The effectiveness of several devices in simulating the effects of a rocket plume on the flow field of a typical missile in the transonic Mach number range was investigated. Two plume-shaped solid bodies and three step-type plume simulators were tested. The effects on model pressure distribution of small angle of attack and plume-simulator position were investigated. The analysis showed that all the plume simulators tested can give approximately the same model afterbody pressure distribution at transonic Mach numbers and small angles of attack as an actual rocket plume. (Author).