Accident Overview
A Sikorsky S-76A helicopter was conducting a positioning flight with two pilots and two medical personnel on board. The flight departed under night instrument meteorological conditions with prevailing visibility of less than 1/4 mile. The departure airport elevation was 1,381 feet mean sea level.
Flight Sequence
After becoming airborne, as the helicopter passed through 1,600 feet, it entered a descending left turn. The descent and turn continued until the helicopter struck the side of a hill at an elevation of approximately 1,000 feet.
Cockpit Voice Recorder Findings
Review of the cockpit voice recorder revealed that the pilot called out the descending turn to the co-pilot, who was flying the helicopter at the time. The co-pilot did not acknowledge the pilot's call. Additionally, the pilot did not take control of the helicopter from the co-pilot. The co-pilot commented about a possible gyro failure and asked if the pilot was taking control, but the pilot did not acknowledge those remarks or answer the question.
Operational Context
No evidence of a pre-existing failure or malfunction was found with the helicopter. According to the company operations manual, the minimum visibility required for an instrument departure was 1/4 mile, which matched the reported conditions at the time of departure.
Pilot Background
Both pilots had failed upgrade checks in the preceding year. However, both had successfully passed their respective 6-month instrument flight rules proficiency checks with no problems noted.