This short analysis may be useful in determining the real tactical possibilities of "glider trains" and in adopting the course to be followed in possible studies of these questions. In this analysis most prominent are: (a) the power required for the train in level flight; (b) its speed; (c) climb; and (d) the type of airplane best suited for towing as well as design requirements for transport gliders.

From Introduction: "The present paper covers step 1 of the outlined investigation, includes methods of computing the variation of wing and tail loads, and gives numerical results of the application of the theory to the BT-9B airplane. Finally, theoretical formulas are developed and charts are given for computing the maximum increments of wing load, the down-tail load, and the up-tail load following a given elevator displacement."

Uranium hexafluoride has the distinction of being the only stable gaseous compound of uranium known up to the present moment. Because of this property it is the only compound that can be used for processes of isotope separation, such as diffusion, thermal diffusion, centrifuge separation, distillation, and other of a similar nature. Here is a short description of the properties of UF{sub 6} and is intended for a reader interested only casually in this compound. UF{sub 6} is a very reactive compound and a very strong fluorinating agent. It is immediately hydrolized by water. In fluorinating reactions it is reduced to the green highly stable UF{sub 4}. It reacts instantaneously with hydrogen at room temperature. It fluorinates many metals; sodium and mercury are attacked in the cold, lead, zinc, tin and iron on heating; platinum and gold react only above 400 C. With organic compounds like alcohol, ether, benzene or toluene, immediate fluorination takes place with formation of HF and carbon or carbonaceous material. The compound forms colorless, very volatile, beautiful transparent crystals of high refractive index. Melting point = 69.5{sup o}; boiling point at 760 mm = 56.2{sup o}; D20{sup o} = 4.68. The crystals melt water pressure to …

Report presenting cooling tests of a Northrop A-17A attack airplane equipped with a conventional NACA cowling and then with a wing-duct cooling system. Ground cooling for the wing-duct system without cowl flap was better than for the cowling with flap, but was improved by installing a cowl flap. Satisfactory temperatures were maintained in climb and high-speed flight, but a greater quantity of cooling air was needed for the wing-duct system.

Note presenting testing of two series of stiffened flat sheet specimens tested under edge compression using various end conditions: round ends, flat ends, and continuous panels. The specimens consisted of aluminum-alloy flat sheet stiffened by three hat-shaped extruded aluminum-alloy stiffeners. The results indicated that the length of the specimen has an insignificant effect on the ultimate compressive load.

Note presenting computations made to determine the effects of some airplane design trends on the fin area and the dihedral angle required for lateral stability. The specific factors studied were wing loading, moments of inertia in roll and yaw, wing chord, and tail length. The results of the computations are presented in the form of diagrams of variations of fin area with dihedral angle for neutral stability.

"The thermal properties are presented for the exhaust heated wing de-icing system of a Lockheed 12-A airplane which has successfully prevented a wing icing in 25 hours of flying in various icing conditions. The quantities of heat supplied for de-icing of the wings under various conditions were measured and are presented. The distribution of temperatures above the ambient air temperature for the wing surface under various operating conditions are given" (p. 1).

From Summary: "The present paper is a continuation of the general study of flutter published in NACA reports nos. 496 and 685. The paper is mainly devoted to flutter in three degrees of freedom (bending, torsion, and aileron) for which a number of selected cases have been calculated and presented in graphical form. The results are analyzed and discussed with regard to the effects of structural damping, of fractional-span ailerons, and of mass-balancing. The analysis shows that more emphasis should be put on the effect of structural damping and less on mass-balancing."

"On the assumption of infinitely small disturbances the author develops a generalized integral equation of airfoil theory which is applicable to any motion and compressible fluid. Successive specializations yield various simpler integral equations, such as Possio's, Birnbaum's, and Prandtl's integral equations, as well as new ones for the wing of infinite span with periodic downwash distribution and for the oscillating wing with high aspect ratio. Lastly, several solutions and methods for solving these integral equations are give" (p. 1).

Data complied regarding wells and other water resources, including water quality analysis, measurements, and other relevant information.

"At the request of the Bureau of Aeronautics, Navy Department, tests were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane. The object of the tests was to determine the power-off static lateral and longitudinal stability and control of the complete model" (p. 1).

Note presenting a study of stability and control of airplanes by means of dynamic scale models in the 12-foot free-flight wind tunnel. Tests of a scale model of the F-36A airplane were used to develop the testing technique and to afford a comparison of tests of a model in the tunnel with flight tests of the corresponding airplane. Results regarding longitudinal stability and control and lateral stability and control are provided.

Brief discussions of experimental methods, kinetics, and the catalysts used in the production of D{sub 2}O are presented (J.E.D.)

Report presenting a simple equation that can be used to facilitate the appraisal of the conventional jet as a means of propulsion. The equation can be used to estimate the performance of a large variety of aeropropulsive devices. The results using this equation indicate that attainable propulsive efficiencies at high speeds below sonic velocity are certain to be lower than is common at low speeds with the conventional propeller.

Report presenting an investigation of the lateral motion resulting from a disturbance of the type produced by asymmetric loss of thrust for a hypothetical average airplane equipped with an automatic pilot. Plots of the resultant motion and various modes that constitute the motion are presented for fixed controls and for various amounts of autopilot.

Report issued by the U.S. Bureau of Mines on the use of oil field brine in secondary recovery methods. Characteristics of the brine, and methods used in recovery processes are presented. This report includes tables, graphs, maps, and illustrations.

Report presenting an investigation of a slot-lip aileron and a plain aileron, singly and in combination, on an NACA 23012 wing with a full-span flap. The characteristics of these lateral-control devices were essentially the same as those of similar devices on the wing with full-span NACA slotted flaps as tested in a previous investigation.

Report presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23012 airfoil with a 30 percent-chord Maxwell leading-edge slat and a slotted and a split flap. The main purpose was to determine the optimum slot cap of the Maxwell slat for, and the aerodynamic section characteristics of, the airfoil with several deflections for both types of flaps. Curves of lift, drag, and pitching-moment characteristics for optimum arrangements are provided.

From Summary: "Tests have been made to determine the effect of a gap at the flap nose upon the aerodynamic section characteristics of an NACA 0009 airfoil with a plain flap and tab. The results are presented in the form of airfoil and flap section characteristics for several flap deflections, tab deflections, and for four sizes of gap."

"Tests were made in the 20-foot propeller-research tunnel to investigate the possibility of obtaining increased net efficiencies of propeller-nacelle units by enclosing the engines in the wings and by using extension shafts. A wing of 5-foot chord was fitted with a propeller drive assembly providing for several axial locations of tractor propellers and pusher propellers. A three-blade 4-foot propeller and a three-blade 3 1/2-foot propeller of special design were tested in this wing with spinners and fairings ranging in diameter from 6 to 16 inches" (p. 1).