Farnborough Air Show

Airbus peers into future of single-aisle designs

 - July 17, 2010, 3:09 AM

As Airbus considers an A320-replacement to compete against prospective single-aisle models from Boeing and emerging challengers from Russia and Asia, it is also looking at technologies that could contribute to even longer-term designs in a program dubbed “A30X.” Mindful that modern jetliners are expected to have working lives of at least 40 years, chief operating officer for customers John Leahy said Airbus needs “future technology for future aircraft.”

The company recognizes that its established single-aisle duopoly with Boeing will be diluted if planned projects from Canada, China and Russia progress beyond the taxiway, but is unfazed by such possible competition. Technologically, emerging designs offer “no step change,” said strategy and future-programs senior vice president Ian Dawkins, speaking before he took a new position last month as chief executive of OnAir, the Airbus/SITA cabin communications systems joint venture.

Among its A30X studies, Airbus is looking at “long-term, game-changing technologies” for application in future alternative configurations in 2025 and beyond, including the anticipated open-rotor or high-bypass-ratio engines. Dawkins cited potential in “breakthrough” technology areas such as fuel cells, innovative structures, “smart” wings, and new cockpits and air traffic management (ATM) systems.

Fuel cell technology does not yet offer a viable opportunity for aerospace application, according to Dawkins. The requirement in the coming 20 years will be to find a way to integrate fuel cells into a multifunctional system that will reduce fuel burn and enable aircraft to be emission-free on the ground, he said.

Future composite materials and metals are expected to permit innovative structures that Dawkins said could provide an optimum mix for performance and operability. This would include the novel mechanical properties of nanoscale materials, whose use of very small particles offers new mechanical effects such as altered electronic properties.

The likely high future price of fuel is driving consideration of “smart” wing technologies, including developed winglets (such as the “sharklets” being offered on the A320) and natural and hybrid laminar flow. Dawkins said the new aerodynamics could provide “anti-contamination” or low-drag wing surfaces.

Airbus believes “a quantum leap in SFC [specific fuel consumption] reduction” could be available through innovative engine technologies, such as open-rotor designs. It sees advanced turbofans employing ultra-high-bypass ratios as constituting a “next generation after [the CFM] LeapX and [Pratt & Whitney geared turbofan] GTF,” according to Dawkins. The manufacturer has suggested new side- or overhead-mounted rear-engine installations to accommodate larger fan diameters (and perhaps reduce internal, if not also external, sound levels).

Nor has the cockpit been ignored in Airbus “blue-sky” thinking about future technologies. Dawkins said lower crew workload is among characteristics of innovative cockpits that will offer improved mission management (through next generation “interactivity”). New flight decks will take full advantage of forthcoming ATM systems that Airbus believes provide the “key to air-transport growth.”

Viewing itself as an aircraft integrator, the manufacturer is “defining and developing future on-board ATM capabilities and operations.” As such, Airbus is working to support “overall coherence and convergence of the 300 [single European sky ATM research] SESAR projects,” at the core of which is the introduction of four-dimensional trajectories that accommodate predicted aircraft positions. Future ATM must ensure air transport growth, while minimizing environmental impact, said Dawkins.

All such potential advances are major elements in the manufacturer’s mind as it works to understand necessary future design characteristics, said Dawkins. “The requirements will drive technology and decisions [we make],” he noted.

Airbus expects an A320-replacement design in the mid- to late-2020s could be an all-composite construction, powered by open-rotor fans. “We do not know enough about all-composites structures yet,” said Leahy. The best powerplant will “probably be an open-rotor fan, but engine-makers have not figured it out. [That will take until] the middle or the end of the next decade–not before.”

More immediately, introduction of a fourth (probably open-rotor) powerplant choice for the A320, if Airbus decides to go down that path by offering a new engine option later this year, would confirm what the company perceives as current industry uncertainty. Powerplant manufacturers say the best foreseeable technology is not yet available, while airlines are saying that they cannot wait while fuel prices continue to rise: they want an interim improvement.