From Summary: "By the use of a form of the Prandtl-Glauert method that is valid for three-dimensional flow problems, the value of the maximum incremental velocity for compressible flow about thin ellipsoids at zero angle of attack is calculated as a function of the Mach number for various aspect ratios and thickness ratios. The critical Mach numbers (within the accuracy of the Prandtl-Glauert method) of the various ellipsoids are also determined. The results indicate an increase in critical Mach number with decrease in aspect ratio which is large enough to explain experimental results on low-aspect-ratio wings at zero lift."

Note presenting a flight investigation of a three-blade propeller in climb and at high speed to determine the effects of blade power loading. Increasing the blade power coefficient from 0.06 to 0.09 was found to increase the efficiency approximately 8 percent at an airplane Mach number of 0.7 and a propeller-tip Mach number of 1.13. In climb, an increase in power loading over the range of blade power coefficients investigated was shown to reduce efficiency, as a consequence of increased induced drag losses.

Memorandum presenting a method for calculating the stick-fixed longitudinal stability of a wing-fuselage configuration at subcritical Mach numbers. The method applies to unswept- and swept-wing configurations. The stability parameters estimated by the method show reasonable agreement with the experimental values for the 23 configurations used in the comparison.

"A convenient method has been developed for determining the scavenging efficiency or the charging efficiency of two-stroke-cycle engines. The method consists of introducing a suitable tracer gas into the inlet air of the running engine and measuring chemically its concentration both in the inlet and exhaust gas. Monomethylamine CH(sub 3)NH(sub 2) was found suitable for the purpose as it burns almost completely during combustion, whereas the "short-circuited" portion does not burn at all and can be determined quantitatively in the exhaust" (p. 1).

Report presenting testing of two rocket-propelled research models to determine the effect of the intersection of thin aerodynamic surfaces and the effect of moderate sweepback of thick aerodynamic surfaces on low-lift buffeting. Results regarding trim changes and drag are also provided. It was discovered that low-lift buffeting may be induced at high subsonic speeds by interference due to the intersection of thin aerodynamic surfaces.

Report presenting a flight investigation of four air-to-air missiles mounted by pylons on a rocket-powered basic wingless buffet-research vehicle to determine the trim, buffet, and drag characteristics of the combination.

Report presenting a flight and preflight evaluation of an automatic thrust-coefficient control system in a twin-engine ram-jet missile. A flicker-type single-loop servocontrol system is shown to be a usable way of controlling ram-jet thrust coefficients.

"The field of a uniformly loaded wing in subsonic flow is discussed in terms of the acceleration potential. It is shown that, for the design of such wings, the slope of the mean camber surface at any point can be determined by a line integration around the wing boundary. By an additional line integration around the wing boundary, this method is extended to include the case where the local section lift coefficient varies with spanwise location (the chordwise loading at every section still remaining uniform)" (p. 471).

Memorandum presenting an investigation to determine the automatic lateral stability characteristics of a model equipped with a gyro stabilizing unit that gave response to bank and yaw. Stable flights were obtained with the flicker-type automatic control, and the amplitude of the oscillations was decreased by adding the attachment which provided hunting control.

"A two-dimensional investigation utilizing pressure-distribution measurements and schileren photographs has been made of the flow and force characteristics of slab-sided airfoils of 2-percent thickness at transonic Mach numbers. The airfoils had various combinations of elliptically shaped leading and trailing edges from a fineness ratio of 0 to 10. The aerodynamic characteristics and an analysis of the flow past the models are presented" (p. 1).

Note presenting the application of the Laplace transformation to the solution of the lateral and longitudinal stability equations. The expressions for the time history of the motion in response to a sinusoidal control motion are derived for the general case in which all initial measurements are assumed different from zero.