The coronavirus pandemic has dealt airlines an unprecedented blow -- to get back in business they will have to reinstill confidence in travellers and avoid a patchwork of restrictions, says the head of the industry's trade association.

As nations around the world snapped their borders shut and ordered people to stay at home to slow the spread of the virus, airline traffic was brought to a near-total halt.

Reassuring travellers about security measures will be key for air traffic to resume successfully Reassuring travellers about security measures will be key for air traffic to resume successfully Photo: AFP / NARINDER NANU

"We've never seen anything like this," said Alexandre de Juniac, head of the International Air Transport Association which represents some 290 airlines.

Airlines have parked between 80 and 90 percent of their aircraft, some 4.5 million flights have been cancelled and an estimated $314 billion in revenues will be lost this year.

"There is no precedent for a crisis of this level," he told AFP in an interview.

Airlines have parked most of their aircraft during the coronavirus crisis Airlines have parked most of their aircraft during the coronavirus crisis Photo: GETTY IMAGES NORTH AMERICA / Christian Petersen

But some airlines have announced plans to begin to increase flights in the coming weeks as restrictions are eased and nations open their borders.

"One of the keys to restarting travel is a robust process of checking passengers," said de Juniac, adding that this would reinstill confidence and help to convince governments to lift border closures.

Many flights have had empty seats as few people could or wanted to fly during the crisis, but airlines are resisting keeping seats empty as a health measure as it is very expensive Many flights have had empty seats as few people could or wanted to fly during the crisis, but airlines are resisting keeping seats empty as a health measure as it is very expensive Photo: AFP / LAURENT THOMET

He said the industry was working on developing procedures that would be safe and permit economically viable operations.

They will not include leaving seats empty to spread out passengers.

Biofuels and efficient engines will be key for the airline industry to cut its emissions Biofuels and efficient engines will be key for the airline industry to cut its emissions Photo: AFP / Fabrice COFFRINI

"Empty seats don't provide added security," said de Juniac.

"But the economic impact would be absolutely catastrophic," he said, requiring airlines to raise prices by 50 to 100 percent.

Discusions at the UN's International Civil Aviation Organization and between major countries are aiming to broker a "convergent approach that is harmonised around the world on health checks".

Alexandre de Juniac, who used to run Air France, leads the airline industry's trade association IATA Alexandre de Juniac, who used to run Air France, leads the airline industry's trade association IATA Photo: AFP / Jung Yeon-je

Measures applied by airlines and airports, he said, would avoid the kind of "patchwork" of rules adopted by nations following the 9/11 attacks in 2001, when al-Qaeda militants hijacked four planes and crashed them into buildings in the United States.

Among the measures being proposed are mandatory health declarations, temperature checks, mask-wearing throughout terminals and on planes, provision of prepacked meals, regular disinfection of aircraft cabins and restrictions on luggage.

The industry hopes that such measures, along with planes' air filtration systems, will reassure both passengers and governments that air travel can be resumed safely even though a vaccine for the novel coronavirus is not expected until next year at the earliest.

IATA does not expect air traffic to return to its pre-crisis level until 2023.

Airlines have already announced the layoff of tens of thousands of staff as they try to survive.

De Juniac noted that only three or four airlines have gone belly up, including Virgin Australia, which voluntarily entered administration in April.

The airline industry also plans to keep its promises in terms of the environment -- cutting 2005 CO2 emissions by half by 2025.

"We're trying to convince governments to dedicate a part of the economic support plans to developing biofuels," said de Juniac.

He said airlines might replace their fleets a bit more slowly -- which would mean old aircraft that consume more fuel and spew out more pollution do not get replaced as quickly.

"But we'll also have fewer planes flying and therefore a bit lower emissions," said de Juniac.

Concerning governments tying aid to environmental obligations, as France has done with a state-backed loan for Air France, he said it complicated efforts to find urgent responses to the crisis.

"In any case, we're going to honour our environmental promises," he said.