Airbus will fly a carbonfibre fuselage panel on its A340-300 testbed this year as part of its investigation of acoustic transmission within the A350 XWB's composite cabin.
The new twinjet is Airbus's first design with a carbonfibre fuselage skin instead of aluminium. Acoustic ground tests to compare the material's behaviour with a metallic skin have already been carried out. "The question is what that means for noise inside the aircraft when in a flight environment," says A350 chief engineer Gordon McConnell. "So to be able to get that correlation correct, we'll test-fly a carbon panel inserted into A340 MSN001."
This aircraft, which is the 19-year-old original A340-300 development testbed, will be modified this summer with a 4.3m (14ft)-long section of its aluminium fuselage skin aft of the wing replaced with a 14m² (151ft²) carbonfibre panel. It is due to begin testing later this year with different types of acoustic insulation material to understand the effect in a real flight environment, to help Airbus "de-risk" the A350's production and flight-test programmes.
"We'll measure the noise transmission through this panel," says McConnell. "This will allow us to freeze the design with a good level of confidence that we've got the acoustic treatments right to provide a good environment inside the aircraft and avoid having to play with the material later on during the A350 flight-test programme.