An understanding of the vortical structures and vortex breakdown is essential for the development of highly maneuverable and high angle of attack flight. This is primarily due to the physical limits these phenomena impose on aircraft and missiles at extreme flight conditions. Demands for more maneuverable air vehicles have pushed the limits of current CFD methods in the high Reynolds number regime. Simulation methods must be able to accurately describe the unsteady, vortical flowfields associated with fighter aircraft at Reynolds numbers more representative of full scale vehicles. It is the goal of this paper to demonstrate the ability of Detached-Eddy Simulation, a hybrid RANS-LES method, to accurately predict vortex breakdown at Reynolds numbers above 1 million. Very detailed experiments performed at Onera with LDV and pressure measurement are used to compare simulations utilizing both RANS and DES turbulence models.