Note presenting a survey of the 1200 degrees Celsius isothermal sections of the iron-nickel-molybdenum and the cobalt-iron-molybdenum ternary systems. The phases occurring in the systems were identified by means of x-ray diffraction and by etching methods, and the phase boundaries at 1200 degrees Celsius were determined microscopically, using the disappearing phase method with quenched specimens. Results regarding the specific phases and phase diagrams are provided.

Report presenting calculation studies to evaluate the influence that wing bending flexibility has on the structural response to gusts for three twin-engine transports and one four-engine bomber. The manner in which dynamic response factors for acceleration and bending moment vary with different assumed airplane operational factors is shown.

Report presenting a procedure for predicting the upwash components of the upflow angles in the region above or below the wing-chord planes of sweptback wing-fuselage-nacelle combinations. Comparisons of predicted and measured upflow angles are shown for six semispan models with 40 degree sweptback wings.

Note presenting a suggestion for classifying the compressible potential flows according to the location and number of singularities in the subsonic region of the hodograph plane, which seems to offer a convenient criterion for systematic investigation of these flows with Chaplygin's original method. The primary object of the paper is to present and analyze a few useful solutions of compressible potential flow with the exact gas law.

"A procedure for analyzing statically indeterminate trusses in the plastic stress range is presented which is applicable to trusses having any number of redundant members. A numerical example is used to illustrate the procedure" (p. 1).

Report presenting an investigation of the observed discrepancy at supersonic speeds between theoretical and apparent experimental average flat plate friction-drag coefficients calculated from boundary layer total-pressure surveys. Some of the qualities investigated included the effects of the total-pressure probe, heat transfer through the leading-edge region, change in leading-edge radius and strength of the leading-edge wave, possible early transition to turbulent flow, and the slight streamwise pressure gradient in flat plate flow were investigated for plates with very sharp leading edges.

Report presenting a method for quickly estimating the separation point of a laminar boundary layer in a compressible flow. The method should be usable for any two-dimensional flow in which classical boundary-layer assumptions are satisfied. Results obtained from a variety of calculations indicate that for all velocity gradients, the amount of velocity recovery possible before laminar separation occurs decreases as Mach number increases.

Equations are presented for the attenuation characteristics of several types of mufflers. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers and the results are compared with theory. The experiments were made at room temperature without flow and the sound source was a loud-speaker. A method is given for including the tail pipe in the calculations. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts have been included for the assistance of the designer.

Report presenting an analysis to determine the pressure distribution, span loading, and rolling moment due to small angles of sideslip at supersonic speeds for a series of thin, sweptback, tapered wings with wing tips parallel to the axis of wing symmetry. Three basic series of Mach numbers and plan-form combinations are considered, all of which have supersonic trailing edges in conjunction with both leading edges subsonic, one leading edge subsonic and one leading edge supersonic, and both leading edges supersonic.

Flight tests were made of the flying qualities of an F-47D-30 airplane to determine the longitudinal stability and control and stalling characteristics. The results indicated that the airplane was unstable with stick free in any power-on condition even at the most forward center-of-gravity position tested.

From Introduction: "The purpose of this paper is to describe one of the means developed for measuring this quantity on a given airplane type- a trailing arm with wheel. A prototype velocity indicator was tested in the Langley impact basin to determine its accuracy. A description of the operation of this type of vertical-velocity indicator, the results of the impact-basin and flight tests, and general evaluation of the indicator are presented herein."