919 Matching Results

Search Results

Advanced search parameters have been applied.

Wind-Tunnel Investigation of the Low-Speed Static Stability and Control Characteristics of a Model of Bell MX-776

Description: An investigation has been made in the Langley stability tunnel to determine the low-speed static stability and control characteristics of a model of the Bell MX-776. The results of the investigation indicated that the basic model configuration was longitudinally stable in the angle-of-attack range from about -16 deg. to 16 deg. but that the stability was a minimum near O deg angle of attack. The data indicated an aerodynamic-center position about 0.64 body diameters behind the center of gravity at low angles of attack. Reduction in the size of the front horizontal fins increased the longitudinal stability. With 20 percent of the span of the normal front horizontal fins cut off the aerodynamic center was about 1.04 body diameters behind the center of gravity, and with front horizontal fins having the same area as the front vertical fins, the aerodynamic center was 2.26 body diameters behind the center of gravity (at low angles of attack).
Date: July 6, 1949
Creator: Queijo, M. J. & Michael, W. H., Jr.
Partner: UNT Libraries Government Documents Department

Supersonic Wave Interference Affecting Stability

Description: Some of the significant interference fields that may affect stability of aircraft at supersonic speeds are briefly summarized. Illustrations and calculations are presented to indicate the importance of interference fields created by wings, bodies, wing-body combinations, jets, and nacelles.
Date: March 8, 1958
Creator: Love, Eugene S.
Partner: UNT Libraries Government Documents Department

The flexible mounting of an airplane engine

Description: Discussed here is the suggested installation of the 'unbalanced' 8-cylinder VE-engine. The suggestion was that a flexible mounting be used instead of bolting the engine rigidly to the airplane structure. It was concluded that a flexible connection between the engine and the airplane is probably possible. A flexible connection primarily diminishes the vibrations due to inertia and, to a lesser degree, those due to torque variation. However, engines vibrate more when freely suspended than when rigidly mounted, and this vibration has a detrimental effect on all connections between the engine and the airplane. Therefore, in view of the relatively insignificant advantages which may be derived from the elastic suspension of the engine, the present rigid mounting is to be preferred. Vibration reduction can be achieved by incorporating in the fuselage as many of the rigid airplane parts as possible.
Date: July 1923
Creator: Kutzbach, K.
Partner: UNT Libraries Government Documents Department

Flight measurements of the dynamic longitudinal stability of several airplanes and a correlation of the measurements with pilots' observations of handling characteristics

Description: The dynamic longitudinal stability characteristics of eight airplanes as defined by the period and damping of the longitudinal oscillations were measured in flight to determine the degree of stability that may be expected in conventional airplanes. An attempt was made to correlate the measured stability with pilots' opinions of the general handling characteristics of the airplanes in order to obtain an indication of the most desirable degree of dynamic stability. The results of the measurements show that the period of oscillation increases with speed. At low speeds a range of periods from 11 to 23 seconds was recorded for the different airplanes. At high speeds the periods ranged from 23 to 64 seconds. The damping showed no definite trend with speed.
Date: July 15, 1936
Creator: Soulé, Hartley A.
Partner: UNT Libraries Government Documents Department

Flight measurements of the velocity distribution and persistence of the trailing vortices of an airplane

Description: Report regarding the measurement of velocity distribution and persistence of the trailing vortices of a propeller-driven fighter-type airplane. Vortex strength did not decrease appreciably up to 35 seconds after the vortices had been shed. When flying in the trailing wake of another airplane, the pilot reported that it was difficult to maintain a precise course and that the disturbance was similar to severe turbulence.
Date: March 1955
Creator: Kraft, Christopher C., Jr.
Partner: UNT Libraries Government Documents Department

An investigation of a supersonic aircraft configuration having a tapered wing with circular-arc sections and 40 degree sweepback: Static longitudinal stability and control characteristics at a Mach number of 1.59

Description: Report presenting an investigation in the 4- by 4-foot supersonic tunnel to determine the static longitudinal stability and control characteristics of a supersonic aircraft configuration at a Mach number of 1.59. The model had a 40 degree sweptback tapered wing with 10-percent-thick circular-arc sections normal to the quarter-chord line.
Date: June 29, 1950
Creator: Spearman, M. Leroy & Hilton, John H., Jr.
Partner: UNT Libraries Government Documents Department

