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  Partner: UNT Libraries Government Documents Department
 Decade: 1920-1929
 Collection: National Advisory Committee for Aeronautics Collection
Abacus giving the variation of the mean pressure of an aviation engine as a function of its speed of rotation
Comparing the results of the calculations for computing the mean pressure of an aviation engine for any number of revolutions, with those of experiment, the writer, by numerous examples, shows the perfect agreement between them. This report will show that, by means of a special abacus, an engineer can instantly plot the characteristics of an engine. digital.library.unt.edu/ark:/67531/metadc53605/
Absolute coefficients and the graphical representation of airfoil characteristics
It is argued that there should be an agreement as to what conventions to use in determining absolute coefficients used in aeronautics and in how to plot those coefficients. Of particular importance are the absolute coefficients of lift and drag. The author argues for the use of the German method over the kind in common use in the United States and England, and for the Continental over the usual American and British method of graphically representing the characteristics of an airfoil. The author notes that, on the whole, it appears that the use of natural absolute coefficients in a polar diagram is the logical method for presentation of airfoil characteristics, and that serious consideration should be given to the advisability of adopting this method in all countries, in order to advance uniformity and accuracy in the science of aeronautics. digital.library.unt.edu/ark:/67531/metadc53725/
Absolute dimensions of Karman vortex motion
No Description digital.library.unt.edu/ark:/67531/metadc53809/
Absorbing landing shocks
Tires, steel springs, hydraulic shock absorbers, and axle travel are all examined in relation to absorbing landing shocks. digital.library.unt.edu/ark:/67531/metadc56246/
Accelerations in flight
This report deals with the accelerations obtained in flight on various airplanes at Langley Field for the purpose of obtaining the magnitude of the load factors in flight and to procure information on the behavior of an airplane in various maneuvers. The instrument used in these tests was a recording accelerometer of a new type designed by the technical staff of the National Advisory Committee for Aeronautics. The instrument consists of a flat steel spring supported rigidly at one end so that the free end may be deflected by its own weight from its neutral position by any acceleration acting at right angles to the plane of the spring. This deflection is measured by a very light tilting mirror caused to rotate by the deflection of the spring, which reflected the beam of light onto a moving film. The motion of the spring is damped by a thin aluminum vane which rotates with the spring between the poles of an electric magnet. Records were taken on landings and takeoffs, in loops, spins, spirals, and rolls. digital.library.unt.edu/ark:/67531/metadc65749/
Accelerations in flight
This work on accelerometry was done at McCook Field for the purpose of continuing the work done by other investigators and obtaining the accelerations which occur when a high-speed pursuit airplane is subjected to the more common maneuvers. The accelerations obtained in suddenly pulling out of a dive with well-balanced elevators are shown to be within 3 or 4 per cent of the theoretically possible accelerations. The maximum acceleration which a pilot can withstand depends upon the length of time the acceleration is continued. It is shown that he experiences no difficulty under the instantaneous accelerations as high as 7.8 G., but when under accelerations in excess of 4.5 G., continued for several seconds, he quickly loses his faculties. digital.library.unt.edu/ark:/67531/metadc65854/
Accelerometer design
In connection with the development of an accelerometer for measuring the loads on airplanes in free flight a study of the theory of such instruments has been made, and the results of this study are summarized in this report. A portion of the analysis deals particularly with the sources of error and with the limitations placed on the location of the instrument in the airplane. The discussion of the dynamics of the accelerometer includes a study of its theoretical motions and of the way in which they are affected by the natural period of vibration and by the damping, together with a report of some experiments on the effect of forced vibrations on the record. digital.library.unt.edu/ark:/67531/metadc65750/
Adaptation of aeronautical engines to high altitude flying
Issues and techniques relative to the adaptation of aircraft engines to high altitude flight are discussed. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2. High altitude engines. 3. Influence of air density on proportions of mixture. 4. Methods of varying proportions of mixture. 5. Automatic prevention of fuel waste. 6. Design and application of air pressure regulators to high altitude flying. digital.library.unt.edu/ark:/67531/metadc53936/
Aerial convention of October 13, 1919
The aerial convention delegates are listed as well as the set of rules that were developed during the session. digital.library.unt.edu/ark:/67531/metadc55281/
Aerial navigation by dead reckoning
The problem to be solved, as presented to the pilot or observer of an aircraft, is as follows: The aircraft starting from A must land at B, the only data being the speed of the airplane, the altitude and the orientation D of the course. The above data would be amply sufficient, were it not for the fact that the airplane is constantly subjected to a wind of variable direction and strength. digital.library.unt.edu/ark:/67531/metadc55696/
