Renewed attempts are to be made on Friday to search the main fuselage of the Coast Guard Rescue 116 helicopter which has been located in 40m of water off Blackrock island in north Mayo.
The Naval Service diving team is hoping sea conditions will have eased by early Friday morning to allow pairs of divers to inspect the wreckage of the Sikorsky S-92 and confirm if the bodies of three missing airmen are within it.
The helicopter fuselage was located on Wednesday morning by an underwater remotely operated vehicle (ROV) deployed from the Irish Lights ship Granuaile.
Relatives of senior pilot Capt Dara Fitzpatrick and her three missing air crew – Capt Mark Duffy, winch crew Paul Ormsby and Ciarán Smith – were on board the Naval Service patrol ship LE Eithne when they were informed that the wreckage had been identified.
The ROV had to be withdrawn from sea shortly afterwards and lifted back on board the Granuaile at about midday, due to the conditions created by strong north to northeasterly winds.
The winds are not forecast to ease significantly until late Thursday or early Friday.
The relatives of the air crew had boarded the ship at Blacksod early yesterday morning and had been taken to Blackrock island 13km west to visit the last known position of the helicopter.
It was the first time they had been able to visit the site close to where the helicopter lost communication in the early hours of March 14th while approaching Blacksod for a routine refuel.
The Coast Guard Dublin-based search-and-rescue helicopter had been tasked to support its Sligo-based counterpart on the night of March 13th on a medical evacuation 241km west off the Mayo coast.
The identification of the main fuselage has been described as "hugely significant" by Garda Supt Tony Healy of Belmullet Garda station and Coast Guard incident manager Niall Ferns.
Air Accident Investigation Unit (AAIU) chief inspector Jurgen Whyte said it was "hugely positive" and he was "hopeful" the bodies of the airmen could also be found.
“We could hear the beacon, we were homing in on the beacon, and . . . We located the main part of the wreckage, which is the helicopter itself,” Mr Whyte said.
“It is just a matter of getting the weather window to the get the ROV down to work its way through the wreckage,” Mr Whyte said.
The next stage would be “a matter for the ROV operators and Navy and Garda divers, but obviously we will treat this with great respect, and if we can access into the aircraft then hopefully we will be successful in recovering the three missing crew members,” he added.
Mr Whyte said the priority was locating the three men, and only then would the focus shift to the flight recorder and fuselage.
The AAIU confirmed earlier this week that the tail section of the helicopter made “some contact” with the western slopes of Blackrock, but no direct impact with the lighthouse had been found. Its investigators hope retrieval of the black box will yield vital information about the final moments of the aircraft.
No mayday was issued, and no transponders or personal locator beacons worn by the crew were detected when the helicopter crashed.
Lighter easterly winds by Friday will flatten the swell around Blackrock island, and the first dive may be made during slack water at low tide.
However, the Coast Guard has stressed that safety is paramount, and the Naval Service diving team will have to assess conditions in an area of sea surges and strong tides.
The LE Samuel Beckett took over from the LE Eithne as on-scene co-ordinator on Wednesday night.