Airbus UpNext, the airframer’s innovation arm, has completed the installation of its eXtra Performance Wing onto a Cessna Citation VII business jet that will next year serve as a flying testbed for the project.

Featuring a high aspect ratio of 17:1, the long, slender structure is equipped with folding tips and multiple automatic load-alleviation systems – based around biomimicry – designed to save weight and enhance aerodynamic efficiency.

Modification work on the Citation began in summer last year and the jet’s original wing was removed in October by project partner Tarmac Aerosave at Cazaux airbase in southwest France.

Acknowledging the unusual step, Franck Delaplace, who is in charge of the eXtra Performance Wing demonstrator, says the team “had to be careful not to damage the rest of the aircraft” during the removal process.

Prior to cutting off the wings, the business jet was suspended in a “zero-stress configuration” using a specially adapted cradle, to ensure “we did not apply any loads during that operation”, says Sebastien Blanc, technical director for the project.

Standard non-destructive testing of the fuselage then verified “that the aircraft was safe to reinstall the wing”, he adds.

Then a metallic “transition box” was installed at the wing root in late 2024, to act as a bridge between the fuselage and the new composite wing – a vital modification given that it is “a non-Airbus aircraft” says Blanc.

Installation of the wing – built at the airframer’s UK wing centre of excellence in Filton near Bristol – began in June and “more or less a couple of weeks after we put on the foldable parts”, says Delaplace.

Reassembly of the twinjet, including the refitting of its engines, was completed in July.

Ground testing of the Citation began in August, which, in addition to ground vibration, structural and aeroelastic testing of the new wing, will also include assessment of the newly installed fly-by-wire controls that replace the jet’s legacy mechanical system.

Further system testing will continue into early 2026, readying the demonstrator for its maiden sortie around mid-year; flight tests – all remotely piloted – are scheduled to run until the end of the project in December.

Blanc says the aim of the project is not only to prove the aerodynamic efficiency of the wing itself but mainly the efficacy of its “active control functions”, including morphing ailerons and pop-up spoilers linked to gust sensors fitted to the front of the aircraft.

“To make if efficient in terms of fuel consumption you need to be able to do a high-aspect-ratio wing which is light enough not to lose all your aerodynamic benefits to additional mass,” says Blanc.

The load-alleviation systems to be tested are key “enabling technologies” for a longer, thinner wing, he adds.

And while the folding wing-tips are in part incorporated to allow access to current airport gates – as seen on the Boeing 777X, for example – the “semi-aeroelastic hinge” used on the eXtra Performance Wing “could be released in flight for load alleviation purposes”, says Blanc.

Spanning some 20m (65ft), the eXtra Performance Wing fitted to the demonstrator is a scaled-down version of a narrowbody-sized structure with a span of around 50m. The folding tips account for about one-third of the length of each wing.

Outside of UpNext, the airframer is also working on wing concepts for a next-generation single-aisle through its Wing of Tomorrow programme.