Features Aircraft manufacturers
Hot wings for the future of aviation

At an undisclosed location, likely in Canada, the future of sustainable business aviation is taking shape. The aviation industry is working on the next revolutionary leap. A technological game changer that will lead to a 10 to 15 per cent reduction in fuel burn and emissions. Similar to how a Pratt & Whitney geared turbofan engine and a revolutionary, resin-infused advanced composite wing, developed by Bombardier’s then Shorts Brothers plant in Belfast, paved the way for the most efficient and versatile airplane in its class. Now the Airbus A220.

A new-generation narrow-body replacement for the Airbus A320 and Boeing 737 families of jetliners will not be launched using existing wing and propulsion technologies. (Although Boeing will have to use existing technology for a new mid-market airplane to replace an ageing global fleet of 757, 767 and A310 airplanes.) 

Part stingray in appearance, the Bombardier EcoJet is a family of scalable demonstrators to test the performance characteristics of Blended Wing-Body (BWB) design. Blending the wing seamlessly with the fuselage produces a single lift service that lowers drag and will significantly reduce fuel-burn compared with conventional jets. Cutting emissions by up to 50 per cent. 

The research into EcoJet technologies began 15 years ago in concept. Bombardier began the first phase of testing with a small-scale model of a BWB aircraft featuring a 2.5-metre wingspan. A second phase of testing launched in 2022, using a model more than double the wingspan of the first test vehicle, representing approximately 16 per cent of a large business jet. Earlier this year, Bombardier announced the University of Victoria Centre for Aerospace Research and British Columbia’s SME Quaternion Aerospace as early partners in the EcoJet project. 

Data collected from each test phase will shape the development of the next fleet of test vehicles. But don’t expect Bombardier to come out with a clean sheet design before the end of the decade. No manufacturer has reached that point and Bombardier notes the flight-testing program involving its BWB designed vehicles will be held over multiple years to generate increasingly precise data in representative environments. 

The hottest wing about to enter service belongs to the Boeing 777x. A third-generation variant of the world’s best-selling widebody. Expected in late 2025 or 2026. Using the 787 as a template, the 777x features a 71.8 metre, all composite wing, 6.9 metres longer than the existing triple-seven, with foldable wing tips (FWT) that reduce the length of the wing to the original size. 

A first for commercial aviation, foldable wings have been a feature on advanced military aircraft needed to park in small spaces on an aircraft carrier. Boeing had first offered foldable wing tips on the original 777. More than 30 years later, it is an idea whose time has come. 

Similar to a blended wing, the new wing gives the 777x greater lift, reducing fuel burn by an estimated 10 per cent. The foldable wing tip enables the aircraft to use airport gates that can already support an existing 777. On the ground, the 777 will taxi to the runway with wings folded. It will take 20 seconds to extend and lock the wing tips into place.

In mid-August the launch of the 777x aircraft encountered another delay as Boeing discovered problems in a structural component between the engine and the plane’s wings in a test flight. The 777x program was launched in 2013 to build the world’s largest and most efficient twin-engine jet, with seating for up to 426 and a 13,500 km range (both targeted for the 777-9 variant). 

The 18-foot-wide demonstrator of Bombardier’s EcoJet research project flew for the first time in 2022.

Boeing patented its foldable wing in the early-1990s. Airbus patented its own foldable wing in 2014 and is considering a hinged wing for its A320 replacement. 

In September 2021, Airbus launched the eXtra Performance Wing project. The project seeks to develop a wing that can change shape and form during flight to maximize its aerodynamic efficiency. Last November, the eXtra Performance Wing project demonstrator, a modified Cessna Citation VII business jet, took off for the first time. 

The eXtra Performance Wing design incorporates active control technologies, as well as physical changes to the wing structure. Airbus explains gust sensors on the front of the aircraft will register changes in turbulence, triggering relevant adjustments to the control surfaces of the wing. “This system is designed to be entirely automatic,” says Sebastien Blanc, eXtra Performance Wing Technical Director. “The eXtra Performance Wing technologies, which change the shape of the wing by mimicking a bird’s feathers, will adjust automatically to maximise aerodynamic flow.”

The targeted wingspan of the eXtra Performance Wing will be approximately 52 metres, compared with an A320 wingspan of 35.8 metres. A one-third scale version of the eXtra Performance Wing will be attached to the Cessna and undergo ground testing later this year before first flights begin in 2025. Airbus notes the eXtra Performance Wing technologies could be applicable to any kind of aircraft and propulsion system. 

It is estimated that narrow-body aircraft account for half of commercial aircraft emissions produced today. Producing wings that are longer, leaner and lighter will be one of the aviation industry’s biggest opportunities to improve fuel efficiency, reduce emissions and achieve the industry’s ICAO-led target of net zero carbon emissions by 2050.

“The drive to be leaders of sustainability makes us do things differently. While aerospace has been fantastic at becoming more efficient decade by decade, the bold promise we have made to sustainability, and the technology we need to get there drives us in a different direction,” said Steve McCullough, senior vice president of engineering and product development at Bombardier.

David Carr is a former editor of Wings and Helicopters magazines.