Report presenting an investigation to determine the effects of various design parameters on the lateral-stability characteristics of a glider towed by a single towline. The investigation showed that it is possible to obtain inherent lateral stability with a single towline system.

An investigation was made in the Langley high-speed 7-by 10-foot tunnel to determine the high-speed longitudinal stability end con&o1 characteristics of a 0.01-scale model of the Grumman XF9F-2 airplane in the Mach number range from 0.40 to 0.85. The results indicated that the lift and drag force breaks occurred at a Mach number of about 0.76. The aerodynamic-center position moved rearward after the force break and control position stability was present for all Mach numbers up to a Mach number of 0.80.

Report presenting a wind-tunnel investigation performed at low speed to determine the aerodynamic characteristics of a 51.3 degree sweptback semispan wing equipped with 16.7-percent-chord plain flaps and ailerons with various spans and spanwise locations and one with span of aileron with trailing-edge angles of 6, 14, and 25 degrees. Results regarding the wing aerodynamic characteristics, aileron-control characteristics, spoiler control characteristics, and effect of wing-tip shape are provided.

Report presenting an investigation at subsonic and transonic speeds in the high-speed 7- by 10-foot tunnel to determine the aerodynamic characteristics of a 42.7 degree sweptback wing with a 20-percent-chord and 50-percent-span outboard aileron. The investigation was performed in transonic flow over a bump on the tunnel floor and in subsonic flow on one of the tunnel side walls.

Report presenting a survey of the present status of research on boundary-layer control and its possible applications in aeronautics. The applications considered include reduction of profile drag by the elimination of turbulent separation, increase of the maximum lift coefficient through control of separation, use of suction and blowing slots near the trailing edge of the airfoil as a means of lateral control, use of boundary-layer control as a means of increasing the efficiency of diffusers and bends, and the use of boundary-layer control to influence shock-boundary-layer interaction at high speeds.

Report presenting the results of flight tests showing lateral oscillation in the Bell X-1 and calculations created to determine the effects of changes in several mass and aerodynamic parameters on the lateral oscillations. Calculations indicate that lateral stability should be improved by a more positive inclination of the principal axis of inertia or a reduction of the value of yawing moment of inertia.

Memorandum presenting measurements made in the transonic speed ranges of the static-pressure position error at a distance of 0.96 chord ahead of the wing tip of both the 8-percent-thick-wing and the 10-percent-thick-wing X-1 airplanes, and at a point 0.6 maximum fuselage diameter ahead of the fuselage nose of the X-1 airplanes. Results regarding the accuracy of pitot-static heads, static-pressure error of wing-tip installation, static-pressure error of the fuselage-nose installation, and error in total pressure are provided.

A supplementary investigation on the stabilization of the Jettisonable nose section of the X-2 airplane has been conducted in the Langley 20-foot free-spinning tunnel. It was found that the nose section could be stabilized by the addition of curved fins which could be folded against the fuselage for normal flight.

"Four 90 degree two-dimensional turning passages designed by the method of characteristics were tested at an inlet Mach number of 1.71. The measured losses varied from 5 to 15 percent of the inlet stagnation pressure. The smallest loss was obtained for a passage in which separation on the convex surface was minimized through the introduction of a favorable pressure gradient" (p. 1).

Report presenting an analysis of the effects of compressibility on the pressure coefficients of several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of linearized equations of compressible flow. The results indicated that the theoretical methods predict the subsonic pressure-coefficient changes over the central portion of the body but do not predict the pressure-coefficient changes near the nose.

Report presenting the hydrodynamic characteristics of a swept planing-tail hull as determined by water tank testing. The hull shape was based on results from previous testing indicating that symmetrical airfoil sections and slender boom-like afterbodies lower the drag. Results regarding spray characteristics, take-off stability and trims, landing stability, resistance, and directional stability are presented.

Report presenting a supersonic compressor design with supersonic velocity at the entrance of the stator on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The starting conditions and stability of the flow in rotor and stator are discussed, and the desirability of the variable-geometry stators and adjustable guide vanes is indicated.

