What happened
On 14 March 2017, a Sikorsky S-92A helicopter, registration EI-ICR, was involved in an accident at Black Rock, Co. Mayo, Ireland. The aircraft was engaged in a Search and Rescue (SAR) operation at the time of the occurrence. While the full sequence of the flight dynamics is still under investigation, wreckage has been recovered from both the shoreline and the seabed.
The investigation
The AAIU has conducted extensive reviews of wreckage, interviews with numerous agencies, and analysis of various data sources. Investigators examined the Multi-Purpose Flight Recorder (MPFR), the Health and Usage Monitoring System (HUMS), and ground-based tracking data such as AIS and SkyTrac. A Digital Video Recorder (DVR) was recovered from the seabed and analyzed by the NTSB, though no video footage from the accident flight was found on the recovered media.
During the examination of the MPFR, investigators identified a technical issue where a formatting error caused the recorded latitude and longitude to be less accurate than the actual aircraft position. Additionally, the investigation has reviewed the operator's Safety Management System (SMS) and the regulatory oversight of SAR operations in Ireland.
Findings
- A software formatting error in the helicopter's data output caused the Flight Data Recorder to record a coarse position with significantly reduced accuracy, dropping from approximately 61 ft to 247 ft.
- The operator's Safety Management System (SMS) has raised concerns regarding its efficacy based on the review of safety and compliance records.
- The aircraft's HUMS provided more precise position data than the FDR, which allowed investigators to analytically reconstruct the flight path.
Safety action
- An interim safety recommendation has been issued to the manufacturer to update the Sikorsky S-92A software to ensure the FDR records the most accurate position information available.
- An interim safety recommendation has been made to the operator regarding the effectiveness of their Safety Management System.