Report presenting an investigation of an NACA 1-80-100 nose inlet fitted alternately with an elliptical, a parabolic, a 14 degree-inch conical, and a 22 degree-inch conical central body at subsonic and transonic speeds in the 8-foot transonic tunnel. Drag, surface-pressure, and pressure-recovery measurements were obtained at 0 degrees angle of attack through a range of Mach numbers. Results regarding tunnel boundary interference, surface-pressure distribution, external drag, pressure recovery, and propulsive thrust comparison are provided.

Report presenting an investigation in the transonic tunnel to determine the dynamic and static stability characteristics of the Mark-6, Mark-4, TX-13, and Mark-5 special weapons and the effects of modifications of them for a range of Mach numbers.

Report presenting a concept for interrelating the wave drag of wing-body combinations at moderate supersonic speeds with axial distributions of cross-sectional area has been developed. Details of preliminary experiments meant to test the concept are also provided.

Report presenting flight experiments with a freely falling model to observe the effects of steady rolling on the pitching and yawing motions of a body-tail combination. Steady rolling introduces yawing moments into the pitch oscillations and pitching motions into the yaw oscillations. Results regarding the experimental effects of steady-roll on no-roll natural frequencies, comparison of measured and experimental effects of steady rolling on the no-roll natural frequencies, and effects of roll as applied to the design of missiles are provided.

Report presenting a method for estimating the effect of blade-thickness taper on the inlet axial-velocity distribution of an entrance rotor-blade row with an axial inlet, and the influence of this velocity distribution on the alignment of the rotor blade for zero effective angle of attack. The method is developed for compressible and incompressible nonviscous fluids, and results are presented for incompressible flow into a plane, two dimensional cascade and for compressible flow into an entrance rotor-blade row with tapered blades.

From Introduction: "In the present paper, an analysis of the power-off landing maneuver is presented in which an attempt is made to consider both the aerodynamic characteristics of the airplane and the human capabilities of the pilot. In this paper, the type of pilot judgment considered is that of a pilot with previous flight experience, although not necessarily flight experience in any particular airplane under discussion."

Report presenting a comparison of studies relating to the use of Freon-12 as a substitute medium for air in aerodynamic testing and methods for predicting the aerodynamic characteristics of bodies in air. The Freon charging and recovery system for the Langley low-turbulence pressure tunnel is described.

Note presenting a calculation of the column buckling stress in the range where the component plates have buckled using the method of split rigidities. Tests were carried out for a considerable range of slenderness ratios on three H-sections and two square tube sections.

From Introduction: "Light-airplane accident data, compiled by Crash Injury Research of Cornell University Medical College, indicate that human beings have often withstood declarations in excess of those imposed in airplane crashes involving extensive damage to the airplane structure (ref. 1). This study also correlates the extent of damage to the airplane structure with the injury incurred by the occupants during crash accidents."

From Introduction: "A solution of the type of reference 2 is necessary to give the stream-sheet thickness and curvature for the blade-to-blade (S1 surface) solution considered in this report. The equations for the solution of the S1 surface of revolution are presented in reference 3. The purpose of the subject report is to continue the work of reference 3 by applying the method to a specific problem in order that the practicability of the method and the time involved in computing a solution may be determined."

Report presenting an analysis of 48,187 hours of normal-acceleration and airspeed data obtained on a four-engine type of transport airplane in commercial operation on an eastern United States route from November 1947 to February 1950 to determine gusts and gust loads for operations. Results regarding the presentation of data, effect of changes in operating conditions, effect of seasons, comparison with other results, reliability, acceleration, gusts, and airspeeds are provided.

Report presenting a stability analysis of a long flat rectangular plate subjected to uniform longitudinal compressive stress and support along its longitudinal edges and one or more other longitudinal lines by elastic line supports. This was performed in order to provide more information about stabilization methods for thin-wing construction. The effective stiffness of different supports and the buckling observed in different structures is provided.

Report presenting flight testing in two single-rotor helicopters to determine the load factors due to maneuvers. Additional information has also been obtained from military pilot training and commercial air-mail operations with helicopters. Results regarding the means of attaining maximum flight loads, predictability of load factors, and design limit load factors are provided.