Aerial navigation : on the problem of guiding aircraft in a fog or by night when there is no visibility
The use of magnetic fields and wire to navigate aircraft in conditions of poor visibility is presented. This field may be considered to be derived from a double lemniscate, considered in the particular case where the origin is a double point formed from the magnetic field of the slack wire, from the field produced by the return currents and from the field due to the currents induced in the conducting mass. These fields are dephased in two ways, one in the direction of the wire, the other in a direction perpendicular to it. digital.library.unt.edu/ark:/67531/metadc53657/
Aerial photography : obtaining a true perspective
A demonstration was given within the last few days at the British Museum by Mr. J. W. Gordon, author of "Generalized Linear Perspective" (Constable and Co.), a work describing a newly-worked-out system by which photographs can be made available for the purpose of exactly recording the dimensions of the objects photographed even when the objects themselves are presented foreshortened in the photograph. digital.library.unt.edu/ark:/67531/metadc277511/
Aerial transportation
The origin of air traffic dates from the war. The important development of aeronautic industries and the progress made in recent years, under the impelling force of circumstances, rendered it possible, after the close of hostilities, to consider the practical utilization of this new means of economic expansion. digital.library.unt.edu/ark:/67531/metadc53663/
Aero dopes and varnishes
Before proceeding to discuss the preparation of dope solutions, it will be necessary to consider some of the essential properties which should be possessed of a dope film, deposited in and on the surface of an aero fabric. The first is that it should tighten the material and second it should withstand weathering. digital.library.unt.edu/ark:/67531/metadc65251/
Aerodynamic characteristics of aerofoils I
The object of this report is to bring together the investigations of the various aerodynamic laboratories in this country and Europe upon the subject of aerofoils suitable for use as lifting or control surfaces on aircraft. The data have been so arranged as to be of most use to designing engineers and for the purposes of general reference. The absolute system of coefficients has been used, since it is thought by the National Advisory Committee for Aeronautics that this system is the one most suited for international use, and yet is one for which a desired transformation can be easily made. For this purpose a set of transformation constants is included in this report. digital.library.unt.edu/ark:/67531/metadc65743/
Aerodynamic characteristics of aerofoils II : continuation of report no. 93
This collection of data on aerofoils has been made from the published reports of a number of the leading aerodynamic laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for the use of designing engineers and for purposes of general reference. The absolute system of coefficients has been used, since it is thought by the National Advisory Committee for Aeronautics that this system is the one most suited for international use, and yet is one for which a desired transformation can be easily made. For this purpose a set of transformation constants is included in this report. The authority for the results here presented is given as the name of the laboratory at which the experiments were conducted, with the size of the model, wind velocity, and date of test. digital.library.unt.edu/ark:/67531/metadc65774/
Aerodynamic characteristics of aircraft with reference to their use
Economic and design characteristics are examined in the design of airplanes and airships. digital.library.unt.edu/ark:/67531/metadc277393/
Aerodynamic characteristics of airfoils at high speeds
This report deals with an experimental investigation of the aerodynamical characteristics of airfoils at high speeds. Lift, drag, and center of pressure measurements were made on six airfoils of the type used by the air service in propeller design, at speeds ranging from 550 to 1,000 feet per second. The results show a definite limit to the speed at which airfoils may efficiently be used to produce lift, the lift coefficient decreasing and the drag coefficient increasing as the speed approaches the speed of sound. The change in lift coefficient is large for thick airfoil sections (camber ratio 0.14 to 0.20) and for high angles of attack. The change is not marked for thin sections (camber ratio 0.10) at low angles of attack, for the speed range employed. At high speeds the center of pressure moves back toward the trailing edge of the airfoil as the speed increases. The results indicate that the use of tip speeds approaching the speed of sound for propellers of customary design involves a serious loss in efficiency. digital.library.unt.edu/ark:/67531/metadc65858/
Aerodynamic characteristics of airfoils III : continuation of reports nos. 93 and 124
This collection of data on airfoils has been made from the published reports of a number of the leading aerodynamic laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for the use of designing engineers and for purposes of general reference. The absolute system of coefficients has been used, since it is thought by the National Advisory Committee for Aeronautics that this is the one most suited for international use and yet is one for which a desired transformation can be easily made. The authority for the results here presented is given as the name of the laboratory at which the experiments were conducted, with the size of the model, wind velocity, and date of test. digital.library.unt.edu/ark:/67531/metadc65832/
