The ATTILA project is aimed at the design, manufacture and testing of an advanced testbed for aeroelastic wind tunnel testing of tiltrotor aircraft. The testbed will consist of a suitably instrumented aeroelastically scaled cantilevered half-wing with powered nacelle-proprotor system representative of the full-scale NGCTR-TD design. Advanced fiber optic sensor and contactless rotating power and data transfer techniques will be used. The design process, coupled with test iterations, is supported by detailed structural and aeroelastic simulations using a range of complementary codes. The ATTILA testbed will first be subjected to a wind-on shakedown test in the DNW LLF 6x6m test section in Froude scaled conditions.