Aer Lingus is to halve the working hours and pay of staff because of reductions in capacity and passenger travel due to the coronavirus.
In a bulletin to around 5,000 staff, the airline stated: "The sharp and swift global decline in demand for air travel is without precedent."
The airline says it is cutting capacity by 75% compared to the same time last year, and overall pay for all personnel will be reduced by 50%.
Management said the changes will be delivered as fairly as possible across every level of the organisation initially for the months of April and May and reassures staff that "they are intended to be emergency and temporary in nature".
However, the airline warned: "If the operating schedule reduces further, or if full grounding of operations is required, there will be a necessity for further measures."
It added: "The response we are communicating today has been designed to safeguard the financial position of the business, to enable us to operate our reduced schedule and the additional activities that arise in responding to the crisis.
"We know these are unsettling times and we want to provide staff with certainty on a level of pay and working hours."
The airline told employees, both rostered and non-rostered staff across all operational and support areas, that they will be placed on reduced working time while operating the reduced schedule.
The airline pledges to remain in dialogue with unions, saying there has been constructive engagement to date.
Fórsa trade union official Ashley Connolly said that given the impact of the public health crisis on the airline industry, the union was relieved that the airline had been able to keep everyone in a job.
"This is obviously devastating news for cabin crew and other Aer Lingus staff struggling to pay rent and mortgages. We will be advising them about their rights to social welfare payments and other protections," she said.
Meanwhile, the DAA, which manages Dublin and Cork airports, has ruled out pay increases and frozen recruitment as it scales back passenger operations due to the virus.
For the next month, 3,500 staff will be paid their rostered hours, but will take one week's mandatory leave and/or time off in lieu.
In a statement, the DAA confirmed that airline passenger traffic has fallen "dramatically" here and across the world due to the pandemic.
The organisation said future passenger operations will be determined by factors including Ireland's travel policies in relation to the pandemic, airline operations, and the travel policies of the airports' main overseas markets.
The DAA says passenger flights will continue to be facilitated for as long as they continue to operate. Intending passengers should continue to contact their airline in relation to their specific flight.
It said: "As a result of this, DAA intends to begin shortly to scale back its passenger operations at Dublin and Cork airports, while keeping its runways open to maintain Ireland's vital supply chain."
DAA Chief Executive Dalton Philips said: "We have a national responsibility to keep our airports open for Ireland's supply chain and to help ensure that essential flight operations for cargo can continue.
"However, passenger numbers at Dublin and Cork have decreased so rapidly in recent days that we have no choice but to begin to scale back passenger operations at both airports."
He said Dublin and Cork airports will continue to work with their airline partners to help get Irish citizens home to their families and allow passengers from overseas to do the same.
In relation to staffing issues, he said: "For the next month, staff will be paid their rostered hours but will take one week's mandatory leave and/or time in lieu. During this period, DAA intends to carry out essential maintenance, deep cleaning and the regulatory training that is mandatory for many of its employees."
There will be no pay increases in 2020 and all recruitment has also been frozen.
He also cautioned: "Additional measures may also be taken."
Mr Philips said the DAA was also examining options to establish a "volunteer Employee Task Force" that could help the State at this critical time by assisting the HSE, helping with local community efforts or other activities.
He praised the "fantastic" staff at Dublin and Cork airports, who he said had been supporting scared and anxious passengers while keeping airports open to maintain the flow of essential and emergency goods.