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 lift, drag, and pitching-moment coefficients, lift-drag ratios, and center-of-pressure positions for four airplane-like configurations determined from tests at a range of Mach numbers and angles of attack. The wings and nose shapes were modified for each of the configurations.

Report presenting flight measurements of the pressures on the horizontal tail surfaces of a typical propeller-driven pursuit airplane during stalled pull-outs at high Mach number. Unit loads measured on the stabilizer at safe maneuvering limits were not only considerably in excess of the design unit loads, but also occurred in a direction opposite to the design loads. Revision of the tail-load design requirements and manner of specifying safe maneuverability limits to pilots appears necessary.

The effects of inlet-air-flow distortions on the performance of the J65-B-3 turbojet engine were determined over a range of altitudes from 15,000 to 50,000 feet at a flight Mach number of 0.8. Radial inlet-air-flow distortions apparently do not affect the radial distribution of pressure after the first few compressor stages, while the circumferential inlet-air-flow distortion carried completely through the engine. For the distortions investigated, at rated exhaust-gas temperature and fixed-area exhaust-nozzle operation, the primary effect of the radial inlet-air-flow distortions was to reduce the engine air flow, and the primary effect of the circumferential distortion was to impose a temperature profile on the turbine, both resulting in reduction of thrust.

Report presenting an investigation at sea-level static conditions to determine the effects of radial discharge of cooling air from turbine rotor blades on turbine performance in two turbojet engines, one with a centrifugal compressor and the other with an axial-flow compressor. Results regarding the performance characteristics, efficiency comparisons, and some interpretation are provided.

Report presenting an investigation in the 4- by 4-foot supersonic pressure tunnel to determine the effects of body indentation on the minimum drag and maximum lift-drag ratio of a 60 degree swept-wing-body combination. A secondary goal of the tests was to determine the effect on the maximum lift-drag ratio of modifying the inboard plan form of the 60 degree swept wing. Lift, drag, and pitching-moment data are presented.

Report presenting an investigation of the longitudinal aerodynamic characteristics of a model with a 45 degree sweptback wing of aspect ratio 3 and a 45 degree sweptback cruciform tail at transonic speeds and small angles of attack by a free-fall recoverable-model technique. Results regarding lift, drag, static longitudinal stability, dynamic longitudinal stability, and loading distribution over the fuselage are provided.

Memorandum presenting an investigation of the performances of two annular diffuser designs applicable to turbojet afterburner installations to determine the effectiveness of injection and suction boundary-layer controls. Results regarding inlet measurements, flow observations, static-pressure distributions, downstream velocity distributions, and mean performance coefficients are provided.

"A method of predicting equilibrium operating performance of turbojet engines has been developed, with the assumption of simple model processes for the components. Results of the analysis are plotted in terms of dimensionless parameters comprising critical engine dimensions and over-all operating variables. This investigation was made of an engine in which the ratio of axial inlet-air velocity to compressor-tip velocity is constant, which approximates turbojet engines with axial-flow compressors" (p. 673).

Report presenting the results of force and moment tests at Mach numbers from 3.0 to 6.3 on bodies of revolution of fineness ratios from 5 to 10 and on flat-bottom bodies of fineness ratio 10 along with theoretical predictions for these bodies. Testing included eight cone and cone-cylinder models, six nose-cylinder models, and three flat-bottom bodies.

"Small-perturbation spectral-analysis techniques are used to obtain the root-mean-square flame-generated turbulence velocities and the attenuating pressure fluctuations stemming from interaction of a constant-pressure flame front with a field of isotropic turbulence in the absence of turbulence decay processes. The anisotropic flame-generated turbulence velocities are found to be of about the same intensity as those of the incident isotropic turbulence, the lateral turbulence velocities being always lower, but the longitudinal velocity is somewhat increased for flame-temperature ratios over 7" (p. 599).

