"The purpose of the present work is to extend the previous investigation and to derive additional airfoil sections designed to minimize the undesirable characteristics of the previously tested airfoils. The tests of these additional airfoils were made in the Langley two-dimensional low-turbulence tunnel (LTT)" (p. 2).

From Introduction: "The research program included clean-up tests (unpublished data) and stability and control tests (reference 1) made in the NACA Langley full-scale tunnel. An investigation of the aerodynamic characteristics of the power-plant installation in the Cleveland altitude wind tunnel is discussed in this report."

From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."

Report discusses calibration testing performed on a Kollsman type G-1 and an NAF No. 1 pitot tube at several Mach numbers and angles of attack. The effect of drain holes on the flow within the pitot tube was analyzed and the ability to estimate the error in the total pressure was created. The accuracy of the extrapolated and estimated values were found to be within reasonable limits.

From abstract: "Some investigations have been made to ascertain the similarity of the mechanism of action of radiation which are different in their specific ionization. A suggested approach was to determine if the energies absorbed from the different types of radiation are additive in their lethal effects on biological objects. In an attempt to determine the additivity of ionizing radiation various dose combinations of fast neutrons, gamma rays and beta rays were administered to Drosophila eggs. These test objects were chosen because their dimensions are such that they tend to absorb these three radiations uniformly throughout their volume. Although the three radiations were found to vary in their biological effectiveness, per unit energy absorbed, all three were shown to be completely additive in their lethal effect on these organisms."

Report presenting the horizontal and vertical components of the induced velocity in front of an inclined propeller in a horizontal stream obtained by a magnetic-analogy method. The problem was formulated in terms of the linear theory of the acceleration potential of an incompressible nonviscous fluid.

Report presenting an investigation to determine the stability and control characteristics of a straight-wing, tailless fighter model with a pusher propeller in the free-flight tunnel. The investigation consisted principally of force and flight tests of a powered dynamic model. Results regarding longitudinal stability, longitudinal control, trim at high angles of attack, lateral stability, and lateral control are provided.

Abstract: "A polarographic method for the determination of tuballoy in thorium peroxide cakes in all sold medium was found to give satisfactory results. Fluorescent analyses on effluents containing thorium gave good results if the thorium content was kept below 1 mg/liter."

Report discussing testing to determine the effect of ethylene dibromide on the knock-limited performance of S reference fuel. An increase in ethylene-dibromide content did appear to decrease the knock-limited performance of the fuel up to a certain point and at all but the extremes of fuel-air mixtures.

Report presenting the effects of large variations of lateral area on the lateral stability and control characteristics of a free-flying model when ailerons are used as the principal control as determined by flight tests. The effects of the lateral-force parameter were investigated for a wide range of values of the directional-stability parameter and the rotary-damping-in-yaw parameter.

"The danger of shocks and separation in high-speed flight due to the presence of externally carried fuel tanks and bombs is pointed out, and a rough analysis of the phenomena involved is attempted. A discussion is given of the application and limitations of the superposition methods for calculating local velocities in the region between the wing and the external stores, and for predicting critical Mach numbers. Some suggestions for improved designs are also presented" (p. 1).

Report presenting tests of two typical low-drag airfoils of 90-inch chord to determine the effects of surface projections, grooves, and sanding scratches on boundary-layer transition. Data were obtained for projections of various sizes and chordwise locations on both low-drag airfoils.

Report presenting tests conducted with two typical low-drag airfoils of 90-inch chord to determine the effects of surface projections, grooves, and sanding scratches on boundary-layer transition. Data were obtained for projections of various sizes and chordwise locations on both low-drag airfoils.

"In conjunction with a program of research on the general problem of stability of airplanes in the climbing condition, tests have been made of a spring-loaded tab, which is referred to as a "springy tab," installed on the elevator of a low-wing scout bomber. The tab was arranged to deflect upward with decrease in speed which caused an increase in the pull force required to trim at low speeds and thereby increased the stick-free static longitudinal stability of the airplane. It was found that the springy tab would increase the stick-free stability in all flight conditions, would reduce the danger of inadvertent stalling because of the definite pull force required to stall the airplane with power on, would reduce the effect of center-of-gravity position on stick-free static stability, and would have little effect on the elevator stick forces in accelerated flght" (p. 1).

Report presenting a series of dynamic tests undertaken on a model of a hull of JRM-1 in order to provide information on the probable water loads during rough water landings. The impact acceleration and trim data are analyzed to show the trend of accelerations with wave size and length-height ratio.

Report presenting an investigation of the antiknock effectiveness of N-methyl-aniline and xylidines as fuel additives under severe engine operating conditions. 5-percent concentrations by weight were blended with an alkylate blending agent and a virgin-base gasoline.

"In order to determine the lead susceptibility of several fuels, leaded and unleaded fuels from the same stock were blended and tested in a full-scale air-cooled aircraft-engine cylinder. The fuels were S-4 reference fuel, virgin-base stock, aviation alkylate, neohexane, and blends of 25-percent benzene with 75-percent virgin-base stock and 25-percent toluene with 75-percent virgin-base stock" (p. 1).

Abstract: "A survey report of the known production and experimental methods for the preparation of anhydrous tuballoy tetrachloride with references of each method."

Report issued by the U.S. Bureau of Mines regarding the concentration of manganese ore along the Missouri River valley. The report contains maps, tables, graphs, photographs, and illustrations.

Report presenting an examination of the surfaces of used cast-iron piston rings from various single-cylinder aircraft engine tests by electron diffraction. Generally, the oxide patterns were obtained to an appreciable extent from only the top compression ring of the piston-ring assembly; the other rings gave predominately a graphite pattern.

Note presenting selected pressure-distribution diagrams for a number of conventional and special airfoils. The conventional airfoils include the NACA 22, 44, and 230 series airfoils and Clark Y family and the special airfoils consist of circular-arc sections of several thicknesses and a number of synthetic airfoils. The pressure distributions are in most cases given for several lift coefficients including that at the ideal angle of attack.

Report with Supporting maps and calculation tables on the Abajo Mountains District, Geen River Desert Area, Utah.

A report with corollary maps and calculation tables on the Blanding District.

Report issued by the Bureau of Mines over investigations conducted on the 1944 fire at the East Ohio Gas Company. Descriptions of the plant, and construction of the gas tanks are listed. A detailed description of the disaster, and its aftermath are also presented. This report includes tables, maps, illustrations, and photographs.