Report presenting an evaluation of a piston-type gas-generator engine by comparing the performance of a transport airplane powered with than engine with the same airplane powered by different engines. The engines compared were a turbojet engine, a turbine-propeller engine, a compound engine, and a turbosupercharged reciprocating engine utilizing a variable-area exhaust jet nozzle. Results regarding optimum altitude and transport performance are provided.

Report presenting an investigation of the experimental performance of chlorine triflouride and hydrazine measured over a range of propellant mixtures in a 100-pound-thrust rocket engine. Experimental values of specific impulse, volume specific impulse, heat rejection per propellant weight, nozzle thrust coefficient, and characteristic velocity were obtained as functions of percent fuel by weight in the propellant mixture.

Memorandum presenting a calculation of the amount of possible correction for coordinated turns with limited bank angle and level sideslips for a large transport airplane, the C-54D. The results indicate that for all instances from the end of the runway, coordinated turns are the more effective maneuver.

Report presenting surveys of the flow of the asymmetric adjustable nozzle of the 6- by 6-foot supersonic wind tunnel, which were made to determine the uniformity of the air stream. Test techniques for minimizing the effects of stream irregularities and the results of force and pressure-distribution tests of a swept-wing model are presented to illustrate the effectiveness of these techniques.

Report presenting an analysis to determine the applicability of existing propeller theory and the theory of oscillating airfoils to the problem of determining the magnitude of the forces on propellers in pitch or yaw. The steady-state method for calculating propeller forces appears to give satisfactory results.

Report presenting wind-tunnel testing to determine the independent effects of Mach and Reynolds numbers on the aerodynamic characteristics of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and with camber and twist. Results regarding the fuselage alone and the effects of camber and twist are also provided.

Report presenting an investigation of the effects of various mass, aerodynamic, and dimensional parameters on the dynamic lateral stability of the Douglas D-558-2 airplane. Results regarding an airplane with the flaps and gear retracted, airplane at sea level with flaps deflected 50 degrees and landing gear lowered, and effect of assumed modifications to airplane are provided.

Report presenting tests to determine the recovery of total pressure attainable at a range of Mach numbers, which were performed with models with twin-scoop inlets situated on the sides of a long forebody. Results regarding ducts without slots and ducts with slots are provided.

Investigation conducted in the altitude wind tunnel to study the effect of Reynolds number on the performance of an axial-flow compressor. The compressor was operated as a part of a turbojet engine over a range of pressure altitudes and compressor-inlet Reynolds numbers. Results regarding compressor efficiency, air flow, and a comparison with axial-flow compressors of different design are provided.

Memorandum presenting a study to determine the possible blending agents or additives that may be used to supplement current high performance number, rich rating components in future aviation fuels. The study indicated that such high rich rating blending agents as toluene and xylene cannot be made available in sufficient quantities to maintain the rich rating performance of the fuels when reducing the lead content from 4.6 to 3.0 ml per gallon.

Report presenting an investigation of the operation of two submerged-type inlets in a wind tunnel at subsonic and transonic speeds. The pressure recovery was relatively constant throughout the lower subsonic speed range. The ability of the divergent-walled inlet to operate with satisfactory pressure recovery at higher free-stream Mach numbers than was possible with the parallel-walled inlet is attributed to the difference in the boundary-layer characteristics of the two types of inlets.

Abstract: Processes are described for preparing small samples of 42 wt. % U-Al alloy (uranium enriched with U235) for pile irradiation studies. In the course of this work it was found that the size of the massive Al-U grains remains substantially unaltered during hot rolling.

Report discussing the progress of the Ames Laboratory in metallurgy for the period from April, 1949 through September, 1949.

"The hydrodynamic characteristics of a 1/10-size powered dynamic model of the XP5Y-1 flying boat were determined in Langley tank no. 1. Stable take-offs were possible at all practicable positions of the center of gravity and flap deflections. An increase in gross load from 123.5 to 150.0 pounds (21.5 percent) had only a slight effect on the stable range for take-off" (p. 1).

"On the basis of linearized supersonic-flow theory, generalized equations were derived and calculations made for the lift and damping in roll of a limited series of thin sweptback tapered wings. Results are applicable to wings with streamwise tips and for a range of supersonic speeds for which the wing is wholly contained between the Mach cones springing from the wing apex and from the trailing edge of the root section. A further limitation is that the tip Mach lines may not intersect on the wing" (p. 395).

From Introduction: "Data are presented in graphical form to show the engine performance over a range of altitudes from 5000 to 50,000 feet and flight Mach numbers from 0.21 to 0.97. Curves are presented to show the windmilling characteristics of the engine. All engine performance data obtained in the investigation are also presented in tabular form."