Use of an airborne platform for a directed energy system is currently severely limited by aero-optic aberrations arising from density variations in air flowing over the aircraft; the primary limitation is for aft pointing applications. Innovative Technology Applications Company (ITAC), in collaboration with the University of Notre Dame (ND), is working to develop, design, construct and test a turret/adaptive fairing that provides a large field of regard for propagation of a lethal beam from an airborne platform at up to transonic speed. The conceptual design incorporates a fairing that includes a tuned cavity between the aperture and the aft-fairing that excites a resonance mode that robustly regularizes optical aberrations imposed by the shear layer over the entire Mach number range. The cavity will be exposed to the flow only when using the beam in an aft pointing direction. Optical-aberration regularization is the exact requirement for robust feed-forward adaptive-optic correction of a laser propagated through the controlled shear layer. This paper will describe the importance of understanding aeroacoustic behavior to effectively develop aero-optic capability that is based on cavity resonances.