"This report presents the results of wind-tunnel tests of a 0.22-scale model of the North American XP-82 airplane with several modifications designed to reduce the buffeting of the airplane. The effects of various modifications on the air flow over the model are shown by means of photographs of tufts. The drag, lift, and pitching-moment coefficients of the model with several of the modifications are shown" (p. 1).

"An analysis is presented of the influence of wing aspect ratio and tail location on the effects of compressibility upon static longitudinal stability. The investigation showed that the use of reduced wing aspect ratios or short tail lengths leads to serious reductions in high-speed stability and the possibility of high-speed instability" (p. 1).

An experimental and analytical investigation of the flutter of sweptback cantilever wings is reported. The experiments employed groups of wings swept back by rotating and by shearing. The angle of sweep range from 0 degree to 60 degrees and Mach numbers extended to approximately 0.85. A theoretical analysis of the air forces on an oscillating swept wing of high length-chord ratio is developed, and the approximations inherent in the assumptions are discussed. Comparison with experiment indicates that the analysis developed in the present report is satisfactory for giving the main effects of sweep, at least for nearly uniform cantilever wings of high and moderate length-chord ratios.

Report discussing the mutual interference effects of tail surfaces and a stern propeller on a model of the XB-42.The main focus was to determine the effect of tail surface-propeller spacing upon the periodic tail surface loading coincident with propeller blade passage.

Memorandum describing preliminary investigations of two 3-inch-diameter slotted test sections over a range of pressure ratios from 1.3 to 10.0. The two test sections varied based on the number of slots and amount of open space, but they showed no appreciable difference in performance. Results regarding the slots with no chamber around the test section and with a closed chamber around the test section are provided.

Report presenting an investigation of the low-speed, power-off static longitudinal stability and control characteristics of a canard model with a triangular wing and horizontal tail in the free-flight tunnel. Results regarding the horizontal tail used to overcome change in stability and horizontal tail used for longitudinal control are provided.

"Flight tests were conducted on a R-2800-21 engine in the P-47G airplane to determine the effect on the wall temperatures of cylinder 10 of throttling the charge in the intake pipe and of injecting a water-ethanol coolant into the intake pipe. Cylinder 10 was chosen for this investigation because it runs abnormally hot (head temperatures of the order of 45 F higher than those of the next hottest cylinder) at the medium and high-power conditions. Tests with interchanged cylinders showed that the excessive temperatures of cylinder 10 were inherent in the cylinder location and were not due to the mechanical condition of the cylinder assembly" (p. 1).

"An investigation was conducted to determine the effect of turbine-disk cooling with air on the efficiency and the power output of the radial-flow turbine from the Turbo Engineering Corporation TT13-18 turbosupercharger. The turbine was operated at a constant range of ratios of turbine-inlet total pressure to turbine-outlet static pressure of 1,5 and 2.0, turbine-inlet total pressure of 30 inches mercury absolute, turbine-inlet total temperature of 12000 to 20000 R, and rotor speeds of 6000 to 22,000 rpm, Over the normal operating range of the turbine, varying the corrected cooling-air weight flow from approximately 0,30 to 0.75 pound per second produced no measurable effect on the corrected turbine shaft horsepower or the turbine shaft adiabatic efficiency" (p. 1).

In accordance with a request of the Bureau of Aeronautics, Navy Department, tests were performed in the Langley 20-foot free-spinning tunnel to determine the spin and recovery characteristics of a 1/24 scale model of the Grumman XTB3F-1 airplane. The airplane is a two-place, midwing torpedo bomber equipped with a tractor propeller and an auxiliary jet engine. The effect of control setting and movement on the erect and inverted spin and recovery characteristics of the model were determined for the normal loading.

"About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included" (p. 1).

From Summary: "The results of numerous unrelated tests of dive-recovery flaps are collected in this report and presented in a form suitable for use in the preliminary design of dive-recovery flap installations. Since the data were obtained for airplane models of quite widely varying configurations, and are limited largely to a Mach number of 0.80, it is recommended that each new installation be carefully flight-tested before final approval. A flight-test procedure is outlined which will insure a maximum degree of safety."

Memorandum presenting an investigation of a model with a ramp that produced an oblique shock wave in front of an annular duct inlet, which was tested at Mach numbers between 1.36 and 2.01 to determine the effect of reducing the entrance Mach number on the total-pressure recovery after diffusion. The results showed that the maximum total-pressure recovery of the model investigated was considerably improved through the addition of a ramp.

Report discussing testing on a series of tapered swept wings under conditions simulating rolling flight. The lift, longitudinal-force, and pitching-moment characteristics for three swept wings are provided. The results indicated that a decrease in taper ratio on a swept wing caused a small decrease in damping in roll at low and moderate lift coefficients.

