"Investigations have been made in flight and in wind tunnels to determine which components of turbojet installations are most critical in icing conditions, and to evaluate several methods of icing protection. From these studies, the requirements necessary for adequate icing protection and the consequent penalties on engine performance can be estimated. Because investigations have indicated that the compressor-inlet screen constitutes the greatest icing hazard and is difficult to protect, complete removal or retraction of the screen upon encountering an icing condition is recommended" (p. 1).

From Introduction: "This report shows correlation between actual transient data obtained from the engine and solutions to a simulated system set up on an analog computer. Data are presented for response of engine speed to changes in set speed when the power plant was being controlled by a relay-type electronic governor that acted to maintain set speed by varying propeller pitch. Correlation obtained for sea-level conditions between actual time data and analog solutions is discussed."

From Wing Thickness: "A brief review of the effect of wing thickness and thickness distribution on the high-speed performance and stability characteristics of a representative configuration is presented."

Memorandum presenting the results of an investigation to establish rupture and total-deformation strengths at 1200 and 1800 degrees Fahrenheit for typical commercial treatments of low-carbon N-155 alloy. The results show that there were large differences in strength between the heats of bar stock at temperatures above 1200 degrees Fahrenheit except when a 2200 degree Fahrenheit solution treatment was used.

"The significance of additive drag is discussed and equations for determining its approximate value are derived. Charts are presented giving values of additive drag for open-nose inlets and for annular-nose inlets with conical flow at the inlet. The effects of variable inlet total-pressure recovery and static pressures on the center body are investigated, and an analytical method of predicting the variation of pressure on the center body with mass-flow ratio is given" (p. 1).

The results of an experimental investigation of the load distribution over two triangular wings in sideslip at Mach numbers from 1.20 to 1.79 are presented and compared with theory. The two wings tested have identical plan form, 45 degrees sweepback of the leading edge, and an aspect ratio of 4.0. One model was composed of round-nose airfoil sections and the other of sharp-nose, biconvex sections. For both wings the maximum thickness of streamwise sections was 6 percent and was located at the 30-percent chord.

Report presenting visual observations and flow analyses made of annular liquid flow with cocurrent air flow in 2- and 4-inch-diameter horizontal transparent tubes. The experiments occurred over a range of air mass velocities, air temperatures, and Reynolds numbers. Results regarding the velocity and thickness of liquid films, description of water-film disturbances, effect of flow variables on liquid-film characteristics, and relation between disturbances and flow conditions are provided.

A semiempirical method, in which potential theory is arbitrarily combined with an approximate viscous theory, for calculating the aerodynamic pitching moments for bodies of revolution is presented. The method can also be used for calculating the lift and drag forces. The calculated and experimental force and moment characteristics of 15 bodies of revolution are compared.

Memorandum presenting a summary of heat-resistant materials obtained from interviews with alloy producers, jet-engine manufacturers, and research laboratories in Britain during October and November 1950. The primary subjects of interest included the properties of materials and service requirements for gas turbines, criteria used for judging and inspecting materials, and research developments of both a practical and fundamental nature in the field.

Report presenting wind-tunnel testing at Mach numbers of 1.5 and 2.0 to investigate the force, moment, and control characteristics of a canard missile configuration and its components in pitch and sideslip. The missile had small all-movable horizontal control surfaces at the nose and a cruciform wing at the rear, all of trapezoidal plan form. Trailing-edge flaps on the vertical fins were provided to supply directional control.

Report presenting the effects of variation of trailing-edge angle and trailing-edge thickness on the lift characteristics of a 10-percent-chord thick symmetrical NACA airfoil section with a 25-percent-chord plain flap as determined from wind tunnel tests over a range of Mach numbers. Results regarding the section lift and pitching-moment characteristics, variation of lift coefficient with flap deflection, schileren photographs, and effect of angle of attack are provided.

The effects of mass-flow ratio on the additive drag and normal-shock position of a single oblique-shock diffuser are presented. Also evaluated is the variation with operating condition of the velocity distribution at the combustion-chamber inlet. A comparison with connected-pipe data is included.

