Report discussing tests in a combustion chamber to obtain smoking characteristics data on a variety of hydrocarbon fuels. Details about the smoking tendencies and burning rates of the fuels in uncontrolled and controlled tests are provided.

"Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables" (p. 1).

Report presenting an investigation to determine the effect of the location of the diffuser vanes with respect to the supercharger outlets and the effect of flow conditions at the impeller inlet on the air-flow distribution in the outlets of the engine-stage supercharger of an 18-cylinder double-row radial aircraft engine. The effect of flow conditions at the impeller inlet was investigated by distorting the flow at the inlet and noting the effect in the supercharger outlets. Results regarding the diffuser effect and inlet effect are provided.

From Introduction: "The present report has been prepared to discuss the indications obtained from the University of Chicago turbulence indicator in relation to simultaneous measurement of atmospheric gustiness made by the NACA, which are summarized herein."

Data are presented of the flow conditions in the vicinity of an NACA D sub S -type cowling. Tests were made of a 1/2 scale-nacelle model at inlet-velocity ratios ranging from 0.23 to 1.02 and angles of attack from 6 deg to 10 deg. The velocity and direction of flow in the vertical plane of symmetry of the cowling were determined from orifices and tufts installed on a board aligned with the flow. Diagrams showing velocity ratio contours and lines of constant flow angles are given.

Report discussing an investigation of the effect of variations in pitch distribution on propeller efficiency at low Mach numbers. The three 10-foot-diameter propellers tested consisted of three blades mounted on a streamline body and were tested for a blade-angle range from 15 degrees to 60 degrees. Information about the propeller thrust, power coefficients, force-balance measurements, and total pressure in the propeller wake is provided.

"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).

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.

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.

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.

"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).

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 a discussion of some of the parameters that enter into the equation of the path of a missile which is pursuing its target. The missile is assumed to be guided by a target seeker that might be employed in any one of several ways. Results regarding the normal-pursuit navigation, constant navigation, proportional navigation, line-of-sight navigation, and effect of angle of attack and sideslip are provided.

Report discussing the icing characteristics of a rectangular-throat pressure-type carburetor. Serious ice was not found to form under the conditions of this particular test, although visible ice and frost formed in certain areas.

"A preliminary analysis has been made of the conditions of stability of free oscillations of a hinged rotor in hovering flight. The case analyzed is a rotor with hinges allowing freedom in flapping and lagging and having a completely reversible cyclic pitch-control system, so that a twisting moment on a blade moves the control stick without hindrance from spring or friction constraint. The principal results of this study are presented in the form of a stability chart" (p. 1).

From Introduction: "An investigation of the power-plant installation of a single-engine torpedo-bomber-type airplane has been conducted in the NACA Cleveland altitude wind tunnel at the request of the Bureau of Aeronautics, Navy Department. A similar investigation was previously conducted on a three-tenths scale mock-up of the forward portion of the fuselage of this airplane in the Langley 20-foot tunnel. (See reference 1)."

"The gross weight, beam, and afterbody length of 12 contemporary flying boats and amphibians with pointed afterbodies are tabulated and correlated. For most of the hulls considered, the afterbody length-beam ratios are shown to be directly proportion to the gross-load coefficients" (p. 1).

Report presenting the knock-limited performance of nine fuels comprising isolated members of four classes of hydrocarbons in the form of three-dimensional plots of fuel-air ratio, compression temperature, and compression-air density.

Report presenting the performance of a 22-inch-diameter pulse-jet engine using a net of low-loss modified air valves at ram pressures equivalent to simulated flight speeds. Results regarding combustion-air weight flow, flight thrust, maximum combustion-chamber pressure, specific fuel consumption, pressure cycle, and valve life are provided.

Report discussing the results of accelerated erosion tests to determine the separate effects of the passage of fuel, water, and ice particles through a supercharger. Recommendations for preventing erosion are provided, including materials choice and joint design.

Report discussing measurements of the overall drag coefficient of the XP-51 in dives using three different methods. The three instruments used to measure drag variation are compared for accuracy. A comparison of the drag results obtained from this test are also compared to the results obtained from previous wind tunnel testing.

"Flight tests were conducted on a twin-engine fighter airplane at pressure altitudes up to 10,000 feet with simulated conditions of moderate, heavy, and excessive rain to determine the increase in enthalpy of the charge air due to the turbosupercharger, to determine the rate of enthalpy increase of the charge air resulting from a sudden increase of engine power, and to compare the conditions that caused induction-system icing in flight with those that resulted in icing of the same carburetor and supercharger inlet elbow in laboratory tests" (p. 1).

Report presenting the dimensional parameters of ram-compression power plants as related to their thrust and economy performance and an investigation of the speed and range performance possibilities of a family of pilotless airplanes powered with one of the power plants. The analysis of the power plants includes the power-plant configuration, aerodynamic and thermodynamic cycle, constants used in the computations, power-plant performance, and operation of the power unit with fixed areas at various flight speeds. The investigation of the aircraft included a description of its characteristics, speed, range, effect of wing selection of speed, and effect of size on performance.

Report presenting an investigation for the determination of the behavior of ceramic bodies in tension at elevated temperatures for the purpose of determining data for the design of ceramic blades for gas turbines. Observations were made of six special ceramic bodies in order to determine their tensile strength and creep during prolonged loading under a range of stresses and temperatures.