Aircraft production ramp-ups of any scale are fraught with risk. They require huge investment in production lines, detailed monitoring and organization of supply chains and the ability to juggle in-service support with the priorities of manufacturing. Even if a company manages to handle those challenges, a rare feat in aviation, it still is at the mercy of many factors beyond its control such as a sudden swing in oil prices or a global economic downturn.
Consequently, it is not surprising that most aircraft programs run into trouble during production ramp-ups. Four years after launch, in 2008, the innovative, carbon-fiber Boeing 787 was due to enter service, but it was not nearly ready because Boeing had overestimated the capabilities of its suppliers. The result was a three-year delay and a new aircraft program several billion dollars over budget.
Airbus also suffered supply chain problems with the A350, which missed its production target in 2015 due to a shortage of toilets. Those issues were minor, however, compared with hold-ups to A320neo deliveries caused mainly by shortages of Pratt & Whitney PW1100G engines. At one point in early 2018, more than 60 otherwise-complete A320neos were awaiting engines outside the Airbus factory gates. And although Airbus and Pratt & Whitney are now working through the backlog, there have been repercussions: When European carrier Primera Air collapsed in October, it blamed its failure partly on “prolonged Airbus delays of the A321neo fleet.”
Aircraft Production Rate Increases
Despite numerous missteps in the recent past, aircraft manufacturers are willing to gamble on further rate increases because they see more than enough demand to sustain them. Aircraft order backlogs are at near-record highs, and the explosive growth of passenger demand in Asia—along with the significant fleet renewal requirements of U.S. and European carriers—means they are confident there will be customers for their aircraft.
Even so, the acceleration of output is breathtaking. Airbus is moving from 42 A320s (current-generation and Neo) per month in 2016 to 60 in 2019 and has ambitions to go further. “There shouldn’t be any doubt on the commercial viability of a higher rate at 70 or 70-plus,” said Airbus Chief Financial Officer Harald Wilhelm on a first-quarter earnings call, adding: “So it’s all about the industrial feasibility that has to be studied.”
With final assembly lines in Toulouse, Hamburg, Mobile (Alabama) and Tianjin, Airbus says it is confident it can match production capacity to market demand for the foreseeable future. “In addition, the new BelugaXL fleet coming online during the next years will amply meet the ramp-up capacity needs for transporting our major components between the sites,” says Airbus spokesman Martin Fendt.
To protect its market share, Boeing is raising narrowbody production, from 42 737s per month in 2016 to 57 737NG and MAX aircraft per month in 2019. Monthly 787 production rates are also increasing, from just under 12 in 2016 to 14 next year, while Airbus expects to reach 10 A350s per month by the end of this year.
Narrowbody Engine Production
Ultimately, the appeal of next-generation aircraft rests on the enhanced fuel efficiency of their engines. Leaving aside the trickle of A380s and 747-8s still being produced, every new aircraft requires an additional two-plus engines—two to go under the wings, plus a certain number of spares. This means that in 2019 roughly 3,000 new engines will be needed to keep up with A320 and 737 production—an output of around eight units each day.
“The Leap ramp-up is unlike anything we—or the industry for that matter—have ever seen,” says Gael Meheust, CFM president and CEO.
Having delivered 77 Leap engines in 2016, CFM is on track to produce 1,100 in 2018 and more than 2,000 in 2020. Already, the Leap ramp-up has been three times faster than that of the CFM56-7B, even though the OEM is simultaneously churning out huge volumes of current-generation equipment: 1,671 CFM56 engines in 2016, 1,400 in 2017 and an expected 1,000 in 2018.
“Faced with numbers like that, we knew we had to do things differently,” says Meheust, on the challenges of Leap production.
Planning for high-volume Leap output began in 2008. Since then, CFM partners GE Aviation and Safran have invested more than $1 billion in an extra 3.5 million ft.2 of manufacturing space, plus significant sums in new equipment.
Safran has also added three new factories—in the U.S. (New Hampshire), France and Mexico—to produce Leap fan cases and carbon-fiber blades, while GE’s new plant in Indiana is dedicated to Leap core assembly and Leap 1B final assembly. This is along with another four new GE facilities in Alabama, Mississippi and North Carolina that specialize in additive manufacturing, ceramic matrix composites and coatings for the Leap and other GE engines. “There are about 2,200 total employees at these eight sites, and the number is expected to continue to grow over the next couple of years as the ramp-up continues,” says Meheust
Widebody Engine Production
While not as intimidating as the number of narrowbody engine orders, backlogs for new-generation large engines are also substantial. Rolls-Royce has 1,379 Trent XWBs on order, as well as 358 already flying on the A350. On the 787 it has 490 Trent 1000s in service and 331 on order. GE Aviation has a backlog of roughly 1,800 for its competing GEnx, which powers the 787 and 747-8. GE also has more than 700 orders for the forthcoming GE9X, while Rolls-Royce has a backlog of 458 Trent 7000 engines for the A330neo, which is on the cusp of service entry.
