Ryanair and Aer Lingus owner International Consolidated Airlines Group (IAG) are among the best-placed carriers to see out the Covid-19 crisis, analysts say.
Airlines globally could lose €230 billion in revenues this year as passenger flights are grounded amid efforts to halt the spread of coronavirus in Europe and the US, according to some estimates.
Stephen Furlong and Ross Harvey, analysts with Irish stockbrokers Davy, say in a note published on Wednesday that Ryanair and IAG, which owns Aer Lingus and British Airways, "look to be the most secure" among Europe's airlines.
Both Irish carriers are winding down passenger flights and expect to remain grounded over the next two months as tough travel restrictions remain in place.
Mr Furlong and Mr Harvey point out that if no aircraft fly for the next year, Ryanair has 18 months of available cash while IAG has 16 months.
Easyjet, Ryanair's main rival, has 10 months while another low-cost carrier, Wizz, has eight.
"We believe that these airlines are well positioned to withstand an impact to European traffic, similar to that of China, which has begun to see bookings stabilise in the third month after the outbreak," the analysts say.
Ryanair has €4 billion in cash while IAG has €7 billion. Mr Furlong explained on Wednesday that Ryanair has 327 aircraft that it owns outright and thus can borrow against if needed. IAG has 65.
At the other end of the scale, Air France-KLM and Germany's Lufthansa have three to six months in cash before they have to start borrowing against aircraft.
Norwegian Air Shuttle, which had been in financial trouble before Covid-19 struck, has one to two months before it has to draw down the final 90 per cent of its state-guaranteed loans. Norway has guaranteed loans of 3 billion kroner (€255 million) to the airline.
The analysts suggest that pent-up demand and low fuel prices could revive European aviation quickly.
However, they say that cutting fares to lure travellers back and other challenges indicate that recovery could take time.
In the longer term, they argue that the industry is likely to consolidate and grow in line with the economy, rather than ahead of it, as airlines have been doing.
This could lead to less demand for aircraft, putting those airlines that are left in a stronger bargaining position with manufacturers such as Airbus and Boeing. "Only time will tell," say Mr Furlong and Mr Harvey.
Industry body, the International Air Travel Association, says airlines could need $200 billion (€185 billion) in government aid to see them through the coronavirus crisis.