A final report on the fatal 2017 crash of an Irish Coast Guard S-92 search-and-rescue helicopter has highlighted prior concerns over obstacles not appearing in terrain-avoidance databases. 

As far back as 2013, CHC Ireland (CHCI), which operates the S-92 on behalf of the Irish Coast Guard, was made aware that lighthouses on islands like the one struck by Rescue 116 in March 2017 were not included in the onboard navigational software, according to a final report on the incident by the Air Accident Investigation Unit Ireland.

Four people were on board Rescue 116 when it crashed in the early hours of March 14, 2017: pilot Capt. Dara Fitzpatrick, co-pilot Capt. Mark Duffy, and winch operators Paul Ormsby and Ciaran Smith. 

The aircraft, a Sikorsky S-92A, had been en route from Dublin, on Ireland’s east coast, to Blacksod, County Mayo, on Ireland’s west coast, where the crew intended to refuel before assisting another helicopter to rescue an injured fisherman 140 nautical miles offshore. 

Just nine nautical miles from its destination in Blacksod, and flying at 200 feet above the sea, the aircraft struck Black Rock island, which rose 282 feet above the waters.

The aircraft lost control and plunged into the sea, killing all four crewmembers, according to the official report, published Nov. 5.

The 350-page report delves deeply into the causes of the accident, including CHC’s safety culture, the accuracy of automated route planners and maps and whether the pilots and crew were familiar enough with the terrain where they were flying, at night, over water.

The report includes a probable cause, 12 contributory causes and 42 safety recommendations for both CHC and the IAA for operating SAR aircraft. It does not assign blame or liability for the accident.

Nineteen of the 42 safety recommendations made at the conclusion of the report are addressed to CHC Ireland. A further 15 recommendations are made to the Minister for Transport.

They range from reviewing CHCI’s safety culture, staffing levels, training and overall organization structure to revisiting what agencies are responsible for oversight of SAR operations in Ireland. The report found that employees often were discouraged from reporting safety issues or preferred to file them informally rather than through a structured safety reporting process.

Detailed in the AAIU report are email chains that highlighted the danger posed by lighthouses and other obstacles near helipad approaches at the several coastal bases used by the Irish Coast Guard.

In June 2013, a CHC pilot emailed several of their colleagues a warning that while flying the preplanned route taken by R116 at the time of the crash (called APBSS), Black Rock lighthouse did not appear in the onboard terrain-avoidance system.

In that email, “the pilot stated that at ‘310’ feet high, the lighthouse was an ‘obvious hazard,’” the report stated.

Later the same month, on June 28, a pilot emailed the manufacturer of the enhanced ground proximity warning system (EGPWS) directly to inquire about updating the system and inform them that “a few islands and lighthouses locally do not appear on the database.” 

When asked for further details, the pilot responded and the system’s manufacturer opened an investigation into the issue, which was closed without action in 2015. 

CHC told investigators that the issue with Black Rock should have been reported to its internal safety management system and it did not receive “actionable information” on which obstacles should be added to the databases. 

The report also indicates the crew of R116 may have been overly dependent on the pre-planned route and the flight management system, believing that the APBSS route to Blacksod helipad would provide adequate lateral clearance if dutifully followed. 

“Both Flight Crew members reviewed the APBSS route separately, but neither identified the presence of Black Rock,” the report said. “It is probable that each pilot believed, as they flew to join it, that the design of the APBSS route would provide adequate terrain separation if the FMS was used to follow the route, and that obstacles need only be considered if going off the route.”

The S-92 cockpit environment may also have contributed to the mishap because “the combination of cockpit lighting and colored documents, the size of font used in some documents, the tabulation of a large amount of numerically dense information and the combined portrait/landscape presentation of some routes, including APBSS” was “suboptimal.” The pilots’ night vision may also have been hampered by the helicopter’s external lights, the investigation found. 

While the weather was not inclement and the pilot confirmed she could see the ocean surface during the approach at 200 feet (60 meters), the Irish west coast was unfamiliar to east coast SAR crews, the report said. There is less ambient light on the west coast and fewer visual navigational aids than they would have been used to seeing on approach. 

“The operating environment on the west coast would have been more challenging than east coast crews were familiar with, particularly regarding the availability of visual cues in the littoral environment,” the report said. 

During the descent to Blacksod, the commander asked the co-pilot to confirm with the EGPWS that the path ahead was free from obstacles. The co-pilot said that the approach was clear for 10 miles (16 kilometers), according to the report, which found that Black Rock was not in the EGPWS databases. 

The crew also was not able to see Black Rock on radar because it was obscured by a nearer waypoint marker, the report found. Before the flight, both pilots reviewed the pre-planned approach for the Blacksod helipad but neither found the Black Rock would be in their path. Backup paper charts for the approach area did not extend as far as Black Rock, according to the report. 

Only when it was 1,800 feet (600 meters) from the island did the helicopter’s forward-looking infrared (FLIR) sensor, operated by the winchman, pick up Black Rock. He twice advised the pilot to bank right before finally announcing over the intercom for her to “come right now, come right, COME RIGHT,” according to the report.  

“Shortly after this, the helicopter pitched up rapidly and rolled to the right,” the report said. At 12:46 a.m., just eight seconds after that final communication, the helicopter collided with the western end of Black Rock and spun out of control into the surrounding sea. The main wreckage of the Helicopter came to rest on the seabed to the east of Black Rock, at a depth of 120 feet (40 meters). 

All four crewmembers perished. Commander Fitzpatrick managed to exit the helicopter and inflate her lifejacket but was at least 30 feet (10 meters) underwater at the time. “Cold-water shock, darkness and overall sense of shock militated against her survival,” the report said. 

Co-pilot Duffy was found still belted into his seat in the cockpit wreckage. He was found to have suffered multiple injuries. Winch operators Paul Ormsby and Ciaran Smith were never recovered. They remain lost at sea.