A wind-tunnel investigation to determine the downwash angles in a transverse plane behind the wings of six wing-body combinations at Mach number 0.25. A triangular wing of aspect ratio 2.0 and a trapezoidal wing of aspect ratio 3.0 were tested in combination with three geometrically similar slender bodies of revolution.

Report presenting a low-speed wind-tunnel investigation to determine the aerodynamic derivatives arising from acceleration in sideslip for a 60 degree triangular, a 45 degree sweptback, and an unswept wing. The magnitude of the sideslip acceleration derivatives encountered and the effect of wing plan form on the derivatives was small in the low angle-of-attack range. Results regarding acceleration derivatives and sideslip derivatives are provided.

Memorandum presenting wing and tail-load data on a swept-wing airplane to determine the flight conditions and maneuvers in which maximum wing and tail loads were experienced, and, where pertinent, to relate these loads to the important stability and control changes that occurred. The results indicated that maximum wing loads and bending moments would be expected at relatively low Mach numbers. With increasing Mach number, a relieving effect on the wing-panel loading coefficients was noted, which appears to be due to premature flow separation on the outboard wing sections.

Memorandum presenting wing and tail-load data on a swept-wing fighter airplane analyzed to determine the flight conditions and maneuvers in which maximum wing and tail loads were experienced, and, where pertinent, to relate these loads to the important stability and control changes that occurred. The results indicated that maximum wing loads and bending moments would be expected at relatively low Mach numbers. Results are also presented on the use of controls in the various maneuvers for which loads data were obtained.

From Summary: "Flight measurements of the aerodynamic wing loads on the D-558-II airplane have been made in the Mach number range from 1.0 to 2.0. Nonlinear wing-panel characteristics occurred with variations in angle of attack. These nonlinear characteristics were apparent primarily at the lower supersonic speeds."

Report presenting an investigation of the performance of pentaborane fuel at relatively low equivalence ratios using a 9.75-inch-diameter ramjet engine using pentaborane at an average equivalence ratio of approximately 0.23. Time histories of the flight conditions and combustion chamber conditions, total-temperature ratio, fuel flow, pressure recovery, thrust, propulsive thrust, and drag coefficients, and comparison with hydrocarbon fuel are provided.

From Introduction: "In comparison with the shaft-driven rotor, the jet rotor is shown in references 1 and 2 to provide direct reductions in helicopter empty weight and to increase the pay-load capacity by (1) eliminating the gear-reduction train between the rotor shaft and the power plant, (2) eliminating the antitorque tail rotor, and (3) using a power plant of low specific weight."

Report presenting a transonic compressor rotor with double-circular-arc blade sections, which was designed and tested to investigate the aerodynamic effects of using a short blade chord and a high aspect ratio and to obtain more blade-element data. Results regarding overall performance, rotor-inlet conditions, rotor-outlet conditions, and rotating-stall characteristics and blade vibrations are provided.

An investigation of the performance of the mixed-oxides-of-nitrogen-ammonia propellant combination over a range of conditions with several injectors. Results regarding specific impulse, characteristic velocity, and thrust coefficient as functions of oxidant-fuel weight ratio are provided.

Report presenting a full-scale, free-jet investigation to determine the performance of a side-inlet supersonic diffuser designed for a flight Mach number of 2.75. Several internal modifications made to improve diffuser-outlet flow uniformity were also evaluated. Results regarding the general characteristics of the diffuser and effect of diffuser modifications on flow distribution are provided.

Report presenting an interferometric study of the flow over a two-dimensional isentropic compression surface at a Mach number of 3.0. The flow field was essentially that of a strong-branch-shock configuration resulting from a surface flow turning that corresponded to an empirical limiting value of free-stream normal-shock pressure rise.

Report presenting testing of a supersonic mixed-flow compressor of large weight-flow capacity with a stator with swept and tilted blades was tested over a range of air tip speeds. As rotor speed increased, stage efficiency decreased continuously. Results regarding the overall compressor performance, flow fluctuations, and static-pressure distribution are provided.

