Tests are expected to be carried out today on items discovered in Mayo - to determine if they belong to the missing crew of Rescue 116.
A helmet and lifejacket washed up on a beach near Clogher on Saturday morning.
The Coastguard helicopter crashed in March with the death of all four crewmembers - however the bodies of Ciaran Smith and Paul Ormsby have never been found.
It is understood items including a helmet and lifejacket were found on Elly beach near Clogher on the Co Mayo coast early on Saturday morning.
Rescue 116 crashed on March 14 with four crew on board after it struck Blackrock Island, 12 miles off the coast of Co Mayo.
The bodies of winchmen Paul Ormsby and Ciaran Smith have not been recovered despite months of intensive seabed, surface and shore searches.
Also on board were Captain Dara Fitzpatrick and Captain Mark Duffy.
An inquiry is trying to determine how Rescue 116 went down.
Ireland's Air Accident Investigation Unit (AAIU) has established that the Sikorsky S-92's internal warning system did not include the 80m (262ft) high rocky outcrop and its working lighthouse in its database.