Report presenting measurements of the normal force and pitching moment of a rectangular tail surface at Mach 1.9 to determine the interference effects due to trailing shock waves from an axisymmetric body with a jet exiting from a sonic nozzle in the base. The data were obtained at various jet pressure ratios and locations of tail with respect to the body. Results regarding tail location, tail pitching moment, and tail-shock-wave effects on base pressure are provided.

Report discussing an investigation into the mutual interference loads on a supersonic bomber configuration and store during separation of the store. Tests were performed at several airplane angles of attack, store angles of attack, and airplane sidestep angles. The aerodynamic characteristics of the various components and coefficients of forces are provided in tables.

"An investigation of the rolling effectiveness of spoiler and aileron aerodynamic controls on a fighter-type airplane has been conducted at Mach numbers from 0.6 to 1.5 by the Langley Pilotless Aircraft Research Division by utilizing rocket-propelled test vehicles. No effects of mutual interference between the midspan spoiler and the outboard aileron were detectable. Above the speed of sound, the ailerons were relatively ineffective as compared with the spoiler because of wing twisting" (p. 1).

Memorandum describing an investigation using two airplanes, an F6F-3 and F-86A, each fitted with servo equipment for varying in flight the lateral and directional stability and handling characteristics, which have been flown by test pilots to simulate the predicted dynamic behavior of six prototype airplanes. The methods of simulation and the types and ranges of variables considered are presented and the results of the individual programs are discussed.

Report discussing testing of a model of the Douglas A4D-1 to determine its low-speed yawing stability derivatives. The model was tested in clean and landing configurations with horizontal and vertical tails on and off and an investigation into the effect of slats and flaps on the wing-alone derivatives.

Report discussing testing on the performance of two stator-blade shapes with and without boric oxide deposits. The deposits were found to cause total pressure losses and decreases in the blade-exit flow angle. Information about the cascade throat area, boundary-layer momentum thickness, total pressure ratio, and exit flow angle and tangential component of velocity is provided.

Memorandum presenting an icing investigation conducted to determine the general de-icing and runback characteristics of three production samples of electric rubber-clad cyclic de-icing boots. The overall de-icing characteristics of two of the boots investigated were quite similar. Results regarding boot surface temperatures and general de-icing and runback characteristics are provided.

From Summary: "A preliminary experimental investigation is being conducted to determine the feasibility of preventing rain from impinging on aircraft windshields by means of high-velocity jet-air blast. The results indicate that rain deflection by jet blast appears feasible for flight speeds comparable with landing and take-off speeds of interceptor-type jet aircraft; however, attainment of good visibility through the mist generated by raindrop breakup presents a problem. For the simulated windshield and the lower windshield angles used in the investigation, air-flow rates of the order of 3.3 pounds per minute of unheated air per inch of windshield span were required for adequate rain deflection at a free-stream velocity of 135 miles per hour."

From Summary: "A photographic technique for investigating water droplets of diameter less than 200 microns falling freely in air at temperatures between 0 C and -50 C has been devised and used to determine: (1) The shape of frozen droplets, (2) The occurrence of collisions of partly frozen or of frozen and liquid droplets, and (3) The statistics on the freezing temperatures of individual free-falling droplets."

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.

"Wind-tunnel tests were conducted to determine the effects of a ventral fin on the static characteristics of a triangular-wing airplane model. Data were obtained for angles of sideslip up to 18 degrees at angles of attack of 0, 6, 12, and 18 degrees at Mach numbers from 0.25 to 0.94. The results of the tests indicated that the ventral fin did not produce as much yawing moment per unit of exposed area at any angle of sideslp as the vertical tail" (p. 1).

Report presenting the results of oscillation tests to measure the dynamic-rotary stability derivatives of an airplane model at high subsonic speeds. Measurements taken included the damping in pitch, damping in yaw, damping in roll, and the yawing moment due to rolling velocity.

Report discussing zero-lift drag data for several bomb configurations at various Mach numbers. Seven configurations were tested with different combinations of interchangeable noses and tail cones with fins, some with different surface conditions. Surface conditions were not found to affect the drag, but the thickness of the tail fins and shape of the noses did change the shape of the drag curve.