An investigation into the loss of Coastguard helicopter Rescue 116 and its four crew members in March 2017 is still ongoing.
The Air Accident Investigation Unit (AAIU) says a final report will not be publicly available within 12 months of the date of the accident.
But it adds that an interim statement, detailing the progress of the investigation and any safety issues raised, will be made.
"The investigation is endeavouring to issue this interim statement before the anniversary," the AAIU says.
"However, it is not possible to say at this time when the interim statement will be published."
Captain Dara Fitzpatrick was the first confirmed casualty of the crash of helicopter Rescue 116 off the Mayo coast | Image: Irish Coast Guard/RollingNews.ie
Captain Mark Duffy was member of the crash of helicopter Rescue 116 | Image: Irish Coast Guard/RollingNews.ie
Paul Ormsby | Image: Irish Coast Guard/RollingNews.ie
Ciaran Smith | Image: Irish Coast Guard/RollingNews.ie
Captain Dara Fitzpatrick, Captain Mark Duffy, crewmen Paul Ormsby and Ciaran Smith all died in the incident at Blackrock in Co Mayo.
No trace has been found of Mr Ormsby or Mr Smith.
A preliminary report into the fatal crash back in April 2017 found the aircraft's on-board warning system did not include data relating to Blackrock Island.