The Irish Aviation Society says it is investigating an incident during which a Ryanair pilot suffered a breakdown while trying land a plane in near Rome.
The co-pilot had to take over the controls of the Boeing 737 during the incident last year.
It later emerged that the pilot had recently buried one of his children.
The Authority said it has received Ryanair's full report on the incident and it will make the findings of its own investigation known to Ryanair and to the aviation industry.
In a statement, the Department of Transport confirmed that the Air Accident Investigation Unit have initiated a separate investigation into the incident.
The incident, which occurred in Italian airspace in September 2005, was not notified to the Italian Aviation Authorities.
The Italian Air Accident Investigation Unit will decide on Monday if they will lead the investigation in which case the Irish Air Accident Investigation Unit will assist them under International Convention.
The Air Accident Investigation Unit have informed Ryanair of its intention to assist the Italian Investigation Authorities or to carry out the investigation if delegated to do so by the Italian Authorities.
Ryanair responded by saying the Irish Aviation Authority were informed.
'A detailed internal investigation was undertaken and the findings and recommendations that were implemented, were seen and approved by the IAA,' according to Ryanair.
They said they would be happy to assist the Italian and or the Irish Authorities with any investigation.
