<div class="htmlview paragraph">Wind tunnel tests were conducted at subsonic and transonic Mach numbers to determine the performance levels of exhaust nozzles installed in an aircraft. These tests were conducted with dual nozzles mounted in rigs simulating the entire airplane and with a single nozzle installed in a shaft-mounted rig simulating the aft end of half the airplane. Baseline isolated tests were also conducted with a single exhaust nozzle mounted on a cylindrical shaft. These tests showed that the better the simulated installation, the more valid the results. They also showed that a shaft mounted simulated airplane installation could provide valid trends for selecting the optimum nozzle installation.</div>