Report presenting a flight test of a supersonic research pilotless aircraft in which large-amplitude aileron oscillations, most likely aileron compressibility flutter, were encountered in the transonic and supersonic speed ranges. Results regarding power-on flight and coasting flight are provided.

Note presenting an analysis and comparison of atmospheric turbulence as experienced by rocket-powered models and temperature lapse-rate data obtained from rawinsonde soundings in 38 cases by using an assumed temperature lapse-rate stability boundary as a basis for comparison. A limited correlation has been obtained which indicates that atmospheric conditions classified as being unstable will generally be turbulent, but a marginal or stable classification does not necessarily indicate smooth air.

Report presenting some equations that give the interference on the trailing-vortex system of a uniformly loaded finite-span wing in a circular tunnel containing partly open and partly closed walls, with special reference to symmetrical arrangements of the open and closed portions. Methods are given for extending the equations to include tunnel shapes other than circular.

Although the corrosion resistance of sheet duralumin can be greatly improved by suitable heat treatment, protection of the surface is still necessary if long life under varied service conditions is to be insured. The coatings used for this purpose may be grouped into three classes: the varnish type of coating, the oxide type produced by a chemical treatment of the surface, and metallic coatings, of which aluminum appears to be the most promising. Since the necessary weather exposure tests are not complete, some of the conclusions regarding the value of various surface coatings are necessarily tentative.

Report discussing an investigation to determine the effects of aeroelasticity on the rolling effectiveness of a model of a McDonnell F3H-1 airplane wing. The plane was found to be subject to aeroelastic losses that varied with Mach number and altitude.

Report presenting an investigation to determine the effects of aeroelasticity on the rolling effectiveness of an 8.06-percent-scale model of the McDonnell F3H-1 airplane wing. The investigation used rocket-propelled models in free flight over a range of Mach numbers. The results indicate that the airplane is subject to aeroelastic losses varying from about 7 percent at Mach number 0.5 to 46 percent at Mach number 0.90 at sea level.

"Methods are presented that use general correlative time-response input and output data for a linear system to determine the frequency-response function of that system. These methods give an exact description of any linear system for which such transient data are available. Examples are shown of application of a method to both an underdamped and a critically damped exact second-order system, and to an exact first-order system with and without dead time. Experimental data for a turbine-propeller engine showing the response of engine speed to change in propeller-blade angle are presented and analyzed" (p. 547).

Memorandum presenting a two-dimensional wind-tunnel investigation of the effects of maximum-thickness location on fluctuating pressures and normal-force coefficients on 9-percent-thick airfoils, which indicated that for normal-force coefficients up to 0.6, the section variables had little effect on the pressure pulsations and root-mean-square normal-force-coefficient fluctuations. Results regarding pressure fluctuations and normal-force-coefficient fluctuations are provided.

"A general algebraic method of attack on the problem of controlling gas-turbine engines having any number of independent variables was utilized employing operational functions to describe the assumed linear characteristics for the engine, the control, and the other units in the system. Matrices were used to describe the various units of the system, to form a combined system showing all effects, and to form a single condensed matrix showing the principal effects. This method directly led to the conditions on the control system for noninteraction so that any setting disturbance would affect only its corresponding controlled variable" (p. 581).

Memorandum presenting an analysis of a large number of liquid-metal-to-air heat-exchanger cores for the nuclear-powered liquid-metal turbojet cycle to determine which types yield the best overall net thrust per total engine weight. The performances of all exchangers considered were initially evaluated at a median condition. The performance of the best of each of the four types was compared with that of a shell-and-tube exchanger with the air flowing through the tubes, operating at the same condition.

"An investigation was made of the trim and dynamic response characteristics of the free-floating horizontal tail of a 1/7-scale model of the complete tail of the Grumman XF10F-1 airplane in the Langley 8-foot transonic tunnel at Mach numbers up to 1.13. The complete tail was mounted in the tunnel on a 3 degree conical support body. Various configurations were investigated. A loss in damping of the horizontal tail at transonic speeds was shown by both tunnel and flight tests" (p. 1).

Note presenting extensive data relating properties of wrought N-155 alloy under static, combined static and dynamic, and completed reversed dynamic stress conditions. Time periods for fracture ranged from 50 to 500 hours at room temperatrue, 1000, 1200, 1350, and 1500 degrees Fahrenheit. Results regarding the rupture and fatigue strengths, fatigue strengths based on cycles to failure, influence of superimposed fatigue loads on creep, influence on superimposed fatigue stress on elongation in the rupture test, stress-strain characteristics under fatigue loading, damping effects, influence of cyclic speed on fatigue properties, influence of notches on fatigue, surface finish, and limitations of findings are provided.