Most major U.S. airlines report they’re closely following Airbus’s proposal to launch a long-range version of the Airbus A321, but the carriers note it’s too early to discuss purchase plans.

American Airlines has been most vocal in asking for a Boeing 757 replacement for long missions, such as New York to Paris, New York to Manchester, U.K., and New York to Madrid. American’s next smallest long-haul airplane—the Boeing 767—has 209 seats in its new configuration, so losing the overwater Boeing 757 could pose challenges for some thin routes. In the short-term, American will continue to fly nearly 20 757s across the Atlantic, but executives have said they’re actively seeking a replacement for the fleet. By year-end, American expects to have 95 757s, down from 117 in January 2014. 

“The 757 is just a phenomenal airplane,” Fern Fernandez, American’s vice president of marketing, said. “We are looking at Boeing and Airbus to deliver an airplane that replaces the 757. We really haven’t seen an airplane from either of the manufacturers with the range the 757 has. We are eagerly awaiting a solution.”

JetBlue has also said it may be interested in a long-range A321. With a current fleet of A321s and A320s, JetBlue does not fly to any destinations requiring long-range narrowbody aircraft. But JetBlue has said it may want to fly into deep South America from New York and Fort Lauderdale, Florida, and the Airbus A320neos it has ordered likely do not provide enough range. A long-range A321 could also allow JetBlue to fly across the Atlantic, though airline executives have repeatedly said flying to Europe is not in short-term plans. 

“We’re certainly looking at [the long-range A321],” Scott Laurence, JetBlue’s senior vice president for planning, told analysts. “We’ve got our best engineers looking at that. Airbus is looking at that. I think the jury is out and the thing about that airplane is that if it is able to be a 757 replacement, it could be a game-changer in terms of narrowbodies flying across the ocean. So again, there’s a lot of work that needs to be done in terms of figuring out exactly what the capability of that airplane is.”

Among other major U.S. carriers, Delta Air Lines would seem to have a similar problem as American, though a Delta spokesman declined to comment on the carrier’s future plans. Delta now operates 127 Boeing 757-200s with an average age of 19.8 years, and 16 Boeing 757-300s with average age of 11.6 years. Delta expects to keep all of its 757-300s and 50-60 of its 757-200s for about another decade. 

Many of Delta’s 757s fly short, thick routes like Atlanta-Orlando, and can easily be replaced by Airbus A321s or Boeing 737-900s. Delta has ordered 45 A321s, the first of which will arrive in 2016, while the 737s have already started arriving, with deliveries to continue through 2018. But Delta is also flying 757s in its long-haul operation. Current overseas 757 routes for Delta include Boston-Paris and New York-Dakar, Senegal.  Starting in April, Delta also will fly a 757 between Philadelphia and London. 

United Airlines, meanwhile, is at a bit of a disadvantage compared to its competitors, as it is most reliant on the trans-Atlantic 757 but has no obvious replacement for it. United operates a robust transatlantic schedule using former Continental Airlines 757s, mainly from Newark, New Jersey. Destinations include London, Berlin, Stockholm, Amsterdam and Barcelona. 

Under its current management team, United has only ordered Boeing narrowbody aircraft, including the Boeing 737 MAX. But with Boeing unlikely to build a 757 replacement, at least in the near future, United likely would have to go with Airbus for a quick fix. Analyst Scott Hamilton of Leeham Co. said it is possible United would look at the long-range A321 and noted that United could also replace some of its older A319s and A320s at the same time. “If United decides that it wants to replace the 757s on trans-Atlantic routes and wants to order 25 of them, then it would make sense to order the A320, as a compatible airplane,” Hamilton said. “For Airbus, it could be a sales leader for additional A320 sales.”

In the short-term, United is aggressively retiring its 757s. It expects to end the year with 94 757s, having removed 37 this year. Until the MAX aircraft arrive, United considers the Boeing 737-900 a logical replacement for many routes, including from California to Hawaii and across the country. United’s most-dense 737-900s have 179 seats, while its domestic 757s have 182 seats. 

United, however, isn’t talking publicly about replacement. “We have ongoing discussions with all of our manufacturers, and we don’t discuss our future fleet plans,” United spokesman Luke Punzenberger said.