A MAJOR search for three rescuers missing after an Irish Coast Guard helicopter crashed into the Atlantic is focusing on a three-hour window to find the aircraft amid fierce weather conditions.
Organisers hope a critically timed operation between low tides on Sunday will lead them to the Sikorsky S92 and the bodies of three men who have not been found since the helicopter disappeared without warning off Co Mayo early on Tuesday morning.
The search has been narrowed to a 100 metre by 80 metre section of the ocean around Blackrock lighthouse, around 13km offshore from Blacksod, where the aircraft was intended to land to refuel moments before it vanished.
The detection of a black box signal in that area has buoyed hopes that the bulk of the wreckage can be found along with the three remaining crew members.
Declan Geoghegan, of the Irish Coast Guard, said the likelihood is that the black box recorder is still attached to the helicopter and it was also more likely than not that the missing crew members are still inside.
"If you look at helicopter crashes, 92 or 93 per cent of the time the bodies are found within the wreckage of the fuselage, it is so small," he said.
"The other thing is that they are either strapped in or tethered – one or the other."
Captain Dara Fitzpatrick, (45), the only one of the crew to be recovered so far, was found critically ill in the water on Tuesday and later confirmed dead.
The highly-experienced and ground-breaking pilot, well known to Irish television audiences for her role in a fly-on-the-wall documentary about the Coast Guard, was the mother of a three-year-old son.
Her funeral will be held at Glencullen in south county Dublin on Saturday morning.
The other three crew, who have yet to be found, are chief pilot Mark Duffy from Dundalk, Co Louth, as well as Ciaran Smith and Paul Ormsby, both winchmen from north Co Dublin.
It is hoped if Sunday's tightly-managed operation to try and locate the helicopter is successful, then a "bigger window" will be available on Monday during which divers or remotely operated underwater vehicles will be deployed to the wreckage.
The Commissioner Of Irish Lights ship, the Granuaile, which is equipped with a heavy lifting crane, is being loaded with equipment at Galway as it makes its way to the scene.
Two naval ships, Garda RIB boats and trawlers, with local fishermen who have expert knowledge of the waters, will be used to mount Sunday's operation.
The underwater terrain, part of the lighthouse rock, and dangerous underwater currents in the area are adding to difficulties.
Coastal and sea surface searches are continuing over the weekend.
Significant sections of the helicopter were found close to Blackrock lighthouse on Thursday evening.
But air accident investigators say there is no evidence the aircraft struck the rock or the lighthouse.
A number of St Patrick's Day parades close to Blacksod in Co Mayo have been cancelled as a mark of respect.
The Dublin-based helicopter crew was providing cover for another Coast Guard helicopter involved in an early-morning evacuation of a crewman needing urgent medical attention on a UK-registered trawler, approximately 150 miles (240km) west of Eagle Island in Co Mayo.
It had flown directly to the scene from the Irish capital, travelled around 10 miles (16km) out to sea, then turned back towards land to refuel.
There was no indication of any danger moments before it vanished, with the crew's final transmission: "Shortly landing at Blacksod."
