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The 300 H.P. Benz Aircraft Engine
This report provides a description of the Benz 300 H.P. aircraft engine containing 12 cylinders placed at a 60° angle. It includes a detailed description of the development of the constructional points, particularly the cylinders, pistons, and connecting rods, as well as the engine fitting, lubrication, oil pumps, bearings, oil tank, fuel pump, carburetors, and cooling system. There are seven pages of illustrative figures at the end of the report.
The 1000 HP Traffic Airplane of the Zeppelin Works in Staaken
Report details the characteristics and advantages of the swift traffic airplane constructed by Zeppelin Works at Staaken. The maximum speed, weight, construction, layout, and landing capabilities of the plane are included.
N.A.C.A. Langley field wind tunnel apparatus: The tilting manometer
A description is given of a tilting manometer designed to meet the requirements of a manometer for use in the wind tunnel at the Langley Memorial Aeronautical Laboratory. This gauge was designed to meet the requirements of a manometer in use in connection with a static pressure plate to indicate the wind speed in the tunnel. The requirements are noted. The sensitivity of the gauge must be made inversely proportional to the pressure to be measured. The gauge must be accurately and quickly set for any desired pressure.
N.A.C.A. Recording Air Speed Meter
A new type of air speed meter is described which was designed by the technical staff of the National Advisory Committee for Aeronautics. The instrument consists essentially of a tight metal diaphragm of high natural period which is acted upon by the pressure difference of a pitot-static head. The resulting deflection of this diaphragm is recorded optically on a moving film.
Abacus for the Reduction of English Measures to the Metric System and Vice Versa
This report presents a description of an abacus with three scales: one for English measures, one for metric measures, and one with the "points of reduction", as well as construction details. There is also a detailed description on how to use the abacus.
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.
Absolute Coefficients and the Graphical Representation of Aerofoil 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.
Abstracts from the German Technical Press: Rates for Flights Organized by the State
Report presenting tariffs that are written for all aircraft manufacturing companies to follow regarding aircraft orders.
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.
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.
Aerodynamic Characteristics of Aerofoils
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.
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.
Airplane Balance
The authors argue that the center of gravity has a preponderating influence on the longitudinal stability of an airplane in flight, but that manufacturers, although aware of this influence, are still content to apply empirical rules to the balancing of their airplanes instead of conducting wind tunnel tests. The author examines the following points: 1) longitudinal stability, in flight, of a glider with coinciding centers; 2) the influence exercised on the stability of flight by the position of the axis of thrust with respect to the center of gravity and the whole of the glider; 3) the stability on the ground before taking off, and the influence of the position of the landing gear. 4) the influence of the elements of the glider on the balance, the possibility of sometimes correcting defective balance, and the valuable information given on this point by wind tunnel tests; 5) and a brief examination of the equilibrium of power in horizontal flight, where the conditions of stability peculiar to this kind of flight are added to previously existing conditions of the stability of the glider, and interfere in fixing the safety limits of certain evolutions.
Airplane Crashes: Engine Troubles: A Possible Explanation
The aim was to bring attention to what might be the cause of some aircraft accidents for which there was no satisfactory explanation. The author notes that in testing aircraft accidents at the Bureau of Standards, it happened frequently that the engine performance became erratic when the temperature of the air entering the carburetor was between 0 C and 20 C. Investigation revealed the trouble to have been caused by the formation and collection of snow somewhere between the entrance to the carburetor and the manifold, probably at the throttle.
Airplane Superchargers
Discussed here are the principles and operation of aircraft engine superchargers used to maintain and increase engine power as aircraft encounter decreases in the density of air as altitude rises. Details are given on the design and operation of the centrifugal compressors. A method is given for calculating the amount of power needed to drive a compressor. The effects of the use of a compressor on fuel system operation and design are discussed. Several specific superchargers that were in operation are described.
Alfalfa.
A guide to growing and using alfalfa on the farm. Includes recommendations for different regions of the United States.
