A combined experimental-numerical study of the jet interaction flowfield associated with sonic injection of a gas into a turbulent, high-speed crossflow (M=4.0) was conducted with an innovative configuration for jet-thruster applications. This configuration consists of a sonic primary jet, flanked by arrays of smaller secondary sonic injectors that interact with the flowfield created by the primary jet. The mass flow from the small secondary jets ranged from 0.5-1% of that from the primary jet. Pressure sensitive paint was used to measure the pressure field acting on the surface. Forces and moments acting on the flat plate were quantified by integration of the pressure field. Schlieren photographs were used to analyze the main flow features generated by the jet interaction. The numerical solution used the Reynolds-averaged Navier-Stokes equations and Wilcox's κ-ω turbulence model