"So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability" (p. 1).

We have set ourselves the problem of calculating the laminar flow on a body of revolution in an axial flow which simultaneously rotates about its axis. The problem mentioned above, the flow about a rotating disk in a flow, which we solved some time ago, represents the first step in the calculation of the flow on the rotating body of revolution in a flow insofar as, in the case of a round nose, a small region about the front stagnation point of the body of revolution may be replaced by its tangential plane. In our problem regarding the rotating body of revolution in a flow, for laminar flow, one of the limiting cases is known: that of the body which is in an axial approach flow but does not rotate.

Report presenting results obtained with quiescent fuel-air mixtures and with small diffusion flames, which indicate that combustion efficiencies close to 100 percent were obtained at pressure much lower than those found in turbojet combustors at altitudes of 60,000 feet.

Report presenting an investigation of a 45 degree sweptback-wing model with interchangeable round and sharp leading edges to determine the effect of leading-edge separation on the loads experienced by the models in gusts. Leading-edge separation was found to increase the gust load, which appeared to vary based on the gust-gradient distance and velocity.

Report presenting a correlation of carbon deposition of 19 fuels in a turbojet combustor as a function of the boiling point and of the flame height at the sooting point of the fuels in a simple wick lamp for a particular combustor operating at a single set of conditions. Two similar investigations with different combustors, operating conditions, and nine different fuels yielded similar correlations on the same graph.

From Summary: "An all-internal conical compression inlet with annular bleed at the throat was investigated at Mach 5.0 and zero angle of attack. The minimum contraction ratio of the supersonic diffuser, coincident with a mass-flow ratio of 1.0, was determined to be 0.084 as compared with the isentropic contraction ratio of 0.04 at Mach 5.0. The over-all inlet performance was very sensitive to the amount of annular bleed at the throat because of the extensive boundary layer."

"The wave drag of a combination of slender bodies of revolution at zero angle of attack is studied with a view to determining the arrangements for which the total drag is a minimum. Linearized theory is used to calculate the pressure distribution in the field surrounding the bodies. The interference drag coefficient is computed for different arrangements" (p. 1).

Note presenting a study of the factors that affect the survival of human beings in airplane accidents followed by fire by conducting full-scale crashes of transport- and cargo-type airplanes. Some of the factors studied include thermal injury, toxic gases, missiles, and structural destruction of occupied compartments are provided.

Report presenting a wind-tunnel investigation to determine the effects of a section modification on the aerodynamic characteristics of a wing with 35 degrees of sweepback. The wing was modified by increasing the leading-edge radius of the NACA 64A010 section and adding a small amount of camber to the forward portion of the chord. Lift, drag, pitching-moment, and trailing-edge-flap hinge-moment characteristics of the modified wing are compared with results from the original wing.

A study is made of the advantages that can be realized in compressible-flow research by employing a substitute heavy gas in place of air. The present report is based on the idea that by properly mixing a heavy monatomic gas with a suitable heavy polyatomic gas, it is possible to obtain a heavy gas mixture which has the correct ratio of specific heats and which is nontoxic, nonflammable, thermally stable, chemically inert, and comprised of commercially available components. Calculations were made of wind-tunnel characteristics for 63 gas pairs comprising 21 different polyatomic gases properly mixed with each of three monatomic gases (argon, krypton, and zenon).

Report presenting the total drag coefficients of 60 degree cone cylinders of fineness ratio 2.07 measured in free flight from Mach numbers of 1.5 to 8.2. Results regarding the smooth 60 degree cone cylinder, rifled models, and discontinuity lines in the shadowgraph pictures are provided.

Small metal spheres of various densities were fired at high speed into thick targets of copper and lead. In general, it was found that all of the penetrations could be correlated quite well for engineering purposes by a function relating the depth of penetration to the impact momentum per unit volume.

Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord. Results regarding the leading-edge radius effects and maximum thickness-chord ratio are provided.

