Report discusses the maximum lift coefficients for conventional and tailless airplanes in the gliding and landing conditions. Three areas are used to calculate the coefficients: wing area alone, wing area plus horizontal-tail area, and wing area plus horizontal- and vertical-tail areas.

"The determination of flight Mach number from measurements of indicated airspeed and pressure altitude is shown to be relatively simple and leads to direct and accurate computation of true airspeed. A simplified chart is presented for determining flight Mach number and true airspeed for a range of values of indicated airspeed, pressure altitude, and air temperature. A table of standard atmospheric values is included" (p. 1).

Report discussing the results of testing to discover the effects of fuel-vapor loss on F-3 and F-4 knock-limited performance ratings and inspection properties of two aviation fuels, 28-R and 33-R. The percentage of loss at several temperatures, ability to meet Army-Navy fuel specifications, and antiknock rating change is described.

Report discusses the results of an investigation into the tightness, shear strength, tensile strength, and life under pulsating loads of hollow, hydraulically expanded rivets made of 17S-T aluminum alloy. The countersunk-head rivets with inserts had a much higher maximum load in shear than the modified-roundhead rivets, which did not have inserts.

Report describes a balanced-diaphragm device for measuring dynamometer torque of single-cylinder or multicylinder engines that was developed for laboratory use. Design variables are described, included desired torque-measuring device characteristics, diaphragm design, pilot valve, the torque-indicating instrument, the capacity range, ability of reversed operation, and double-acting operation. The accuracy is described as satisfactory and effects of other variables are negligible.

Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.

Report discusses the results of testing on the pressure distribution at several longitudinal sections of the vertical tail surface of the Curtiss P-40K airplane at various angles of attack and angles of yaw and with the propeller removed and propeller operating. Results regarding the chordwise pressure distributions, effects of propeller operation on the spanwise distribution of normal-force coefficient, total normal-force coefficients, and effect of propeller operation on the variation of vertical-tail normal-force coefficients are presented.

Report discusses methods of determining the iron contamination of used lubricating oil in order to study wear rates of piston rings and cylinder barrels of aircraft engines. Two methods of separating iron from used lubricating oil are presented. The results of the analyses of the oil are presented and the methods are evaluated.

Report describes exploratory testing to determine the feasibility of using a hydrofoil with a type of flying boat afterbody called a planing tail. Several hydrofoil locations were examined, including no hydrofoil, and the effects of resistance characteristics were charted. The researchers concluded that it is possible to add a single hydrofoil to that type of afterbody to provide additional hydrodynamic lift without introducing instability.