"Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a mechanical analog constructed for the study of the trajectories of droplets around aerodynamic bodies" (p. 1).

A method is described for calibrating airspeed installation on airplanes at transonic and supersonic speeds in vertical-plane maneuvers in which use is made of measurements of normal and longitudinal accelerations and attitude angle. In this method all the required instrumentation is carried within the airplane. An analytical study of the effects of various sources of error on the accuracy of an airspeed calibration by the accelerometer method indicated that the required measurements can be made accurately enough to insure a satisfactory calibration.

From Summary: "Force characteristics determined from tank tests of a 1/5.78 scale model of a hydro-ski-wheel combination for the Grumman JRF-5 airplane are presented. The model was tested in both the submerged and planing conditions over a range of trim, speed, and load sufficiently large to represent the most probable full-size conditions."

The stator-blade angles in the twelfth through fifteenth stages of a 16-stage axial-flow compressor were increased 3O. The over-all performance of this modified compressor is compared to the performance of the compressor with original blade angles. The matching characteristics of the modified compressor and a two-stage turbine were obtained and compared to those of the compressor with original blade angles and the same turbine.

Memorandum presenting the results of a wind-tunnel investigation of the damping in pitch of a model triangular wing with an aspect ratio of 4 combined with a slender pointed body. The investigation was conducted at Mach numbers from 0.10 to 0.95 for Reynolds numbers of 550,000 and 1,250,000 with additional data obtained at Reynolds numbers of 3,000,000 and 6,000,000 at Mach number 0.23. Results regarding the effects of oscillation amplitude, Mach number, Reynolds number, angle of attack, frequency, and pitching axis position are provided.

Report presenting a study and experimental investigation on the pressure rise across shock waves required to cause separation of the boundary layer on a flat plate. The interaction of shock wave and boundary layer was investigated experimentally when the boundary layer was caused to separate from the surface of a tube. Results regarding testing and correlation with other results are provided.

An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or low-speed combustiion blow-out characteristics of the two fuels. Turbine-discharge radial temperature profiles were nearly the same at altitudes up to 35,000 feet.

Report presenting the results of an investigation to determine the effects of simulated skin wrinkling of the wing surface on the aerodynamic characteristics of two wing-body combinations. The lift, drag, and pitching moment of a low-wing wing-body combination with a plane triangular wing of aspect ratio 3 are presented for a range of Mach and Reynolds numbers.

From Summary: "Results of flight-path computations are presented for launchings from a straight deck and the curved ramp under conditions of insufficient lift at the instant of take-off."

From Summary: "Data are presented on the instrumentation and calibration technique used in determining the position error of angle-of-attack sensors mounted on the fuselage of a 35 degree swept-wing fighter airplane. The true angle of attack was determined by the use of a nose boom with five angle-of-attack vanes spaced 20 inches apart on alternate sides of the boom. Errors due to boom bending, upwash around the boom, and vane floating angle were measured and corrections applied to all indicated angles of attack."

Report presenting an investigation of flutter of wings mounted on the after portion of a body free to pitch was made in the flutter research tunnel. Uniform wings of 0 and 45 degrees sweep were tested at various positions rearward of the pitch axis. A low-frequency flutter was observed on the unswept wing, but no flutter was obtained for the swept wings.

From Introduction: "The purpose of the present paper is to investigate the effect of two-speed gearing on the take-off efficiency under certain conditions. The present paper gives charts from which the efficiencies can be readily computed for optimum rotational speeds. Also included is a brief discussion of the static thrust of thin propellers, including the effect of camber on the static thrust."

Report presenting a method for predicting the drag due to lift and lift-drag ratio of all-movable wing and body combinations and all-movable wings in the presence of bodies at supersonic speeds. The method is used to calculate the factors for configurations at which experimental data are available.

From Summary: "The loitering and range performance of airplanes equipped with several different turbojet engines was analytically investigated by applying the results of off-design cycle analyses to specific airplane characteristics. The method of off-design cycle analysis is presented herein and is verified by a check with experimental data. For all engines considered, the loitering and the range fuel flows obtained with rated tail-pipe nozzle area, variable engine speed operations were within 2 or 3 percent of the optimum fuel flow obtainable with any method of engines operation. The optimum loitering altitude generally occurred between approximately 25,000 and 35,000 feet with corresponding optimum flight Mach numbers of 0.4 to 0.65. In general, the optimum range fuel flows occurred at 3000 to 5000 feet higher altitude and at approximately 0.15 higher flight Mach numbers than the optimum loitering fuel flow."

Report presenting an investigation of a model of the Douglas X-3 to determine some methods to improve the low-speed longitudinal stability and control characteristics. Some of the components tested included plain and slotted leading-edge flaps and plain, split, and slotted trailing-edge flaps. Results regarding the effect of various factors on longitudinal stability and flap characteristics are presented.