What happened
On the evening of 12 December 1996, a Sikorsky S-76B helicopter, registration G-HAUG, crashed into the north face of the Carlingford Mountains near Omeath, County Louth. The aircraft was operating a flight from Aldergrove Airport to Ballyedmond, Northern Ireland, under Special Visual Flight Rules (SVFR).
During the descent, the crew was navigating using a GPS-based approach procedure. While performing checks and adjusting the aircraft's heading, the helicopter struck the terrain at an elevation of 960 feet. The impact resulted in three fatalities, as all three occupants—the pilot flying, the non-flying pilot, and a passenger—were killed.
The investigation
The investigation, conducted by the AAIU with assistance from the UK AAIB, examined the flight path, the aircraft's navigational systems, and the crew's actions. Investigators analyzed the Cockpit Voice Recorder (CVR) and the RNAV-2 computer memory to reconstruct the final moments of the flight.
Key areas of focus included the crew's reliance on the non-flying pilot for navigation, the use of the Horizontal Situation Indicator (HSI) in map mode, and the aircraft's configuration during the descent. The investigation also reviewed the meteorological conditions, which included low visibility and cloud cover, and the pilots' experience levels and flight planning.