Aerodynamic characteristics of airfoils IV : continuation of reports nos. 93, 124, and 182
This collection of data on airfoils has been made from the published reports of a number of the leading Aerodynamic Laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for the use of designing engineers and for purposes of general reference. The authority for the results here presented is given as the name of the laboratory at which the experiments were conducted, with the size of the model, wind velocity, and year of test. digital.library.unt.edu/ark:/67531/metadc65896/
Aerodynamic characteristics of airfoils V : continuation of reports nos. 93, 124, 182, and 244
This collection of data on airfoils has been made from published reports of a number of the leading aerodynamic laboratories of this country and Europe. The information which was originally expressed according to the different customs of the several laboratories is here presented in a uniform series of charts and tables suitable for the use of designing engineers and for purposes of general reference. The authority for the results here presented is given as the name of the laboratory at which the experiments were conducted, with the size of the model, wind velocity, and year of tests. digital.library.unt.edu/ark:/67531/metadc65940/
The aerodynamic characteristics of seven frequently used wing sections at full Reynolds number
This report contains the aerodynamic properties of the wing sections U.S.A. 5, U.S.A. 27, U.S.A. 35 A, U.S.A. 35 B, Clark Y, R.A.F. 15, and Gottingen 387, as determined at various Reynolds numbers up to an approximately full scale value in the variable density wind tunnel of the National Advisory Committee for Aeronautics. It is shown that the characteristics of the wings investigated are affected greatly and in a somewhat erratic manner by variation of the Reynolds number. In general there is a small increase in maximum lift and an appreciable decrease in drag at all lifts. digital.library.unt.edu/ark:/67531/metadc65886/
Aerodynamic characteristics of thin empirical profiles and their application to the tail surfaces and ailerons of airplanes
No Description digital.library.unt.edu/ark:/67531/metadc65343/
Aerodynamic computation of gliders
In the following discussion, a knowledge of the theoretical principles of airplane construction is assumed, as presented in detail by Vogt and Lippisch. A few quantities will however be otherwise designated, in accordance with the Gottingen symbols. digital.library.unt.edu/ark:/67531/metadc55788/
The Aerodynamic Forces on Airship Hulls
This report describes the new method for making computations in connection with the study of rigid airship, which was used in the investigation of the navy's ZR-1 by the special subcommittee of the National Advisory Committee for Aeronautics appointed for this purpose. It presents the general theory of the air forces on airship hulls of the type mentioned, and an attempt has been made to develop the results from the very fundamentals of mechanics without reference to some of the modern highly developed conceptions, which may not yet be thoroughly known to readers uninitiated into modern aerodynamics, and which may, perhaps, for all time remain restricted to a small number of specialists. digital.library.unt.edu/ark:/67531/metadc65834/
Aerodynamic laboratory at Cuatro Vientos
This report presents a listing of the many experiments in aerodynamics taking place at Cuatro Vientos. Some of the studies include: testing spheres, in order to determine coefficients; mechanical and chemical tests of materials; and various tests of propeller strength and flexibility. digital.library.unt.edu/ark:/67531/metadc55750/
Aerodynamic laboratory at Cuatro Vientos
This report presents a description of the design of the Cuatro Vientes wind tunnel. digital.library.unt.edu/ark:/67531/metadc65237/
The Aerodynamic Laboratory of the Belgian Service Technique de L'Aeronautique
This report provides a description of the wind tunnel housing and motors. digital.library.unt.edu/ark:/67531/metadc58832/
The aerodynamic plane table
This report gives the description and the use of a specially designed aerodynamic plane table. For the accurate and expeditious geometrical measurement of models in an aerodynamic laboratory, and for miscellaneous truing operations, there is frequent need for a specially equipped plan table. For example, one may have to measure truly to 0.001 inch the offsets of an airfoil at many parts of its surface. Or the offsets of a strut, airship hull, or other carefully formed figure may require exact calipering. Again, a complete airplane model may have to be adjusted for correct incidence at all parts of its surfaces or verified in those parts for conformance to specifications. Such work, if but occasional, may be done on a planing or milling machine; but if frequent, justifies the provision of a special table. For this reason it was found desirable in 1918 to make the table described in this report and to equip it with such gauges and measures as the work should require. digital.library.unt.edu/ark:/67531/metadc65817/
The aerodynamic properties of thick aerofoils suitable for internal bracing
