"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).

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.

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.

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 some results obtained from a general investigation of the effects of sideslip on the aerodynamic characteristics of thin sweptback tapered wings with side edges parallel to the axis of wing symmetry. Span load distributions have been calculated for several families of wings sideslipping at an angle of attack.

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.

Report presenting an investigation to find the approximate variation of the drag coefficient with Reynolds number of several cylinders with different cross-sectional shapes. Data were obtained for circular cylinders, elliptical cylinders of two fineness ratios, rectangular and diamond cylinders of three fineness ratios, and two isosceles triangular cylinders.

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 a study of the application of two-dimensional data and span-loading theory for estimating the local loading characteristics on a swept wing with flaps. Estimated results are compared with results measured at large scale on a 45 degree sweptback wing of aspect ratio 6 with a 0.4-span double-slotted flap. Results regarding chordwise loading, spanwise loading, and local lift curves are provided.

Report presenting gust-velocity data obtained by reevaluating the normal accelerations and airspeeds from V-G records taken on civil transport airplanes from 1933 to 1950. The reevaluation was made on the basis of a derived gust velocity, which is related to the effective gust velocity by a conversion factor that is a function of the type of airplane and operating altitude.

Note presenting three different types of pressure indicators developed at the Massachusetts Institute of Technology. Each has a unique feature, but all are designed with an attempt to combine both high-frequency response and high resolving power into one instrument. Five different types of pressure receivers were tested, including the cylinder, flat-diaphragm, spherical-diaphragm, catenary-diaphragm, and stretched-diaphragm, or membrane types. The pressure indicators are dynamically calibrated by means of a shock tube.

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: "The trajectories of droplets in the air flowing past an NACA 65A004 airfoil at an angle of attack of 4 deg were determined. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented to cover a large range of flight and atmospheric conditions. The effect of a change in airfoil thickness from 12 to 4 percent at 4 deg angle of attack is presented by comparing the impingement calculations for the NACA 65A004 airfoil with those for the NACA 65(sub 1)-208 and 65(sub 1)-212 airfoils."