Report discusses the results of testing of thallium as an antiknock agent in an internal-combustion engine. From Introduction: "On a weight basis, the thallium vapors were found to have several times the antiknock value of tetraethyl lead, which was added to the fuel. The amount of thallium vapor necessary to raise the antiknock properties of a gasoline up to exact equivalence with a benzol-gasoline mixture was determined in these engine tests."

Report presenting tests to determine the behavior of landplanes when they are forced to land on the water. The report is incomplete.

Report presenting the utilization of the differential equation of Chaplygin's jet problem to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows.

Report presenting tests on a single-cylinder, air-cooled engine to determine the effect of several different exhaust-stack shapes on the design and performance of the individual cylinder exhaust-gas jet-propulsion systems. Results regarding the effect of nozzle area and stack shape on exhaust-gas jet thrust, effect of nozzle area and stack shape on overall performance for the S-shape, the 90 degree bend, and the 180 degree bend, the effect on the shape on engine power and volumetric efficiency, and the effect of a branched stack on engine power are provided.

Report discussing the difficulty in pulling of high-speed dives, which is primarily due to the effect of compressibility on the lift of the wing. Some of the means described for providing increased longitudinal control include auxiliary flaps and a controllable stabilizer.

Report presenting an iteration method employed to obtain the flow of a compressible fluid past a curved surface. For small Mach numbers and thin shapes, the results obtained by the iteration process agree with those obtained by the Poggi method.

A criterion is developed for the stiffness required of elastic lateral supports at the ends of a compression member to provide stability. A method based on this criterion is then developed for checking the stability of a continuous beam-column. A related method is also developed for checking the stability of a member of a pin-jointed truss against rotation in the plane of the truss.

A monocoque box beam consisting of a 24S-T aluminum-alloy sheet reinforced by four bulkheads and by longitudinal stringers and corner posts was subjected to bending loads as follows: pure bending about the lift axis, cantilever bending about the lift axis, and pure bending about both lift and drag axis. Longitudinal strains were measured for loads up to a load at which permanent set became measurable. The loads were sufficient to produce buckling of the sheet between stringers on the compression side of the box. The only noticeable effect of this buckling was a small increase in extreme-fiber strain on the compression side. The measured strains and measured deflections differed less than 10 percent from those computed from the simple beam theory after taking account of the effective width of the buckled sheet. The effect of the bulkheads on the distribution of stringer strain was negligible.

"The use of different forms of wide-flange, thin-wall steel beams is becoming increasingly widespread. Part of the information necessary for a national design of such members is the knowledge of the stress distribution in and the equivalent width of the flanges of such beams. This problem is analyzed in this paper on the basis of the theory of plane stress. As a result, tables and curves are given from which the equivalent width of any given beam can be read directly for use in practical design" (p. 1).

"An investigation has been made in the Langley full-scale tunnel of a 47.5 degree sweptback wing-fuselage combination equipped for boundary-layer control by suction. The wing aspect ratio was 3.5, the taper ratio was 0.5, and the airfoil sections normal to the quarter-chord line were NACA 64(sub 1)-A112. The wing configurations tested included the wing with various combinations of extensible leading-edge and split flaps" (p. 1).

Report presenting an investigation to determine the cause for a discrepancy between theoretical and experimental pressure distributions found during a two-dimensional investigation of flapped airfoils in a 2- by 8-inch supersonic tunnel. The results indicated that a tunnel-boundary-layer and model-flow interaction effect on the flow over models mounted directly from the walls in supersonic wind tunnels exists.

Report presenting an experimental and analytical investigation of the flutter of uniform sweptback cantilever wings. The experiments used groups of wings sweptback by rotating and by shearing with angles of sweep ranging from 0 to 60 degrees. Results regarding the experimental investigation and a discussion and comparison of the analytical and experimental results are provided.

