American Airlines is evaluating the future of its Airbus A350-900 commitments, as it continues to deal with the varied orderbook it gained through its merger with US Airways four years ago.

The Fort Worth-based carrier’s order for 22 A350s is on the small side for a single aircraft type in its fleet, says Doug Parker, chairman and chief executive of American, on the sidelines of the Airlines for America (A4A) Summit in Washington DC today.

“The current [A350] delivery size – we’re either going to need to have a bigger delivery size or figure out if there is something else we can do,” says Parker.

American is in discussions with Airbus over its orders, he adds when asked about the status of the A350 order.

The smallest fleets among American’s 956 mainline aircraft were its 24 Airbus A330s and 20 Embraer 190s at the end of June. However, the carrier plans to retire nine A330-300s, leaving it with just 15 A330-200s, and all of the E190s by the end of 2019.

United Airlines faced a similar dilemma with its order for 35 Airbus A350-1000s. Executives said that it would be difficult to operate the aircraft efficiently when spread out over its seven US hubs. This, and statements that it was evaluating alternatives to the order, sparked speculation that the carrier could cancel the order.

Instead, earlier in September, United upped the order to 45 A350s, converted it to the smaller -900 and pushed the first delivery back by three years to 2022. The aircraft will replace Boeing 777-200ERs in its fleet as those jets pass 25 years of age.

American could make a similar move. The Flight Fleets Analyzer shows that the airline’s oldest 777-200ER will be 25 years old in 2023, creating the potential need for a replacement around that time.

The carrier operates 47 777-200ERs that were delivered between 1998 and 2006, Fleets Analyzer shows.

American has deferred its A350 order twice. It moved its first deliveries back by two years to 2020 this April, after a one year deferral to late 2018 in July 2016.

Both changes to the carrier’s A350 deliveries were attributed to balancing the former American and US Airways delivery streams, and reducing capital expenditures.

American converted the US Airways order for 22 A350-800s to the -900 shortly after their merger closed in December 2013.

US Airways first placed the A350 order in 2007 with the first delivery scheduled for 2014.