Report presenting an investigation of the effects of many of the parameters significant to wing flutter on several untwisted rotating models to determine their significance with respect to stall flutter of propeller blades. The parameters included torsional stiffness, section thickness ratio, sweepback, length-chord ratio, section center-of-gravity location, blade taper, Mach number, and fluid density. Results regarding the considerations on method of presentation, experimental data and discussion, some possible applications, and a comparison of experiment with classical-flutter theory are provided.

"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).

"The over-all component performance characteristics of the J71 Type IIA three-stage turbine were experimentally determined over a range of speed and over-all turbine total-pressure ratio at inlet-air conditions af 35 inches of mercury absolute and 700 deg. R. The results are compared with those obtained for the J71 Type IIF turbine, which was previously investigated, the two turbines being designed for the same engine application. Geometrically the two turbines were much alike, having the same variation of annular flow area and the same number of blades for corresponding stator and rotor rows" (p. 1).

From Summary: "An investigation of a 1/21-scale model of the Chance Vought F7U-3 airplane in the combat-loading condition has been conducted in the Langley 20-foot free-spinning tunnel. The recovery characteristics of the model were determined by use of spin-recovery rockets for the erect and inverted spinning condition. The rockets were so placed as to provide either a yawing or rolling moment about the model center of gravity. Also included in the investigation were tests to determine the effect of simulated engine thrust on the recovery characteristics of the model."

An investigation has been conducted in the Langley 20-foot free-spinning tunnel on a l/18-scale model of the Ryan X-13 airplane to determine the size parachute required for emergency-spin recovery during demonstration spins. Test results for erect spins indicate that a stable 12.73-foot-diameter parachute with a drag coefficient of 1.11 (based on the 12.73-foot projected diameter) is the minimum size required to insure satisfactory recovery in an emergency. The use of a stable parachute is recommended. Test results for inverted spins indicate that the l2.75-foot-diameter parachute is also satisfactory to terminate inverted spins.

Report presenting a brief experimental investigation of a method for designing fuselage side air inlets with high internal total-pressure recovery and zero spillage drag at a specified design inlet mass-flow ratio. With a scoop designed according to the concept, near-zero spillage drag can be attained at the design inlet mass-flow ratio through a range of Mach numbers. Results regarding pressure recovery and drag due to the scoop are provided.

Report presenting an experimental investigation to study several wing-root inlet configurations at Mach number 1.9. The inlets were of triangular and rectangular shape and external compression was provided by two-dimensional wedge surfaces. Results regarding the pressure-recovery and mass-flow data, effect of inlet side plates and curved diffusers, exit and inlet total-pressure distributions, improvement of exit total-pressure profiles, and inlet tests at zero flight speed are provided.

Report presenting testing to determine the interference effects of various sting-support configurations on the base pressure and foredrag characteristics of a wing-fuselage combination with a turbulent boundary layer. The primary variable investigated was the length of the constant-diameter portion of a sting support. Results regarding the base-pressure interference and foredrag interference are provided.

Memorandum presenting an investigation to determine the feasibility of increasing the specific weight flow of a transonic axial-flow compressor inlet stage by decreasing the hub-tip ratio. The current phase of the investigation was conducted to determine the blade-element and the overall performance of the complete stage. Results regarding the overall performance, blade-element performance, and stator-blade-element performance 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.

Report presenting a flight program using the Northrop X-4 semitailless airplane to investigate the effect on the longitudinal and lateral stability and control of thickened elevons with trailing-edge thickness one-half the control-hinge-station thickness. The investigation consisted of speed runs, wind-up turns, abrupt rudder-fixed rolls, and longitudinal pulses between a range of Mach numbers.

Report presenting an investigation at the Lewis laboratory to develop air-cooled, strut-supported turbine blades. Six blades were investigated in a full-scale turbojet engine to obtain data on blade durability and blade-cooling effectiveness and strut temperature. Results regarding the heat-transfer investigation and blade-durability investigation are provided.

