Aer Lingus was forced to cancel a flight to Boston this afternoon due to the cabin crew dispute over new rosters.
It is not yet clear if further flights will be affected later today.
The airline has said around 30 cabin crew indicated they were not willing to co-operate with new rosters, which were introduced today.
Management and unions have been in dispute over implementation of new rosters linked to the Greenfield cost reduction programme.
Staff have engaged in a work-to-rule for the last 14 weeks.
Aer Lingus last week warned cabin crew that if they did not operate the new rosters, they would be removed from the payroll.
The company says the new rosters comply with the Greenfield programme, which cabin crew have already voted to accept.
However, the IMPACT trade union says the rosters exceed the terms of Greenfield and an arbitration, and will cause undue hardship to staff.
IMPACT has confirmed that some members of staff have been invited by management to attend individual 'informal' meetings related to this matter.
Union official Christina Carney said staff would attend the meetings accompanied by a union representative.
Earlier, Ms Carney said that her members were continuing to operate their agreed conditions of employment in line with their old rosters.
