Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil with a 30 percent-chord Maxwell leading-edge slat and a slotted and a split flap. The main purpose was to determine the optimum slot cap of the Maxwell slat for, and the aerodynamic section characteristics of, the airfoil with several deflections for both types of flaps. Curves of lift, drag, and pitching-moment characteristics for optimum arrangements are provided.

Report presenting drag measurements in the two-dimensional low-turbulence tunnel of an available 100-inch-chord model of the NACA 23016 wing section. Results regarding the curves of section drag coefficient plotted against Reynolds number for various surface conditions and lift coefficients, variation of drag coefficient with lift coefficient, and effects of skin friction are provided.

Report presenting testing to determine which of three spinner-diffuser designs on an NACA cowling was the most effective in cooling a Pratt & Whitney R-2800 engine installation. The results of pressure-distribution studies in front of and behind each bank of cylinders are presented for a wide range of propeller-operating conditions.

Report presenting an investigation of carburetor-air scoops designed for the XTB2D-1 airplane in the NACA propeller-research tunnel. The purpose of the investigation was to determine the performance of several scoops and to make modifications necessary to improve the pressure recovery without adversely affecting the drag of the airplane. The investigation included tests of nine carburetor-air scoops with numerous boundary-layer-bypass and ducting modifications, the original engine cowl, and two canopies.

From Introduction: "An investigation of the power-plant installation of a single-engine torpedo-bomber-type airplane has been conducted in the NACA Cleveland altitude wind tunnel at the request of the Bureau of Aeronautics, Navy Department. A similar investigation was previously conducted on a three-tenths scale mock-up of the forward portion of the fuselage of this airplane in the Langley 20-foot tunnel. (See reference 1)."

Report discussing the results of accelerated erosion tests to determine the separate effects of the passage of fuel, water, and ice particles through a supercharger. Recommendations for preventing erosion are provided, including materials choice and joint design.

Report discussing tests to determine the performance of an aircraft engine cylinder using nitrous oxide to provide additional supercharging. The test results of injecting it as a gas and calculated results of injecting it as a liquid are described.

Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.

Report presenting an investigation to determine the loci of possible positions of a heavy bomber in space following a 12-second interval.

Report discussing the results of power-off wind tunnel tests of a twin-engine cargo airplane equipped with wheel skis. Stability characteristics are described for two flap positions and three ski positions. The effect of fairing the main skis in the retracted position on the drag coefficient is also described.

Report presenting testing in the two-dimensional tunnel of four models submitted by the Glenn L. Martin Company as intermediate sections of the wing of the XB-33 airplane. Each airfoil model had different types of flaps or no flaps at all. Results regarding the lift and drag data, lift coefficients, effect of flap positions, aileron effects, drag coefficients, and hinge-moment coefficients are provided.

"At the request of the Bureau of Aeronautics, Navy Department, tests were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane. The object of the tests was to determine the power-off static lateral and longitudinal stability and control of the complete model" (p. 1).

Report comparing the drag of an airplane with a conventional body with that of an airplane carrying cargo in a detachable airfoil-shaped body. Information about the performance, longitudinal stability, and control characteristics of a lifting-body cargo airplane is also provided and compared with a conventional cargo airplane.

From Introduction: "This report presents the results of these tests which cover a total of about 70 flying hours on this airplane."

Report presenting testing of a model of the Douglas DC-3 airplane for several loading conditions. The load factor for the complete airplane, for the horizontal tail, and the force to start moving the elevator downward were estimated for some steady spins. Testing occurred at 2500 feet and 10,000 feet.

Report presenting force tests and measurements of the pressure distribution over the elevator and forward part of the fuselage on a flying model of the Curtiss XP-55 airplane in the full-scale tunnel. The results of the elevator pressure measurements are given in this paper. Results regarding chordwise pressure distributions, span-load distribution, and normal-force coefficients are provided.

Report presenting a study of the installation of 1800-horsepower engines in the PB2Y-3 airplane in place of the current 1200-horsepower engines. Stability and spray tests were made to determine the performance of the model on the water when tested at both the present and projected conditions of gross load and engine power. Results regarding aerodynamic tests and hydrodynamic tests are provided.

Report presenting an investigation to determine the effect of jet motors on the stability of the PB2Y-3 airplane at a gross load of 76,000 pounds. Results regarding Model 131J, Model 131J-1, and Model 131J-2 are provided.

"Flight tests were conducted on a twin-engine fighter airplane at pressure altitudes up to 10,000 feet with simulated conditions of moderate, heavy, and excessive rain to determine the increase in enthalpy of the charge air due to the turbosupercharger, to determine the rate of enthalpy increase of the charge air resulting from a sudden increase of engine power, and to compare the conditions that caused induction-system icing in flight with those that resulted in icing of the same carburetor and supercharger inlet elbow in laboratory tests" (p. 1).

Report discussing measurements of the overall drag coefficient of the XP-51 in dives using three different methods. The three instruments used to measure drag variation are compared for accuracy. A comparison of the drag results obtained from this test are also compared to the results obtained from previous wind tunnel testing.

Tank tests were made of a hull model of the Hughes-Kaiser cargo airplane for estimates of take-off performance and maximum gross load for take-off. At hump speeds, with the model free to trim, the trim and resistance were high, which resulted in a load-resistance ratio of approximately 4.0 for a gross load coefficient of 0.75. With a 4000,000-lb load, the full size craft may take off in 69 sec over a distance of 5600 ft.

Report presenting experimental data on the distribution coefficients of technical xylidines for the system gasoline-water. The distribution coefficient is defined as the ratio of the concentration of xylidines in the gasoline layer to that in the water layer. Results regarding the effect of concentration of xylidines, effect of aromatic content of fuel, effect of sea water, and effect of temperature are provided.

Report discussing the effect of internal coolants on the knock-limited performance of a liquid-cooled multicylinder aircraft engine. Both water and water-ethanol mixtures were tested at several carburetor-air temperatures. Fuel-nozzle injection of the coolant was found to be more effective than injection through intake-manifold spray jets.

Report discussing testing of aromatic amines as antiknock additives, and more specifically the suitability of overwater storage for these fuel blends. 12 aromatic amines of three different concentrations at two temperatures were measured. The chemical properties of the most promising fuel blends are described in more detail and correlations were noted.