From Introduction: "The effects of variations in altitude, flight Mach number, and exhaust-nozzle-outlet area on the compressor performance characteristics are graphically presented. A complete tabulation of the compressor performance data is also presented."

From Summary: "An investigation was conducted in the NACA Cleveland altitude wind tunnel to determine the operational characteristics of the Westinghouse 19B-2, 19B-8, and 19XB-l jet-propulsion engines. The 19B engine is one of the earliest experimental Westinghouse axial flow engines. The 19XB-1 engine is an experimental prototype of the Westinghouse 15 series, having a rated thrust of 1400 pounds. Improvements in performance and operational characteristics have resulted in the 19XB-2B engine with a rated thrust of 1600 pounds. The operational characteristics were determined over a range of simulated altitudes from 5000 to 30,000 feet for the 19B engines and from 5000 to 35000 feet for the 19XB-l engine at airspeed from 20 to 380 miles per hour."

From Introduction: "The present paper is restricted to a discussion of wing theory subject to the assumptions of linearized compressible flow. It therefore employs solutions of Laplace's equation and the wave equation for cases where the boundary condition are specified in the plane of the wing."

From Introduction: "Recent developments in the statistical theory of extreme values (references 4 to 10) have indicated a somewhat more rational approach to the problem of predicting the probability of occurrence The present report summarizes some of these findings, indicates the method of application, and evaluates their applicability to certain gust-load problems ."

Report presenting an investigation to determine which of two ceramic coatings, L-7C and A-417, developed by the National Bureau of Standards is more suitable as a protective coating for turbine blades in a turbojet engine. Four cast Vitallium turbine blades, two coated with each of the ceramics, were installed in a turbine wheel of a turbojet engine and subjected to accelerated cyclic life tests.

Tests of a PB2Y-3 flying boat were made at the U.S. Naval Air Station, Patuxent River, Md., to determine its hydrodynamic trim limits of stability. Corresponding tests were also made of a 1/8-size powered dynamic model of the same flying boat in Langley tank no. 1. During the tank tests, the full-size testing procedure was reproduced as closely as possible in order to obtain data for a direct correlation of the results. As a nominal gross load of 66,000 pounds, the lower trim limits of the full-size and model were in good agreement above a speed of 80 feet per second. As the speed decreased below 80 feet per second, the difference between the model trim limits and full-scale trim limits gradually became larger. The upper trim limit of the model with flaps deflected 0 deg was higher than that of the full-size, but the difference was small over the speed range compared. At flap deflections greater than 0 deg, it was not possible to trim either the model of the airplane to the upper limit with the center of gravity at 28 percent of the mean aerodynamic chord. The decrease in the lower trim limits with increase in flap …

An investigation of a 1/18-scale dynamically similar model of the North American B-45 airplane was made to observe the ditching behavior and determine the proper landing technique to be used in an emergency water landing. Various conditions of damage were simulated to determine the behavior which probably would occur in a full-scale ditching. The behavior of the model was determined from high-speed motion-picture records, time-history acceleration records, and visual observations. It was concluded that the airplane should be ditched at the maximum nose-high attitude with the landing flaps full down for minimum landing speed. During the ditching, the nose-wheel and bomb-bay doors probably will be torn away and the rear of the fuselage flooded. A violent dive will very likely occur. Longitudinal decelerations of approximately 5g and vertical accelerations of approximately -6g (including gravity) will be experienced near the pilots' compartment. Ditching braces installed in the bomb bay will tend to improve the behavior slightly but will be torn away along with the bomb-bay doors. A hydroflap installed ahead of the nose-wheel doors will eliminate the dive and failure of the nose-wheel doors, and substantially reduce the motions and accelerations.

Report presenting tests to determine the effect of sweepback angle and aspect ratio on the drag at supersonic speeds of wings of NACA 65-009 airfoil section. The current report is part of a bigger investigation and includes results for aspect ratios of 3.8 and 5.0. Results regarding the drag coefficient and general effect of aspect ratio are provided.

From Summary: "Drag measurements at transonic speeds on rectangular airfoils and on airfoils swept back 450 are reported. These airfoils, which were mounted on cylindrical test bodies, are part of a series being tested in free drops from high altitude to determine the effect of variation of basic airfoil parameters on airfoil drag characteristics at transonic speeds. These rectangular and swept-back airfoils had the same span, airfoil section (NACA 65-009), and chord perpendicular to the leading edge. The tests were made to compare the drag of rectangular and sweptback airfoils at a higher aspect ratio than had been used in a similar comparison reported previously."