An instrument for recording the position of airplane control surfaces

Description: N.A.C.A. has developed an instrument which makes a continuous record of the angular position of the control surfaces of an airplane, not only in steady flight but during acrobatics as well. It has proven useful in researches into stability and controllability, and from records obtained from it many otherwise obscure details of piloting technique have been available for the instruction of pilots, from novices to seasoned experts.
Date: August 1923
Creator: Ronan, K. M.
Partner: UNT Libraries Government Documents Department

A method for measuring the product of inertia and the inclination of the principal longitudinal axis of inertia of an airplane

Description: Report presenting a simple method of experimentally determining the product of inertia and the inclination of the principal longitudinal axis of inertia of an airplane. The results of the method are provided and a description of the equipment and techniques are given for a simple model and a conventional airplane. Results regarding moments of inertia about the body reference area, the product of inertia and inclination of the principal axis, and the principal moments of inertia are provided.
Date: April 1954
Creator: Boucher, Robert W.; Rich, Drexel A.; Crane, Harold L. & Matheny, Cloyce E.
Partner: UNT Libraries Government Documents Department

A method for estimating variations in the roots of the lateral-stability quartic due to changes in mass and aerodynamic parameters of an airplane

Description: Report presenting a method for estimating variations in the roots of the lateral-stability quartic due to changes in mass and aerodynamic parameters of an airplane. The method is applied to three high-speed airplanes and the changes in their lateral stability characteristics are determined by considering increments in various airplane parameters.
Date: January 1954
Creator: Gates, Ordway B., Jr. & Woodling, C. H.
Partner: UNT Libraries Government Documents Department

The motions of rolling symmetrical missiles referred to a body-axis system

Description: Report presenting the linearized equations of motion have been derived for a rolling missile with slight aerodynamic asymmetries. Time histories of rolling-missile motions referred to a body-axis system have been prepared to show the types of missile motions that can be encountered.
Date: November 1956
Creator: Nelson, Robert L.
Partner: UNT Libraries Government Documents Department

Matrix methods for determining the longitudinal-stability derivatives of an airplane from transient flight data

Description: Three matrice methods are developed and presented for determining the longitudinal-stability derivatives from transient flight data. In these methods the expressions for some of the stability derivatives are in the form generally used in stability calculations. The first method requires the combination of four measurements in time-history form, two of which must be incremental elevator deflection and incremental tail load and the other two measurements can be chosen from a possible three, namely incremental load factor, pitching velocity, and angle of attack. The method demonstrates the use of the tail load to separate the pitching-moment derivatives and to determine the downwash derivative. (author).
Date: 1954
Creator: Donegan, James J.
Partner: UNT Libraries Government Documents Department

Matrix method of determining the longitudinal-stability coefficients and frequency response of an aircraft from transient flight data

Description: From Summary: "A matrix method is presented for determining the longitudinal-stability coefficients and frequency response of an aircraft from arbitrary maneuvers. The method is devised so that it can be applied to time-history measurements of combinations of such simple quantities as angle of attack, pitching velocity, load factor, elevator angle, and hinge moment to obtain the over-all coefficients. Although the method has been devised primarily for the evaluation of stability coefficients which are of primary interest in most aircraft loads and stability studies, it can be used also, with a simple additional computation, to determine the frequency-response characteristics. The entire procedure can be applied or extended to other problems which can be expressed by linear differential equations."
Date: December 15, 1950
Creator: Donegan, James J. & Pearson, Henry A.
Partner: UNT Libraries Government Documents Department

The problem of longitudinal stability and control at high speeds

Description: In high-speed dives many airplanes exhibit a dangerous tendency to continue diving in spite of the application of large control forces. Wind-tunnel tests have confirmed that these difficulties are not peculiar to any particular configuration, so that the problem is of interest to all designers of high-speed airplanes. The purpose of this report is to acquaint designers with the cause of difficulties and with the means now known for their alleviation.
Date: 1943
Creator: Hood, Manley J. & Allen, H. Julian
Partner: UNT Libraries Government Documents Department

Lateral and directional dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements

Description: Report presenting lateral and directional dynamic response characteristics of a 35 degree swept-wing fighter-type airplane determined from flight measurements and compared with predictions based on theoretical studies and wind-tunnel testing. Results regarding the frequency responses, theoretical and experimental transfer functions, stability derivatives, aeroelastic effects, response at low frequency, and effects of minor derivatives, product of inertia, and flight-path angle are provided.
Date: December 12, 1952
Creator: Triplett, William C. & Brown, Stuart C.
Partner: UNT Libraries Government Documents Department

