From Summary: "Section characteristics for use in wing design are presented for the NACA 23012 airfoil with plain and split flaps of 20 percent wing chord at a value of the effective Reynolds number of about 8,000,000. The flap deflections covered a range from 60 degrees upward to 75 degrees downward for the plain flap and from neutral to 90 degrees downward for the split flap. The split flap was aerodynamically superior to the plain flap in producing high maximum lift coefficients and in having lower profile-drag coefficients at high lift coefficients."

"By use of an approximate equation for the wave drag of slender bodies of revolution in a supersonic flow field, the optimum shapes of certain boattail bodies are determined for minimum wave drag. The properties of three specific families of bodies are determined, the first family consisting of bodies having a given length and base area and a contour passing through a prescribed point between the nose and base, the second family having fixed length, base area, and maximum area, and the third family having given length, volume, and base area. The method presented is easily generalized to determine minimum-wave-drag profile shapes which have contours that must pass through any prescribed number of points" (p. 1).

Report presenting testing on parabolic bodies of revolution of two fineness ratios in the transonic and supersonic range. One had a body fineness ratio of 7.87 and one had a ratio of 12 and were tested under different Mach number ranges. Experimental results and drag estimates of various portions of the body are provided.

Report discussing tests on the effect of 2-percent additions of 13 aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The amines tested gave good rich mixture response at standard F-4 operating conditions, but were sensitive to engine severity at lean fuel-air ratios.

"The flexural vibration of a rotating propeller blade with clamped shank is analyzed with the object of presenting, in matrix form, equations for the elastic bending moments in forced vibration resulting from aerodynamic forces applied at a fixed multiple of rotational speed. Matrix equations are also derived which define the critical speeds end mode shapes for any excitation order and the relation between critical speed and blade angle. Reference is given to standard works on the numerical solution of matrix equations of the forms derived" (p. 1).

"A series of wind tunnel tests of a rectangular Clark Y wing was made with the NACA spinning balance as part of a general program of research on airplane spinning. All six components of the aerodynamic force and moment were measured throughout the range of angles of attack, angles of sideslip, and values omega b/2v likely to be attained by a spinning airplane; the results were reduced to coefficient form. It is concluded that a conventional monoplane with a rectangular Clark y wing can be made to attain spinning equilibrium throughout a wide range of angles of attack but that provision of a yawing moment coefficient of -0.02 (against the spin) by the tail, fuselage, and interferences will insure against attainment of equilibrium in a steady spin" (p. 231).

"The tests reported herein were made for the purpose of determining the high-speed load distribution on the wing of a 3/16 scale model of a scout-bomber airplane. Comparisons are made between the root bending-moment and section torsional-moment coefficients as obtained experimentally and derived analytically. The results show good correlation for the bending-moment coefficients but considerable disagreement for the torsional-moment coefficients" (p. 1).

Report discussing an analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft along with equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.

"An investigation was conducted to compare the knock-limited performance of a 20-percent triptane blend in 28-K fuel with that of 28-R and 33-R fuels at high engine speeds, cruising speeds, and two compression ratios in an K-1830-94 multicylinder engine. Data were obtained with the standard compression ratio of 6.7 and with a compression ratio of 3.0. The three fuels were investigated at engine speeds of 1800, 2250, 2600, and 2800 rpm at high and low blower ratios" (p. 1).

This is the second report giving the results obtained in the NACA 20-foot wind tunnel on the drag due to landing gears. The present report gives the results of tests of nonretractable and partly retractable landing gears intended for heavier low-wing monoplanes of the transport and bomber type.

The hydrodynamic characteristics of a preliminary design of the Martin XP6M-1 flying boat have been determined. Longitudinal stability during take-off and landing, resistance of the complete model, and behavior during taxiing and landing in rough water are presented.

The following report covers an investigation that was done to supplement available experimental data on flow fields behind wings of an aircraft at supersonic speeds, as well as to furnish more quantitative information on the choice of the theoretical method for a given configuration and the accuracy to be expected when using such a method.

