Airbus has confirmed a formal range figure for the A350-900ULR of 9,700nm, but stresses that this was always the intended performance capability for the type.
The airframer had not given a specific range for the aircraft when it was launched by Singapore Airlines in 2015, but did point to a figure of 9,700nm last year.
Singapore Airlines had indicated a range of 8,700nm but Airbus claims this was based on the length of the Singapore-New York route on which it intended to deploy the aircraft.
Airbus says that this figure has been "incorrectly assumed" to be the limiting range of the twinjet, which will be delivered to Singapore Airlines from next year.
The airframer has consistently stated that the aircraft would be capable of flights of 19h duration.
Airbus has revised, relatively recently, an information page on the A350 on its Internet site to include the 9,700nm range figure. But it had previously told FlightGlobal, in March last year, that it would offer this range on the -900ULR version.
It insists that the figure "hasn't changed" from the originally-intended maximum range specification.
Airbus is to modify the basic A350-900 to increase the fuel capacity by around 17% as part of the -900ULR development.
Qantas Airways has previously reportedly expressed interest in the -900ULR, as well as the Boeing 777-8, for possible specialised long-range operations from Sydney or Melbourne.