Abstract: The work is aimed at determining the overall installation performance of the convergent ejector nozzle/afterbody with or without fixed auxiliary inlet doors. The experimental mach numbers range from 0.6 to 1.2. The nozzle pressure ratio extends from 2.6 to 4.3. The corrected secondary weight flow ratio is 3.5%. The testing technique presented gives the correlation of the axial momentum tare forces of bellows with the pressure measured in the bellows. The wind tunnel test data can be revised in timely manner with the tare forces computed. The tests show that due to the effect of the tertiary flow the nozzle thrust coefficient and efficiency of the ejector nozzle with fixed auxiliary inlet doors increase by 1 to 1.6% and 1.6 to 2.8% respectively compared with one without these doors.