The object of this investigation was to determine the characteristics of various types of wings having sufficient depth to entirely inclose the wing bracing, and also to provide data for the further design of such sections. This type of wing is of interest because it eliminates the resistance of the interplane bracing, a portion of the airplane that sometimes absorbs one-quarter of the total power required to fly, and because these wings may be made to give a very high maximum lift. Results of the investigation of the following subjects are given: (1) effect of changing the upper and lower camber of thick aerofoils of uniform section; (2) effect of thickening the center and thinning the tips of a thin aerofoil; (3) effect of adding a convex lower surface to a tapered section; (4) effect of changing the mean thickness with constant center and tip sections; and (5) effect of varying the chord along the span. digital.library.unt.edu/ark:/67531/metadc65724/
Aerodynamic properties of thick airfoils II
This investigation is an extension of NACA report no. 75 for the purpose of studying the effect of various modifications in a given wing section, including changes in thickness, height of lower camber, taper in thickness, and taper in plan form with special reference to the development of thick, efficient airfoils. The method consisted in testing the wings in the NACA 5-foot wind tunnel at speeds up to 50 meters (164 feet) per second while they were being supported on a new type of wire balance. Some of the airfoils developed showed results of great promise. For example, one wing (no. 81) with a thickness in the center of 4.5 times that of the U. S. A. 16 showed both uniformly high efficiency and a higher maximum lift than this excellent section. These thick sections will be especially useful on airplanes with cantilever construction. (author). digital.library.unt.edu/ark:/67531/metadc65803/
The aerodynamical laboratory of the Vienna Technical High School
We will give here only a short explanation of the operation of the plant and deal principally with the question of what it has accomplished. digital.library.unt.edu/ark:/67531/metadc53660/
Aerodynamics and ballistics
Ballistics is a science hundreds of years old and this report is an attempt to show how these older principles can be used in the newer science of aerodynamics. digital.library.unt.edu/ark:/67531/metadc55683/
Aeromechanical experimentation (wind tunnel tests)
The following report endeavors to show that aeromechanical experimentation has become an important aid to theory. digital.library.unt.edu/ark:/67531/metadc277465/
Aeronautic instruction in Germany
This report contains a list of the courses relating to aeronautics announced in Germany, both in the technical high schools and in the universities. digital.library.unt.edu/ark:/67531/metadc53650/
Aeronautic instruments
The development of aeronautic instruments. Vibrations, rapid changes of the conditions of flight and of atmospheric conditions, influence of the air stream all call for particular design and construction of the individual instruments. This is shown by certain examples of individual instruments and of various classes of instruments for measuring pressure, change of altitude, temperature, velocity, inclination and turning or combinations of these. digital.library.unt.edu/ark:/67531/metadc277462/
Aeronautic instruments. Section I : general classification of instruments and problems including bibliography
This report is intended as a technical introduction to the series of reports on aeronautic instruments. It presents a discussion of those subjects which are common to all instruments. First, a general classification is given, embracing all types of instruments used in aeronautics. Finally, a classification is given of the various problems confronted by the instrument expert and investigator. In this way the following groups of problems are brought up for consideration: problems of mechanical design, human factor, manufacturing problems, supply and selection of instruments, problems concerning the technique of testing, problems of installation, problems concerning the use of instruments, problems of maintenance, and physical research problems. This enumeration of problems which are common to instruments in general serves to indicate the different points of view which should be kept in mind in approaching the study of any particular instrument. digital.library.unt.edu/ark:/67531/metadc65775/
Aeronautic instruments. Section II : altitude instruments
This report is Section two of a series of reports on aeronautic instruments (Technical Report nos. 125 to 132, inclusive). This section discusses briefly barometric altitude determinations, and describes in detail the principal types of altimeters and barographs used in aeronautics during the recent war. This is followed by a discussion of performance requirements for such instruments and an account of the methods of testing developed by the Bureau of Standards. The report concludes with a brief account of the results of recent investigations. For accurate measurements of altitude, reference must also be made to thermometer readings of atmospheric temperature, since the altitude is not fixed by atmospheric pressure alone. This matter is discussed in connection with barometric altitude determination. digital.library.unt.edu/ark:/67531/metadc65776/
Aeronautic instruments. Section III : aircraft speed instruments
Part 1 contains a discussion and description of the various types of air speed measuring instruments. The authors then give general specifications and performance requirements with the results of tests on air speed indicators at the Bureau of Standards. Part 2 reports methods and laboratory apparatus used at the Bureau of Standards to make static tests. Methods are also given of combining wind tunnel tests with static tests. Consideration is also given to free flight tests. Part 3 discusses the problem of finding suitable methods for the purpose of measuring the speed of aircraft relative to the ground. digital.library.unt.edu/ark:/67531/metadc65777/
