About 80 per cent of the world's airlines could be bankrupt by July without support.
The impact of coronavirus on overseas travel may be worse than expected, with an international airline boss predicting things won't be normal until 2023.
New analysis from the International Air Transport Association (IATA) says it will take years until long-haul travel recovers to pre-pandemic levels.
"We have published today a new forecast about the potential recovery of the air traffic, and what we see is that things should come back to normal in 2023, which is later than our previous forecast," IATA chief executive Alexandre de Juniac told ABC News Breakfast this morning.
"That shows, you know, the importance and the severity of this crisis on air transport. We should join progressively the historical trends by the beginning of 2023.
"What we have planned is to restart the industry, first by reopening domestic markets, then regional continental markets, such as Asia-Pacific, or Europe, or North America.
"At the end of 2020, the traffic should be between 50 to 55 per cent of the same level that was in place in 2019.
"So, we would lose something like half the traffic for 2020."
The IATA's report found quarantine-on-arrival measures – like the two-week quarantine enforced in Australia – would continue to damage travel confidence.
Its survey of air travellers found 86 per cent were concerned about being quarantined while travelling and 69 per cent would reconsider travelling if it meant being locked down in quarantine for 14 days.
IATA urged governments to find alternatives, warning they must "not make that prognosis worse by making travel impracticable with quarantine measures".
It has suggested a layering of temporary measures until there was a vaccine or instant-results tests, such as temperature screening, preventing travel to symptomatic travellers, health declarations of asymptomatic travellers and vigorous contact tracing.
"[Quarantine] is a major deterrent," de Juniac told ABC.
"We are not sure that it is necessary to impose this type of measure, provided we have [a] multi-layer approach: various sanitary checks and health controls that would guarantee that the risk of contamination is absolutely minimal and low, and the risk of transferring the virus from one country to another is also under control and minimal."
The IATA's report also found the recovery of the air industry would be led by domestic travel and "globally agreed and implemented biosecurity standards" were critical if the industry was to recover.
De Juniac told the ABC the airline industry faced a revenue loss of $496 billion this year.
He said if it hadn't been for government support for airlines across the world, many would already be bankrupt.
"There is a risk that some airlines would go to bankruptcy," he said.
"So, we are relying on the support packages and the rescue plans that have been put together by governments and that have been announced by governments, with, I have to say, very supportive and open attitudes to help us. But without this plan, half of the airlines could be bankrupt in June, and 80 per cent could be bankrupt in July."