United Airlines (UA, Chicago O'Hare) has been working "very, very hard to use the pandemic as a way to get back into New York JFK" and is planning an aggressive expansion at the airport, Chief Executive Scott Kirby said during the carrier's third-quarter earnings call.

"Our initial return, I think, would be coming back into the transcontinental and perhaps service to our hubs... I look forward to getting back and competing aggressively and for our customers who want to be able to fly in those transcontinental markets," Kirby said.

United's hubs which would fall under the "transcontinental" label for prospective services from JFK are Los Angeles Int'l and San Francisco, CA. In the western and southern US, the airline also has bases at Houston Intc'l and Denver Int'l.

United Airlines left JFK in 2015 to focus its New York metro services at New York Newark, one of its key hubs, and to a lesser degree at New York La Guardia (which is served by United but is not its base). However, in August this year, Kirby hinted that the return to JFK was very much on the cards. He now elaborated that the combined factors of infrastructure expansion at the airport and the reduction in demand caused by the COVID-19 pandemic meant that airport capacity would not be a constraint for the carrier.

According to the ch-aviation capacities module, JFK's largest airlines are currently Delta Air Lines (DL, Atlanta Hartsfield Jackson) (36.4% market share by capacity) and JetBlue Airways (B6, New York JFK) (29.8%). While American Airlines (AA, Dallas/Fort Worth) has a base at JFK, its market share at the airport currently stands at just 6.6%.