Report regarding the ongoing development of both multi-alkali photocathodes and improved photomultipliers.

From Introduction: "These data have been collected for presentation in this report to illustrate the performance of turbojet and ram-jet cycles utilizing several of the more promising high-energy fuels. Results are presented in terms of engine over-all efficiency and thrust per pound of airflow as functions of flight Mach number."

Report presenting an investigation in the Langley Unitary Plan wind tunnel to determine the drag and static longitudinal and lateral stability characteristics of a model of the Grumman F11F-1F airplane at Mach numbers 1.56, 1.76, 2.06, and 2.53. The investigation included the effects on performance and stability of modifications, including a wing-root leading-edge fillet and horizontal tails with negative dihedral of 10 degrees and 30 degrees. Information regarding net external minimum drag coefficients, neutral points, directional stability, and positive effective dihedral is provided.

From Summary: "The convective heat transfer from the surface of an ellipsoidal forebody of fineness ratio 3 and 20-inch maximum diameter was investigated in clear air for both stationary and rotating operation over a range of conditions including air speeds up to 240 knots, rotational speeds up to 1200 rpm, and angles of attack of 0 deg, 3 deg, and 6 deg. The results are presented in the form of heat-transfer coefficients and the correlation of Nusselt and Reynolds numbers. Both a uniform surface temperature and a uniform input heater density distribution were used."

Report presenting a compilation of sea-level static and flight-performance data for existing and designed U.S. axial-flow turbojet and ram-jet engines. Factors considered include engine size, performance, and weight, and actual and theoretical performances are compared.

Memorandum presenting an airborne missile simulator used to represent visually the predicted flight behavior of the Navy XASM-N-7 Bullpup air-to-surface missile, which is guided along the line of sight to the target by bang-bang radio signals controlled by the pilot of the launch airplane. Quantitative response measurements showed that the simulator gave a good representation of the trajectory and control characteristics predicted for the Bullpup missile, and the simulation appeared plausible to the pilots.

Memorandum presenting an investigation of an airplane model to determine the effect of area suction trailing-edge flaps and several leading-edge modifications on the aerodynamic characteristics of a 45 degree sweptback wing. The wing had an aspect ratio of 2.8 and a taper ratio of 0.17.

Report discussing an investigation of the thermal stabilities of a commercial grade of ethyl decaborane and decaborane at two temperatures. Equations developed from the results of the experiment are also provided. Ethyl decaborane was found to be more stable to pyrolysis than pentaborane but less stable than decaborane.

Memorandum presenting a high subsonic Mach number turbine with high suction-surface diffusion investigated experimentally. The subject turbine was designed for a high weight flow per unit frontal area, a high specific work output, and a relative critical velocity ratio of 0.82 at the rotor hub input.

Report presenting summaries of full-scale engine tests of pentaborane, pentaborane-JP-4 fuel mixtures, and trimethylborate-methyl-alcohol-azeotrope fuels. Tests were conducted at an altitude of 50,000 feet and Mach number of 0.8. Results regarding the fuel effects on overall performance, effects on component performance, effect of turbine-outlet temperature on engine performance, and miscellaneous observations are provided.

Supersonic performance of variable two-dimensional inlets designed for engine-inlet matching.

Report presenting the small-disturbance equation for flow at Mach number 1, which is studied with the objective of determining closed analytic solutions representing possible fluid motions. Two families of exact solutions were found. It is possible to put the solutions together in such a way as to simulate the flow over the rear half of an infinite body.

A summary is given of the background and present status of the pure-planing theory for rectangular flat plates and v-bottom surfaces. The equations reviewed are compared with experiment. In order to extend the range of available planing data, the principal planing characteristics for models having sharp bottom surfaces having constant angles of dead rise of 20 degrees and 40 degrees. Planing data were also obtained for flat-plate surfaces with very slightly rounded chines for which decreased lift and drag coefficients are obtained.