Report presenting an investigation to study the aerodynamic characteristics of an aspect-ratio-20 wing with thick airfoil sections and employing boundary-layer control by suction. The results include the effects of varying suction flow rate, suction-slot configuration, wing surface condition, flap deflection, and Mach number are provided.

Note presenting a theoretical investigation of the flow over infinite wedges to test a conclusion that in a region of falling pressure, a thick velocity profile can be more stable than a thin profile although the velocity at the edge of the boundary layer and the pressure gradient are the same for both profiles. The investigation also leads to the interference that the calculated effects of a change in boundary-layer thickness on the stability and on the local roughness Reynolds number should be essentially unchanged by replacing the Schlichting single-parameter family of velocity profiles by the Hartree single-parameter family of velocity profiles.

"Convective heat-transfer coefficients in dry air were obtained for an ellipsoidal spinner of 30-inch maximum diameter for both stationary and rotating operation over a range of conditions including airspeeds up to 275 miles per hour, rotational speeds up to 1200 rpm, and angles of attack of zero and 4 degrees. The results are presented in terms of Nusselt numbers, Reynolds numbers, and convective heat-transfer coefficients. The studies included both uniform heating densities over the spinner and uniform surface temperatures" (p. 1).

Memorandum presenting techniques for the measurement of the energy spectrum of flow fluctuations in both axial and lateral flow directions. A simple spectrum analysis is presented by which quantitative distinction may be made between turbulence and the flow disturbances associated with sound waves in ducts. Results regarding the measurement and analysis of turbulent-flow fields containing random and periodic flow fluctuations, effect of random sound disturbances on turbulence spectrum, and effect of combustion on combustor approach-stream spectrum are provided.

Memorandum presenting an investigation of the starting characteristics of mixed oxides of nitrogen - liquid ammonia rocket engines with light metal additives in the ammonia flow line for ignition. The oxidant consisted of 70 percent by weight nitrogen tetroxide and 30 percent nitric oxide. Results regarding the ignition experiments with 100-pound-thrust engine, 1000-pound-thrust engine experiments, and low-temperature experiments are provided.

From Introduction: "As part of a comprehensive investigation of the J40 turbojet engine conducted at the NACA Lewis altitude wind tunnel, the steady-state engine performance of the prototype J40-WE-8 turbojet engine without afterburner was obtained and is presented herein. A basic redesign of the compressor and other modifications in the compressor and the combustor were incorporated in the XJ40-WE-6 turbojet engine (references 2 and 3). In this report the modified engine is designated "the prototype J40-WE-8 without afterburner."

The performance of a turbojet engine with a two-stage turbine, an adjustable first-stage turbine stator, and a variable-area exhaust nozzle was investigated at selected constant engine speeds and two simulated flight conditions. For the particular component characteristics of the engine investigated, little improvement in thrust levels of interest by use of an adjustable rather than an optimum fixed first-stage turbine stator.

Report presenting the results of strength tests on thick-skin wing structures. Some of the factors that were found to have influence on the buckling behavior and strength are shown with data and the conditions under which a combination of multiweb and multipost construction may be used are discussed. Results regarding circular-arc airfoils, multiweb beams, and multipost stiffened beams are provided.

From Summary: "Pressure distributions and force characteristics have been determined for a body of revolution consisting of a fineness ratio 5.75, circular-arc, ogival nose tangent to a cylindrical afterbody for an angle-of-attack range of 0 degrees to 35.5 degrees. The free-stream Mach number was 1.98 and the free-stream Reynolds number was approximately 0.5 x 10 sup 6, based on body diameter. Comparison of the theoretical and experimental pressure distributions shows that for zero lift, either slender-body theory or higher-order theories yield results which are in good agreement with experiment."

Memorandum compiling summaries from NACA reports on fuel that were published between July 1945 and 1952. The summaries are intended to be detailed enough to eliminate the need to obtain the complete report.

The variation of the intensity of buffeting experienced throughout the operational region of the semitailless Northrop X-4 airplane and the values of maximum and peak normal-force coefficients in the Mach number range from 0.42 to 0.92 have been determined. The results are compared with data obtained with the swept-wing Douglas D-558-II airplane.