Their light aircraft crashed on the Blackstairs mountains on the Carlow-Wexford border.
A hill walker found the wreckage and contacted police. There were no survivors.
The men had taken off from Ballyboy Airfield near Athboy on Sunday morning, heading towards County Wexford.
Police and air investigators are coordinating the search from the nearby village of Kiltealy
JULIAN BRAY ++44(0)1733 345581, Journalist, Broadcaster, Aviation Security & Operations Expert, Travel / Cruise Industry, EQUITY, NUJ, Broadcast COOBE ISDN ++44 (0)1733 345020 (DUAL CODEC) SKYPE: JULIAN.BRAY.UK e&oe Cell: 07944 217476 or iPhone 0743 530 3145 #VENDOR 10476453 http://feeds.feedburner.com/BraysDuckhouseBlog