Altitude performance evaluation of J71-A-11 turbojet engineData were obtained with five exhaust-nozzle areas and with the variable-area exhaust nozzle interlinked with the control system at conditions simulating flight at a Mach number of 0.8 and altitudes of 35,00 and 45,000 feet. Data simulating operation at zero flight Mach number at an altitude of 15,000 feet are also included. Engine component performance data are presented in addition to the overall engine performance.