Two low-acceleration transonic-flutter vehicles were launched and flown. The first carried two test wings, one of which fluttered at M = 0.92 at a frequency of 61.4 cycles per second. The reference flutter speed determined from two-dimensional theory for an unswept wing in incompressible flow is conservative when compared to the experimental flutter speed. The second vehicle carried two test wings, one of which failed at M = 0.71 because of low-frequency divergent oscillation. Since this failure was not caused by conventional flexure-torsion flutter, no comparison with a reference flutter speed can be made.

Report presenting the effects of changes in Reynolds number on the longitudinal aerodynamic characteristics of a 52 degree sweptback wing with an aspect ratio of 2.88 and NACA 64(sub 1)-112 airfoil sections. The model was tested with the leading edge both smooth and rough. Results regarding force and pitching-moment results, flow observations, and discussion of force and moment characteristics are provided.

Report presenting a study of the flight characteristics of the canard configuration at transonic and supersonic speeds. Known problems concerning the low-speed characteristics of the canard are also investigated.

Report discussing testing on a series of tapered swept wings under conditions simulating rolling flight. The lift, longitudinal-force, and pitching-moment characteristics for three swept wings are provided. The results indicated that a decrease in taper ratio on a swept wing caused a small decrease in damping in roll at low and moderate lift coefficients.

Report discussing the aerodynamic characteristics of three sets of blades over as wide a range of operating conditions as possible. One set of blades was conventional, one had blades that embodied sweep, and one was a nonswept set with thinner blade sections. The sweptback blades were found to be generally inferior to the straight blades, but the Mach numbers tested were not high enough to include speeds that might benefit from sweepback.

From Summary: "Results are presented of an experimental investigation of the characteristics of NACA submerged inlets on a model of a fighter airplane for Mach numbers from 0.30 to 0.875. The effects on the ram-recovery ratio at the inlets of Mach number, angle of attack, boundary-layer thickness on the fuselage, inlet location, and boundary-layer deflectors are shown. The data indicate only a slight decrease in ram-recovery ratio for the inlets ahead of or just behind the wing leading edge as Mach number increased, but showed large decreases at high Mach numbers for the inlets aft of the point of maximum thickness of the wing."

Memorandum presenting the beneficial effects on stability limits and combustion efficiency produced by the application of surfaces immersed in the combustion zone to a ram-jet-type burner. Investigations were made with one, two, three, and four rows of wedges at simulated sea-level and altitude subsonic ram-jet flight conditions. The addition of rows of wedges immersed in the combustion zone regularly extended the stability limits of combustion.

Report presenting control requirements and parameters for a ram jet with a variable-area exhaust nozzle, which have been analyzed from calculated performance charts covering flight Mach numbers from 0.6 to 3.0 and altitudes from sea level to 30,000 feet. Requirements for maximum efficiency, safe and stable operation, maximum range of thrust at a given flight Mach number, and control of fuel flow are discussed and control parameters are selected.

The results of power-off force tests and flight tests of a model with a thin unswept low-aspect-ratio wing are presented. The tests were made with the flaps retracted and deflected. The effects on the lateral flight characteristics of decreasing directional stability were noted.

Report presenting an investigation of icing and ice protection at the inlet of a turbojet engine in the altitude wind tunnel. A method of ice protection was studied that uses hot gas bled from a turbine inlet and injected into the air stream ahead of the compressor inlet. Ice was either prevented or accumulated slowly at various engine speed levels.

Memorandum presenting a correlation of available two-dimensional airfoil data to determine the effects of compressibility on the location of the section aerodynamic center at low lift coefficients. The results indicate that large forward or rearward movements of the aerodynamic center with Mach number are possible.

Report regarding the results of an investigation at high Reynolds numbers and low Mach numbers in the full-scale tunnel to determine the effect of leading-edge high-lift devices and split flaps on the maximum-lift and lateral characteristics of a rectangular wing of aspect ratio 3.4 with circular-arc airfoil section. Results regarding the maximum lift and stalling characteristics on the basic wing, effect of split-flap deflection, effect of leading-edge high-lift devices, and lateral characteristics with the flaps are provided.