The supersonic locally-conical flow over a 5° semi-apex circular cone at a Mach number of 1.8 and angles of attack (AOA) ranging from 10° to 35° is studied computationally using the three-dimensional Navier-Stokes equations. An implicit upwind flux-difference splitting scheme was used to obtain the numerical solution of the governing equations. Three flow patterns were predicted depending on the AOA. These flow patterns are; steady symmetric flow at AOA = 10°, steady asymmetric flow for 15° AOA 25° and unsteady asymmetric flow with vortex shedding for AOA ?. 30° . A number of passive control methods including vertical, fixed or erected, fins, two side strakes and four strakes in two different arrangements, oblique and cross, are used to restore the flow symmetry over the cone. A comparison between the studied control methods is carried out to select the best method of control. The four cross-strake method was found to be the best of the tested control methods.