Air Corps training operations at Casement Aerodrome, outside Dublin, were cancelled yesterday after what appears to have been industrial action by fire crew.
The Defence Forces press office yesterday confirmed that members of the fire crew who were to have been on duty yesterday did not turn up for work.
It is understood six of the seven-strong crew gave notification of being sick.
As a result, all fixed-wing aircraft training flights were cancelled. However, the action did not prevent the Government jet from taking off from Baldonnel in the morning. Helicopters were also unaffected.
The sick call-in, is understood to have resulted from a dispute over rostering.
Air Corps sources said there had been a change in arrangements in the operation of rosters for the fire crews in recent weeks. There are 27 fire crew members, rostered in teams of seven each day. They have complained that on the days when they are on "stand-by duty", where they previously went home, they have been ordered to stay at the aerodrome. The sources say there has been a shortage of fire crew staff in recent years.
A Defence Forces spokesman yesterday confirmed the action had taken place. He said a full crew was expected on duty today.
The senior press officer, Cmdt Eoghan O Neachtain, said: "There was a rostering problem but this problem has not interfered with the operation of the Government jet. We understand a full fire crew service will resume tomorrow."