"In the course of an investigation to find a satisfactory vertical tail for the XP-62 airplane, a 0.45-scale vertical tail model on a stub fuselage was tested in the Langley 7- by 10-foot tunnel. This model was fitted with a flat plate to represent the horizontal tail surface. The data are presented herein for their general interest value rather than their application to this particular airplane" (p. 1).

From Summary: "The development and the use of a chart for estimating the pressure losses in jet-engine combustion chambers are described. By means of the chart, the pressure losses due to fluid friction and to momentum changes in the air flow accompanying combustion can be separately evaluated. The over-all pressure losses computed from the pressure-loss chart are within 7 percent of the experimental values for the three types of combustion chambers considered herein."

From Introduction: "The results of the tests made with unheated internal flow are reported in reference 1. It is the purpose of this paper to attempt to express simply the efficiency loss as a function of the parameters which govern propeller operation and the internal air flow. The derived equations are correlated with the data presented in reference 1."

From Introduction: "Because of the importance of spray height, it is the purpose of the work considered in this report to attempt to determine a correlation for the main spray height in relatively smooth water."

Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.

"In order to determine the crystal structure of some currently used heat-resisting alloys, a preliminary investigation of eight leading forged alloys - S816, S590, Gamma Columbium, Hastelloy B, 16-25-6, 19-9 DL, Nimonic 80, and N155 (low carbon) - was conducted by X-ray diffraction methods. The predominant phase in each alloy was found to be a solid solution of the chief alloying elements. The crystal structure of the solid solution was the face-centered cubic type" (p. 1).

From Summary: "Bending-stress and bending-moment coefficients are presented for application to design of circular shell-supported fuselage frames of variable cross section for applied radial load, applied moment, and applied tangential load. A ring which is properly reinforced in the region of maximum bending moment is shown to have a structural efficiency higher than that of a similar ring of uniform cross section. The structural efficiency is given in terms of the relative weights of the reinforced and nonreinforced rings."

Report discussing testing on 22 inch-diameter pulse-jet engines to determine the effect on performance of a change in combustion-air temperature from approximately 80 degrees to 130 degrees. The effects on jet thrust, combustion-air flow, and engine thrust are described.

Note presenting tests under combined axial load and normal pressure on 29 24S-T aluminum alloy sheet-stringer panels. Empirical formulas were derived for predicting the effect of normal pressure on the strain for buckling of sheet between stringers. Results of buckling, sheet load, strains, buckling, and failure are provided.

Note presenting an analysis of the available data on the longitudinal stability characteristics of sweptback wings at low speeds. The analysis indicated that the shape of the pitching-moment curve near the stall for sweptback wings is greatly dependent on the aspect ratio. The addition of a horizontal tail behind the wings may be destabilizing and requires further investigation.

Note presenting an investigation of the effects of tip dihedral on lateral stability and control characteristics by flight tests of models in the free-flight tunnel. The results indicate that at high lift coefficients, tip dihedral may cause a lightly damped lateral oscillation, which does not occur with full-span dihedral at similar values of effective dihedral and directional stability.

Report discussing the effects of various inlet pressures, inlet temperatures, wheel speeds, pressure ratios, and cooling-air flows on the performance of a radial-flow exhaust-gas turbosupercharger turbine with a 12.75-inch tip diameter. Information about efficiency is provided for a given blade-to-jet speed ratio.

Report presenting the effects of wide variations of dihedral, vertical-tail area, and lift coefficient on lateral stability and control and on general flying characteristics as determined by flight tests in the free-flight tunnel. The geometric dihedral angle and vertical-tail angle were varied in order to vary the effective dihedral angle and directional stability of the model. Results regarding spiral stability, oscillatory stability, lateral control, and general flight behavior are provided.

Note presenting a determination of the effects of large variations of the directional-stability derivative and the rotary-damping-in-yaw derivative on the lateral stability and control characteristics of a free-flying model via flight tests. The effects of each parameter were investigated for three values of the lateral-force derivative.

"Flight tests of an A-26B airplane have been conducted to determine the changes in maximum speed, as affected by changes in carburetor ram and aerodynamic refinement of the nacelles, resulting from the addition of sealed spinners and modification of the charge air system, cowling, and nacelle afterbodies. The changes in nacelle drag resulting from these modifications were measured independently by means of a revolving wake survey rake behind the nacelle and boundary layer rakes on the cowling, and provide a quantitative check of the speed measurements as well as a means of analyzing the components of nacelle drag" (p. 1).

Report presenting flight tests to determine the cooling characteristics of a two-row radial engine at altitude in a twin-engine airplane and to investigate the accuracy with which low-altitude cooling-correlation equations can be used for making cooling predictions at higher altitudes. Satisfactory correlation of the cooling variables was obtained at both altitudes by the NACA-cooling method.

Report presenting flight testing at altitudes of 5000 and 20,000 feet to investigate the cooling-air pressure recovery and distribution for a two-row radial engine enclosed in a low-inlet-velocity cowling for a twin-engined airplane. The effect of flight variables on average recovery and circumferential, radial, and longitudinal distribution are presented for level flight; also included is a comparison of pressure-drop measurements across the engine, as indicated by nine different combinations of pressure tubes.

Results of flight tests of a control-feel aid presented. This device consisted of a spring and dashpot connected in series between the control stick and airplane structure. The device was tested in combination with an experimental elevator and bobweight which had given unsatisfactory dynamic stability and control-feel characteristics in previous tests. The control-feel aid effected marked improvement in both the control-feel characteristics and the control-feel dynamic longitudinal stability of the airplane.

Report presenting flight measurements made to determine the characteristics of a pair of experimental ailerons designed to provide a close degree of balance and maintain a linear variation of aileron effectiveness with aileron angle through a large deflection range. Results regarding the small-deflection tests, large-deflection tests, effect of stretch on stick forces, and analysis of extended-span ailerons are provided.

Report presenting general tank tests of a scale model of the hull of the Boeing XPBB-1 flying boat in tank no. 1. Testing occurred on the forebody alone, the forebody with the afterbody, and the forebody with the afterbody and tail extension, which represented the complete hull. Results regarding the resistance, trimming moment, and length of the planing bottom wetted by the water are provided.

"The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages" (p. 1).

Report presenting aerodynamic testing of 12.208-foot-diameter two-blade hollow steel propellers before and after alteration for thermal de-icing in the 16-foot high-speed tunnel to determine the effect of the alterations on propeller efficiency. The propeller had Clark Y blade sections tested on a 2000-horsepower dynamometer at a range of blade angles and airspeeds. Results regarding accuracy, the effect of the alteration, effect of internal air flow, effect of compressibility, and coefficient of mass flow of de-icing air are provided.

Note presenting an application of the theory of Lagrangian multipliers to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate.

"The object of the present work is first to investigate accurately the processes during stress corrosion, in particular, for light metal alloys and, as the first part of the investigation, to determine its laws; and secondly to explain its causes for various alloys and thereby find means for its partial or complete elimination and thus make possible the production of light metal alloys free from any stress corrosion. In the present paper some of the results of the investigation are given and the fundamental problems of stress corrosion discussed" (p. 1).