An instructor and a young trainee pilot were killed when the light aircraft they were flying crashed in a wood.
Damien Deegan and Niall Doherty died when the Cessna 150H came down a few miles short of the airfield near Birr, Co Offaly as darkness fell.
Mr Deegan, from the nearby village of Crinkle, was in his 20s and a trainee pilot. It is understood he was well advanced in his training with a high number of hours under his belt. Mr Doherty, in his 30s, from Roscrea, Co Tipperary, was his instructor.
A Garda Air Support and emergency services search was launched after their plane lost contact with Air Traffic Control at around 4.50pm on Sunday. The wreckage was discovered later in the evening in woodland less than two miles from Birr Airfield, from where the men had set off.
Mr Deegan and Mr Doherty were members of the local Ormand Flying Club, based in Birr. The club paid tribute to the men in a statement online.
"A very sad day for the Ormand Flying Club having lost two of our friends," it said. "Our thoughts and prayers are with both families tonight."
It is understood the plane took off from Birr Airfield and was headed south when it began to experience difficulties - the cause of which is still unknown.
The Irish Aviation Authority confirmed the plane lost contact with Air Traffic Control in Shannon. "The aircraft dropped off screen and the controllers alerted the emergency services and Gardai," said a spokesman.
The Air Accident Investigation Unit (AAIU) of the Department of Transport was then notified.
Garda Air Support and emergency services launched a search at around 6.30pm and discovered the plane in the Clonkelly Upper area - a woodland area not far from Birr Airfield. The AAIU and gardai are now investigating the circumstances of the accident. The scene of the wreckage has been preserved as the authorities carry out their investigations.