Analysis of Wing Truss Stresses Including the Effect of Redundancies
Report discusses airplane wing trusses are generally designed to contain redundant members (stagger wires and external drag wires) which, according to common practice, are not taken into account in calculations, so as to simplify the stress analysis by rendering the structure statically determinate. A more accurate method, in which the redundancies are included, involves a solution by means of Castigliano's method of least work. For the purpose of demonstrating the practical application of the method of least work this report presents examples for stresses of several cases of loading worked out for a structure similar to that of the Curtiss JN-4h.
Analytical methods for computing the polar curves of airplanes
This report presents a method of calculating polar curves which is at least as precise as graphical methods, but it more rapid. Knowing the wind tunnel test of a wing and the performances of an airplane of the same profile, it is easy to verify the characteristic coefficients and, at the same time, the methods determining induced resistances.
Aneroid investigations in Germany
Report presenting an experiment of aneroid development and a theoretical study of the equilibrium of forces acting on the vacuum box.
Angles of Attack and Air Speeds During Maneuvers
From Introduction: "The following report was prepared at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics, as it seemed desirable that there should be some study of the attitude assumed by an airplane, and more particularly of its motion with respect to surrounding air when maneuvering, either in ordinary turns, spirals, climbs, and dives, or in those more spectacular feats commonly known as stunts. It is important to secure this information, among other reasons, in order ti have definite knowledge as to the distribution of load on the wings, and so to furnish the basis for improved accuracy in stress analysis."
Annual Report of the National Advisory Committee for Aeronautics (6th). Administrative Report Including Technical Reports Nos. 83 to 110
Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, expenditures, House of Representatives bill 14061, a copy of the bill introduced to the House of Representatives to regulate air navigation, and a compilation of technical reports produced.
The Art of Writing Scientific Reports
As the purpose of the report is to transmit as smoothly and as easily as possible, certain facts and ideas, to the average person likely to read it, it should be written in a full and simple enough manner to be comprehended by the least tutored, and still not be boring to the more learned readers.
Beautifying the Farmstead
Revised edition. Report giving practical ways for families to beautify farmsteads. Contains sections on design, locations of buildings, walkways, driveways, lawns, trees and other plants.
Beef Production in the Corn Belt
This bulletin discusses beef production in the Corn Belt of the United States with special regard to feed preparation, cattle selection, and methods for fattening cattle.
The Beet Leaf-Beetle and Its Control
Report discussing the beet leaf-beetle, which is common in the Rocky Mountain region. Discussion include physical appearance, geographic distribution, life cycle, affected plants, and methods of control.
Bibliography of Petroleum and Allied Substances in 1918
From Introduction: "This bulletin is the fourth in the series of petroleum bibliographies being published by the Bureau of Mines, the preceding, Bulletins 149, 165, and 180, being complications for the years 1915, 1916, and 1917, respectively. In this bulletin the same general plan has been followed in arranging the references, but a few changes and additions have been made in classification, the more important changes being in the classes "Geology and Origin" and "Refining and Refineries." During the year German periodicals were not available, and as in the bibliography for 1917, references to articles in foreign journals that were not available have been taken from other sources and credit given to those sources."
A Biological Survey of Alabama
Booklet describing the biology of Alabama in two sections: (1) physiography and life zones, and (2) mammals. It also includes an annotated species list of mammals, bibliography, and index starting on page 81.
British Certificates of Airworthiness
This report details the rules and regulations for obtaining a British airworthiness certificate. Aircraft loading and construction are especially important.
The Calculated Performance of Airplanes Equipped With Supercharging Engines
In part one of this report are presented the theoretical performance curves of an airplane engine equipped with a supercharging compressor. In predicting the gross power of a supercharging engine, the writer uses temperature and pressure correction factors based on experiments made at the Bureau of Standards (NACA report nos. 45 and 46).. Part two of this report presents an estimation of the performance curves of an airplane fitted with a supercharging engine.
Calculation of Wing Spars
A simplified formula for calculating wing spars is presented.
Calculation of Wing Spars
The author presents a comparison and combination of the numerical and geometrical determinations of the maximum M, when calculating the maximum bay moment.
Calculation of Wing Spars
The author presents a comparison and combination of the numerical and geometrical determinations of the maximum M, when calculating the maximum bay moment.