Report presenting the steady-state performance of the YJ73-GE-3 turbojet engine in an altitude test chamber for a range of exhaust-nozzle areas, simulated altitudes, and Mach numbers. A method of performance calculation based on engine pumping characteristics is provided. Results regarding performance maps, pumping characteristics and performance prediction, thrust correlation, effect of inlet temperature on performance, calculated performance from pumping characteristics, and altitude-ignition characteristics are provided.

A cermet composition was investigated as a potential material for gas-turbine blades. Blades of HS-21 alloy were also operated in the engine simultaneously to provide a basis of comparison. The cermet blades survived as long as approximately 312-1/2 hours at about 1500 degrees F with an average midspan centrifugal stress of approximately 11,500 psi.

Note presenting a method for studying the transient behavior of the flapping motion, as well as for calculating the steady-state flapping amplitudes, of free-to-cone and seesaw rotors operating at extreme flight conditions. The method is general and can be applied to blades of any airfoil section, mass distribution, twist, plan-form taper, root cutout, and flapping-hinge geometry.

Report presenting an investigation to determine the effects of several factors associated with the propeller installation on the ability of a wing with plain flaps to deflect a propeller slipstream downward as a means for achieving vertical take-off. Some of the factors considered were propeller blade angle, mode of propeller rotation, propeller location, and ratio of wing chord to propeller diameter.

Report presenting an analysis of approximately 100,000 hours of V-G data from one type of four-engine civil transport airplane to determine the magnitude and frequency of occurrence of the gust loads and gusts. The data were obtained during routine operations over the course of seven years on five different routes. Results regarding the accelerations experienced, gusts encountered, operating airspeeds, gust-load envelopes, and gust-velocity envelopes are provided.

Report presenting a low-speed investigation in the two-dimensional low-turbulence tunnel to study a sweptback wing-root air-inlet configuration believed suitable for transonic-speed jet-powered airplanes. Two models were tested: a basic model with an NACA 64-008 wing with quarter-chord sweepback of 45 degrees and an inlet model with a triangular-shaped inlet installed in the wing root. Results regarding the original and modified inlets and the final inlet are provided.

Report presenting an investigation of the effectiveness of a wing equipped with large-chord slotted flaps in rotating the thrust vector of propellers through the angles required for vertical take-off and for flight at very low speeds in the 300 mph 7- by 10-foot tunnel. Results regarding static-thrust condition, tests with forward speed, and comparison of results for plain-flap and slotted-flap configurations are provided.

Memorandum presenting an investigation to determine the altitude performance characteristics of the YJ73-GE-3 turbojet engine in an altitude chamber. The component performance was determined at two positions of the inlet guide vanes over a range of engine speeds, exhaust-nozzle areas, and flight conditions. Results regarding compressor performance, combustor performance, turbine performance, and altitude performance of components at rated conditions are provided.

Report presenting an investigation of the effects of sideslip on the aerodynamic loading characteristics of a 45 degree sweptback wing of aspect ratio 4 for a range of angles of attack, angles of sideslip, and Mach numbers. The load distributions, root bending-moment coefficient, and rolling moment due to sidestep were explored.

Report presenting an investigation of the effect of longitudinal body fences on the performance of a top-inlet-fuselage combination in the 8- by 6-foot supersonic wind tunnel. The investigation was conducted at a range of Mach numbers, angles of attack, and a range of inlet mass-flow ratios. The thrust-minus-drag of the top-inlet configuration with fences was higher than the bottom-inlet configuration without fences over most of the range, with the reverse being true at all lift coefficients at Mach 2.0 and higher lift at Mach 1.8.

Report presents information about free-flight rocket-propelled model testing to determine the effect of some wing geometry variables on low lift drag at a range of Mach numbers. Results regarding the effect of airfoil section, wing nose droop and nose flaps, plan form, and wing vertical position are provided.

Report presenting pressure distributions calculated for some symmetrical wing-body combinations at zero lift. Of particular interest is the effect of indenting the body on the distribution of pressure over the wing.