Report presenting aerodynamic and icing investigations on a model of a turbojet-engine nacelle in order to provide icing protection for the engine, protective screen, and accessory housing by the introduction of hot gases into the inlet-air stream. Adequate ice protection was afforded when the minimum kinetic temperature in the protective screen was greater than 32 degrees Fahrenheit.

"This paper presents the results of measurements of longitudinal stability of a 1/50-scale model of the XP-88 airplane by the wing-flow method. Lift, rolling-moment, hinge-moment, and pitching-moment characteristics as well as the downwash at the tail were measured over a Mach number range from approximately 0.5 to 1.05 at Reynolds numbers below 1,000,000. No measurements of drag were obtained" (p. 1).

Report presenting tests at Mach numbers between 1.36 and 2.01 of a twin-scoop duct inlet that had slots in the walls of the duct contiguous to the forebody and immediately behind the inlet. The mass flow and total-pressure recovery through the diffusor were measured during tests in which the slot length was constant and the slot width and ramp angle were varied. Results regarding mass flow and total-pressure recovery are provided.

Report presenting a wind-tunnel investigation to determine the effect of propeller operation on the characteristics of submerged inlets. The tests were performed with a model of a hypothetical fighter airplane powered by a turbine-propeller unit. The propeller had eight blades with thin airfoil shanks and dual rotation and the submerged inlets were placed in the fuselage behind the propeller and forward of the wing.

"As one phase of a comprehensive canopy load investigation, conventional front and rear sliding canopies which are typified by installation on the SB2C-4E airplane, were tested in the Langley full-scale tunnel to determine the pressure distributions and the aerodynamic loads on the canopies. A preliminary analysis of the results of these tests is presented in this report. Plots are presented that show the distribution of pressure at four longitudinal stations through each canopy for a range of conditions selected to determine the effects of varying canopy position, yaw, lift coefficient, and power" (p. 1).

Report presenting a partial-span wing tested to determine the cause of a flutter which had occurred in high-speed flight. Changes were made to the wing stiffness, location of the center of gravity of the wing, and the mass balance of the aileron. Results regarding the effect of wing changes on flutter, effect of aileron changes on flutter, shock-wave study, and static aerodynamic coefficients are provided.

Results of previous model ditching tests of the Lockheed Constellation airplane are reported. Further model tests have been made to determine the probable ditching characteristics and the proper ditching technique for the airplane with the Speedpak attached. This paper presents the results of these tests. Design information was furnished by the Lockheed Aircraft Corporation. A three-vies drawing of the airplane with the Speedpak attached is shown. The tests were made in calm water at the Langley tank no.2 monorail.

The performance characteristics of the 19B-8 and 19XB-1 turbojet engines and the windmilling-drag characteristics of the 19B-6 engine were determined in the Cleveland altitude wind tunnel. The investigations were conducted on the 19B-8 engine at simulated altitudes from 5000 to 25,000 feet with various free-stream ram-pressure ratios and on the 19XB--1 engine at simulated altitudes from 5000 to 30,000 feet with approximately static free-stream conditions.

A 0.1-size powered dynamic model of a large, high-speed flying boat was landed in Langley tank no. 1 into oncoming waves 4 feet high (full size). The model was tested with two afterbodies of differing lengths (4.12 and 6.63 beams). The short afterbody had a constant angle of dead rise of 22.5deg and a keel angle of 6.5deg. The long afterbody had warped dead rise and a keel angle of 8.5deg. The vertical accelerations were slightly greater and the maximum angular accelerations and maxim= trims were slightly less for the model with the long afterbody than for the model with -the short afterbody. A wave length of 210 feet (full size) imposed the highest accelerations on the model with either the long or the short afterbody.

Report presenting an examination of the characteristics of variable-area and fixed-area atomizing nozzles in relation to use in aircraft gas-turbine engines. A variable-area fuel nozzle and a fuel-distribution control that were used int eh experimental operation of a turbojet engine are described. Results regarding nozzle characteristics and fuel distribution, effect of atomization on engine operating characteristics, and fuel-system characteristics during engine operation are provided.

This report contains the results of the wind tunnel investigation of the pressure distribution on the flying mock-up of the Consolidated Vultee XP-92 airplane. Data are presented for the pressure distribution over the wing, vertical tail and the fuselage, and for the pressure loss and rate of flow through the ducted fuselage. Data are also presented for the calibration of two airspeed indicators, and for the calibration of angle-of-attack and sideslip-angle indicator vanes.