The XHC-575 is a tilt-rotor convertiplane (like V-22 Osprey) but utilize novel layout with joined wing. This configuration have several advantages like increased stiffness, lower weight and reduced induced drag, but I select this layout in order to decouple engine from wing. In a classical layout - rotors at wingtip, lift generated by the jet engine applied at wingtip, so bending arm equal to half of wingspan, that additionaly increase wing weight (lift from wing in cruise applied more closer to fuselage). In this case the engine mounted at short stub pylon, thick airfoil and short bending arm reduce weight penalty. Wing serve only as lift producing device and don't loaded by additional forces due to engine installation, that save us additional pounds of weight. Also, when wing free from engine loading, you can increase aspect ratio.