Report presents the results of experimental and theoretical research conducted on flow separation associated with steps, bases, compression corners, curved surfaces, shock-wave boundary-layer reflections, and configurations producing leading-edge separation. Results were obtained from pressure-distribution measurements, shadowgraph observations, high-speed motion pictures, and oil-film studies. The maximum scope of measurement encompassed Mach numbers between 0.4 and 3.6, and length Reynolds numbers between 4,000 and 5,000,000.

The statistical approach to the gust-load problem, which consists in considering flight through turbulent air to be a stationary random process, is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, normal, and lateral gusts on the wind stresses is also considered.

From Summary: "Data from ditching investigations conducted at the Langley Aeronautical Laboratory with dynamic scale models of various airplanes are presented in the form of tables. The effects of design parameters on the ditching characteristics of airplanes, based on scale-model investigations and on reports of full-scale ditchings, are discussed. Various ditching aids are also discussed as a means of improving ditching behavior."

Part I of this report presents a brief review of methods available to the helicopter designer for obtaining desired stability characteristics by modifications to the airframe design. The discussion is based on modifications made during the establishment of flying-qualities criteria and includes sample results of theoretical studies of additional methods. The conclusion is reached that it is now feasible to utilize combinations of methods whereby stability-parameter values are realized which in turn provide the desired stability characteristics. Part II reviews some of the methods of predicting rotor stability derivatives. The procedures by which these rotor derivatives are employed to estimate helicopter stability characteristics have been summarized.

An analysis has been made to determine the effect of chord size on the weight and cooling characteristics of shell-supported, air-cooled gas-turbine blades. In uncooled turbines with solid blades, the general practice has been to design turbines with high aspect ratio (small blade chord) to achieve substantial turbine weight reduction. With air-cooled blades, this study shows that turbine blade weight is affected to a much smaller degree by the size of the blade chord.

The technical memorandum briefly summarizes the growth of interest in aeroelastic phenomena as aircraft speed increased and wing designs changed for faster aircraft. Different types of aircraft vibrations are then introduced, and the mathematical basis for the theory behind them is described. Special attention is given to static oscillations, wing flutter, and the flutter of skin panels. The last section of the memorandum deals with the prevention of flutter by design specifications.

"An investigation has been conducted in the Langley 20-foot free-spinning tunnel on a l/19-scale model of the North American T-28C airplane to determine the spin and recovery characteristics. The T-28C airplane is similar to the T-28B airplane except for slight modifications for the arresting hook. The lower rear section of the fuselage was cut out and, consequently, the lower part of the rudder was removed to make a smooth fairing with the fuselage" (p. 1).

From Summary: "Solutions of mainstream flow patterns for three-dimensional, laminar, incompressible thin-boundary-layer flows (over flat or slightly curved surfaces) having similarity with respect to stationary polar coordinates in the plane of the surface are derived. The solutions are summarized in a table."

Note presenting laminar burning velocity measured at pressures of 1 atmosphere and below and critical boundary velocity gradient for flashback at pressures below 1 atmosphere over a range of compositions for hydrogen-air burner flames. Pressure exponents of 0.23 for burning velocity and 1.35 for flashback velocity gradient was found. Results regarding blowoff and general stability loop, burning velocity, relations among various combustion properties, and reaction order from pressure exponents are provided.

Note presenting an investigation to determine the effects of wing position on the low-speed static longitudinal and static lateral stability of airplane models with fuselages of square and rectangular cross sections and unswept and 45 degree sweptback surfaces. The results of the investigation indicated that at low angles of attack, the complete unswept models with the wing in the high position were more stable or least longitudinally unstable. The results also showed that wing-fuselage interference causes an increase in effective dihedral angle when the wing is moved to the high position.

Report discussing a flight investigation of rocket-powered models of a tailless triangular-wing airplane configuration was made through the transonic and low supersonic speed range at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. An analysis of the aerodynamic coefficients, stability derivatives, and flying qualities based on the results obtained from the successful flight tests of three models is presented.