The investigation into the fatal March 14 crash of an Irish Coast Guard Sikorsky S-92A, EI-ICR, continues after the helicopter crashed at Black Rock Island, about 17km off the coast of Mayo on Ireland’s west coast, in the very early hours of the morning killing all four crew members on board.
Operated by CHC Helicopter under contract to the Irish Coast Guard, the S-92A, call sign Rescue 116, was providing top cover for another Irish Coast Guard S-92A, Rescue 118, during a medical evacuation of an injured fisherman some 250km west of Blacksod.
At around 12.45am local time, Rescue 116 reportedly disappeared from air traffic control surveillance in the vicinity of Black Rock Island prompting an immediate search in the area for the helicopter and its crew.
The following afternoon, after signals transmitted from the S-92A’s Multi Purpose Flight Data Recorder (MPFDR) were received, investigators from Ireland’s Air Accident Investigation Unit (AAIU) were airlifted onto the island where they discovered sections of wreckage from Rescue 116.
It is believed the S-92A was flying over the island while en route to making an approach to Blacksod Bay, Mayo, on the mainland to refuel.
“Wreckage has been recovered from the general area of Blackrock Light House … primarily from the tail area of the helicopter,” the statement from the AAIU six days after the accident said.
“At this early stage in the investigation it is not possible to be definitive about the exact nature of damage to the recovered wreckage or indeed the circumstances of the accident. However, there appears to be marks on some of the recovered wreckage which are consistent with the tail of the aircraft contacting rocky surfaces on the western end of Blackrock. The investigation has not yet definitively identified the initial point of impact.”
A remotely-operated vehicle (ROV) sent down inspect a specific area of the seabed and confirmed the bulk of the helicopter’s fuselage was lying about 60m off Black Rock Island at a depth of approximately 40m.
On March 24, the S-92A’s MPFDR was successfully recovered from the wreckage with AAIU investigators saying they are confident data should be able to be extracted from the unit due to the good condition of the recorder.
The MPFDR was flown to the UK’s Air Accidents Investigation Branch (AAIB) at Farnborough for download and analysis.
It is understood there was no MAYDAY call before the accident with reports that the crew’s final transmission was “Shortly landing at Blacksod.”
In January, inspections were carried out on the Irish Coast Guard’s five S-92As after the global S-92 fleet were required to have their tail rotor pitch change shaft (TRPCS) assembly bearings inspected following an emergency airworthiness directive (AD) issued by the US Federal Aviation Administration (FAA) on January 13.
At the time, the FAA said its emergency AD was prompted by reports from three S-92A operators losing tail rotor control caused by a failed TRPCS assembly bearing.