Rescue 116 family: 'We are devastated'
Review of helicopter after system failed to warn of rock
An internal review is being carried out by the company which supplied the Rescue 116 helicopter after investigators raised concerns over the aircraft's on-board system used to identify hazardous obstacles.
A preliminary report found the route guide for the Sikorsky S-92A helicopter did not have information displaying Black Rock, the 232ft-tall island which the aircraft hit before crashing into the sea 12km off the Co Mayo coast.
The interim investigation also raised concerns over the locator beacons worn by the four crew members, which did not emit any signals upon its crash.
The bodies of two of the crew - Captain Dara Fitzpatrick (45) and Captain Mark Duffy (51) have since been recovered.
Their two colleagues, winch operator Ciarán Smith (38) and winchman Paul Ormsby (53) are still missing.
The Irish Coast Guard issued an emotional statement a month on from losing four of its colleagues, saying: "We will not leave you. You are not alone. Help is on its way. Hold hope."
Niamh Fitzpatrick, the sister of pilot Dara, said: "As a family, we are devastated and distressed for all the families involved." She added the family did not wish to comment on the Air Accident Investigation Unit report. The families of the crew members were briefed on the report before it was released.