"The main purpose of this paper is to present the results of measurements made on the Cal-Tech computer. The diagrams present only a small portion of the data which were obtained from the computer and which are given in complete form in the tables" (p. 1-2).

Report presenting an evaluation of the flying qualities of the Douglas DC-3 airplane to determine its longitudinal and lateral stability and control characteristics and its stalling behavior.

Report presenting an investigation at low-speed of the two-dimensional characteristics of a 10.51-percent-thick symmetrical airfoil with area suction for boundary-layer control near the leading edge. The lift and suction-flow characteristics were determined with different porous surfaces for various suction velocity distributions obtained by varying the permeability arrangement. Results regarding the plain airfoil, airfoil with various chordwise extents of area suction, effect of external surface and permeability arrangement, and effect of free-stream velocity are provided .

Note presenting an investigation at low speed of the two-dimensional characteristics of a 10.51-percent-thick symmetric airfoil with area suction for boundary-layer control near the leading edge. The lift and suction-flow characteristics were determined with different porous surfaces consisting of perforated plates and sintered steel for various suction velocity distributions obtained by varying the permeability arrangement.

Report presenting a determination of the tunnel-wall interference for a two-dimensional-flow, rectangular, closed-throat wind tunnel over a range of Mach numbers. Aerodynamic data obtained showed that the influence of the walls becomes progressively greater with increasing Mach number and increasing chord-height ratio.

Report presenting an investigation in flight at free-stream Mach numbers up to 0.76 to determine the behavior of laminar and turbulent boundary layers passing through shock waves. Boundary-layer and pressure-distribution measurements were made on a short-span airfoil built around a wing of a fighter airplane. Results regarding laminar flow ahead of the shock wave, turbulent flow ahead of the shock wave, comparison at full scale of laminar and turbulent boundary layers, and effect of Reynolds numbers on boundary-layer profiles with shock waves are provided.

"The results of calculations are presented for the purpose of showing the effects of ionization and electronic excitation on the flow properties of one-dimensional shock waves in xenon gas. The calculations are based on statistical-mechanics theory with the assumption that thermal equilibrium exists at all points in the flow. The calculations are made by both including and neglecting the effects of electronic excitation, and the results of the calculations are qualitatively compared with experimental data" (p. 1).

Report presenting studies with a low-speed kinetic-friction apparatus to clarify the role of certain variables with molybdenum disulfide, including moisture, shear area, surface finish, and several other variables. Results regarding the effect of humidity, effect of shear area, effect of surface finish, effect of adding water to molybdenum disulfide, and effect of humidity with bonded films are provided.

Note presenting a summary of all phases of an investigation of fretting corrosion that has been conducted over a period of several years. Part I describes a test machine for measuring fretting damage under controlled experimental conditions. Part II presents data for mild steel fretted against itself, with a number of characteristics taken into consideration. Part III suggest a mechanism for the fretting process.

Report presenting the hydrodynamic drag of three surface-piercing untapered struts at approximately 0 degrees angle of yaw at depths up to 6 chords for speeds up to 80 fps at various angles of rake. The section drag coefficient was determined from plots of drag against depth. Results regarding drag, spray, and cavitation and ventilation are provided.

Report presenting an investigation in the 9-inch supersonic tunnel to determine the effects of varying Reynolds number at each of three Mach numbers on the wave drag of seven boattail bodies of revolution designed for minimum wave drag. Results indicated that there was little variation in the pressure distribution with Reynolds number. Results regarding pressure distributions and wave drag are provided.

Note presenting testing under combined axial load and lateral pressure on 12 bonded sandwich panels with simply supported loaded edges and free unloaded edges. The maximum load and mode of failure were observed for all the panels. Lateral deflections and axial strains were also measured.

Note presenting a method for computing the steady-state span load distribution on an elastic airplane wing for specified airplane weights and load factors. The method is based on a modification of the Weissinger L-method and applies at subcritical Mach numbers.

Report presenting one-dimensional, steady-state, compressible, viscous flow relations which permit the determination of flow conditions at any radial position in a ducted helicopter blade. The relations are required for estimating the performance of proposed helicopter jet-propulsion systems which involve ducting air or gases through the blade from root to tip.

Note presenting a method for calculating the stresses produced by rectangular cutouts of any size in torsion boxes. The problem is divided into a "box problem" and a "cover problem". Three sets of tests are provided.

"An analysis is made of the transient heat-conduction effects in three simple semi-infinite bodies: the flat insulated plate, the conical shell, and the slender solid cone. The bodies are assumed to have constant initial temperatures and, at zero time, to begin to move at a constant speed and zero angle of attack through a homogeneous atmosphere. The heat input is taken as that through a laminar boundary layer. Radiation heat transfer and transverse temperature gradients are assumed to be zero" (p. 1).

Report presenting an investigation to develop simple, inexpensive electric analogs for determining temperatures of cooled turbine blades. Analogs were made for a 13-fin shell-supported air-cooled blade, a strut-supported air-cooled blade, and a liquid-cooled blade.

"The purpose of this paper is to provide a derivation of the general integral form of the boundary equation without neglecting the Reynolds normal-stress term. Two special cases of this equation are given explicitly" (p. 2).

Note presenting a description of the use of silver chloride as a material for photoelastic stress analysis, which offers the possibilities of studying both elastic and plastic states of stress in a crystalline metallike material on either a microscale or macroscale. In order to use it, however, it is necessary to relate the stress state quantitatively with the observed relative retardation and extinction angle.

From Summary: "A method has been proposed for predicting the effect of a rapid blade-pitch increase on the thrust and induced-velocity response of a helicopter rotor. General equations have been derived for the ensuing motion of the helicopter. These equations yield time histories of thrust, induced velocity, and helicopter vertical velocity for given rates of blade-pitch-angle changes and given rotor-angular-velocity time histories. The results of the method have been compared with experimental results obtained with a rotor mounted on the Langley helicopter test tower."

Report presenting an investigation of the effect of vertical chine strips on the planing characteristics of two prismatic surfaces having angles of dead rise of 20 degrees and 40 degrees. Wetted lengths, resistance, and center-of-pressure location were determined at speed coefficients up to 25.0, load coefficients up to approximately 80.0, and trims up to 30 degrees.

Note presenting an investigation of the effect of cooling on boundary-layer transition in the steady flow of air in the entrance of a smooth round tube. The primary purpose was to investigate the practical possibilities of delaying the transition point, and thus increasing the transition Reynolds number, by cooling the laminar boundary layer in a gas. The results indicate that the effect of cooling on transition is not likely to be significant in any normal internal flow.

Torsion tests were made on a cylindrical semimonocoque shell of circular cross section. The cylinder was first tested without a cutout, and then with a rectangular cutout which was successively enlarged through six sizes varying from 30 degrees to 130 degrees in circumference and from 1 to 2 bays in length. Strain measurements were made with resistance-type wire strain gages near the cutout on the stringers, the skin, and the rings for each size of cutout, and the stresses obtained are presented in tables. (author).

Report presenting about 50,000 hours of V-G data obtained from one type of four-engine civil transport airplane operated over three different commercial airline routes of the United States from 1949 to 1953, which were analyzed to determine the magnitude and frequency of occurrence of gust loads and gusts. The frequency of occurrence of the gust loads and the gusts for the present operations is in general agreement with those from similar operations of other civil transports recently investigated.