United Airlines has recently priced a proposal to acquire Airbus A321LR single-aisle aircraft as replacements for the RB.211-535E4-powered Boeing 757-200s it operates on transatlantic routes, according to UK-based aviation technical consulting firm IBA Group.

The proposal studied by United specifically centered on A321LRs fitted with 16 Polaris business-class seats, 72 Economy Plus extra-legroom seats and 90 economy seats, IBA Group head of advisory Paul Lyons said during a webinar on low-cost long-haul airlines the company held recently. Each of the 757-200s United now operates on transatlantic services carries 169 passengers: 16 in Polaris business class, 45 in Economy Plus and 108 in the economy cabin.

While Lyons and Mike Yeomans, the firm’s head of valuations, recognized that the A321neo “has been receiving a lot of attention” and noted the interest various carriers have shown in the type's latest Airbus Cabin Flex (ACF) version, they questioned whether the 240-seat maximum capacity of the A321neo ACF (at the A321LR’s 97-tonne maximum takeoff weight) would suit airlines’ longer-haul service needs.

In a 240-seat cabin configuration, all A321LR seat rows would provide a seat pitch of just 28 inches; the second doors on the left and right sides of the aircraft’s fuselage would be removed and therefore unavailable for potential emergency evacuations. Yeomans questioned whether a 28-inch seat pitch would provide enough passenger comfort for any A321neo service of more than five hours in duration. “It’s something we’ve identified, or noted, as perhaps happening with the Wow Air and Norwegian situations,” said Yeomans. Norwegian doesn’t operate A321neos or A321LRs yet, but in 2019 the carrier plans to take the first eight of 30 A321LRs it has ordered and operate them on routes to the U.S. from European cities such as Berlin, Brussels, Budapest, and Prague.

Wow Air already operates A321neos (though not yet ACF-configured A321LRs) configured for 220 seats at mixed 30- and 31-inch pitches on routes from Iceland to North America—all of which extend at least five hours in flight duration. Although Norwegian has yet to receive its first A321LR, it operates 189-seat Boeing 737 Max 8s configured to seat 189 passengers on transatlantic services. So Norwegian could conceivably configure its A321LRs to offer a 29-inch seat pitch.

Lyons also noted that the A321LR’s cruise speed of Mach 0.78 is “relatively low … compared to some of its competitors” such as the Mach 0.85-cruising Boeing 787, possibly producing a negative “knock-on effect for utilization on some of the shorter-length but still long-haul sectors” operated by the A321LR.

However, IBA Group does not doubt that the A321LR, fitted with a third auxiliary center fuel tank, will offer sufficient range for even longer-haul transatlantic services. Lyons pointed out the Airbus had flown an A321neo a distance of 4,750 nm in that configuration non-stop from Mahé in the Seychelles to Toulouse with the aircraft’s weight configured for the test flight to represent 162 passengers and with 11 technicians and five crewmembers aboard.