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Investigation of frequency-response characteristics of engine speed for a typical turbine-propeller engine

Description: Experimental frequency-response characteristics of engine speed for a typical turbine-propeller engine are presented. These data were obtained by subjecting the engine to sinusoidal variations of fuel flow and propeller-blade-angle inputs. Correlation is made between these experimental data and analytical frequency-response characteristics obtained from a linear differential equation derived from steady-state torque-speed relations.
Date: March 24, 1950
Creator: Taylor, Burt L., III & Oppenheimer, Frank L.
Partner: UNT Libraries Government Documents Department

A flight and analog computer study of some stabilization and command networks for an automatically controlled interceptor during the final attack phase

Description: Report presenting studies of the final attack phase of an automatically controlled interceptor in flight and electronic simulators to investigate various airplane command and stabilization networks and to develop simple but adequate simulation techniques for the synthesis of automatic control systems. Results regarding automatic control with a simple command system, automatic control with the improved command system, and evaluation of the automatic control system in typical final attack maneuvers are provided.
Date: March 23, 1955
Creator: Turner, Howard L.; Triplett, William C. & White, John S.
Partner: UNT Libraries Government Documents Department

A flight study of requirements for satisfactory lateral oscillatory characteristics of fighter aircraft

Description: Report presenting a pilot-opinion survey conducted with a conventional fighter airplane fitted with special servo devices for varying in flight the dihedral effect, static directional stability, and directional damping. Results showing the boundaries that define satisfactory and tolerable lateral oscillatory characteristics are presented.
Date: July 25, 1951
Creator: Liddell, Charles J., Jr.; Creer, Brent Y. & Van Dyke, Rudolph D., Jr.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of the effects of profile modification and tabs on the characteristics of ailerons on a low-drag airfoil

Description: An investigation has been made to determine the effect of control-surface profile modifications on the aerodynamic characteristics of an NACA low-drag airfoil equipped with a 0.20-chord and a 0.15-chord aileron. Tab characteristics have been obtained for 0.20-aileron chord tabs on two of the 0.20-chord ailerons. Basic data are presented from which the effect of tabs can be calculated for specific cases. The data are sufficient for the solution of problems of fixed tabs with a differential linkage, as well as simple and spring-linked balancing tabs.
Date: 1944
Creator: Crane, Robert M. & Holtzclaw, Ralph W.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of drooped ailerons on a 16-percent-thick low-drag airfoil

Description: Report presenting a wind-tunnel investigation to determine the practicability of the dropped-aileron-type lateral-control device on NACA low-drag airfoils. Section aerodynamic characteristics of an NACA 66(215)-216 airfoil with an aileron of normal profile and an aileron of straight-sided profile with a modified nose shape are presented for various aileron locations, hinge centers, and aerodynamic balances.
Date: August 1947
Creator: Holtzclaw, Ralph W. & Dods, Jules B., Jr.
Partner: UNT Libraries Government Documents Department

Full-scale wind-tunnel and flight tests of a Fairchild 22 airplane equipped with external-airfoil flaps

Description: Wind-tunnel and flight tests have been made of a Fairchild 22 airplane equipped with a wing having external-airfoil flaps that also perform the function of ailerons. Lift, drag, and pitching-moment coefficients of the airplane with several flap settings, and the rolling- and yawing-moment coefficients with the flaps deflected as ailerons were measured in the full-scale tunnel with the horizontal tail surfaces and propeller removed. The effect of the flaps on the low speed and on the take-off and landing characteristics, the effectiveness of flaps when used as ailerons, and the forces required to operate them as ailerons were determined in flight. The wind-tunnel tests showed that the flaps increased the maximum lift coefficient of the airplane from 1.51 with the flap in the minimum drag position to 2.12 with the flap in the minimum drag position to 2.12 with the flap deflected 30 degrees. In the flight tests the minimum speed decreased from 46.8 miles per hour with the flaps up to 41.3 miles per hour with the flaps deflected. The required take-off run to attain a height of 50 feet was reduced from 820 to 750 feet and the landing run from a height of 50 feet was reduced from 930 to 480 feet. The flaps for this installation gave lateral control that was not entirely satisfactory. Their rolling action was good but the adverse yaw resulting from their use was greater than is considerable, and the stick forces required to operate them increased too rapidly with speed.
Date: July 1937
Creator: Reed, Warren D. & Clay, William C.
Partner: UNT Libraries Government Documents Department