Aeronautic instruments. Section IV : direction instruments
Part one points out the adequacy of a consideration of the steady state gyroscopic motion as a basis for the discussion of displacements of the gyroscope mounted on an airplane, and develops a simple theory on this basis. Principal types of gyroscopic inclinometers are described and requirements stated. Part two describes a new type of stabilizing gyro mounted on top of a spindle by means of a universal joint, the spindle being kept in a vertical position by supporting it as a pendulum of which the bob is the driving motor. Methods of tests and the difficulties in designing a satisfactory and reliable compass for aircraft use in considered in part three. Part four contains a brief general treatment of the important features of construction of aircraft compasses and description of the principal types used. digital.library.unt.edu/ark:/67531/metadc65778/
Aeronautic instruments. Section V : power plant instruments
Part 1 gives a general discussion of the uses, principles, construction, and operation of airplane tachometers. Detailed description of all available instruments, both foreign and domestic, are given. Part 2 describes methods of tests and effect of various conditions encountered in airplane flight such as change of temperature, vibration, tilting, and reduced air pressure. Part 3 describes the principal types of distance reading thermometers for aircraft engines, including an explanation of the physical principles involved in the functioning of the instruments and proper filling of the bulbs. Performance requirements and testing methods are given and a discussion of the source of error and results of tests. Part 4 gives methods of tests and calibration, also requirements of gauges of this type for the pressure measurement of the air pressure in gasoline tanks and the engine oil pressure on airplanes. Part 5 describes two types of gasoline gauges, the float type and the pressure type. Methods of testing and calibrating gasoline depth gauges are given. The Schroeder, R. A. E., and the Mark II flowmeters are described. digital.library.unt.edu/ark:/67531/metadc65779/
Aeronautic instruments. Section VI : aerial navigation and navigating instruments
This report outlines briefly the methods of aerial navigation which have been developed during the past few years, with a description of the different instruments used. Dead reckoning, the most universal method of aerial navigation, is first discussed. Then follows an outline of the principles of navigation by astronomical observation; a discussion of the practical use of natural horizons, such as sea, land, and cloud, in making extant observations; the use of artificial horizons, including the bubble, pendulum, and gyroscopic types. A description is given of the recent development of the radio direction finder and its application to navigation. digital.library.unt.edu/ark:/67531/metadc65781/
Aeronautic instruments. Section VI : oxygen instruments
This report contains statements as to amount of oxygen required at different altitudes and the methods of storing oxygen. The two types of control apparatus - the compressed oxygen type and the liquid oxygen type - are described. Ten different instruments of the compressed type are described, as well as the foreign instruments of the liquid types. The performance and specifications and the results of laboratory tests on all representative types conclude this report. digital.library.unt.edu/ark:/67531/metadc65780/
Aeronautic instruments. Section VIII : recent developments and outstanding problems
This report is section VIII of a series of reports on aeronautic instruments. The preceding reports in this series have discussed in detail the various types of aeronautic instruments which have reached a state of practical development such that they have already found extensive use. It is the purpose of this paper to discuss briefly some of the more recent developments in the field of aeronautic instrument design and to suggest some of the outstanding problems awaiting solution. digital.library.unt.edu/ark:/67531/metadc65782/
Aeronautic insurance
The problem of insuring the emerging commercial aeronautic industry is detailed. The author also motes that a complete solution cannot be obtained until the necessary statistics are compiled. digital.library.unt.edu/ark:/67531/metadc54177/
Aeronautical instruments
No Description digital.library.unt.edu/ark:/67531/metadc53948/
Aeronautical museums
Different methods of presenting aeronautical artifacts are examined. digital.library.unt.edu/ark:/67531/metadc55809/
Aeronautical record : no. 1 (to June, 1923)
"...considerations have prompted us to pay special attention to the development of aeronautical industries and aerial navigation as a commercial enterprise and to publish an analytical review of events in the aeronautical world and of the attendant problems.". digital.library.unt.edu/ark:/67531/metadc277519/
Air cooling : an experimental method of evaluating the cooling effect of air streams on air-cooled cylinders
In this report is described an experimental method which the writer has evolved for dealing with air-cooled engines, and some of the data obtained by its means. Methods of temperature measurement and cooling are provided. digital.library.unt.edu/ark:/67531/metadc65234/
Air-flow experiments
This report describes the apparatus used to take air-flow photographs. The photographs show chiefly the spiral course of the lines of flow near the tip of the wing. They constitute therefore a visual presentation of the phenomena covered by airfoil theory. digital.library.unt.edu/ark:/67531/metadc58543/