Abstract: The report describes the results of an experimental study involving the injection of a gaseous secondary jet into an unbounded supersonic flow field which was uniform outside of a turbulent boundary layer. The investigation was principally concerned with the formulation of the shock wave shapes and streamline patterns to be associated with typical turbulent, two-dimensional jet-interaction flows. In support of this objective, results are presented for a Mach 5 test conducted using a flat-plate model containing a sonic secondary jet directed normal to the main-stream. The jet-interaction flow field was primarily investigated for jet strengths (ratio of jet gas stagnation pressure to free-stream static pressure) of 180 and 550. Intermediate strengths were also studied but in lesser detail. Local flow properties were measured throughout the flow field and surface pressure distributions were recorded fore and aft of the secondary jet. From these data and complementary shadowgraph studies, the streamline pattern and attendant shock structure were formulated.