical personnel on board. The flight departed from an airport at 1,38 and81 feet MSL under night instrument meteorological conditions, with visibility less than 1/4 mile.
After the helicopter reached an altitude of 1,600 feet, it entered a descending left turn. The aircraft eventually struck the side of a hill at an elevation of approximately 1,000 feet, resulting in 4 fatalities.
Flight data from the cockpit voice recorder (CVR) indicated that the pilot called out the descending turn to the co-pilot, who was the flying pilot, but the co-pilot did not acknowledge the call. The pilot also failed to take control of the aircraft from the co-pilot and did not respond to the co-pilot's inquiry regarding a potential gyro failure or the co-pilot's question about whether the pilot would assume control.
The investigation
The investigation found no evidence of any pre-existing mechanical failure or malfunction within the helicopter. Records indicated that while both pilots had failed upgrades during the previous year, they had both successfully completed their 6-month IFR checks without noted issues. Additionally, the company operations manual specified a minimum visibility of 1/4 mile for instrument departures.