Rolls-Royce is partially through a push to double production, and in the first half of 2018 it delivered 259 engines across all new- and current-generation Trent lines. That was almost 25% more than in the prior-year period, and the British manufacturer is targeting 600 deliveries for the full year.
The ramp-up has meant investment in facilities such as Dahlewitz in Germany, which opened a Trent XWB-84 line in 2017, and Seletar in Singapore, which opened in 2012 to perform wide-chord fan-blade manufacturing plus engine assembly and testing. Besides supplementing the capacity of Rolls-Royce’s main line in Derby, England, the other facilities provide a measure of redundancy.
“The delivery of large- engine programs involves planning for the continuity of supply, and dual sourcing is an important element in ensuring the program has sufficient flexibility to cope with disruption, such as damage to an individual facility,” says Tim Boddy, Trent XWB marketing manager.
“Who you pick as supply chain [partners] also matters,” he adds. “In recent [new engine] programs, we’ve purposefully relied on major players and then gradually opened supply out to secondary, smaller suppliers as the engine has matured.” One example is UMW Aerospace in Malaysia, which delivered its first fan case for the Trent 1000 in 2017.
Rolls-Royce also has expanded its Derby facilities and says that its combined global production capacity has risen to one Trent XWB per day.
Learning From The Past
The delays to the 787 program were attributed largely to the fact that Boeing had initially outsourced about two-thirds of the aircraft’s production (versus less than half for previous models) and was unable to effectively monitor a more diverse supply chain. The problem forced Boeing to buy out Vought, which made part of the aircraft’s fuselage, and for subsequent programs the OEM brought certain capabilities back in-house. One example is the composite wing for the 777X, which Boeing will produce at its Everett, Washington, facility rather than with Mitsubishi Heavy Industries in Japan, which makes the 787’s wing.
As an international company since its inception, Airbus often said that it was better equipped to organize cross-border supply chains than its competitor. Even so, it suffered problems close to home with delays to A350 cabin equipment from French company Zodiac. Like Boeing, it has also pursued some in-sourcing—albeit for commercial reasons—deciding last year to develop a nacelle in-house for the A320neo geared turbofan, in competition with current monopoly supplier United Technologies.
Quality issues in CFM’s supply chain put Leap production about a month behind schedule at the start of 2018. The company had already adopted a multisource strategy for critical parts but admits this has “presented some challenges as we try to get each of the suppliers up the learning curve and stabilize first-time yields and cycle times,” says Meheust.
Rolls-Royce also recognizes the need to support and strengthen its supply chain. “One thing that we have always understood is the need for consistency of process to support higher-volume production,” says Boddy.
Along with multisourcing, both Rolls-Royce and CFM retain in-house capabilities for the more advanced components in their engines. For example, CFM produces the fan blades and ceramic composites across several of its own sites, while Rolls-Royce has used its turbine blade manufacturing capabilities to help ease the pressure of issues with its Trent 1000 engines. “Certainly, recent maintenance requirements on Trent 1000 engines have stretched our supply chain, but we believe we’ve taken some important steps along the way to address the challenges created specifically by the ramp-up we see across the sector,” notes Boddy.
Planning for the future
To test their ability to handle higher production rates, manufacturers must plan ahead. CFM, for example, conducts test runs internally and with its suppliers, producing parts for a short period at the higher rates anticipated for the following year. In doing so, the company would evaluate factors such as capacity, process time, training, tooling, inventory management and buffer stock—and then incorporate the lessons learned into the manufacturing process.
Rolls-Royce has also sought to iron out any wrinkles in production in advance. “One of our most significant investments to support this was the creation of a designated pre-production facility for the Trent XWB, where we rehearsed and refined the engine-build process in great detail prior to entering into in-service production,” says Boddy.
While testing internal and supplier capabilities is prudent, the best way to ensure a smooth production ramp-up is to make products as easy to manufacture as possible. “Perhaps the most important lesson we learned was to get the engine design right the first time,” says CFM’s Meheust.
Before launching the Leap engine, CFM evaluated 18 different architectures according to their producibility, reliability, ease of maintenance and maintenance costs. It then ran thousands of hours of component, engine and flight tests on dozens of different engine builds. For the first time, CFM also implemented a “manufacturing readiness review,” which would preclude the use of any technology on the Leap that could not be manufactured at the required rate.
Boddy says that Rolls-Royce also aims for ease of manufacturing “to ensure we’re not building unnecessary challenges into the system.” In addition, the company is pursuing new technologies such as additive manufacturing to reduce the need for complex forged parts. It has also tackled complexity in other ways, for instance by manufacturing the Trent XWB-84 intercase from several parts that could be laser-welded together rather than made from a single casting. Boddy says this was because the OEM “recognized the challenge of relying on a very small number of suppliers who can deliver complex forgings.”
There are signs that the cumulative effect of these exhaustive preparations is paying dividends. For example, production of the 737 MAX and the A350—and the engines for them—is now proceeding relatively smoothly, while Airbus and Pratt & Whitney are working hard to put the A320neo’s problems behind them. But further challenges for narrowbody production await, especially if output targets are increased again.