From Summary: "The effects of ice formations on the section lift, drag, and pitching-moment coefficients of an unswept NACA 65A004 airfoil section of 6-foot chord were studied.. The magnitude of the aerodynamic penalties was primarily a function of the shape and size of the ice formation near the leading edge of the airfoil. The exact size and shape of the ice formations were determined photographically and found to be complex functions of the operating and icing conditions."

"An empirical relation has been obtained by which the change in drag coefficient caused by ice formations on an unswept NACA 65A004 airfoil section can be determined from the following icing and operating conditions: icing time, airspeed, air total temperature, liquid-water content, cloud droplet impingement efficiencies, airfoil chord length, and angles of attack. The correlation was obtained by use of measured ice heights and ice angles. These measurements were obtained from a variety of ice formations, which were carefully photographed, cross-sectioned, and weighed" (p. 1).

In this study in which an airplane simulator with one degree of freedom (pitch) was used, results were determined for three conditions of airplane dynamics. For an undamped natural frequency of 1/2 cps with a damping ratio of 0.18 and for an undamped natural frequency of 1 cps with a damping ratio of 0.11, moderate longitudinal stick forces and displacements were desired.

Note presenting flight tests conducted with a medium-size single-rotor helicopter, of which one blade was equipped with strain gages, to determine the relative effects of atmospheric turbulence and moderate maneuvers on the periodic rotor blade moments. The results indicate no significant increase in the total blade moments due to atmospheric turbulence of moderate pull-up maneuvers which produced center-of-gravity acceleration increments of less than about 0.15g. Results regarding moment records, maximum vibratory moments, harmonic analysis of moment records, and applicability of NACA helicopter VGHN recorder surveys are provided.

Note presenting an experimental study using liquid nitrogen made to verify the existence of a temperature gradient as the factor causing the increase in pressure and to investigate the effect on pressure of altering the temperature gradient. The effect on pressure of different heat-leak rates into the container and different quantities of liquid was also investigated. Results regarding the typical pressure history and temperature gradient, effect of stirring liquid on pressure, effect of heat-leak rate and liquid content on pressure, and effect of vapor mixing on pressure are provided.

Note presenting a study of the interrelation of aging during creep and of creep during aging in polycrystalline aluminum alloys containing 1 to 4 percent copper. Experimental procedures included interrupted creep tests, tensile tests of crept specimens, quantitative metallographic determination of the percent precipitation during creep, hardness measurements on unstressed and stressed aged alloys, X-ray studies of deformation in the crystalline lattice, and microscopic examination of the surface-deformation markings.

Report presenting an investigation of direct measurements of the thermal conductivity of reacting gas systems. The hot-wire measurement technique was used at a range of temperatures and pressures. A comparison of the theoretical and experimental results are provided.

Report presenting a study of the minimization of inviscid fluid drag for thin aerodynamic shapes subject to imposed constraints on lift, pitching moment, base area, or volume. The problem is transformed to one or determining a two-dimensional potential flow satisfying either Laplace's or Poisson's equations with boundary values fixed by the imposed conditions.

"A stability analysis is made of long flat rectangular plates subjected to both shear and compressive loads. The edges of the plates are taken to be simply supported and the plates are supported along one or two intermediate longitudinal lines by lines of deflectional springs (elastic line supports). The results of the analysis are presented in the form of charts that are useful in the determination of the buckling load of plates stiffened by stringers or webs" (p. 1).

"Analytical and experimental studies have been made of the channel flow of air through porous resistances inclined at an angle of 3.5 degrees to the axis of the channel with the air discharging to the atmosphere. These studies determine the channel wall shape that would yield a uniform discharge through the porous resistance" (p. 1).

Report presenting hydrodynamic impact testing made with a multimode elastic model consisting of a rigid prismatic float and a flexible wing and a comparison with similar experimental results for a single-mode system and with theoretical solutions. Testing was conducted in smooth water at two fixed trims and two flight-path angles over a range of velocities. Results regarding accelerations, time histories, oscillatory accelerations, elastic-body acceleration data, and rigid-body acceleration data are provided.

