Airbus has begun the first phase of load testing on a demonstrator wing developed under its Wing of Tomorrow programme that will eventually see the structure tested to destruction.
Initial down-bending cases have been performed at the airframer’s Aerospace Integrated Research & Test Centre site in Filton, near Bristol in southwest England, confirms Sue Partridge, head of Wing of Tomorrow.
While an aircraft’s wing flexes upwards in flight, its own weight and that of the components attached to it, notably the engines, cause it to sag when on the ground.
Down-bending simulates that effect and, as it is “lower weight and lower risk”, is the ideal starting point for further evaluations, says Partridge: “It is a good pipe-cleaner for the whole test set-up – a test of a test.”
A further phase of recalibration and reconfiguration of the test equipment will then be required before the testing of “major cases” begins towards the turn of the year, ultimately leading to the “failure case” several months later.
Partridge says the results to date have “confirmed that our predictions were as we expected” and that the test infrastructure is working correctly ahead of the “higher-risk, higher-loaded testing”.
Wing of Tomorrow is developing a long, slender composite wing designed to equip a future replacement for the A320neo family on which Airbus is working through its Next Generation Single Aisle (NGSA) programme.
While the structural performance of the material is one critical aspect, Wing of Tomorrow is also evaluating whether a composite component can be produced at the same high rates as currently achieved with metallic structures.
Another demonstrator, the so-called “run-at-rate wing”, is being built at the Advanced Manufacturing Research Centre facility located adjacent to Airbus’s wing production facility in Broughton, North Wales.
Most of the structure is complete, says Partridge, with the equipping of the fuel system finished in late October. The wing will now be closed, removed from the jig and the control surfaces installed.
Each step is designed to check the stress on the industrial system and “confirm the things we think are the right choices to move forward with”.
That includes understanding where automation in the production process makes sense, and where to retain manual assembly.
“What we deliver to the business is learning – what works and what doesn’t work, what’s the right choice for the next-generation aircraft.”
The Wing of Tomorrow design also includes a folding element, with the outer 4-5m (13-16ft) of the wing folding upwards to allow access to current narrowbody gate infrastructure. While Boeing is using a similar system on its developmental 777X widebody, only the final 3.5m of its much longer wing folds.
“We will take forward lots of learning into the next phase – there is lots more testing to do,” says Partridge.
Meanwhile, Airbus has completed the preliminary design of a further scaled wing demonstrator designed to evaluate the different challenges posed by the integration of an open-rotor engine such as CFM International’s RISE powerplant.
Development work has been part-funded through the first phase of an Aerospace Technology Institute (ATI) programme called Aviation.
Airbus is now in the process of seeking additional ATI funding for a follow-on phase that will see the manufacture from 2027 onwards of a scaled demonstrator of the inner half of the wing, ending outboard of the engine pylon.
Although the fan size on an ultra-high bypass ratio engine will require a degree of gulling to the wing to achieve the necessary ground clearance “we are just pushing that a little bit further” given the still-larger fan diameter on an open-rotor engine.
Airbus has yet to select a propulsion supplier or preferred engine architecture for the NGSA, which is targeted for service entry from 2035 onwards.
Partridge spoke to FlightGlobal at the ATI’s annual conference in Newport, South Wales, on 4 November.