"A supersonic compressor design having supersonic velocity at the entrance of the stator is analyzed on the assumption of two-dimensional flow. The rotor and stator losses assumed in the analysis are based on the results of preliminary supersonic cascade tests. The results of the analysis show that compression ratios per stage of 6 to 10 can be obtained with adiabatic efficiency between 70 and 80 percent. Consideration is also given in the analysis to the starting, stability, and range of efficient performance of this type of compressor" (p. 1).

Report presenting an investigation in the high-speed 7- by 10-foot tunnel to determine the high-subsonic aerodynamic characteristics of three different types of flying-boat hull: a planing-tail hull, a blended hull, and an airfoil-forebody swept hull.

Report presenting comparative tests of the rolling power of plain constant-chord, full-delta, and half-delta ailerons on delta wings with varying degrees of sweepback were tested on rocket-propelled test vehicles. Results regarding the effect of leading-edge sweepback, a comparison of rolling effectiveness, and comparison with theory are provided.

Report presenting the pressure-recovery characteristics of a model with two scoops situated on the aft position of a long forebody and connected through diffusors to a common settling chamber at a range of Mach numbers. The effects of interaction between the flow in the two air-induction systems and of varying the mass flow through the boundary-layer scoops were studied. Results at several different angles of attack are provided.

Memorandum presenting an investigation of the effect of skewed plain nose flaps on a thin, low-aspect-ratio triangular wing in combination with a high fineness-ratio fuselage conducted at low speeds and high Reynolds numbers. The plan form of the flaps was such that the flap chord varied from zero percent of the wing chord at the model center line to 100 percent at about 91-percent wing semispan. The results indicated that the nose flaps provided a significant delay in the occurrence of both the leading-edge type of separation and tip stalling.

Report presenting testing using a Northrop X-4 to obtain stability and control data during airplane acceptance tests. The data includes a time history of a complete pull-up, time histories of several level and accelerated flight runs, and the effect of dive-brake extension on the longitudinal and lateral trim.

The data obtained from the flight of a simplified (dummy) rocket-propelled model of the MX-656 have been analyzed to determine the booster-model characteristics and the model-alone characteristics up to a Mach number of 1.3. The data indicate that the model-booster combination is satisfactory. The model alone is longitudinally stable i n the Mach number range covered by the test (0.9 to 1.3) with the center of gravity at -15 percent of the mean aerodynamic chord. With the stabilizer setting at 0 deg. the variation of normal-force coefficient with Mach number is not large. The total-drag-coefficient variation with Mach number is not unusual. About 12 percent of the total drag at a Mach number of 1.3 can be attributed to body base drag.

"An investigation of the spin and recovery characteristics of a 1/24-scale model of the Grumman AF-2S, -2W airplane was conducted in the Langley 20-foot free-spinning tunnel. The effects of controls on the erect and inverted spin and recovery characteristics for a range of possible loadings of the.airplane were determined. The effect of a revised-tail installation (small dual fins added to the stabilizer of the original tail and the vertical-tail height of the original tail increased) and the effect of various ventral-fin and antispin-fillet installations were determined" (p. 1).

Report presenting the flying qualities of a C-54D airplane measured as a preliminary to an investigation to determine the necessity of additions or revisions to flying-quality requirements in view of the problems associated with making instrument approaches to low altitudes. Results regarding control friction, dynamic longitudinal stability, static longitudinal stability, maneuvering stability, take-off and landing characteristics, effectiveness of the trim tabs, trim changes, and stalling characteristics are provided.

Report presenting an investigation in the full-scale tunnel of the low-speed longitudinal characteristics of a 47.5 degree sweptback wing-fuselage combination with various extensible leading-edge-flap and plain trailing-edge-flap arrangements. Results regarding the basic longitudinal characteristics, extensible leading-edge flaps, plain trailing-edge flaps, and flap combinations are provided.

In determining the experimental performance of an air-cooled turbine, the heat-transfer characteristics must be evaluated. The suggested formulas that are required to determine these characteristics are presented. The formulas have a form in which dependent parameters are expressed as unknown functions of independent parameters. Methods of experimenting to determine these functions are suggested. In some cases general heat-transfer discussions that lead to the suggested forms of the formulas are given.

Report presenting results of a tank investigation of a 1/8-size powered dynamic model of the Grumman JRF-5 airplane fitted with tandem hydro-skis and auxiliary wing-tip skids suitable for operation on water, snow, and ice. Results regarding take-off and landing tests are provided.