Report presenting five lubricants of different base stock tested using groups of 1/2-inch air-melt AISI M-1 tool-steel balls under rolling-contact fatigue conditions in the fatigue spin rig. A methyl silicone, mineral oil, glycol, sebacate, and adipate were used. All other test conditions were held constant at a test temperature of 100 degrees Fahrenheit and a maximum theoretical Hertz stress of 725,000 pounds per square inch in compression.

From Introduction: "A study of crash-impact survival in light airplanes is reported in references 1 and 2. A similar study for fighter airplanes is reported in reference 3. This report discusses crash-impact survival in transport airplanes."

The wing employed in this investigation had a 67-percent-chord slotted flap in combination with a 33-percent-chord plain rear flap equipped with a full-span blowing nozzle. The tests were conducted in a static-thrust facility at the Langley Aeronautical Laboratory. The investigation indicated that the plain rear flap alone with a low momentum coefficient for boundary-layer control provided larger turning angles than the combined slotted and plain flaps without boundary-layer control.

Report presenting an investigation of spoilers at a Mach number of 1.93 to determine the effects of height and chordwise location on the section pressure distributions and section aerodynamic characteristics of a two-dimensional, 6-percent-thick symmetrical wing. Spoilers of three different heights were tested at three different chordwise locations. Results regarding pressure distributions, aerodynamic characteristics, and shock boundary-layer interaction are provided.

Report presenting a study of the effect of fiber orientation on fatigue life for both races and balls in the fatigue spin rig. In both balls and races, a concentration of fatigue failures was observed in that portion of the specimens with the highest angle of intersection of fiber flow lines from the surface.

Schlieren photographs have been compiled of the two-dimensional flow at transonic speeds past 37 airfoils. These airfoils have variously shaped profiles, and some are related in thickness and camber. The data for these airfoils were analyzed to provide basic information on the flow changes involved and to determine factors affecting transonic-flow attachment, which is a transition from separated to unseparated flow at the leading edges of two-dimensional airfoils at fixed angles as the subsonic Mach number is increased.

Report presenting a vortex burner in which the vortex strength could be varied at constant flow rate, which was used for a study of propane-air vortex flames. Results regarding the measurement of vortex strength, turbulence, flames in vortex flow, the fuel-lean vortex flame, and stability of vortex flames are provided.

Note presenting friction, wear, and surface-failure properties of various materials as determined in liquid nitrogen. Data were obtained at a sliding velocity of 2300 feet per minute and a load of 1000 grams with a hemisphere sliding on the flat surface of a rotating disk. Results regarding metals and metal compounds, nonmetals, and some miscellaneous observations are provided.

Report presenting an investigation of the effects of distributed surface roughness, consisting of lathe-tool marks, on the skin friction of a turbulent boundary layer over a body of revolution at Mach number 2.01. The investigation was made on three ogive-cylinders at zero angle of attack over a surface-roughness range from 23 to 480 microinches root mean square. Results indicated that the effects of distributed surface roughness on a turbulent boundary layer at Mach number 2.01 are generally similar to those found at Mach number 1.61 and at subsonic speeds.

Report presenting an investigation to determine the effect of single and multiple two-dimensional roughness elements on the temperature distribution, pressure distribution, and heat transfer at Mach 3.1. Results regarding recovery temperatures and heat transfer are provided.

Report presenting comparison of transition locations for an open-nose cone, a conventional sharp cone, and a hollow cylinder showed that transition locations on the open-nose cone and hollow cylinder were identical but differed from the sharp cone. Bluntness effects on the open-nose cone were quite similar to those observed on the hollow cylinder.

In this method, the gust velocities are represented as rolling gusts, yawing gusts, and side gusts. Random distributions of gust velocities across the span are taken into account in defining the rolling and yawing gusts. Complex stability derivatives are used to account for the random distribution of side gusts along the fuselage and vertical tail and the lag effects in gust penetration. A sample calculation procedure is presented for obtaining the response of the airplane in each degree of freedom.

Presented is a limited review of some experiences in flight testing of missiles and of wing flutter investigations that may be of interest in missile design. Several types of flutter of concern in missile studies are briefly described. Crude criteria are presented for two of the most common types of flutter to permit a rapid estimate to be made of the probability of the occurrence of flutter. Many of the details of the flutter problem have been omitted, and only the broader elements have been retained so as to give the designer an overall view of the subject.