Report presenting an investigation of ailerons with a beveled trialing edge and a blunt-nose overhang of 35 percent aileron chord on an NACA 66(215)-26 airfoil in two-dimensional flow. Five configurations were tested with various modifications of the aileron nose and adjacent airfoil contour to determine the effect of modifications on lift and aileron hinge-moment characteristics.

Force and flight tests were performance on an all-wing model with windmilling propellers. Tests were conducted with deflected and retracted flaps, with and without auxiliary vertical tail surfaces, and with different centers of gravity and trim coefficients. Results indicate serious reduction of stick-fixed longitudinal stability because of wing-tip stalling at high lift coefficient. Directional stability without vertical tail is undesirably low. Low effective dihedral should be maintained. Elevator and rudder control system is satisfactory.

Report presenting an iteration method for determining the longitudinal control characteristics of a flexible horizontal tail. The method permits factors such as the actual spanwise variation of elasticity and the aerodynamic induction effects due to three-dimensional flow to be accounted for to any degree of accuracy needed. An analysis is also included of the effects of horizontal-tail flexibility on the tail effectiveness, the hinge-moment characteristics, and the control-force gradients in a dive recovery for two modern fighter airplanes.

From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.

Report presenting the results of a drag investigation of twelve military airplanes in order to increase their speed. The main purpose of the report is to point out undesirable aerodynamic features as a guide to airplane designers. Results regarding the power-plant installation, installations in wings, empennages, armament, canopies, and radio antenna are provided.

Report presenting an investigation of the transition of the boundary layer from the laminar to the turbulent regime on the concave side of a plate with a radius of curvature of 8.5 feet. Results regarding the mean speed distribution, effect of curvature on the position of the transition point, effect of the pressure gradient on transition, and effect of free stream turbulence on transition are provided.

Report presenting an investigation of a P-513 airplane with the propeller removed in flight at Mach numbers up to 0.755 and a comparison of those results with those of a wind tunnel test with a scale model.

Report presenting an electron-diffraction examination of cast-iron piston rings used in a single-cylinder test engine, which showed the presence of a layer of graphite covering the surface. The wear curves from the rings studied had shown variation from high rates to very low rates of wear.

From Summary: "The results of the analysis showed that the combined efficiency, which is unacceptably low at speeds less than 300 miles per hour, becomes nearly equal to that of conventional power plants of current design at 500 miles per hour. It was also shown that the efficiency will be increased considerably as the physical limitations on cycle temperature and blower speed are raised and as the efficiencies of the system components are improved."

Report presenting a large air scoop designed for high critical speed, which has been tested in the 8-foot high-speed tunnel on the fuselage of a scale fighter-type airplane. The effects of boundary layer on scoop characteristics were found to be important at all inlet-velocity ratios. Results regarding the boundary-layer surveys, characteristics of original scoop installation, and characteristics of scoop with boundary-layer passage are provided.