United Airlines could convert some of its existing widebody orderbook to the Boeing 777-300ER, following reports that it is preparing to order 10 of the widebody aircraft.

"We are not currently considering purchasing incremental widebody aircraft," a spokesperson for the Chicago-based carrier tells Flightglobal. "We do, however, have the ability to negotiate the substitution of certain aircraft types for other aircraft types as part of our flexible fleet plan, and we are considering the Boeing 777-300ER in this context."

United has firm widebody orders for 24 Boeing 787-9s and 27 787-10s, as well as options for another 10 787-8s and a letter of intent for 36 787s, the Ascend Fleets database shows. It also has firm orders for 35 Airbus A350-1000s.

The comments follow a Bloomberg report that the airline is preparing to place an order for 10 777-300ERs in the near future.

United has a very "measured [and] metred" approach to replacing aircraft in its widebody fleet, its chief financial officer John Rainey has said. This includes the nearly one-for-one replacement of older widebodies as it has taken delivery of 14 787-8s and 787-9s since 2013.

The 787-9 is replacing Boeing 767-300ERs while the A350-1000s are planned as replacements for the airline's 23 ageing Boeing 747-400s, various United executives have said.

United has 148 older generation widebody aircraft in its fleet, including the 747-400s, 51 767-300ERs and 767-400s, and 74 Boeing 777-200s, its most recent fleet plan shows.

Converting existing Boeing orders to the 777-300ER could provide United with a more direct replacement for its 747s sooner than the Airbus widebody. The 777 variant carries 386 passengers in a typical three-class configuration compared to just 369 passengers on the A350-1000 in a typical two-class configuration, the manufacturers' websites show.

United's 747-400s are configured with 374 seats in three classes.

In addition, Boeing has 777 delivery slots available beginning in 2016, Ascend shows. It has 75 deliveries scheduled next year with an annual production target of about 100 aircraft.

This is about two years earlier than United's first A350 delivery, which is scheduled for 2018.

Low seat mile costs could also be a driver behind the potential order conversion. Joao Miguel Santos, Boeing Commercial Airlines' director of sales for Africa, told Flightglobal in September that the 777-300ER has “lower seat-mile costs” than the larger 747-8, which imply that the aircraft has significantly lower costs than the 747-8s predecessor the 747-400.

Boeing could be offering the 777-300ER to United at a lower capital cost than the 787 variants as well. The airframer is known to be seeking "bridge" orders for the widebody for deliveries from about 2016 or 2017 through the introduction of the 777X in 2020. Large discounts are common for these end-of-the-line deliveries.

Source: Cirium Dashboard