Shock-wave equations have been evaluated for a range of Mach number in front of the shock from 1.05 to 4.0. Mach number behind the shock, pressure ratio, derivation of flow, and angle of shock are presented on charts. Values are also included for density ratio and change in entropy.

From Summary: "Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section dropped sharply as the ration D/W was increased from zero to about 0.25. The plain specimens showed quite a pronounced decrease in fatigue strength with increasing width. The holed specimens showed only slight and rather inconclusive evidence of this size effect. The fatigue stress-concentration factor was higher for 75S-T than for 24S-T alloy. Evidence was found that a very small hole would not cause any reduction in fatigue strength."

Note presenting results of mechanical tests of several laminated plastics, including canvas laminate molded at low pressure, grade-C canvas laminate, rayon laminate, paper laminate, and glass-fabric laminate. The following tests were performed: static tension, compression, and torsion tests; long-time creep tests at different stresses on specimens loaded in tension; fatigue tests of unnotched specimens in bending; fatigue tests of notched specimens in bending; fatigue tests in bending at temperatures of -75, 77, and 160 degrees Fahrenheit; and fatigue tests in torsion.

Note presenting the development of fundamental equations for the plastic buckling of a rectangular plate under edge thrusts on the basis of a new set of stress-strain relations for the behavior of a metal in the plastic range. The relations are derived for buckling from a state of uniform compression.

"A tabulation is presented of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables include values of Mach number from 0 to 10.0 in increments of 0.01 and the functions are based on the assumption that air is a perfect gas having a specific-heat ratio of 1.400" (p. 1).

From Summary: "Tests were made to determine bearing yield and ultimate strengths of bare and Alclad 15S-W(exp 1) and 14S-T(exp 1) sheet and plate in thicknesses of 0.064 inch, 0.250 inch, and 0.750 inch. From the results of these tests it was concluded that the ratios of bearing to tensile properties from the with-grain direction were essentially the same as proposed in NACA TN Nos. 901, 920, 974, and 981 for other high-strength aluminum-alloy sheet and plate."

Report presenting bearing tests made of aluminum-alloy sand casings of 195-T4, 195-T6, and 356-T6 to evaluate the bearing strength and tensile properties of the alloys. Comparisons with individually cast bars and specimens machined from slabs indicate that size and form of casing may have a significant effect on mechanical properties. Results of the tensile, compressive, and shear tests are provided in charts and include specified minimum and typical properties for comparison.

Note presenting experiments to study the characteristics of low-aspect-ratio wings at supercritical Mach numbers. The experiments consisted of tests of wings of aspect ratios ranging from infinity to 2. The results indicate that the detrimental effects of compressibility in the supercritical speed range on the stability and performance of aircraft are alleviated to a great degree by the use of low-aspect-ratio lifting surfaces.

Note presenting flight-performance measurements made on an untwisted, plywood-covered rotor in the high-speed and vertical-autorotative-descent conditions. The results were compared with measurements on a similar rotor with 8 degrees of linear washout and with theoretical calculations in order to determine the effects of rotor-blade twist on helicopter performance.

Report presenting a low-scale wind-tunnel investigation in both straight and yawing flow to determine the effects of aspect ratio and sweep on the static and yawing stability derivatives for a series of untapered wings. The effects of sweep on the static stability characteristics, including lift-curve slope, drag, and effective-dihedral parameter, generally became smaller as the aspect ratio decreased.

"Direct-reading design charts are presented for 75S-T aluminum-alloy flat compression panels having longitudinal straight-web Y-section stiffeners. These charts make possible the direct determination of the stress and all panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

Report presenting a graphical method for calculating the linearized lift distribution on thin wings at supersonic speeds. It can be applied to all wing regions except those influenced by interacting flow fields off the wing-plan boundaries.

Note presenting an approximate linearized solution for the wave drag and lift of an airfoil generated by rotating a thin supersonic profile about an axis parallel, or nearly parallel, to its chord. The aerodynamic coefficients are obtained from a surface distribution of sources, of strengths proportional to the local airfoil slopes, about a cylinder whose radius and chord equal those of the original ring airfoil.

Report presenting flight measurements at low speeds to determine the static longitudinal stability, stalling, and lift characteristics of an airplane with a wing sweptback 35 degrees at the quarter-chord line. The airplane was tested without slots on the wing and with slots extending from 40 to 80 percent of the semispan of the sweptback-wing panels measured from the inboard end. Results regarding the static longitudinal stability, stalling characteristics, and lift characteristics are provided.

Report presenting an analysis of the divergence of swept untapered and tapered wings with stiffnesses varying as the fourth power of the chord. The results are presented in a set of charts and approximate formulas that allow for quick estimates of the divergence dynamic pressure and divergence speed.

From Summary: "The plasticity reduction factor in the formula for the buckling stress of a long plate under uniform shear has been computed from the properties of the stress-strain curve for the material. Some limited tests on the shear buckling of 24S-0 aluminum-alloy plates in the plastic region tend to confirm the value of the reduction factor predicted by the theory. Restraint against rotation along the edges of the plate has little or no effect upon the value of the reduction factor according to theoretical calculation."

Report presenting a method to calculate the surface temperatures of bodies in steady flight at any speed in a rarefied gas. Results regarding the incident translational energy, skin temperatures in the absence of solar radiation, internal cooling, the effect of solar radiation on skin temperature, the effect of emissivity on skin temperature, and the effect of accommodation coefficient on skin temperature are provided.

Report presenting an NACA 63(sub 1)-012 airofil section equipped with a single suction slot near the leading edge to determine whether the maximum lift coefficient could be increased by delaying the separation of flow at the leading edge characteristics of the basic section. Maximum lift increased with increasing flow through the slot, rapidly at first, and then at a diminishing rate. Results regarding the effect of boundary layer section and the optimum slot are provided.

From Introduction: "The magnitude of hydrodynamic loads experienced by seaplanes during a landing impact has been investigated experimentally and theoretically by the National Advisory Committee for Aeronautics. The results as reported in references 1 and 2 provide a rational means of determining loads on conventional V-bottom hulls in a step landing."

Report presenting an investigation of a jet diffuser designed to utilize the kinetic energy of the jet from a turbojet engine to reduce discharge pressure at the exhaust nozzle and therefore provide simulated ram-pressure ratios across the engines and altitudes. Curves of performance data for a turbojet engine at several ram-pressure ratios show the range of engine operating conditions obtainable with the jet diffuser.

Note presenting a method for determining the load distribution due to steady roll and pitch for thin flat-plate wings whose plan form is arbitrary except that a part of the leading edge must be supersonic. When the supersonic part of the leading edge is a straight line, these load distributions can be explicitly evaluated for all regions of the wing except those influenced by interacting flow fields off the plan form.

Note presenting a summary of some results of recent research that will aid the designers of an airplane in selecting or modifying a configuration to provide satisfactory stability and control characteristics. A discussion is given of the reasons for the requirements, of the factors involved in obtaining satisfactory flying qualities, and of the methods used in predicting the stability and control characteristics of the airplane.

Note presenting a theoretical investigation of the supersonic wave drag of nonlifting sweptback tapered wings with thin symmetrical double-wedge airfoil sections with maximum thickness at 50 percent chord. For wings of equal root bending stress and given sweepback, taper increases the wing wave-drag coefficient at Mach numbers.

Report presenting an analysis of the low-speed lift, rolling, and pitching characteristics of flap-type controls on a series of sweptback wings, and methods are presented for estimating these characteristics. The methods developed are essentially modifications of the existing methods used in estimating the effectiveness of flap-type controls on unswept wings.