Report presenting tests to determine the behavior of landplanes when they are forced to land on the water. The report is incomplete.

Report discussing the difficulty in pulling of high-speed dives, which is primarily due to the effect of compressibility on the lift of the wing. Some of the means described for providing increased longitudinal control include auxiliary flaps and a controllable stabilizer.

Report presenting an iteration method employed to obtain the flow of a compressible fluid past a curved surface. For small Mach numbers and thin shapes, the results obtained by the iteration process agree with those obtained by the Poggi method.

Report issued by the U.S. Bureau of Mines on the oil production from water injection methods. As noted in the introduction, "it is the purpose of this report to present data such as volume of oil produced monthly, volume of water injected monthly, spacing of wells, number of injection wells and oil wells, and other such pertinent information" (p. 5). This report includes tables, graphs, maps, and illustrations.

Report issued by the U.S. Bureau of Mines on experiments conducted regarding the desulfurization of distillates from crude oil. Characteristics and desulfurization processes are presented. This report includes tables, and a chart.

Report issued by the U.S. Bureau of Mines on testing conducted on coking coal samples for carbon electrode use in aluminum production. The testing methods, and results are presented. This report includes tables.

A model for the capture spectrum of uranium is introduced in which levels occur at 7, 30, 30+D, 30+2D, ..., ev. Gamma ray and neutron widths are derived from the experimental data for values of D between 10 and 25 ev. The constants of the 7 volt level prove to be independent of D. Extrapolation, using the one level formula, gives a capture cross section at (1/40) ev of 4.9 x 10(24) cm2; this number is, however, quite sensitive to the value taken for the resonance activation. Both neutron and gamma ray widths for the higher levels are approximately proportional to D.

Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.

"Measurements of control moments were made in the NACA stability tunnel to determine the operational characteristics of a piston-type control booster on an aileron. The booster was so constructed and installed that pressures picked up from the air stream below the wing acted on a pair of pistons. The data are presented in the form of curves of pressure coefficients acting on the pistons, hinge-moment coefficients, and booster coefficients plotted against aileron deflection" (p. 1).

Report presenting tests in the two-dimensional low-turbulence pressure tunnel to study the interference effects of various pusher-propeller shaft-housing combinations on a low-drag airfoil. Thirty different combinations were tested, variations being made in shaft size, shape, angle, and fillet.

The two-dimensional, incompressible potential flow past a lattice of airfoils of arbitrary shape is investigated theoretically. The problem is treated by usual methods of conformal mapping in several stages, one stage corresponding to the mapping of the framework of the arbitrary line lattice and another significant stage corresponding to the Theodorsen method for the mapping of the arbitrary single wing profile into a circle. A particular feature in the theoretical treatment is the special handling of the regions at an infinite distance in front of and behind the lattice. Expressions are given for evaluation of the velocity and pressure distribution at the airfoil boundary. An illustrative numerical example is included.

Report presenting tests of various types of riveted joint composed of 24S-T sheet and 1/8-inch A17S-T rivets in order to determine the effects of specimen type on shear strengths. The results indicated that there was only a slight variation in shear strength with considerable variation in the types of specimen.

"This report summarizes the work that has been carried on in the experimental investigation of the problem of the general instability of stiffened metal cylinders subjected to combined bending and torsion at the C.I.T. This part of the investigation included tests on 26 sheet-covered specimens. An interaction curve for the case of combined bending and torsion is presented. The results of tests of 17 specimens subjected to pure torsion are also given" (p. 1).

"An analysis is made of the stability of an airplane with ailerons free, with particular attention to the motions when the ailerons have a tendency to float against the wind. The present analysis supersedes the aileron investigation contained in NACA Technical Report no. 709. The equations of motion are first written to include yawing and sideslipping, and it is demonstrated that the principal effects of freeing the ailerons can be determined without regard to these motions" (p. 255).

Report presenting a correlation of the gross-load coefficient and the forebody length-beam ratio for a limited number of present-day multiengine long-range flying boats for which the spray characteristics are known. Results indicate that the gross-load coefficient for comparable spray characteristics varies as the square of the forebody length-beam ratio.

"A simple interaction curve is presented for evaluating the conditions of combined shear and direct stress under which an infinitely long, flat plate with equal elastic restraints against rotation along the edges will become unstable. The theoretical work that led to the interaction curve is presented in the form of appendixes" (p. 1).

Report discusses a theoretical analysis of the lateral stability characteristics of a glider towed by two parallel towlines, which was correlated with previously reported dynamic flight testing. The glider appears to possess sufficient stability for satisfactory pilotless towed flight. The main factors affecting stability were the dihedral angle of the glider and the length of the towlines.

Report presenting a comparison of the results of calculations of the critical flutter speeds of nine uniform rectangular wings without ailerons by two methods: one in which the effect of the wing flutter shape is introduced indirectly by choosing mean values for the wing parameters and one that introduces an additional degree of freedom in the wing-bending flutter mode.

Report discusses the results of testing on the dynamic stability characteristics of various hydrofoil systems for seaplanes, including a flat-hydrofoil tandem system, a 20 degree V-hydrofoil tandem system, a curved-hydrofoil tandem system, a flat-hydrofoil ladder system, a Guidoni S.V.A.-type hydrofoil on a streamline spindle, and several self-propelled models, including the Tietjens hydrofoil system. The instability and spray were compared for the different systems.

Report presenting a method and apparatus for making quantitative tests of the spray characteristics of flying-boat-hull models. The method is applied to three related models of flying-boat hulls which differed in one major characteristic of shape: the overall dead rise.

Report presenting an investigation to determine the departure of the static pressure measured at fuselage static-pressure vents from the static pressure of the ambient air. Several locations for fuselage static-pressure vents on an XB-24F and a Lockheed 12A airplane.

Report presenting a description of the development of thermal ice-prevention equipment by the application of a heated-air ice-prevention system to a Lockheed 12A airplane. Test data indicated that thermal ice-prevention equipment is practical and that the method of utilizing the exhaust gases as a source of heat is satisfactory.

The following memorandum discusses experiments and methods to recover uranium from Colorado-Utah sandstone and leaving the vanadium in the tails, improving filterability.

This report was written to replace the directions submitted on April 12, 1943 with improved directions for the preparation of chemical solution X(OC₂H₅)₅.