Hybrid unmanned aerial vehicles (UAVs) like Tiltrotor VTOLs, Tiltwings or Tailsitters have become increasingly relevant in recent years. Due to their highly nonlinear and over-actuated dynamics a sufficient controller approach is required. Incremental Nonlinear Dynamic Inversion (INDI) is a novel approach capable to stabilize and control hybrid UAVs. However, INDI is a very complex controller approach. Hence, real world flight testing poses a certain risk for a crash. Wind tunnel based virtual flight tests are a possible way validating such a controller approach at minimum risk. Thus, this paper presents validation of an INDI based attitude controller for a Tiltrotor-VTOL conducting dynamic wind tunnel testing. For that purpose, the aircraft is integrated into a wind tunnel using a 3-degrees-of-freedom test rig. This test rig is equipped with load cells measuring the forces acting on the aircraft. On this basis doublets for roll and pitch angle are commanded at different steady state points during the transition. Based on the system responses the controller approach is validated.