"Aerodynamic tests were made with four geometrically similar metal propellers of different diameters, on a Wright "Whirlwind" J-5 engine in an open cockpit fuselage. The results show little difference in the characteristics of the various propellers, the only one of any importance being an increase of efficiency of the order of 1 per cent for a 5 per cent increase of diameter, within the range of the tests" (p. 107).

Report presents the results of tests conducted on 28 wing-fuselage combinations made in the variable-density wind tunnel as a part of the wing-fuselage interference program being conducted therein and in addition to the 209 combinations previously reported in NACA-TR-540. These tests practically complete the study of combinations with a rectangular fuselage and continue the study of combinations with a round fuselage and a tapered wing.

Report presents an investigation carried out in the NACA 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped, first, with a full-span NACA 23012 external-airfoil flap having a chord 0.20 of the main airfoil chord and with a full-span aileron with a chord 0.12 of the main airfoil chord on the trailing edge of the main airfoil and equipped second, with a 0.30-chord full-span NACA 23012 external-airfoil flap and a 0.13-chord full-span aileron. The results are arranged in three groups, the first two of which deal with the airfoil characteristics of the two airfoil-flap combinations and with the internal-control characteristics of the airfoil-flap-aileron combinations. The third group of tests deals with several means for balancing ailerons mounted on a special large-chord NACA 23012 external-airfoil flap. The tests included an ordinary aileron, a curtained-nose balance, a frise balance, and a tab.

"The results obtained from measurements of gust velocities, draft velocities, and ambient-air temperature within thunderstorms for the period from September 11, 1946 to September 16, 1946 at Orlando, Florida are presented herein. These data are summarized in.and presented" (p. 1).

Report presenting an investigation of two symmetrical circular-arc airfoils of 6 and 10 percent thickness equipped with leading-edge and trailing-edge high-lift devices. A trialing-edge flap, drooped-nose flap, and leading-edge extensible flap were all tested. Results regarding the plain airfoils, airfoils with high-lift devices, combined deflection of high-lift devices, and low-drag-control flaps are provided.

"An investigation of the spin and recovery characteristics of a 1/24-scale model of the Grumman AF-2S, -2W airplane was conducted in the Langley 20-foot free-spinning tunnel. The effects of controls on the erect and inverted spin and recovery characteristics for a range of possible loadings of the.airplane were determined. The effect of a revised-tail installation (small dual fins added to the stabilizer of the original tail and the vertical-tail height of the original tail increased) and the effect of various ventral-fin and antispin-fillet installations were determined" (p. 1).

Report presenting free jet tests of a model of the inlets and forebody of the McDonnell XF3H-1 airplane with the original and two alternate nose shapes. Results regarding the total-pressure recovery after diffusion, maximum mass-flow ratio, inlet total-pressure profile, shadowgraphs, flow variation, and pressure oscillations are provided.

From Introduction: "Reported herein are the over-all engine performance and the starting and windmilling characteristics. Data are presented in the form of performance maps at each flight condition to show the effects of altitude and flight Mach number on various engine-performance variables. The effect of engine deterioration with operating time on performance is also discussed."

Report presenting an investigation to determine the static characteristics of a two-blade NACA 10-(3)(062)-045 propeller. Experimental data were obtained for a blade-angle range from -5 degrees to 40 degrees measured at the 0.75 radial station and for tip Mach numbers up to 1.0.

Report presenting an investigation of the section and panel characteristics and loads obtained from pressure measurements over a 35 degree sweptback wing at level-flight lifts for a range of Mach numbers. Section pressure distributions were taken at the root, midspan, and tip stations of a Douglas D-558-II airplane.

Report presenting an investigation to determine the effects of six stabilizing fin plan forms and three body-nose configurations on the static stability of a 20 degree cone-cylinder body of revolution that had a fineness ratio of 8.65. The fin plan forms tested were swept untapered fins with 45 and 60 degrees sweep angles, trapezoidal fins, and delta fins. Results regarding the normal force coefficient, pitching moment coefficient, and center of pressure are provided.

Report presenting the aerodynamic design and design-point performance of a 16-inch impulse-type supersonic-compressor rotor component with turning to the axial direction, including an off-design and stage performance analysis. Results regarding rotor component performance, discussion of rotor performance, stage consideration for rotor performance, stage performance, and stator performance are provided.

Report presenting an investigation at subsonic and transonic speeds of the aerodynamic characteristics of a wing-body configuration designated as a swept biplane, which is composed of a sweptback and sweptforward wing joined at the tips. Results indicate that the plan form prevents the abrupt pitch-up normally encountered on monoplane swept wings. Results regarding subsonic tests, transonic tests, and some additional design considerations are provided.

Report presenting thrust-reversal performance of several basic target-type jet reflectors of various sizes and with various modifications obtained with unheated air over a range of exhaust-nozzle pressure ratios. Maximum, or near maximum, reversal for any deflector occurred at a spacing which was mechanically feasible and did not affect nozzle air flow.

From Summary: "An experimental investigation of a series of four convergent-divergent exhaust nozzles was conducted in the Lewis 8-by-6 foot supersonic wind tunnel at Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a range of nozzle pressure ratios. The thrust characteristics of these nozzles were determined by a pressure-integration technique. From a thrust standpoint, a nozzle designed to give uniform parallel flow at the exit had no advantage over the simple geometric design with conical convergent and divergent sections."

Report presenting an investigation to determine the effect of spanwise variations in thickness ratio on the aerodynamic characteristics of wings at transonic speeds. Lift, drag, and pitching-moment data rare presented for 3 wings with different taper ratios. Testing occurred over a range of Mach and Reynolds numbers.

Report presenting an investigation at two Mach numbers to examine the flow, force, and moment characteristics associated with spoilers mounted on a flat plate at a range of sweep angles. Pressure measurements were obtained over the plate and spoiler faces. The pressures were integrated to determine the spoiler lift, pitching-moment, drag, and hinge-moment characteristics.

Memorandum presenting the methods and instruments used at a particular lab to illustrate the magnitudes of errors associated with Mach number measurements at supersonic speeds and at high altitudes. Data is presented for two modified methods of the basic radar phototheodolite method of position-error calibration.

Report presenting an investigation at two Mach numbers to determine the pressure distributions, chordwise loadings, and spanwise loadings for a series of 25.4-percent-chord trailing-edge controls on a trapezoidal wing with a 23 degree sweptback leading edge, aspect ratio of 3.1, and taper ratio of 0.4.

Report presenting an investigation at low speed of a complete-model configuration with a wing of aspect ratio 4, taper ratio 0.3, and 45 degrees sweepback and had inboard and outboard ailerons. The model was tested over a range of sideslip and angles of attack to determine variations of the aerodynamic coefficients, especially pitching-moment coefficient, with sideslip angle. The results indicate that with ailerons deflected, an appreciable variation of pitching moment with sideslip angle can exist.