Emergency services at Dublin Airport were placed on standby for two separate flights that landed within minutes of each other this afternoon.
An Aer Lingus flight EI-593 from Madrid was on approach to Dublin when the crew advised air traffic controllers that they an a technical issue.
The flight entered a holding pattern over the Irish Sea for a time before commencing its approach to Dublin.
The Airbus A320 jet landed safely at 12.12pm and was met by airport fire crews as a precaution.
There were 137 passengers and a crew of five on board.
The aircraft was escorted to the terminal by several emergency vehicles. The passengers disembarked normally while engineers were waiting to investigate the issue.
In the meantime, as airport emergency services were dealing with the Aer Lingus incident, the crew of another inbound flight issued a May Day distress call.
Norwegian flight DY-3606 from Copenhagen was about 15 minutes from Dublin when the crew confirmed they were declaring a medical emergency.
Airport fire and medical crews were redirected to stand by for the aircraft when it landed shortly after 12.20pm.
A Scandinavian Airlines flight from Olso to Dublin, which had been holding over the Irish Sea and waiting to land, later diverted to Shannon Airport.
That flight is due to return to Dublin after being refuelled at Shannon.