The demand for domestic flights has come a long way since the development began the pandemic in the US earlier this week, the TSA announced that it had screened more than 1 million passengers a day for the first time since early March – a major recovery milestone.

Now with Vacation trip threatens and the availability of Airport COVID-19 tests Many in the aviation industry are turning their attention to the next hurdle: restarting international flights on a large scale.

One possible solution to reopening international routes to the general public is an air travel corridor – an agreement between two cities or countries that allows passengers who test COVID-19 negative to travel without a quarantine requirement. While some have already been established in Asia and Australia, one such corridor that is reportedly being negotiated is located between New York City and London, and after that Wall Street Journal, scheduled to open through the holidays.

According to the Ministry of Transport, talks are currently being held between the federal government, international partners and industry stakeholders. But how likely is it that the airlift actually happens before the end of the year?

Experts say it isn’t impossible, but the timeline would be difficult to execute.

“The timescales are getting very close with US politicians busy with the election and in the UK with post-Brexit economic agreements,” says John Strickland, founder of JLS Consulting in London. “There doesn’t seem to be a huge focus on aviation.”

Another factor that could complicate matters is the COVID-19 infection rate in both countries. The virus is growing in the UK, which the US government could do more cautiously before reaching a deal, says Henry Harteveldt, president of Atmosphere Research. “While New York City has flattened the curve quite a bit, there have been peaks in certain neighborhoods and we’ve seen virus rates spike elsewhere in the US,” he says. “All of this will affect the willingness of governments to cooperate and even the airlines’ interest in the airlift.”

One sign that is good for the Airlift is a successful test of a new app, called Common Pass, which was recently tested on a route from New York to London. The app standardizes COVID-19 test results for aviators, enabling a digital version that is easier for airlines and immigration officials to read. Both the Centers for Disease Control and US Customs and Border Protection have watched the app test and are in “discussions about where to go from here,” according to Paul Meyer, CEO of Common Pass.

“I think it can be helpful,” Harteveldt says of Common Pass. “All of these are important steps to make air traffic so safe from a health and mechanical point of view.”

Resources like Common Pass could potentially help open these corridors at some point. “Technology and reliable data will be important to support the resumption of long-haul flying,” says Strickland.

Flight corridors are now appearing in other regions of the world. Singapore Recently two were established: one in Hong Kong and one in Maldives. New Zealand and Australia have also agreed on more limited version of a corridorOne way flights from New Zealand to select Australian cities. However, analysts say these negotiations, while successful, do not necessarily mean that an airlift from New York to London will be approved anytime soon.

“What will work between countries A and B does not mean that it would also work between countries C and D,” says Harteveldt. “I think there will be a lot of interest in every air corridor that opens up anywhere in the world, from the public response standpoint, from the operational and logistics standpoint, and of course the public health landscape perspective.”