Report discussing the division of load among the wing, fuselage, and tail for several aircraft configurations at subsonic and supersonic speeds. The load that each component carries at various Mach numbers and angles of attack is described.

From Introduction: "Altitude-chamber and wind-tunnel investigations of the performance of turbojet engines such as those reported in references 1 to 4 have shown that the conventional correction factors fail to generalize the engine performance variables at high altitudes. An investigation was therefore made at the NACA Lewis laboratory to determine the altitude performance of the J33-A-23 turbojet engine and to demonstrate the magnitude of departure of actual altitude performance from that predicted from sea-level performance."

Report presenting an experimental investigation to determine the combustion properties of several magnesium-hydrocarbon slurry blends and to indicate the feasibility of the application of slurry-type fuels to high-speed aircraft. High-concentration magnesium slurries showed large improvements in combustion stability and tail-pipe-burner net thrust.

The drag of a body alone, six triangular wings of various aspect ratios, and the combinations were measured at Mach numbers of 1.50 and 2.02 at a Reynolds number of 5.5 million (based on the body length). The experimental drag-interference results were in accordance with calculations based on NACA RM A9E19, 1949, with skin-friction effects taken into account, the interference effect being principally the result of fixing transition on the body by adding a wing.

Report presenting the results of a theoretical and experimental study of ramjet diffuser flow pulsing, commonly referred to as a buzz condition, with and without combustion. The acoustical resonance properties of ram jets are an important factor in establishing the frequency of diffuser flow pulsations.

An analysis of the off-design performance of shock-in rotor-type supersonic blading is presented. The over-all losses are assumed divided into two groups;normal-shock losses, and external-wave losses. Throughout the range of relative entrance Mach numbers from 1.35 to starting, the largest losses can be attributed to the normal shock. An improvement in performance would be expected with a reduction of the normal-shock losses by the introduction of external compression waves.

From Summary: "An analysis of the flight time history of a rocket-propelled model of a 60 degree delta-wing airplane configuration, fired for the purpose of obtaining zero-lift drag data, indicated wing flutter and subsequent failure at low-supersonic Mach numbers. This flutter occurred during the unpowered decelerating portion of the flight. The behavior of the model during flight is discussed and the mass and stiffness characteristics of a duplicate wing are presented."

Report presenting sound measurements at static conditions for a two-blade, 47-inch-diameter propeller over a range of tip Mach numbers. For comparison, spectrums have been obtained at both subsonic and supersonic tip speeds. Results regarding the experimental results and comparison with theory are provided.

Report presenting the performance of the turbine component of a Python turbine-propeller engine with four tail-pipe configurations determined over a range of altitudes, engine speeds, and fuel flows. Results regarding the corrected turbine speed, corrected turbine enthalpy drop, pressure ratio, and efficiency were established on a turbine-characteristic plot.

Report presenting an investigation in the altitude wind tunnel to determine the performance of the Python turbine-propeller engine. Compressor-performance data were obtained for a range of simulated altitudes at a single cowl-inlet ram pressure ratio while the engine was run over its full operable range of engine speeds. Results regarding the deterioration of compressor performance, compressor performance, including efficiency and performance maps, and velocity and static-pressure profiles are provided.

Memorandum presenting a systematic study to determine the effect of molecular structure on the flammability limits of pure hydrocarbon-air mixtures at reduced pressures and room temperature. This report presents results obtained for 17 pure normal paraffins, branched paraffins, and mono-olefins. Results regarding experimental variables and experimental observations are provided.

Report presenting an investigation to determine the aerodynamic characteristics of a series of thin, rectangular wings in the 16-foot high-speed wind tunnel using the transonic bump technique over a range of Mach and Reynolds numbers. Lift, drag, and pitching moment characteristics are presented for wings of 4 different aspect ratios and NACA 63A0XX sections and with 5 different thickness-to-chord ratios.