"A flight investigation of a 1/7-scale rocket-powered model of the XF10F Grumman XF10F airplane in the swept-wing configuration has been made. The purpose of this test was to determine the static longitudinal stability, damping in pitch, and longitudinal control effectiveness of the airplane with the center of gravity at 20 percent of the wing mean aerodynamic chord. Only a small amount of data was obtained from the test because, immediately after booster separation at a Mach number of 0.88, the configuration was directionally unstable and diverged in sideslip" (p. 1).

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.

"A flight test was made to determine the servoplane effectiveness and stability characteristics of the free-floating horizontal stabilizer to be used on the XF10F airplane. The results of this test indicate that servoplane effectiveness is practically constant through the speed range up to a Mach number of 1.15, and the stabilizer static stability is satisfactory. A loss of damping occurs over a narrow Mach number range near M = 1.0, resulting in dynamic instability of the stabilizer in this narrow range" (p. 1).

"The rocket-propelled-model technique has been applied to the investigation of low-lift buffeting. Results of preliminary tests show that severe buffeting, wing dropping, and normal-force changes occur almost simultaneously near zero lift over a Mach number range near 0.9 on unswept wings 12 percent thick. On unswept wings 7 percent thick, buffeting did not occur; however, mild wing dropping and normal-force changes were experienced" (p. 1).

"A method of analysis based on slender-wing theory is developed to investigate the characteristics in roll of slender cruciform wings and wing-body combinations. The method makes use of the conformal mapping processes of classical hydrodynamics which transform the region outside a circle and the region outside an arbitrary arrangement of line segments intersecting at the origin. The method of analysis may be utilized to solve other slender cruciform wing-body problems involving arbitrarily assigned boundary conditions" (p. 1).

Report presenting a theoretical approach to determine the lateral frequency response of a fighter airplane to side gusts and rolling gusts at a Mach number of 0.7 and an altitude of 30,000 feet. Frequency response and power spectral density were determined with the controls fixed and in combination with three different basic types of attitude autopilots.

"An analysis is made of the effects of compressibility on the pressure coefficients about several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of the linearized equations of compressible flow. The results show that the theoretical methods predict the subsonic pressure-coefficient changes over the central part of the body but do not predict the pressure-coefficient changes near the nose. Extrapolation of the linearized subsonic theory into the mixed subsonic-supersonic flow region fails to predict a rearward movement of the negative pressure-coefficient peak which occurs after the critical stream Mach number has been attained" (p. 1125).

"The equations presented in this report 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. The rectangular tunnel is used to demonstrate these methods. The equations are also extended to nonuniformly loaded wings" (p. 361).

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.

Note presenting pressure-distribution expressions and stability derivatives derived by use of linear theory for zero-end-plate triangular vertical tails with subsonic leading edges performing rolling, yawing, and constant-lateral-acceleration motions. Corresponding results for the sideslip motion, most of which have been previously reported, are also included.

Report presenting drag coefficients during power-off transonic flight for the Bell X-1 airplane with a 10-percent-thick wing over a range of Mach numbers and pressure altitudes. The data was compared to an X-1 with an 8-percent-thick wing and a wind tunnel test with a 10-percent-thick wing. Information about necessary angle of attack, drag-rise Mach number, maximum lift-drag ratio, and drag coefficient at zero lift is provided.

From Introduction: "The general objective of this report is a study of the characteristics of the described form of peak holding control. The control has not yet been used in experimental turbojet-engine study.This study is concerned with only one method of extracting the maximum amount of information from a peak output for the purpose of maintaining that peak. The criteria sought in this control process are: maintenance of peak average output, minimum duration of time in undesirable operation, quickness in response to command to reach peak condition, least amount of excursion in the undesirable region, and type of stability."

Report presenting transient data from approximate step and sinusoidal disturbances of fuel flow on a turbojet engine operated at one constant simulated altitude and flight condition. Results regarding coefficients of differential equations, Fourier representation, frequency response, transient analysis, and a comparison of the various analytical methods are provided.

