There is starting to be a routine to this: as Airbus and Boeing advance development of new products, their family concepts start to shrink.

When the Airbus A380 ran into production problems, the freighter version was scrapped and the stretch -900 was kicked into the long grass. The Boeing 787-3 was stillborn even as the -8 and -9 advanced. Now the A350 is experiencing a similar evolution. As the manufacturer focuses on birthing the -900 and designing the -1000, the third family member, the -800, is dying of benign neglect.

Airbus officials insist that the -800 remains a member of the A350 family. However, John Leahy, chief operating officer for customers, stresses that while production slots are scarce, he is focused on selling the higher-margin -900. In fact, there is an effort underway to convert -800 buyers to the -900. Airbus has 118 firm orders for the -800, which is currently due to emerge in 2016.

Similarly, A350 Program Executive Vice President Didier Evrard says there is a clear emphasis on the -900, the lead platform in the program. The next priority is the -1000, the aircraft with which Airbus hopes to break the dominance of Boeing's 777 in the twin-long-haul segment.

The -800's wane is compounded by concerns among potential customers about its performance and per-seat costs. In analyzing future fleet requirements, one airline executive found the -800's per-seat costs were no better than the Boeing 767's, let alone the A330-300's.

At the same time, just bringing the -900 out of development is at a critical stage. “The next two years are going to be extremely important,” Evrard says. First customer delivery of the -900 is planned for the first half of 2014, and it is moving closer to the middle of the year than the start, he acknowledges.

Despite the move taken last year to delay the initial in-service date to 2014, the -900 schedule is tight. Some elements are running ahead of schedule but there are signs of slippage in other areas. While the wings for the static-test elements are due in July, delays may push them into August. Airbus is using a new wing-assembly process to take advantage of greater automation. “It is slower than we thought it would be,” Evrard concedes, but he says it will be a huge boon in high-rate production.

Several internal milestones loom. One is the start of final assembly of the first flight aircraft, MSN1, in July. Airbus also targets power-on when the first two of three fuselage sections are mated to quickly reduce integration risk. Later in the summer, Sections 13/14 (the mid fuselage) and Sections 11/12 (the nose section) are slated to be joined with the aft fuselage.

However, component supply issues remain a concern. Airbus has worked with suppliers “to jointly develop action plans to make it work seamlessly,” says Fabrice Bregier, Airbus COO, who will take over running the company on June 1 when Tom Enders becomes EADS CEO.

“In terms of readiness, they are in reasonable shape,” Evrard notes. But he adds, “we are watching very closely the financial health of the suppliers.” The current financial pressure in Europe is making it difficult for some small companies to obtain loans, Bregier notes.

It is not just about small suppliers—Airbus continues to work with GKN Aerospace and Spirit AeroSystems to make sure their efforts are on track. Progress has been made, but more must be done, Evrard says, to get back on schedule by year-end.

Nonetheless, there have also been several encouraging developments. The process of building the static test article, the first aircraft undergoing assembly, is so far running smoothly. Evrard says, “everybody in the final assembly was pleased with how it came together” with no gaps between sections. Once the wings are mated to the fuselage, it will validate much of the structural assembly process.

Evrard also notes that the company has been trying to incorporate many lessons from other programs. An early complaint about the A380 was that it generated too many built-in-test (BIT) messages, which overwhelmed crews. On the A350, the BIT approach was refined to avoid that, and suppliers were told to have BIT capabilities ready when subsystems are delivered so the software can be updated.