Report presenting an exact solution and a closely concurring approximate energy solution for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. An appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling.

Report presenting an analysis of the effect of wing loading of the landing flare, which indicated that it had an important effect on landing technique and distance. Results regarding the approach and flare path and ground run are provided.

Report presenting tests to determine the critical shear stress of curved sheets. The empirical formula derived from the tests is applicable to panels with a ratio of radius to thickness of 300 or greater, a central angle of 1 radian or less, and a ratio of arc length to axial length not greater than 1.

Report presenting knock-limited small-scale-engine tests of isopropyl-benzene, benzene, and o-xylene blended individually in various concentrations with selected base fuels. Data were obtained to determine the blending sensitivity, lead susceptibility, and sensitivity of the blends to inlet-air temperatures. Isopropylbenzene was found to be the most effective overall.

"The two-dimensional incompressible potential flow over corrugations and bumps of arbitrary shape is derived by conformal transformation. The results are compared with those obtained by the methods of thin-airfoil theory. Some discussion is included of the flow over bumps that protrude both inward and outward from a wall" (p. 1).

"Equations have been derived for the change in the quantities that define the thermodynamic state of air - pressure, density, and temperature - at an abrupt increase in cross-sectional area of flow of compressible air. Results calculated from these equations are given in a table and are plotted as curves showing the variation of the calculated qualities with the area expansion ratio in terms of the initial Mach number as parameter. Only the subsonic region of flow is considered" (p. 1).

"A method is developed for calculating the tunnel-wall corrections to rolling and yawing moments due to aileron deflection on models in closed rectangular wing tunnels. Graphs are presented which permit a rapid determination of these corrections for models mounted in 7- by 10-foot or 8- by 12-foot wind tunnels. The method is so developed that the corrections may be calculated for the deflection of either aileron alone or both ailerons simultaneously" (p. 1).

"The effect on the propulsive efficiency of locking or windmilling one propeller of a six-blade dual-rotating propeller installation was determined in the Langley propeller-research tunnel. Tests were made of both pusher and tractor configurations, with the unpowered propeller both leading and following the powered propeller, which was set at a blade angle of 40 degrees. The maximum propulsive efficiency of the powered propeller in combination with the locked or windmilling propeller was, in all cases, lower than that of the powered propeller operating alone" (p. 1).