Through theoretical and analog results the effects of two nonlinear stability derivatives on the longitudinal motions of an aircraft have been investigated. Nonlinear functions of pitching-moment and lift coefficients with angle of attack were considered. Analog results of aircraft motions in response to step elevator deflections and to the action of the proportional control systems are presented. The occurrence of continuous hunting oscillations was predicted and demonstrated for the attitude stabilization system with proportional control for certain nonlinear pitching-moment variations and autopilot adjustments.

Note presenting the nondimensional lift derivative and the corresponding pitching-moment derivative resulting from constant vertical acceleration as evaluated for a family of thin sweptback tapered wings with streamwise tips traveling at supersonic speeds. The analysis is applicable at those speeds for which the wing leading and trailing edges are both supersonic, provided that the Mach lines from the wing apex intersect the trailing edge and that the Mach line from the leading edge of one tip does not intersect the remote half-wing.

Note presenting a flight investigation of a three-blade propeller in climb and at high speed to determine the effects of blade power loading. Increasing the blade power coefficient from 0.06 to 0.09 was found to increase the efficiency approximately 8 percent at an airplane Mach number of 0.7 and a propeller-tip Mach number of 1.13. In climb, an increase in power loading over the range of blade power coefficients investigated was shown to reduce efficiency, as a consequence of increased induced drag losses.

Memorandum presenting an investigation of the effects of compressibility on the forces, pitching moments, and surface pressures on a wing-nacelle combination. The leading edge of the wing was swept back 37.25 degrees and the nacelle was a body of revolution with a fineness ratio of 6.5. The effects of compressibility on the surface pressures and on the drag of a body of revolution similar to the nacelle were also determined.

In the process of analyzing the longitudinal frequency-response characteristics of aircraft, information on some of the methods of analysis has been obtained by the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. In the investigation of these methods, the practical applications and limitations were stressed. In general, the methods considered may be classed as: (1) analysis of sinusoidal response, (2) analysis of transient response as to harmonic content through determination of the Fourier integral by manual or machine methods, and (3) analysis of the transient through the use of least-squares solutions of the coefficients of an assumed equation for either the transient time response or frequency response (sometimes referred to as curve-fitting methods). (author).

"An investigation has been made at high subsonic speeds of the aerodynamic characteristics in pitch and sideslip of a 1/l4-scale model of the Grumman XF10F airplane with a wing sweepback angle of 42.5. The longitudinal stability characteristics (with the horizontal tail fixed) indicate a pitch-up near the stall; however, this was somewhat alleviated by the addition of fins to the side of the fuselage below the horizontal tail. The original model configuration became directionally unstable for small sideslip angles at Mach numbers above 0.8; however, the instability was eliminated by several different modifications" (p. 1).

Report presenting an investigation of the methods of analyzing longitudinal frequency-response characteristics of aircraft. The methods considered are analysis of sinusoidal response, analysis of transient response to harmonic content through determination of the Fourier integral, and analysis of the transient through the use of least-squares solutions of the coefficients of an assume equation for the transient time or frequency response.

Note presenting tables of thermal properties of stream that have been prepared in an NBS-NACA series. They include, for real gas, the compressibility factor, the density, the specific heat at constant pressure, the enthalpy, the entropy, the free-energy function, the viscosity, and the thermal conductivity.

Report presenting a theoretical investigation of the contribution of horizontal tails to the lift and pitching moment due to angle of attack, a constant rate of pitch, and a constant vertical acceleration. Methods for calculating the flow fields behind wings with constant vertical acceleration are developed.

Memorandum presenting a method for calculating the stick-fixed longitudinal stability of a wing-fuselage configuration at subcritical Mach numbers. The method applies to unswept- and swept-wing configurations. The stability parameters estimated by the method show reasonable agreement with the experimental values for the 23 configurations used in the comparison.

Memorandum presenting an investigation made of the effects of store mounting on the buffet, trim, and drag characteristics of fuselage-mounted external stores between Mach numbers of 0.7 and 1.4 by the use of the rocket-propelled-model technique. Results of the tests are presented in the incremental accelerations in the stores due to buffeting, trim normal- and side-force coefficients, tail helix angles, and drag coefficients plotted against Mach number.