The crystal structures of alloys 61, X-40,X-50, 422-19, 6059, and Vitallium, derived from x-ray diffraction, are discussed. The alloys have been, or are being considered for use in gas turbine applications. The predominant phase was a solid solution of the face centered cubic type of the principal constituent elements.The lattice parameters were found to be between 3.5525 and 3.5662.

Report discussing an investigation to determine the effects of sweepback and low aspect ratio on the aerodynamic characteristics of a wing at high subsonic Mach numbers. Tests were performed at aspect ratios of 2, 3, and 5 and sweepback angles of 0, 30, and 45 degrees. Generally, sweepback and low aspect ratio were found to both delay and lessen the effects of compressibility.

Tests were made in the Langley 7- by 10-foot tunnel on a 0.182-scale model of an F4U-1 airplane with external stores. This paper is concerned mainly with presenting the data obtained in this investigation and with a comparison of some of these data with flight-test results determining the feasibility of estimating flight buffet Mach number from tunnel data. The results of this investigation indicate that the incremental drag coefficient due to external stores may be used to estimate the maximum Mach number that the F4U-1 airplane may reach in flight when it is equipped with external stores. This estimation is conservative for the five configurations investigated by mounts varying from 0 to 10 percent of the flight limit Mach number. The free-stream tunnel Mach number corresponding to sonic flow over the lower surface of the wing in the region of the store is a good indication of the lower limit of buffet in flight of the F4U-1 airplane when equipped with external stores. The fluctuations of total pressure over the horizontal tail are not sufficiently large (maximum of 1 percent q(sub o) to cause buffeting of the airplane.

"A fuel-distribution control for continuous-flow manifold injection on reciprocating engines is described. A method is installation of the control on an engine is suggested. The device controlled the flow to four spring-loaded nozzles within 2 percent of perfect distribution over a wide range of fuel-flow rates and the distribution was practically unaffected by uneven discharge-nozzle pressures" (p. 1).

Report presenting an investigation of two sharp-edge annular inlets with conical central bodies at low airspeeds in the propeller research tunnel to obtain information concerning the surface-pressure, drag, and pressure-recovery characteristics of the inlets at subsonic flight. Results regarding the nose and inner surface of the diffuser, inlet lips, minimum surface pressures and critical Mach numbers, pressure surveys in inlets, and pressure surveys in diffusers are provided.

Report presenting results of chordwise pressure-distribution measurements on a 45 degree sweptback wing at transonic speeds. The two stations for measuring were located at the 18 percent chord from the root and the 87 percent chord. The changes in pressure distribution with Mach number did not indicate any appreciable net loss in section lift, but did indicate large increases in the section drag and diving moment.

From Summary: "Three methods for calculating span load distribution, those developed by V.M Falkner, Wm. Mutterperl, and J. Weissinger, have been applied to five swept wings. The angles of sweep ranged from -45 degrees to +45 degrees. These methods were examined to establish their relative accuracy and case of application. Experimentally determined loadings were used as a basis for judging accuracy. For the convenience of the readers the computing forms and all information requisite to their application are included in appendixes. From the analysis it was found that the Weissinger method would be best suited to an over-all study of the effects of plan form on the span loading and associated characteristics of wings."

Wind-tunnel investigations were made in pitch and yaw with and without split flaps. Presence of the fuselage had negligible effect on values of maximum lift coefficient and slope of lift curve, but caused a destabilizing shift in the rate of change of pitching moment with lift. Effects of fuselage position on drag characteristics were small for wings without flaps, but were appreciable when split flaps were on.

"An investigation has been made at large scale of the characteristics of highly swept wings. Data were obtained at several angles of sideslip on wings having angles of sweep of plus or minus 45 degrees, plus or minus 30 degrees, and 0 degrees. The airfoil sections of the wings varied from approximately NACA 0015 at the root to NACA 23009 at the tip. Each wing was investigated with flaps under flection, partial-span split flaps deflected 60 degrees, full-span split flaps defected 60 degrees and split-flap-type ailerons deflected plus or minus 15 degrees" (p. 1).

"The results of the first flight test of a swept-back four-wing version of Tiamat (MX-570 model C) which was launched at the NACA Pilotless Aircraft Research Station at W4110PB Island, Va. are presented. In general, the flight behavior was close to that predicted by calculations based an stability theory and oscillating table tests of the autopilot. The flight test thus indicates that the techniques employed to predict automatic stability are valid and practical from an operational viewpoint" (p. 1).

An analysis has been made of airfoil data taken on several NACA 16-series propeller airfoils from tests of 5-inch-chord models in the Langley 24 inch high-speed tunnel and l2-inch-chord models in the Langley 8 foot high-speed tunnel, This analysis has shown that the combined effects of Reynolds number changes and variations in airfoil characteristics resulting from differences in models and tunnels are such that when 5 inch-chord and l2-inch-chord data are applied to full-scale propeller design at or near the design condition, differences of less than 1 percent in efficiency will be involved.

