Summary: The effects on stability and control of a pusher propeller behind conventional horizontal and vertical tail surfaces have been determined in the NACA free-flight tunnel by tests of a 1/10-scale model of an NACA submerged-engine pusher airplane design. The investigation consisted of flight and balance tests at windmilling and high-power conditions with a partial-span Zap extensible flap extended and retracted. The effects of changes in vertical-tail area, horizontal-tail incidence, and center-of-gravity location were also determined.