The A380 may be the most spectacular aircraft ever produced by Airbus, but the aircraft-maker's ability to regain traction in the overall widebody segment will largely depend on its new A350.

Rolled out of the paint hangar without the typical fanfare last month, the A350 is not only the answer to Boeing's 787 family, but also to the highly successful 777—it will compete against the proposed 777X, expected to be launched this year. The A350 was initially conceived as a three-member family, but Airbus has been focusing on the -900 baseline and stretched -1000, leaving the industry questioning the future of the -800, particularly since the upgraded A330-300 could largely play its role.

Airbus has collected 637 firm orders for the three variants, most of which (414) are for the -900, although sales of the -1000 have picked up noticeably in the past year, following the late redesign and engine upgrade that led Airbus to delay first delivery by 18 months to 2017. Detailed development of the -1000 is now in full swing, but at the moment all eyes are on the flight tests of the first A350-900.

Airbus powered up the engines on MSN001 on June 2 for the first time and the aircraft was expected to make its first flight late last week. The second and third flight-test aircraft, MSN003 and, MSN002, respectively, are on the final assembly line. Airbus is working with 10 customers this year on their initial aircraft to ensure the production ramp-up will be accomplished as soon as possible. By year-end, the program is scheduled to be producing one A350 per month. The production-rate average before first delivery—planned for the second half of next year—is slated to be two per month; it is expected to rise to three per month by the end of 2014. Airbus ultimately plans to build 10 A350s monthly four years after entry into service, the rate it reached on the A330 program and that Boeing plans for the 787.

Airbus anticipates accumulating 2,500 hr. of flight tests involving five aircraft to achieve certification. MSN001, equipped with about 30 tons of test instrumentation, is flying first, testing basic performance and then opening the flight envelope to extremes, including flutter and maximum dive tests, relatively early in the program.

MSN003 is slated to join the test campaign in early October, equipped with the same level of instrumentation and goals as MSN001, with which it will be interchangeable. The instrumentation comprises more than 450 km (280 mi.) of wiring, an engineer station, multiple computers to record more than 5,000 different measurements and a water ballast system to shift the center of gravity in flight.

A passenger cabin will be installed in the third flight-test aircraft, MSN002, which is scheduled for cabin, evacuation, air-conditioning and systems tests as well as early long flights. It is to take to the air in January 2014.

MSN004 will predominantly be used for avionics-testing starting in February 2014. MSN005 is slated for route-proving and ETOPS certification and is scheduled to begin flying in April of 2014.

Airbus plans to retain only MSN001 as a permanent test aircraft. “We want to use the flight-test aircraft like an airline would and train the processes,” says Didier Evrard, executive vice president and head of the A350 program. The manufacturer is building a hangar for for that purpose that is to be ready before year-end.

One of the many lessons Airbus learned from the A380 testing is the importance of simulating in ground tests the high-altitude thermal and pressure conditions of routine airline services, says A350 Chief Engineer Gordon McConnell. Fault analysis of cracking in the wing rib feet of in-service A380s pointed to the insufficiency of such trials. Airbus has now built in some thermal testing, although parts will only be cooled down locally in ground tests. Also, it is applying nonlinear finite test modeling for the first time and, McConnell says, the forecast capabilities of that method are “incredible.”

According to industry sources, MSN001 is reportedly more than seven tons heavier than planned. McConnell does not confirm the numbers and only indirectly concedes that there still is a weight issue. “At entry into service, the aircraft will be a lot lighter and there is no reason to believe that we will be anywhere but in good shape,” he says.

Airbus is also phasing in program upgrades in the early part of the production ramp-up. That approach ensures schedule adherence but leaves the initial batches of aircraft suboptimal, particularly in terms of weight. The aircraft maker argues that this has been an industry standard in other programs, but there have been customer complaints about it, too.

First flight was preceded by an extensive campaign of ground tests mainly involving MSN5000, the static-test airframe installed in a sophisticated rig in Toulouse near the A380 final assembly line. In early June, Airbus had completed 95% of the tests planned before first flight. The static airframe was subjected to 125% of the maximum load expected during an A350's typical service life—greater than required by airworthiness authorities, in this case the European Aviation Safety Agency (EASA).

“We deliberately went higher, because we wanted to have more margin for the flight tests,” explains McConnell. Airbus hopes to be able to avoid time-consuming inspections if limits are exceeded during flight tests.

Before certification, the MSN5000 airframe will also be subjected to the ultimate load, 150% of the maximum expected load. And Airbus will break the static test aircraft's wing to determine its real tolerance. Another wing, will undergo damage-tolerance testing at IABG's facilities in Erding, Germany.

The ongoing static-test campaign will be followed by a three-part fatigue test to be started later this year.

As the first A350 was approaching first flight in late May, Airbus was already busy planning the next steps. In addition to the flight-test campaign, Evrard considers it to be “the biggest challenge to produce heads of versions for many customers in an industrial way.” Following the traumatic experience in customizing A380s for a variety of airlines in the early phase of production, a smooth ramp-up will depend on building the initial units efficiently and finding ways to quickly incorporate lessons learned in the process. As the A380 has shown, it can take many years to bring recurring costs below the level of revenues per aircraft.

Alongside the -900 flight-testing, Airbus continues work on the two other A350 versions. The -800 was officially scheduled to enter service in 2016, to be followed by the stretched -1000 in 2017, but that timing is no longer being publicized. While it is revealing many details of the development progress made with the -1000 derivative, Airbus does not have much to say about the -800, which no longer plays a significant role in company presentations. According to airline industry sources, Airbus has tried to persuade customers to move away from the -800 and switch to the larger -900 and -1000. The -800's backlog has shrunk to half its former size and now stands at 89 units.

Airbus CEO Fabrice Bregier insists that the -800 will nevertheless be built, in part because not all of the -800 customers are willing to switch to other versions. Hawaiian Airlines says the stretched versions are too large for its requirements. But there is a strong likelihood that Airbus will lose more of the backlog: for example, Kingfisher Airlines ordered five aircraft but is no longer flying.

Observers therefore expect Airbus to officially continue the -800 program but to first develop and certify the -1000, which is in higher demand and appears to hold more strategic importance in Airbus's competition with the proposed Boeing 777-8X and -9X.

Given that the -9X will actually be larger than the A350-1000—fitting in the niche between the current largest medium-sized widebodies (777-300ER, 777-8X and A350-1000) and the A380—Airbus might have to look at a double stretch of the A350 in the medium term. Bregier does not rule out that possibility, but he cautions that it has also not been studied in any detail (see page 92).

Boeing has gone for this approach in the 787 program, with the 787-8 as the baseline. It is now being pressured by many airlines to launch the 787-10 in addition to the -9, which is scheduled to enter service in 2014, to provide an aircraft with more seats. But the double-stretch can be a complex undertaking if the resulting aircraft is not to suffer reduced range.

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