TAP Portugal is poised to defect to the larger Airbus A350-900, becoming the latest in a series of customers to shift away from the shrunk -800 variant.

Airbus parent EADS insists it remains committed to the -800, and is not reviewing the business case, but is discussing options with customers interested in taking the larger -900 following postponement of the -800's development.

TAP had been one of the early signatories for the A350, signing up for 10 of the original A350-800 in 2005 when the type was effectively conceived as a re-engined A330.

The Portuguese flag-carrier subsequently firmed options on another two -800s before Airbus overhauled the A350 design and relaunched it as a new aircraft family, the A350 XWB, in late 2006. Although intended to be an optimised aircraft in its own right, the new version of the A350-800 was revised last year as a smaller version of the -900.

Airbus chose this strategy to increase the -800's range but the airframer also acknowledged that it would raise the type's fuel burn.

While the manufacturer had secured orders for 182 A350-800s in mid-2008 the backlog started sliding away last year as customers began switching to the larger -900. Brazil's TAM and Kuwait's ALAFCO converted 24 -800s to -900s in 2010 and Asiana, Synergy Aerospace and International Lease Finance have all switched either partially or fully to the -900.

Airbus has since pushed back development of the -800 by about two years, postponing entry into service to mid-2016. TAP said its initial deal with Airbus enables it to convert to other variants. "Considering actual and forecasted traffic trends, the A350-900 will better match with TAP's future capacity needs," the airline told Flightglobal.

It has not indicated how many -800s might be switched. Airbus's latest order data also shows lessor CIT - another customer for the original A350 - cancelled its outstanding -800s after converting most of its order for five to the -900 in June. TAP has 12 A350-800s on order and a move to the -900 could potentially bring the -800 backlog down from 135 to 123 aircraft, just two-thirds of the peak total.

EADS chief Louis Gallois, during the company's first-half presentation, said the company was "not questioning the viability" of any of the A350 variants, including the -800.

Amending the development schedule for the -800 would enable EADS to concentrate on the two larger family members, EADS said. Gallois added that the response from airlines has convinced the company to "maintain the three versions", but admitted: "We are in discussions with airlines on the -800 because some of them could be interested in having the -900 before."

Key customers for the -800 include Qatar Airways, US Airways, Hawaiian Airlines and Aeroflot, holding 62 orders between them. Irish lessor Aircraft Purchase Fleet, which took over Italian carrier Air One's order for 12 -800s said it still intends to take the twinjets. Uncertainty surrounds other -800 orders - notably for 10 from two Libyan carriers.

Source: Air Transport Intelligence news