A woman crew member from the Irish Coast Guard helicopter missing off the west of Ireland, who was pulled from the Atlantic, has died as a search continues for three others on board.
Captain Dara Fitzpatrick was 45 and had been with the search and rescue service for more than 20 years.
A search is continuing for the other three crew from the Dublin-based aircraft, which was providing cover for another helicopter involved in an early morning rescue operation. But hopes are fading for their survival.
Contact was lost with the crew at around 1am. An intense sea search was launched off the Co Mayo coast - around six miles west of Blacksod.
Capt Fitzpatrick was located and plucked from the water at around 7am and taken to hospital, but later died.
Mark Abbey, regional director for CHC, the company which operates the helicopters for the Coast Guard, said: "It is with deepest regret that we can confirm that Captain Dara Fitzpatrick passed away following today's accident off the coast of County Mayo in the early hours of this morning.
"We are devastated by this morning's tragic accident. Our thoughts are with Dara's family and friends, as well as those of the three crew who are still missing. The extensive search and rescue mission is ongoing."
Hopes are fading for the survival of the other three crew members, who have yet to be found, acting head of Coast Guard Eugene Clonan said.
An intense search is continuing around six miles (10km) west of Blacksod, Co Mayo, where the Dublin-based Sikorsky S92 disappeared after providing cover for another helicopter involved in an early-morning rescue operation.
The aircraft lost contact at around 12.45am on Tuesday just before it was about to land to refuel, giving no indication of anything wrong.
Capt Fitzpatrick was one of two female Coast Guard pilots who made Irish aviation history three years ago by flying the first all-woman mission for the service.
The pair flew a cardiac patient from west Co Cork to Cork University Hospital before transferring a critically-ill five-year-old child from the hospital to Temple Street Children's Hospital in Dublin.
Rescue 116 was providing topcover for rescue 115 on a medivac off the coast of Erris when contact was lost . pic.twitter.com/gmY3ybbKgG— Fergus Sweeney (@FergusMaSuibhne) March 14, 2017
Coast Guard helicopters from Sligo and Shannon along with the Air Corps maritime patrol aircraft Casa were involved in the search.
They were joined by lifeboats from Ballyglass and Achill, and five local fishing vessels.
A Coast Guard spokesman said the missing helicopter had been providing cover in the evacuation of a crewman who needed urgent medical attention, from a UK-registered fishing vessel approximately 150 miles west of Eagle Island in Co Mayo.
"Owing to the distance involved, safety and communication support, known as Top Cover, was provided by the second Coast Guard helicopter, the Dublin based R116," he said.
"The search operation is being coordinated by the Coast Guard Rescue Coordination Centre in Malin Head.
"Both helicopters refuelled at Blacksod prior to transiting to the scene."
The search was launched off the coast of Co Mayo
Greg Dewhurst, senior forecaster with the Met Office, said there were no unusual weather patterns overnight in the Atlantic between the west coast of Ireland and the reported location of the fishing vessel.
He said: "There were no frontal systems bringing heavy rain. Generally it looks like there were some light south-westerly winds.
"There was quite a bit of cloud around but there were no stormy conditions."