Investigation of low-speed aileron control characteristics at a Reynolds number of 6,800,000 of a wing with leading edge swept back 42 degrees with and without high-lift devices

Description: Report presenting an investigation at a Reynolds number of 6,800,000 to determine the low-speed lateral control characteristics of a 20-percent-chord half-span outboard aileron on a wing with 42 degrees of sweepback at the leading edge. The lateral control, aileron hinge-moment, aileron load, and balance-chamber-pressure characteristics were determined for the wing with and without high-lift and stall-control devices for an angle-of-attack range from -4 degrees through the stall.
Date: July 19, 1949
Creator: Bollech, Thomas V. & Pratt, George L.
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

Investigation of low-speed, power-off stability and control characteristics of a model with a 35 degree sweptback wing in the Langley free-flight tunnel

Description: Report presenting an investigation in the free-flight tunnel to determine the low-speed, power-off dynamic stability and control characteristics of a model with a 35 degree sweptback wing. The investigation consisted of force and flight tests of the model and calculations of the lateral oscillatory stability with wing-tip fuel tanks off and on.
Date: October 28, 1948
Creator: Schade, Robert O.
Partner: UNT Libraries Government Documents Department

Preliminary investigation at transonic speeds of the effect of balancing tabs on the hinge-moment and other aerodynamic characteristics of a full-span flap on a tapered 45 degree sweptback wing of aspect ratio 3

Description: Report presenting an investigation at transonic speeds of the control balancing characteristics of three tabs on a full-span flap on an aspect-ratio-3, 45 degree sweptback wing. The results indicated that all the tabs tested, inset, attached, or detached, would balance the flap hinge moments throughout the speed range.
Date: April 8, 1952
Creator: Lockwood, Vernard E. & Fikes, Joseph E.
Partner: UNT Libraries Government Documents Department

Characteristics of a Sealed Internally Balanced Aileron from Tests of a 1/4-Scale Partial-Span Model of the Republic XF-12 Airplane in the Langley 19-Foot Pressure Tunnel

Description: This paper presents the results of the aileron investigation and includes rolling-moment, yawing-moment, and aileron hinge-moment coefficients and pressure coefficients across the aileron-balance seal through a range of angle of attack, tab deflection, and aileron deflection with flaps neutral and deflected 20 degrees and 55 degrees. Some of the effects of wing roughness and balance seal leakage on the aileron and tab characteristics are also presented.
Date: November 1, 1946
Creator: Graham, Robert R.; Martina, Albert P. & Salmi, Reino J.
Partner: UNT Libraries Government Documents Department

Method for calculating the rolling and yawing moments due to rolling for unswept wings with or without flaps or ailerons by use of nonlinear section lift data

Description: From Summary: "The methods of NACA reports 865 and 1090 have been applied to the calculation of the rolling-moment and yawing-moment coefficients due to rolling for unswept wings with or without flaps or ailerons. The methods are based on lifting-line theory and allow the use of nonlinear section lift data. The method presented in this report permits calculations to be made somewhat beyond maximum lift for wings having no twist or continuous twist and employing airfoil sections which do not display large discontinuities in the lift curves. Calculations can be made up to maximum lift for wings with discontinuous twist such as that produced by partial-span flaps or ailerons, or both. Two calculated examples are presented in simplified computing forms in order to illustrate the procedures involved."
Date: January 29, 1953
Creator: Martina, Albert P.
Partner: UNT Libraries Government Documents Department

Oscillating hinge moments and flutter characteristics of a flap-type control surface on a 4-percent-thick unswept wing with low aspect ratio at transonic speeds

Description: Report presenting free-oscillation tests to determine the dynamic hinge-moment characteristics of a trailing-edge flap-type control surface on a 4-percent-thick unswept wing with low aspect ratio. Tests were made over a range of Mach numbers, reduced frequencies, and low test speeds. Results regarding the effects of wing motion, damping moment and flutter characteristics, spring moments, and theoretical results are provided.
Date: February 23, 1956
Creator: Thompson, Robert F. & Moseley, William C., Jr.
Partner: UNT Libraries Government Documents Department