Flight tests were conducted on a North American P-51D airplane to establish the maximum lift coefficient and the buffeting boundary line as a function of Mach number.

"Requirements of an automatic engine control, as affected by engine characteristics, have been analyzed for a direct-coupled turbojet engine. Control parameters for various conditions of engine operation are discussed. A hypothetical engine control is presented to illustrate the use of these parameters. An adjustable speed governor was found to offer a desirable method of over-all engine control. The selection of a minimum value of fuel flow was found to offer a means of preventing unstable burner operation during steady-state operation" (p. 1).

Memorandum presenting a general treatment of compressible flow in ejectors with friction in the mixing tube included. A secondary object is to show the application of the flow theory to the calculation of the effect of ejector addition on thrust of jet-propelled airplanes and missiles. Results regarding the outline of methods of applying the general theory to some other problems and future explorations of ejector problems are provided.

Report presenting an investigation in the 18- by 18-inch supersonic tunnel to determine design conditions for optimum performance of shock diffusers at Mach number 1.85 with a series of projecting single-shock cones with varying angles. Each cone was tested with a curved and a straight diffuser-inlet section. The effect of angle of attack was investigated for several configurations.

Report presenting an investigation in the 18- by 18-inch supersonic tunnel to determine the total-pressure recovery obtainable at Mach number 1.85 with a shock diffuser with projective cones designed to produce two oblique shocks ahead of the diffuser inlet. The variation of total-pressure recovery with tip projection was investigated for four cones with different included angles. A maximum total-pressure recovery of 94.5 percent was attained with the best configuration at an angle of 0 degrees.

Report presenting testing conducted on two airfoils from a series of rectangular-plan-form airfoils of aspect ratios 7.6 and 5.1 and with NACA 65-006, 65-009, and 65-012 sections using the free-fall method. Results regarding the time histories, ground-velocity data, airfoil drag measurements, and drag coefficients are provided.

"A preliminary investigation was made to determine the effects of gamma radiation on the age-hardening rate of an aluminum-copper alloy at temperatures of 32 and 70 degrees Fahrenheit. The gamma radiation from a 100-milligram radium source appeared to have no significant effect on the age-hardening rate of the alloy. A metallographic examination of the test specimens showed no microstructural changes that could be attributed to gamma radiation" (p. 1).

"The probable spin and recovery characteristics of the XSN2J-1 air-plane have been estimated on the basis of the results of brief test a performed on a model of an airplane of somewhat similar design. The spin-recovery tail-parachute requirements for the airplane were also determined end, in addition, an analysis was made to determine the best method of emergency pilot escape during a spin. The results of the investigation indicate that the recovery characteristics of the airplane will be satisfactory for all probable loading conditions of the airplane" (p. 1).

Report presenting a lateral-control investigation of 3- and 6-percent chord spoilers projecting on the upper surface of a wing of high-aspect ratio. The spoilers were found to give large rolling moments at Mach numbers below the Mach number corresponding to the break in the rolling-moment-coefficient curves. Results regarding section pressure distributions, rolling-moment characteristics, normal-force characteristics, pitching-moment characteristics, wing-torsional considerations, and hinge-moment characteristics are provided.

Flight tests were conducted at the Flight Test Station of the Pilotless Aircraft Research Division at Wallop Island, Va., to determine the longitudinal control and stability characteristics of 0.5-scale models of the Fairchild Lark pilotless aircraft with the tail in line with the wings a d with the horizontal wing flaps deflected 60 deg. The data were obtained by the use of a telemeter and by radar tracking.

Report presenting the results of an investigation conducted in the altitude wind tunnel to determine the performance of a 20-inch ramjet. The investigation was conducted at a range of altitudes and ram-pressure ratios using preheated 62-octane fuel. A net thrust of 8135 pounds educed to standard sea-level conditions, a net-thrust coefficient of 0.74, and an overall efficiency of 12.6 percent were attained at Mach number 1.845 at which the engine with a 5-foot combustion chamber was operated.

Report presenting testing of a full-scale, semispan, horizontal tail surface for a jet-propelled fighter airplane in the 16-foot high-speed tunnel to determine the variation of the chordwise and spanwise pressure distributions with Mach number. Surface irregularities were found to cause appreciable distortion of the pressure distribution. Results regarding chordwise distributions, spanwise distribution, effect of Mach number on root bending moment, and estimated critical Mach numbers are provided.

Report presenting the use of wall perforations on supersonic diffusers to avoid the internal contraction-ratio limitation. Experimental results on a preliminary model of a perforated diffuser at Mach number 1.85 are provided. A theoretical discussion of the flow coefficients and the size and spacing of the perforations are included.