From Introduction: "The purpose of this paper is to present an analysis of the data for the remaining airplanes where the data were sufficient to warrant analysis. The data analyzed represent totals of 351 to 5660 hours of operations with ten types of Navy airplanes and were recorded during the period 1949 to 1953."

Report presenting testing of a towed airplane model in the 19-foot pressure tunnel in conjunction with the development of a flutter testing technique. The model was equipped with an autopilot to keep the model flying straight and level in the tunnel while restrained only in drag. Results regarding period and cycles to damp to half amplitude, time histories, and motions of the flexible wing model are provided.

Report presenting the results of a wind-tunnel investigation to determine the effects of various free-flight rocket-model booster-adapter configurations on the aerodynamic characteristics in pitch and sideslip of a swept-wing, fighter airplane model with a Mach number of 2.01. Results regarding the effect of adapter shape and aerodynamic characteristics of the model alone are provided.

Report presenting results of a wind-tunnel investigation to determine the effects of various free-flight rocket-model booster-adapter configurations on the aerodynamic characteristics in pitch and sideslip of a swept-wing, fighter airplane model for a Mach number of 2.01. Normal-force, lateral-force, pitching-moment, and yawing-moment coefficients of the airplane model were measured, and schileren photographs of the various configurations were obtained.

From Summary: "Measurements of pressure distributions have been made over a wing midsemispan station on the 35 degree sweptback wing of the Douglas D-558-II research airplane at Mach numbers from 1.17 to 2.0. The results of the investigation indicate that, as the angle of attack increased at the higher Mach numbers, the pressure coefficient for a vacuum limited the extent to which the upper-surface pressures could expand. Consequently most of the increase in section normal-force coefficient at high angles of attack can be attributed to the increase in pressure over the lower surface."

Preliminary results are presented from an investigation to determine the influence of afterbody geometry on the effects of a sonic propulsive jet at transonic speeds. The results presented are base pressure coefficient and afterbody pressure-drag coefficient as a function of jet pressure ratio for different values of Mach number and jet temperature. Geometric parameters investigated include boattail angle, jet-to-model diameter ratio, and jet-to-base diameter ratio.

From Summary: "Long-range hypervelocity vehicles are studied in terms of their motion in powered flight, and their motion and aerodynamic heating in unpowered flight. Powered flight is analyzed for an idealized propulsion system which rather closely approaches present-day rocket motors. Unpowered flight is characterized by a return to earth along a ballistic, skip, or glide trajectory. Only those trajectories are treated which yield the maximum range for a given velocity at the end of powered flight. Aerodynamic heating is treated in a manner similar to that employed previously by the senior authors is studying ballistic missiles (NACA RM A53D28), with the exception that radiant as well as convective heat transfer is considered in connection with glide and skip vehicles."

Report presenting some accompanying tables and bibliography for experimental aerodynamic studies in the field of wing controls during the period between January 1946 and February 1955. The tables are grouped according to the following major classifications: trailing-edge flap controls, leading-edge flap controls, and spoiler controls.

Report presenting testing of free-falling recoverable-model tests at transonic speeds on a model with an aspect-ratio-4 triangular wing and a 45 degree sweptback tail in the extended wing-chord plane. Results regarding the lift, drag, stability, tail effectiveness, and buffet boundary are provided.

Report presenting an investigation of the design and tests of a transonic inlet rotor with emphasis placed on increasing the design specific weight flow while maintaining reasonably high pressure ratio and efficiency. Information regarding peak efficiency and how to best achieve it through design is provided.

Report presenting a wind-tunnel investigation to determine the effects of various wing-fence arrangements on the longitudinal characteristics of several wing-fuselage and wing-fuselage-tail combinations with sweptback wings with NACA four-digit thickness distributions. Testing occurred with wings of several degrees of sweepback and a horizontal tail at several tail heights. Results regarding fence development, wing-fuselage combinations, and wing-fuselage-tail combinations are provided.

Report presenting wind-tunnel flutter testing at a range of Mach numbers conducted on a swept-wing towed airplane model equipped with an autopilot system. Results regarding the towed model tests, fixed-root tests, and a comparison between the calculated and experimental flutter characteristics are provided.