Meanwhile, the painstaking search is continuing for the missing crew who are presumed dead following the crash in the early hours of Tuesday, March 14.
R116, a Sikorsky S-92, was providing top cover to another Irish Coast Guard helicopter carrying out a medical evacuation on a fishing boat.
Captain Dara Fitzpatrick, a 45-year-old mother of one, is the only member of the crew whose body has been recovered from the sea.
Co-pilot Mark Duffy, winchman Ciaran Smith and winch operator Paul Ormsby remain to be found.
The black box (flight recorder), which is believed to be in good condition, was recovered by Naval Service divers in 40m of water at 4.30pm yesterday on the eastern side of Black Rock island in Blacksod Bay.
It was found in the submerged helicopter. It is understood that a large part of the helicopter is intact, although damaged. There was no confirmation last night that any bodies had been discovered in the helicopter.
The navy divers handed over the black box to Air Accident Investigation Unit inspector Paul Farrell, who is on the Irish Lights ship Granuaile.
Chief inspector Jurgen Whyte said the black box will be taken under escort to Baldonnel Aerodrome from where it will be flown today to the Air Accidents Investigation Branch in Britain where information from it will be download.
Ten Naval Service divers, working in teams of two, carried out eight dives around the crash site yesterday before light faded and they were forced to quit operations at around 7.30pm.
The divers concentrated their efforts in and around the immediate area where R611 was located.
While the weather conditions appeared calm on the surface it was reported that the divers were having to cope with underwater groundswell which made diving conditions difficult, but still workable.
After they had finished diving, a remotely operated vehicle, equipped with high-definition cameras, continued to search the seabed during the hours of darkness.
A dive platform has been set up above the crash site - about 60m to the east of Blackrock island.
The Granuaile is positioned next to the dive platform and carrying a recompression chamber in case of emergencies.
The Holland 1 remotely operated vehicle is being operated from the Granuaile by experts from the Marine Institute.
Derek Flanagan, Coast Guard divisional controller based at Malin Head, said communications between the divers and from them to the surface were key for a methodical search of the wreckage.
“You are talking about a 40m dive and about nine minutes bottom time,” said Mr Flanagan.
“We have such a small amount of time down there that every minute is crucial so we don’t waste time when we get down there and get the job done and find these people.”
The investigation unit has said it believes the tail of Rescue 116 hit rocks on the western end of Blackrock island, about 13km off the Mayo coast, as it returned to refuel at Blacksod after supporting the medical evacuation from the fishing boat.
There was no indication of anything unusual it vanished, with the crew’s final transmission simply saying: “Shortly landing at Blacksod.”
Weather conditions are expected to be good for the weekend and the Naval Service said its divers will enter the water again this morning.
’We care about the bodies, not the black box’
“We are standing shoulder to shoulder and for us, it’s not about the black box, it’s about the bodies,”says local man John Gallagher in Blacksod, Co Mayo.
For almost two weeks, fishermen and locals from every townland on the Mullet peninsula have rallied together to support the search team looking for the wreckage of Irish Coast Guard helicopter R116. Their operation has now got so big they have moved it from the Ionad Deirbhile to the bigger Halla Naomh Bhreandáin.
What had started out as offerings of tea and coffee, some soup and sandwiches, has now turned into a full Irish breakfast at 8am and beef and lamb curries and stews at 1pm.
“We’re doing between 200 and 250 meals a day”, says Mr Gallagher, who is chairman of Comharchumann (co-op) Forbartha Ionad Deirbhile, in Eachléim, a Gaeltacht village close to Blacksod pier.
“In the beginning, a lot of businesses supplied the food, now clubs such as the Lions Club and the bridge club are providing us with funds and we buy food and get it cooked.
“There is a roster of the local women, about 30 of them.
“Colaiste Uisce [an Irish college and adventure centre in Belmullet], has also been helping us out in terms of cooking.”
While it’s mostly Irish Coast Guard and Civil Defence workers, local volunteers and fishermen that come in for their meals, some of the families of the three missing crew members, Mark Duffy, Ciarán Smith, and Paul Ormsby, come in to eat too.
“‘Hopeful’ is one word I would use to describe them,” says Mr Gallagher, who adds that this is all he will say on the matter so as to respect the privacy of the bereaved.
While he explains about the volunteer operation in the hall, divers are down off Blackrock lighthouse, known locally as “the rock” examining the wreckage of the downed helicopter.
Shortly after 5pm yesterday, news broke that the black box of the craft had been recovered.
“Volunteers are staying here until the job is complete,” he says. “It’s not about the black box for us, the missing bodies are what we care about, the missing people is what we care about,” he said.
People from all over Ireland, it seems, care too.
“An Indian takeaway drove 70 miles to deliver food. Strangers from places such as Wexford have posted us cheques, and a grievance counsellor came here to physically offer help,” says Mr Gallagher.
He describes it as the biggest initiative by the local people he has seen in his lifetime there, but despite that fact, he is not surprised by the level of mobilisation. “I’m not a bit surprised, no,” says Mr Gallagher. “We are a small community surrounded by sea on a tip of a peninsula with one road in and one road out.
“It’s one of the most deprived rural communities in Ireland. We have ourselves and we depend on ourselves.”