"The lifting-surface sidewash behind rolling triangular wings has been derived for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the mark cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form. An approximate expression for the sidewash has been developed by means of an approach using a horseshoe-vortex approximate-lifting-line theory" (p. 455).

Report discussing an investigation into several types and sizes of flaps and spoilers located forward of the elevators on the upper surface of the horizontal stabilizer of a model of a radial-engine pursuit airplane. Information about the elevator characteristics, elevator-fixed and elevator-free balance lift coefficient, and trim drag coefficient for a range of Mach numbers is provided.

Report presenting an investigation in the 4- by 4-foot supersonic pressure tunnel to determine the effect of changes in body cross-section shape on the aerodynamic characteristics of bodies and wing-body combinations. A series of 13 bodies of a given length and volume but various cross-section shapes were tested at a Mach number of 2.01. The results showed that changes in drag at zero lift due to changes in body cross-section shape from the basic circular shape are small and of the same order as the test accuracy.

Report presenting a correlation of combustion-efficiency data obtained in experimental investigations with 14 aircraft gas-turbine combustors. The precision is not good for some combustors, but can help in predicting the efficiency at different operating conditions and in comparing the performance of different combustors from data obtained in unrelated tests.

From Summary: "The combustion performance, and particularly the phenomenon of altitude operational limits, was studied by operating the annular combustor of a turbojet engine over a range of conditions of air flow, inlet pressure, inlet temperature, and fuel flow. Information was obtained on the combustion efficiencies, the effect on combustion of inlet variables, the altitude operational limits with two different fuels, the pressure losses in the combustor, the temperature and velocity profiles at the combustor outlet, the extent of afterburning, the fuel-injection characteristics, and the condition of the combustor basket."

Report presenting the results of tests on a model of a jet-propelled airplane and a comparison of drag, maximum lift coefficient, and elevator angle required for level flight in the wind tunnel and in flight. Results regarding the aerodynamic characteristics, longitudinal control, wing pressure distribution, and dive-recovery flaps are provided.

Memorandum presenting a review of information relating to aircraft fires to determine what new or further research might lead to a substantial reduction of the aircraft fire hazard in flight and following crashes. An examination of fuels, lubricants, and hydraulic fluids as inflammable liquids is presented, together with possible sources of ignition under the general categories of hot surfaces, electric sparks and arcs, flames, and hot gases.

A study relating local-pressure fluctuations to static-pressure distributions on six two-dimensional airfoils. Total-pressure fluctuations and total-pressure loss in the wake of an NACA 65A008 airfoil are also compared. Results regarding local-pressure fluctuations on the models and total-pressure fluctuations in the wake of an NACA 65A008 airfoil are provided.

Report presenting pressure distributions measured along prolate spheroids of fineness ratios 3 to 20 and along a slender body of fineness ratio 12 are compared at subsonic and transonic speeds and several angles of attack. The experimental results, prediction of incompressible pressure distribution along the 0 degree and 180 degree meridians, prediction of subsonic pressure distribution along the meridians, prediction of subsonic pressure distributions around prolate spheroids, effect of fineness ratio and angle of attack on separation, and prediction of transonic pressure distribution.

Report presenting an investigation at Mach number 1.94 of a series of triangular-wing and body combinations to determine the interference lift, drag, and pitching moment. The models had a series of seven flat-plate triangular wings of varying scale, four with semiapex angles of 30 degrees, and three with semiapex angles of 45 degrees. Results indicated that the interference between the wing and the body gave an increase in lift over the wing and body alone, but at the expense of more drag.

Report discussing an investigation to determine whether the crank angle for maximum rate of pressure rise can be used to indicate maximum-economy spark advance. Information about spark-advance tests at constant inlet-air pressure and fuel-air-ratio test results are provided.

From Introduction: "The objectives of this report are to present methods and information sufficient for a lineralized dynamic description of the significant dependent and independent variables of a turboprop engine."