Report presenting the aerodynamic characteristics of several wing-fuselage combinations measured at a Mach number of 0.25. Each combination consisted of a triangular wing with an aspect ratio of 2.0 and body of revolution with a fineness ratio of 12.5. Results regarding wings in the presence of bodies, wing-body combinations, and dorsal fins are provided.

Memorandum presenting a description of the Ames supersonic free-flight wind tunnel, which is a new piece of equipment for aerodynamic research at high supersonic Mach numbers. It has a wide Mach number range extending from low supersonic speeds to Mach numbers in excess of 10. The air stream in the tunnel is imperfect, mainly due to a symmetrical pair of oblique shock waves which reflect down the test section.

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.

Memorandum presenting an investigation to determine the low-speed aerodynamic characteristics of a 45 degree swept wing with leading-edge inlets. The wing had a constant chord and completely spanned the wind tunnel. Results regarding surface-pressure characteristics, lift and pitching-moment characteristics, wake-drag characteristics, and internal-flow characteristics are provided.

From Summary: "An air-launched cone-cylinder test vehicle designed to obtain data at Mach numbers above 4.0 was rocket boosted from a release Mach number of 5.18. The vehicle was launched at an altitude of 35,000 feet and reached peak velocity of 5150 feet per second at 28,500 feet. The total-drag coefficient (based on maximum cross-sectional area) decreased gradually from 0.31 at a Mach number of 1.75 to 0.145 at a Mach number of 5.18, while the Reynold's number (based on body length) increased from 31 x 10 to the 6th power to 107 x 10 to the 6th power."

Report presenting an investigation of the flow behind the lifting surfaces of a model equipped with a 60 degree triangular wing and a 60 degree triangular canard tail. Results regarding the force and moment data, air-stream surveys behind the wing, effective values of downwash and dynamic-pressure ratio, effect of tail height and length, a comparison with previous data, the effects of component area and ratio, and the effect of a canard tail are provided.

Report presenting a theoretical investigation of an automatic control system with primary sensitivity to normal accelerations as used to control a specific supersonic canard missile. The control system is made up of an integrating servomotor that receives a signal from an accelerometer that is sensitive to normal accelerations of the airframe that it is controlling. The acceleration control system appears to work well for obtaining longitudinal control, but works best when combined with a homing seeker or guidance system for controlling directional space.

Report presenting an experimental investigation in a one-sixth sector of an annular turbojet combustor to determine a method of controlling radial exhaust-gas-temperature distribution in a gas-turbine combustion chamber. The adjustment in controlling air was made by ducting the dilution air into the combustion zone in a predetermined manner through hollow radial struts or by modifying the basket-wall open-hole area. Results regarding the temperature distribution, temperature-rise efficiency, total-pressure loss, and altitude operating limits are provided.

Unsteady shock-induced separation of the ramp boundary layer was reduced and stabilized more effectively by external perforations than by external or internal slots. At Mach 2.0 peak total-pressure recovery was increased from 0.802 to 0.89 and stable mass-flow range was increased 185 percent over that for the solid ramp. Peak pressure recovery occurred just before instability. The 7 and one-third-diameter duct ahead of the engine reduced large total-pressure distortions but was not as successful for small distortions as obtained with throat bleed. By removing boundary-layer air the bypass nearly recovered the total-pressure loss due to the long duct.

From Introduction: "Results are presented to indicate the effect of altitude, flight Mach number, and exhaust-nozzle-outlet area on the combustion efficiency, the losses in total pressure occurring in the combustion chamber, and the fractional loss in engine cycle efficiency resulting from combustion-chamber pressure losses. The engine cycle efficiency is also presented.These results are shown graphically as a fraction of corrected engine speed and in tabular form."

Memorandum presenting a description of the equipment used in the Ames supersonic free-flight wind tunnel to obtain the data necessary to measure the aerodynamic characteristics of free-flying models. The model is fired from a gun into the supersonic air stream of a blowdown-type wind tunnel. The action resulting from aerodynamic forces is computed from a time-distance-attitude record of the model flight through the test section.