Low-lift drag and stability data from rocket models of a modified-delta-wing airplane with and without external stores at Mach numbers from 0.8 to 1.36

Description: Report presenting a flight investigation to determine the drag and stability at low lift coefficients of models of a modified-delta-wing airplane at a range of Mach and Reynolds numbers. A summary of the drag and stability data from the tests is provided.
Date: March 26, 1953
Creator: Mitcham, Grady L. & Blanchard, Willard S., Jr.
Partner: UNT Libraries Government Documents Department

A preliminary investigation of the static stability characteristics of four airplane-like configurations at Mach numbers from 3.00 to 6.28

Description: Report presenting side-force and directional-stability characteristics of four airplane-like configurations determined at a range of Mach numbers and angles of sideslip at zero angle of attack. Two configurations had trapezoidal wing and tail surfaces and two had triangular wing and tail surfaces. The directional stability of the configurations generally decreased with increasing Mach number.
Date: March 26, 1956
Creator: Wong, Thomas J. & Gloria, Hermilo R.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Procedure for Determination of Critical Stability and Control Characteristics of Airplanes

Description: This report outlines the flight conditions that are usually critical in determining the design of components of an airplane which affect its stability and control characteristics. The wind-tunnel tests necessary to determine the pertinent data for these conditions are indicated, and the methods of computation used to translate these data into characteristics which define the flying qualities of the airplane are illustrated.
Date: 1944
Creator: Goett, Harry J.; Jackson, Roy P. & Belsley, Steven E.
Partner: UNT Libraries Government Documents Department

The effect of dead rise upon the high-angle porpoising characteristics of two planing surfaces in tandem

Description: Report presenting porpoising tests of three rudimentary models composed of two V-bottom planing surfaces in tandem and fitted with a tail plane. The upper and lower branches of the upper trim limit of stability were determined for three angles of dead rise and two depths of step.
Date: June 1943
Creator: Benson, James M. & Klein, Milton M.
Partner: UNT Libraries Government Documents Department

Calculated effects of geometric dihedral on the low-speed rolling derivatives of swept wings

Description: Report presenting a simple theory to determine the effects of geometric dihedral angle on the rolling derivatives of swept wings. Equations and charts are given to show these effects. A comparison of experimental and theoretical results for the theory are provided.
Date: October 1948
Creator: Queijo, M. J. & Jaquet, Byron M.
Partner: UNT Libraries Government Documents Department

A comparison between the theoretical and measured longitudinal stability characteristics of an airplane

Description: This report covers an investigation of the application of the theory of dynamic longitudinal stability, based on the assumption of small oscillations, to oscillations an airplane is likely to undergo in flight. The investigation was conducted with a small parasol monoplane for the fixed-stick condition. The period and damping of longitudinal oscillations were determined by direct measurements of oscillations in flight and also by calculation in which the factors that enter the theoretical stability equation were determined in flight. A comparison of the above-mentioned characteristics obtained by these two methods indicates that the theory is applicable to the conditions encountered in flight.
Date: June 24, 1932
Creator: Soulé, Hartley A. & Wheatley, John B.
Partner: UNT Libraries Government Documents Department

Static lateral stability characteristics of an airplane model having a 47.7 degree sweptback wing of aspect ratio 6 and the contribution of various model components at a Reynolds number of 4.45 x 10(exp 6)

Description: Report presenting an investigation to determine the low-speed yaw characteristics of an airplane model with a 47.7 degree sweptback wing of aspect ratio 6 and to determine lateral stability contributions of various model components and associated mutual interference. The complete airplane model was directionally stable through the yaw-angle range for angles of attack up to 23 degrees.
Date: September 1, 1953
Creator: Griner, Roland F.
Partner: UNT Libraries Government Documents Department

Effect of wing camber and twist at Mach numbers from 1.4 to 2.1 on the lift, drag, and longitudinal stability of a rocket-powered model having a 52.5 degree sweptback wing of aspect ratio 3 and inline tail surfaces

Description: Report presenting a free-flight investigation to determine the effect of wing camber and twist at Mach numbers from 1.4 to 2.1 on the lift, drag, and longitudinal stability of a configuration with 52.5 degrees sweptback wing of aspect ratio 3, and inline tail surfaces. Results regarding drag, total normal force and pitching moment, and wash at the horizontal tail are provided.
Date: May 7, 1956
Creator: Gillespie, Warren, Jr.
Partner: UNT Libraries Government Documents Department