Memorandum presenting an investigation at the tank no. 2 monorail of the landing on smooth water of a scale model of a hypothetical jet- and rocket-propelled airplane designed to fly at transonic speeds. The test is part of an investigation of the feasibility of the operation from water of high-speed airplanes. The results of the test form a basis for evaluating the improvement in hydrodynamic characteristics.

"An analysis of the effects of compressibility on the longitudinal stability, control, and trim of airplanes flying at high subsonic speeds and a discussion of the causes of and the means for lessening or preventing the diving tendency are presented. Wind-tunnel results for Mach numbers up to 0.90 are included for purposes of illustration and cover several investigations of longitudinal stability and control, airfoil characteristics, dive-recovery aids, and elevator characteristics. Methods are indicated for compensating for the undesirable control tendencies results from the characteristics of the wing at supercritical speeds by the appropriate choice of elevator contour" (p. 1).

A series of 11 fuels ranging in volatility and including various types of hydrocarbons were tested in a single tubular combustion chamber of a turbojet engine under inlet-air conditions simulating engine operation at two speeds at an altitude of 40,000 feet. Temperature-rise data at various fuel-air ratios were obtained for each set of air-flow conditions. Results regarding the effect of combustor inlet-air conditions on temperature rise, four different series of tests, and a review of some general considerations are provided.

"A device has been developed which measures the velocity of sound in fluids at stagnation and is especially adaptable to turbine and compressor testing for which the constituency of the working fluid may be in doubt. By utilizing the shaft frequency of a rotary compressor, the instrument can also be used to provide a direct measurement of the compressor Mach number (ratio of blade-tip velocity to inlet velocity of sound at stagnation). A Helmholtz resonator is employed in the measurement of the sound velocity" (p. 1).

Report discussing an investigation to determine the effects of sweepback and low aspect ratio on the aerodynamic characteristics of a wing at high subsonic Mach numbers. Tests were performed at aspect ratios of 2, 3, and 5 and sweepback angles of 0, 30, and 45 degrees. Generally, sweepback and low aspect ratio were found to both delay and lessen the effects of compressibility.

Report presenting total-pressure recoveries obtained with four-cone inlet combinations at Mach number 1.85. The configurations tested included a cone designed to produce three oblique shocks ahead of the diffuser inlet combined with two other inlets, a cone generated by a parabolic arc in combination with two other inlets, a cone-inlet combination designed to produce an isentropic entrance flow at 0 degrees angle of attack, and a 30 degree single-shock cone combined with a perforated inlet section. Each of the configurations yielded total-pressure recoveries higher than what was reported in previous testing.

"A preliminary investigation was made to determine the effects of gamma radiation on the age-hardening rate of an aluminum-copper alloy at temperatures of 32 and 70 degrees Fahrenheit. The gamma radiation from a 100-milligram radium source appeared to have no significant effect on the age-hardening rate of the alloy. A metallographic examination of the test specimens showed no microstructural changes that could be attributed to gamma radiation" (p. 1).

"An investigation has been made at large scale of the characteristics of highly swept wings. Data were obtained at several angles of sideslip on wings having angles of sweep of plus or minus 45 degrees, plus or minus 30 degrees, and 0 degrees. The airfoil sections of the wings varied from approximately NACA 0015 at the root to NACA 23009 at the tip. Each wing was investigated with flaps under flection, partial-span split flaps deflected 60 degrees, full-span split flaps defected 60 degrees and split-flap-type ailerons deflected plus or minus 15 degrees" (p. 1).

From Summary: "This report presents the aerodynamic measurements made during a Navy investigation conducted in the Langley 8-foot high speed tunnel to determine the actual human tolerance to wind blasts."

Report presenting tests of an NACA 4-(5)(08)-03 two-blade propeller in the 8-foot high-speed tunnel for blade angles of 45 and 60 degrees extending the Mach number range from that of previous tests of the propeller up to Mach number 0.913. When the forward speed was increased from a low value to a forward Mach number of 0.90, the loss in peak efficiency was found to be not more than 47 percent.

Report presenting measurements using the NACA wing-flow method of the lift, pitching-moment, and hinge-moment characteristics of a 35 degree sweptback NACA 65-009 airfoil of aspect ratio 3.04 with a full-span 1/4-chord unsealed plain flap. The tests were carried out at a range of Mach numbers, Reynolds numbers, angles of attack, and flap deflections. Variations of lift and pitching moment with angle of attack or flap deflection were approximately rectilinear at all Mach numbers for moderate angles of attack and flap deflections.