"Data for a liquid-cooled engine with a displacement volume of 1710 cubic inches were analyzed to determine the effect of exhaust pressure on the engine cooling characteristics. The data covered a range of exhaust pressures from 7 to 62 inches of mercury absolute, inlet-manifold pressures from 30 to 50 inches of mercury absolute, engine speeds from 1600 to 3000 rpm, and fuel-air ratios from 0.063 to 0.100. The effect of exhaust pressure on engine cooling was satisfactorily incorporated in the NACA cooling-correlation method as a variation in effective gas temperature with exhaust pressure. Large variations of cylinder-head temperature with exhaust pressure were obtained for operation at constant charge flow" (p. 1).

Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.

Report presenting an investigation in free flight of the rolling effectiveness of plain ailerons in conjunction with wings having 0 and 45 degrees sweepback with several airfoil sections. Results regarding the rolling characteristics of rectangular and sweptback-wing configurations and drag measurements are provided.

"Gust-velocity measurements and air-borne-radar observations obtained during a transcontinental flight in July 1947 have been analyzed as part of a general investigation of the uses of air-borne radar. The analysis indicates that some reduction in turbulence and a consequent reduction in the risk of encountering the larger gust velocities may be obtained by avoiding portions of clouds giving a radar echo" (p. 1).

Memorandum presenting measurements of gust and draft velocities within cumulus clouds at a certain army air field using an AT-6 airplane. The measurements were made to supplement the at a obtained with P-61C airplanes. The data are summarized in tables.

From Summary: "The pressure drops through electrically heated Inconel tubes with length-diameter ratios of 29.25, 58.50, 87.75, and 117.00 have been measured at entrance Mach numbers from approximately 0.12 to the value at which choking occurred. The heat-input rate was varied from zero to the highest values allowable without damaging the tubes. Experimental data and a number of computed variables are presented in tabular form."

Report presenting testing of a twin-scoop duct inlet that enclosed 37.2 percent of the forebody circumference at Mach numbers between 1.36 and 2.01. The approach to each scoop consisted of a ramp that deflected the flow to create an oblique shock wave in front of the duct entrance. Results regarding the inlet proportions, ramp angle, slots, and angle of incidence are provided.

Report presenting free-flight investigations conducted on four 16-inch-diameter ramjet units to determine the performance at high subsonic and supersonic velocities. Data for evaluating the performance were obtained from radio-telemetering and radar-tracking equipment. Results regarding combustion performance, diffuser total-pressure recovery, thrust coefficient, and external drag coefficient are provided.

An investigation was made in the Langley high-speed 7- by 10-foot tunnel to determine the high-speed lateral and directional stability characteristics of a 0.10-scale model of the Grumman XF9F-2 airplane in the Mach number range from 0.40 to 0.85. The results indicate that static lateral and directional stability is present throughout the Mach number range investigated although in the Mach number range from 0.75 to 0.85 there is an appreciable decrease in rolling moment due to sideslip. Calculations of the dynamic stability indicate that according to current flying-quality requirements the damping of the lateral oscillation, although probably satisfactory for the sea-level condition, may not be satisfactory for the majority of the altitude conditions investigated.

Report presenting an investigation of turbine operating temperatures as affected by liquid cooling, especially if materials of high conductivity are used, at gas temperatures up to 1925 degrees Fahrenheit. Results regarding the statio heat-transfer rig and turbine rig are provided. The investigation showed that nonstrategic material such as aluminum alloy can be used in liquid-cooled turbine wheels at high gas temperatures.

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The aileron characteristics of the complete model are presented in the present report with a very limited analysis of the results.

Report presenting measurements downwash angles behind a model of a high-aspect-ratio wing at points near the probable tail location at Mach numbers up to 0.89 in the high-speed tunnel. The model has an NACA 65-210 section, an aspect ratio of 9.0, a taper ratio of 2.5:1, no twist, dihedral, or sweepback. Results regarding experimental data and comparison of experimental and calculated results are provided.

Pressure measurements were made during wind-tunnel tests of the McDonnell XP-85 parasite fighter. Static-pressure orifices were located over the fuselage nose, over the canopy, along the wing root, and along the upper and lower stabilizer roots. A total-pressure and static-pressure rake was located in the turbojet engine air-intake duct. It was installed at the station where the compressor face would be located. Pressure data were obtained for two airplane conditions, clean and with skyhook extended, through a range of angle of attack and a range of yaw.

From Summary: "As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle."

Results of a wind-tunnel investigation at a Reynolds number of 6.8 x 10(exp 6) to determine the static longitudinal stability characteristics of a 42 degree sweptback wing and fuselage combination with a sweptback horizontal tail are provided. Included are the effects of vertical position of fuselage and tail with respect to wing for several combinations of high-lift and staff-control devices. Also included is the effect of a simulated ground.