Report presenting an experimental investigation of boundary-layer suction through slots as a means of increasing the extent of laminar flow on airfoil sections. Results regarding slot geometry and arrangement, suction slots in an unfavorable pressure gradients, suction slots in a favorable pressure gradient, and a determination of the relations controlling the distribution of suction slots are provided.

Report presenting an investigation of the two-dimensional aerodynamic characteristics of 15 NACA airfoils at four Reynolds numbers. The results indicate that the drag coefficient at the design lift coefficient and the maximum lift coefficient are the most important aerodynamic characteristics and are most affected by Reynolds number changes.

"A method developed in a previous report for finding the induced velocity field behind a supersonic wing with known load distribution is used to find the downwash behind a triangular wing with subsonic leading edges. Results are given for the chord plane in the extended vortex wake of the wing and for the vertical plane of symmetry up to about 20 percent of the wing span above the plane of the wing" (p. 1).

From Introduction: "The flare assumed is based primarily on reference 1, in which information permitting calculation of the flare characteristics of an airplane was obtained from flight tests. The results of calculations for airplanes having constant lift-drag ratio during the flare are plotted in chart form."

Report presenting complete pressure-distributions measurements over a 24-inch-chord NACA 65,1-115 airfoil equipped with 20-percent-chord plain ailerons with aerodynamically smooth surfaces. Characteristics determined included airfoil normal-force, pitching-moment, aileron normal-force, and hinge-moment coefficients for a variety of Mach numbers, angles of attack, and aileron deflections. The aileron effectiveness parameter and section pitching-moment parameter are calculated.

Note presenting the stability derivatives valid for a limited range of supersonic speeds for a series of sweptback wings tapered to a point with sweptback or sweptforward trailing edges. The wings were derived by modifying the trailing edge of a basic triangular wing so that it coincided with lines drawn from the wing tips to the wing axis of symmetry.

Note presenting calculations, based on linearized supersonic flow theory and on the additional assumption that the Mach cones yaw with the wing, to determine the effect of thickness on the lateral force and yawing moment of a sideslipping delta wing at supersonic speeds. Generalized equations are derived for delta wings with rhombic profile and constant thickness ratio.

Note presenting an investigation to determine the fatigue-strength values for 24S-T aluminum alloy when subjected to various ratios of biaxial stresses. The stresses considered were both tensile. The results indicated that uniaxial fatigue-strength values in the longitudinal direction cannot be used to predict the fatigue strength, and that biaxial fatigue strength may be as low as 50 percent of the uniaxial fatigue strength.

Report presenting an analysis of two matrix methods for calculating responses of linear systems for given forcing functions and indicial responses in order to find a method suitable for solving the inverse problem of calculating forcing functions from known responses. The results of both methods are compared with exact solutions for both the direct and the inverse problems.

"The amount of foam that can be formed in the presence of certain pure chemical agents was investigated by a new method. The effect of variations in concentration and proportion of Aerosol OT and glycerol was studied and the effects of various other mixtures have been given for comparison. Both Gulf Agent and Aerosol-OT - glycerol mixtures, when present in comparable amounts, prohibited the formation of the normal volumes of foam to the same extent and in the optimum cases reduced it to only one-tenth of its normal value" (p. 1).

Report presenting an investigation of aircraft lubricating oil that is contaminated with various materials used in connection with airplane engines or contained in the fuel. Over 60 of the materials have been tested to determine their influence on the foaming of an aircraft lubricating oil. All but 13 of the compounds were found to have a small or negligible effect, but the other 13 were found to be strong foaming agents.

Note presenting thermodynamic properties of the products of combustion of five different mixtures of air with typical aircraft-engine fuel, which have been calculated from the most reliable thermodynamic data available. The calculations are presented in five charts of internal energy plotted against entropy with values of temperature, specific volume, pressure, and enthalpy indicated corresponding to five different percentages of the fuel-air ratio for perfect combustion.

Report presenting an investigation to determine the underlying causes of the undesirable longitudinal characteristics of a 45 degree swept-forward wing in the moderate and high lift-coefficient range. Several methods were used to create a detailed correlation between separation phenomena and longitudinal characteristics of the wing. Both turbulent and leading-edge separation need to be postponed in order to improve the longitudinal characteristics of this wing.

Report presenting the boundary-layer and stalling characteristics on an NACA 64A006 airfoil section at a Reynolds number of 5,800,000. Data included measurements of lift, drag, and pitching moment, chordwise distributions of pressure, visual studies of the boundary-layer flow, and surveys of the static-pressure and velocity distribution within the boundary layer. Results regarding force and moment characteristics, pressure distributions, and boundary-layer characteristics are provided.

From Summary: "The purpose of this investigation was to determine whether such airplanes could be made to fly uncontrolled for an indefinite period of time without getting into dangerous attitudes and for a reasonable period of time (one to three minutes) without deviating excessively from their original course. The results of this analysis indicated that the uncontrolled motions of a personal airplane could be made safe as regards spiral tendencies and could be greatly improved as regards maintenance of course without resort to an autopilot."

Report presenting testing to determine the force developed in a shock strut as a function of the flexibility of the attached wing structure. Both the experiment and analysis indicated that wing flexibility had some effect on the shape and peak value of the force-time curve in a shock strut.

Note presenting an approximate method developed to predict the location of detached shock waves ahead of two-dimensional and axially symmetric bodies. The method is based on the continuity relation, which is applied to the air that passes the sonic line.

Note presenting an investigation to derive the implications of a previously derived equation for rotating beams.

Note presenting the results of a series of investigations conducted by various laboratories which has led to a nomenclature with definitions of various turbine parameters and a consistent set of physical constants.

"This report is the second phase of a broad program of study of the transient motions of helicopters in autorotative flight. The first phase (reference 1) dealt with the steady-state condition of autorotative vertical descent. This report is concerned with the the transition from the steady condition of hovering to the steady autorotative descent" (p. 1).

"This report is the result of the first part of a broad program to analyze the transient motions of a helicopter, which occur in the various phases of flight following power failure" (p. 1).

Report presenting some methods for the systematic design of group displacements which expedite the liquidation of residuals in certain classes of problem, and the application of these methods is illustrated by numerical examples. Tables of functions are available to use with this method, which leads to much faster and easier computation.

Report presenting a study of experimental pressure distributions and section characteristics for several moderately thick airfoil sections were made. The pressure distributions and section force characteristics of several moderately thick airfoil sections at Mach numbers above the drag-divergence Mach numbers were analyzed.

Report presenting a theoretical study of the oscillations of a towed cable, which indicated that oscillations traveling downwind along the cable are amplified by aerodynamic forces when the airspeed is greater than the speed of propagation of waves along the cable. The theory provides a possible explanation for the violent motions of towed airspeed heads which appear above a certain speed.