The effect of suction and oscillatory blowing (SaOB) on local flow separation in the slat cutout region downstream from a UHBR engine is investigated by means of URANS simulations. The simulation environment mirrors the wind tunnel test of an UHBR high-lift configuration conducted at the small scale low speed wind tunnel at Tel-Aviv University. The validated CFD results are employed to assess the beneficial effect of SaOB compared to individual actuation by means of suction and oscillatory blowing. Both investigated flow control mechanisms are effective in significantly attenuating flow separation and a combined actuation allows to reduce external mass flow requirements by additional 15%. The excitation of the flow in the slat cutout region affects the flow field on large parts of the upper wing. A decrease in lift augmentation by flow control through SaOB compared to oscillatory blowing is most likely attributable to the sensitivities of the longitudinal vortices and corner flow separation.