Report presenting tables for determining the total-absorption coefficients as well was the intensities and spectral distribution of gamma rays at any scattering angle. Both experimental and computed data on gamma rays of quantum energies up to 20 million electron volts for all elements which have significant data available are provided. The accuracy of results is obtained by the use of tables.

A model of one of the twin hulls of the Italian Savoia S-55-X flying boat (N.A.C.A. Model 46) was tested in the N.A.C.A. tank according to the general method. The data obtained from these tests cover a broad range of speeds, loads, and trims and are given in nondimensional form to facilitate their use in applying this form of hull to any other flying boat or comparing it's performance with the performance of any other hulls. The results show that the resistance characteristics at best trim of this model are excellent throughout the speed range. In order to compare the performance of the S-55-X hull with that of the 35, a pointed-step hull developed at the N.A.C.A. tank, the data are used in the computations of take-off example of a twin-hull, 23,500-pound flying boat. The calculations show that the S-55-X hull has better take-off performance.

From Summary: "The data from previous NACA pressure-distribution investigations of plain flaps and tabs have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with flap chord and tab chord are given in chart form and comparisons are made with the theory. With the aid of these charts and the theoretical relationships for a thin airfoil, the aerodynamic characteristics for control surfaces of any plan form with plain flaps and tabs may be determined. A discussion of the basic equations of the thin-airfoil theory and the development of a number of additional equations that will be helpful in tail design are presented in the appendixes. The procedure for applying the data is described and a sample problem of tail design is included."

From Introduction: "The present report gives all the results, including those published in reference 1 and the results of previously un-published tests tests of the airfoils at positive angles of attack."

From Summary: "This report contains the lift, drag, and moment characteristics of tapered Clark Y, Gottingen 393, and USA 45 airfoils as obtained from tests made in the Variable Density Wind Tunnel of the NACA. The results are given at both low and high Reynolds Numbers to show scale effect and to provide data for use in airplane design."

From Introduction: "The results of varying only Reynolds number for several equivalent tip speeds are presented and probable reasons for the apparent variation of adiabatic efficiency with inlet temperature are discussed."

Note presenting an investigation of the fatigue characteristics of riveted joints in aluminum alloy sheet. The purpose of this report is to summarize all the results of fatigue tests that have been made to date in the Aluminum Research Laboratories of lap joints with 1/8-inch aluminum alloy rivets.

"Tensile and compressive stress-strain curves, stress-deviation curves, and secant modulus-stress curves are given for longitudinal and transverse specimens of 17S-T, 24S-T, and 24S-RT aluminum-alloy sheet in thicknesses from 0.032 to 0.081 inch, 1025 carbon steel sheet in thicknesses of 0.054 and 0.120 inch, and chromium-nickel steel sheet in thicknesses form 0.020 to 0.0275 inch. Significant differences were found between the tensile and the compressive stress-strain curves, and also the corresponding corollary curves; similarly, differences were found between the curves for the longitudinal and transverse directions" (p. 1).

"The airflow about a model while being tested is often sufficiently affected by the model support to lead to erroneous conclusions unless appropriate corrections are used. In this paper some new material on the subject is presented, together with a review of the airfoil support corrections used in several other laboratories" (p. 1).

Report presenting an application of the linearized supersonic flow theory to the calculation of the camber and twist required for various lift distributions on a triangular wing with leading edges behind the Mach cone. Several specific examples are used and plots of the cambered surfaces, corresponding lift distributions, and values of the theoretical drag coefficients are presented.

"The tests described in this report were made as part of an investigation of the spinning characteristics of the F4B-2 airplane conducted at the request of the Bureau of Aeronautics, Navy Department" (p. 1).

"Results are presented of compressive stress-strain tests of titanium sheet at temperatures from room temperature up to 800 degrees Fahrenheit, exposure times of 1/2 to 2 hours, and strain rates of 0.002 to 0.006 per minute. The results show that titanium has favorable compressive properties, comparable to those in tension, up through 800 degrees Fahrenheit. Marked anisotropy in compression was also noted" (p. 1).

"The slip theory of plasticity is applied to the problem of calculating the strains associated with biaxial tension for the case of constant stress ratios and is found to be in better agreement with experiment than the octahedral-shear and maximum-shear theories usually employed to analyze such data" (p. 1).

Results presenting testing of a model with heavy beam loading and an angle of dead rise of 30 degrees subjected to smooth-water impacts in the Langley impact basin. Testing was made at fixed trims of 6 degrees, 15 degrees, 30 degrees, and 45 degrees for a range of flight-path angles and consistent beam-loading coefficient. Time histories of horizontal and vertical displacements, vertical velocity, vertical acceleration, and pitching moment are provided.

From Introduction: "This report presents a computational procedure which provides for the rapid and accurate calculation of any streamline in a series of special flows. Detailed information is given on the boundary conditions and equations used for computing the characteristic nets and stream function."

From Summary: "General quenching-distance equations were derived as extensions of the original simple theory of quenching by diffusion of active particles. These equations take into account the possibility of gas-phase chain breaking and branching and the effect of the efficiency of the walls to destroy active particles. The general characteristics of the equations were examined."

From Summary: "The various types of hydrodynamic instability - including porpoising, skipping, and yawing - that may be encountered during take-off or landing of a flying boat are described and the piloting technique required for efficient take-offs and landings is discussed. Suggestions are made for assisting a pilot to become familiar with the take-off and landing qualities of a flying boat that is new to him."

Given here is a brief review of the fundamental principles of the propeller slip-stream theory and its further development through later researches, which demonstrate the connection between the propeller slip-stream theory and Frounde's so-called 'propeller blade theory.' The propeller slip-stream theory, especially in its improved form, now gives us the basis for determining the mutual influence of the parts of the blade, so that, in calculating the shape of the blade, we can get along with certain section characteristics, which have been determined once and for all. It is argued that new theories present the possibility of investigating the phenomena in the vicinity of the propeller, allowing us to calculate its action on the basis of fewer experimental values.

A study was made of the most important factors affecting the range of airplanes. Numerical examples are given showing the effects of different variables on the range of a two-engine airplane. The takeoff problems of long-range airplanes are analyzed.

Report presenting an investigation of the observed discrepancy at supersonic speeds between theoretical and apparent experimental average flat plate friction-drag coefficients calculated from boundary layer total-pressure surveys. Some of the qualities investigated included the effects of the total-pressure probe, heat transfer through the leading-edge region, change in leading-edge radius and strength of the leading-edge wave, possible early transition to turbulent flow, and the slight streamwise pressure gradient in flat plate flow were investigated for plates with very sharp leading edges.

Equations and charts have been presented for the conical part of the sidewash above and below swept wings at small angles of attack. This flow-field component is necessary in making calculations of the wing-induced forces and moments on stores, missiles, and pylons. All supersonic Mach numbers and wing leading-edge sweep angles have been considered.

Report presenting an investigation to determine the effects of loading on the performance of axial-flow fan and compressor blades in a test blower. Results regarding verification of the two-dimensional design data and effects of blade roughness are provided.

Report presenting measurements of lift, drag, and pitching moment of an NACA 0011 airfoil in icing using two types of pneumatic de-icers, one with spanwise inflatable tubes and the other with chordwise tubes. Results regarding the airfoil characteristics with the de-icer operating and effect of primary ice formation on drag, lift, and pitch with the de-icer inoperative are provided.

From Introduction: "The investigation was intended to cover the characteristics of individual cups and of similar cups mounted on complete cup wheals. This report treats the static tests run on the individual cups."