Report presenting measurements downwash angles behind a model of a high-aspect-ratio wing at points near the probable tail location at Mach numbers up to 0.89 in the high-speed tunnel. The model has an NACA 65-210 section, an aspect ratio of 9.0, a taper ratio of 2.5:1, no twist, dihedral, or sweepback. Results regarding experimental data and comparison of experimental and calculated results are provided.

"Flight tests have been made with a P-51D airplane to determine the effect of chordwise vanes on the amplitude of tail buffeting. The tests made during abrupt pull-ups to the buffeting boundary included strain measurements on wing and tail and tuft studies over the wing. The results indicate that the vanes tested have no appreciable effect on the amplitude of tail buffeting" (p. 1).

Memorandum presenting a preliminary investigation to determine the effects of alpha-particle bombardment on the creep rate of aluminum wire at 400 degrees Fahrenheit. The alpha radiation from an 85-millicurie polonium source appeared to decrease slightly the creep rate of the aluminum.

Report presenting an investigation of the effect of tip shape on the aerodynamic characteristics of large-scale 45 degrees swept-forward and 45 degrees swept-back wings. The results show that none of the variations of tip shape investigated nor the addition of bodies of revolution at the tips produced major changes in the characteristics of the swept wings.

Memorandum presenting wind-tunnel tests to determine the aerodynamic characteristics of a 15-percent- and a 35-percent-chord plain trailing-edge flap on the NACA 0006 airfoil section. Simultaneous measurements of section lift, drag, and pitching moment were made over a range of Mach numbers, angles of attack, and flap deflections.

Report presenting an investigation in the two-dimensional low-turbulence tunnels to develop optimum double-slotted-flap configurations for seven thin NACA airfoil sections. Each was equipped with the same flaps and measured at the same Reynolds numbers. Results regarding the lift characteristics and pitching moment are provided.

Report presenting flight tests of rocket-powered models at supersonic speeds to determine the effect of nose fineness ratio of winged bodies on total and component drag at high Mach numbers. Wingless models of three nose fineness ratios and winged models of two nose fineness ratios flown through a range of Mach numbers. Results regarding total drag, body drag, and wing drag are provided.

Investigation at transonic speeds in the high-speed 7- by 10-foot tunnel to determine the rolling-effectiveness characteristics of a spoiler on a double-wedge-type semispan wing with a sweepback angle of 42 degrees. Results regarding the variation of rolling-moment coefficient, spoiler effectiveness, and rolling effectiveness are provided.

Report discussing an investigation of the DM-1 glider, which has an approximately triangular plan form, with auxiliary studies of a model of triangular wings. The pitching-moment coefficient, drag coefficient, and angle of attack with the lift coefficient are provided. Results indicated that the angles of descent without power are likely to be prohibitive and airplanes with the tested type of wings will not be able to land safely without power.

Report presenting comparative drag measurements at zero lift at transonic speeds for two sharp-leading-edge airfoils using the NACA wing-flow method. One airfoil had a symmetrical circular-arc section and one had a symmetrical double-wedge section. The primary difference in the drag characteristics of the two airfoils at zero lift is the earlier drag rise of the double-wedge section.

"A study has been made of the variation of seaplane hull weight with length-beam ratio in a systematic series of hulls designed for constant gross weight and similar spray characteristics. It is found that increases in the length-beam ratio bring about small reductions in the hull weight if it is assumed that seaplanes having the same weight and bottom shape will be designed for the same load factor. A short discussion is also given to show the reduction in load factor that may occur with high length-beam ratios" (p. 1).

Report discussing testing of a model of the pilotless aircraft RM-1 to measure aileron hinge moments in flight in order to determine the reason for loss of roll stabilization at supercritical speeds in flight. The aileron was found to become quickly underbalanced over the full deflection range at supercritical speeds. Information about the general flight behavior, aileron hinge moments, and roll stabilization of the model is provided.

From Summary: "A method for computing the effect of surface roughness on the drag coefficient of an airplane is presented. Calculated results using this method are compared with experimental results from both flight and wind-tunnel tests. In general, the agreement is believed satisfactory."