Reduction in exhaust pressure ratio weight flow had very little effect on the inlet temperature rise. Reduction in exhaust gas temperature lowered the inlet air temperature significantly. Large changes in wing area and variations in lift engine inletexhaust arrangements caused no consistent or significant trends in inlet temperature rise characteristics. In dual lift engine configurations the forward inlet experiences somewhat higher temperatures than the aft inlet. Changes in wing planform shape and height on the fuselage had no appreciable influence on lift engine inlet temperature rise. Forward facing side inlets experience large rises in air temperature for any exhaust nozzle arrangement. Typical aircraft components such as flaps, slats, inletexhaust doors, and landing gear have very little influence on inlet temperature rise. Deflecting the exhaust gases rearward, as in the case of STOL operation, reduced inlet temperature rise significantly at relatively low forward speeds. Moderate headwinds cause a rapid increase in inlet air temperature up to 15 to 20 fps after which the temperatures reduce somewhat. The magnitude of temperature rise is dependent on the inletexhaust arrangement. The motion during vertical ascent and descent apparently alters the pattern of hot gas recirculation and reduces the net inlet temperature rise considerably.