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

Description: Report presenting a description and comparison of several methods of obtaining the time response of linear systems to either a unit impulse or an arbitrary input from frequency-response data. All of the methods give good accuracy when applied to a second-order system; the main difference is the required computing time.
Date: July 1956
Creator: Donegan, James J. & Huss, Carl R.
Partner: UNT Libraries Government Documents Department

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

Description: From Summary: "Several methods of obtaining the time response of Linear systems to either a unit impulse or an arbitrary input from frequency-response data are described and compared. Comparisons indicate that all the methods give good accuracy when applied to a second-order system; the main difference is the required computing time. The methods generally classified as inverse Laplace transform methods were found to be most effective in determining the response to a unit impulse from frequency-response data of higher order systems. Some discussion and examples are given of the use of such methods as flight-data-analysis techniques in predicting loads and motions of a flexible aircraft on the basis of simple calculations when the aircraft frequency response is known."
Date: March 16, 1956
Creator: Donegan, James J. & Huss, Carl R.
Partner: UNT Libraries Government Documents Department

Incomplete time response to a unit impulse and its application to lightly damped linear systems

Description: Report presenting a study of the use of the incomplete time response to a unit impulse as a device to analyze lightly damped linear systems. The incomplete time response to a unit impulse computed from an incomplete time response and complete input adequately describes a light damped linear system without requiring an estimate and correction.
Date: December 1956
Creator: Donegan, James J. & Huss, Carl R.
Partner: UNT Libraries Government Documents Department

Method and tables for determining the time response to a unit impulse from frequency-response data and for determining the fourier transform of a function of time

Description: From Summary: "A simple and rapid method is presented for the determination of the time response to a unit impulse from a frequency-response data and for evaluating the Fourier transform of a function of time. Both methods are applicable to linear functions for which Fourier transforms exist. Tables are presented which greatly reduce the time required to perform the computations. Procedures for performing the calculations by use of the tables are illustrated and outlined step by step."
Date: January 1956
Creator: Huss, Carl R. & Donegan, James J.
Partner: UNT Libraries Government Documents Department

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

Description: Report presenting three matrix methods for determining the longitudinal-stability derivatives from transient flight data. The results obtained for the methods presented depend in a large measure on accurate instrument measurements and require considerable computation to yield adequate engineering answers.
Date: March 1953
Creator: Donegan, James J.
Partner: UNT Libraries Government Documents Department

Experimental study of shock-positioning method of ram-jet-engine control

Description: Report presenting an investigation of ram-jet-engine control by shock positioning on a 16-inch fixed-geometry ram jet at a range of free-stream Mach numbers. The control method appears to offer adequate control of ram-jet-engine operation. Results regarding the steady-state performance, effect of control settings on response and stability, effect of disturbance size and Mach number on response to fuel-flow disturbances, Mach number disturbances, angle-of-attack disturbances, exhaust-area disturbances, and recovery from subcritical engine operation are provided.
Date: August 29, 1955
Creator: Hurrell, Herbert G.; Vasu, George & Dunbar, William R.
Partner: UNT Libraries Government Documents Department

Preliminary results from a limited investigation of the use of controls during service operational training with fighter airplanes

Description: Report presenting results from a limited investigation of the use of controls during service operational training with four fighter airplanes. The service pilots utilized the positive V-n envelope in performing their training missions but rarely approached the negative V-n envelope. Results regarding the operational V-n diagram for the F-86A, F-84G, F2H-2, and F-84G, design curves, maximum elevator rates, maximum aileron rates, rolling velocities, and control surface angles are provided.
Date: June 16, 1953
Creator: Mayer, John P.; Huss, Carl R. & Hamer, Harold A.
Partner: UNT Libraries Government Documents Department

Preliminary results of a flight investigation to determine the effect of negative flap deflection on high-speed longitudinal-control characteristics

Description: Report presenting flight testing on two propeller-driven airplanes with wings of NACA 66-series and NACA 230-series airfoil sections to determine the effect of deflecting the landing flaps upward on the high-speed longitudinal-control characteristics.
Date: December 16, 1947
Creator: White, Maurice D.; Sadoff, Melvin; Clousing, Lawrence A. & Cooper, George E.
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