Airlines face a years-long challenge to rebuild global route maps and networks that were devastated by the COVID-19 pandemic

• Since the 2008 financial crisis, airlines have built sprawling global networks, leveraging international hubs and partner airlines to connect the world.
• Those networks have been left decimated by the coronavirus pandemic.
• As air travel demand returns over the next few years, routes and networks will look very different than what we've gotten used to.
• Read more stories from the Destination Rerouted series here.

During the decade and change since the 2008 financial crisis, US airlines took advantage of a strong economy and soaring travel demand to build and reinforce massive global networks and route maps.

By 2019, it was possible to get just about anywhere in the world with just one stop, at most two, depending on where you lived. A wide range of direct flights between midsize markets and international hubs made this even easier, with myriad partnerships between US carriers and global airlines opening the world, both through alliances, and one-off partnerships and code shares.

Over the course of a short few weeks in 2020, that interconnected network collapsed.

As America's airlines see travel demand beginning to ramp back up, they're cautiously pulling grounded aircraft back into service, and restoring capacity on their domestic networks.

Their international networks, however, are another story.

American Airlines, for instance, plans to fly 55% of its domestic capacity in July, compared to 2019. But the airline will only fly 20% international flights, and many of those are expected to fly fairly empty — good for social distancing, but bad for the airline.

Airlines won't be able to truly build back their international networks until demand returns, and demand won't come back in full force until various travel restrictions, border closures, and quarantine requirements are lifted. That isn't likely happen until the pandemic is brought more under control — something much of the world, including the US, is still struggling to accomplish.

As international travel does return over the next few years, networks and route options will look very different compared to the 2010s.

Massive cuts and dismantling during the pandemic will mean a massive rebuilding effort

With airlines cutting anywhere from 50% to 90% of their capacity through the worst of the pandemic, grounding planes and suspending routes, bringing their sprawling, complex networks back online will be a challenge.

"Humpty Dumpty not only fell off the wall, but was smashed into very tiny pieces," said Henry Harteveldt, cofounder of the Atmosphere Research Group, a travel industry research and analysis firm. "So it's going to take a long time to reassemble the airline network."

In recent years, airlines began looking toward new markets and routes, seeking untested opportunities for profits and market share. United, for example, launched a nonstop flight between Newark, New Jersey and Cape Town, South Africa, betting on a strong leisure market.

As debt-laden, struggling carriers limp back from the pandemic, that kind of experimentation and expansion will likely remain on the back burner. Some routes may use smaller aircraft than before as demand builds back up, and unless there's strong demand from a corporate client, some nonstop flights to those international hubs will have to wait.

"Flights from the major hubs, like Atlanta, San Francisco, Chicago, Houston, sure," Harteveldt added. "But you may not see some nonstop routes like Nashville to London, or Raleigh-Durham to Paris, or New Orleans to London return in the first wave. Maybe the second wave."

R.W. Mann, an airline consultant and former executive, said that one sign that will tell him that everything has returned to normal: American Airlines launching a now-postponed direct flight between Seattle and Bangalore, India, a route that was announced earlier this year with multinational tech companies in mind.

"That's an example of a tech-hub to tech-hub nonstop route that wouldn't work unless you had lots of corporate travel on board," he said. "So that would be my barometer of when things are totally back to normal."

One thing most experts agree on: airlines are highly unlikely to abandon any of their previous hubs.

"They've invested time and money to develop those," Harteveldt said. "They know that if they pull out, a competitor will step right in."

When frequent flyers return to the skies, they're also likely to find themselves on a different plane than they would have before.

Airlines have accelerated retirements of older, larger, and less efficient plane types as they've cut capacity during the pandemic. The "superjumbo" Airbus A380 has been grounded by most airlines, and carriers still flying the iconic Boeing 747 on long-haul flights have been putting more of the planes into storage, and airlines have retired other fleets en masse.

When travelers return, they can expect to see smaller, more efficient, nimbler aircraft.

Narrow-body jets like the Airbus A321XLR and the Boeing 737 Max — once it's cleared to return to service — are also expected to cover longer routes, according to Mike Boyd, an aviation expert and a consultant with Boyd Group International.

"The Airbus A321XLR is a 180 seat airplane" with a degree of flexibility that has a strong appeal for airlines seeking to reinvigorate their route networks, Boyd said.

"You can fly between Providence, Rhode Island and Paris, and between Providence and Albany" with the plane, he said, "and make money on both."