The Caproni Seaplane
The Caproni Company recently built a seaplane of unusual design. The main supporting surfaces consisted of three triplanes in tandem, the lower wings being attached to the hull, which was described as providing accommodation for a hundred passengers. On one of the first flights, the seaplane fell into a lake, nose down, and was destroyed. The authors wish to show that this failure could have been predicted.
Causes of cracking of ignition cable
From Summary: "The experiments described here show that the cracking at sharp bends, observed in the insulation of internal combustion engine high tension ignition wires after service, is due to a chemical attack upon the rubber by the ozone produced by the electric discharge that takes place at the surface of the cable. This cracking does not occur if the insulating material is not under tension, or if the cable is surrounded by some medium other than air. But it does occur even if the insulation is not subjected to electric stress, provided that the atmosphere near the cable contains ozone. The extent of this cracking varies greatly with the insulating material used. The cracking can be materially reduced by using braided cable and by avoiding sharp bends."
Chimneys and fireplaces : they contribute to the health, comfort and happiness of the farm family : how to build them.
A concise explanation of the principles to be observed when building chimneys and fireplaces.
The Choice of Wing Sections for Airplanes
"The subject of the choice of an airfoil section is by no means a closed one, and despite the impossibility of making a single rule serve, it is quite practicable to deduce in a strictly rational manner a series of rules and formulas which are capable of being of the greatest use if we but confine ourselves to the consideration of one element of performance at a time. There are seven such elements of performance which are here taken up in turn. The seven are of different relative importance in different types of airplanes. The seven elements are: maximum speed regardless of minimum; maximum speed for given minimum; maximum speed range ratio; maximum rate of climb; maximum absolute ceiling; maximum distance non-stop; and maximum duration non-stop" (p. 1-2).
Commercial Aviation in Germany: Past and Future
This review of commercial aviation includes postal delivery, package transport, and passenger transport. Both airplanes and airships are covered in this review.
Community Bird Refuges
Report explaining how communities may establish bird refuges. Because birds eat injurious insects and provide aesthetic value to communities, it is desirable to increase their numbers in most communities. Bird refuges may be established on farms, at roadsides, in parks and fairgrounds, at schools and colleges, in cemeteries, and at reservoirs.
Competition for Safety Fuel Tanks
Report describing a competition for safety fuel tanks, including the prizes, requirements that must be fulfilled, some other characteristics, tests, and regulations.
The Corn Earworm As an Enemy of Vetch
"Vetch, which has become an important forage crop throughout the Southeastern States, needs protection from the same insect that works such havoc on corn and cotton. This corn earworm, or cotton bollworm, is the most serious pest that growers of vetch have to combat. The caterpillars eat both the foliage and the seed pods, and, if the infestation is heavy, make the crop practically worthless. Vetch intended for a hay crop generally escapes serious injury, as it is cut before the caterpillars are large enough to do much damage. It is recommended that a crop intended for seed be carefully watched and if the insects become numerous an insecticide be applied at once or the vetch cut for hay. Spraying, dusting, the use of poisoned-bran bait, and other control measures are discussed and summarized in this bulletin." -- p. 2
Cotton Diseases and Their Control
"The principal cotton diseases which cause damage in the Southern States are described and illustrated in the following pages and the best-known methods of controlling them are described." -- p. 3. Diseases discussed include wilt, root knot, anthracnose, bacterial blight, shedding of bolls, rust, Texas root rot, and other minor diseases.
The Coupling of Engines
This report examines the idea of coupling numerous engines together to turn a single propeller, which the author feels would free aircraft design from the problems of multi-engine and propeller design.
Crippling Strength of Axially Loaded Rods
A new empirical formula was developed that holds good for any length and any material of a rod, and agrees well with the results of extensive strength tests. To facilitate calculations, three tables are included, giving the crippling load for solid and hollow sectioned wooden rods of different thickness and length, as well as for steel tubes manufactured according to the standards of Army Air Services Inspection. Further, a graphical method of calculation of the breaking load is derived in which a single curve is employed for determination of the allowable fiber stress.
The danger of stalled flight and an analysis of the factors which govern it
A definition of "stalled fight" is presented as well as a detailed discussion on the how and why it occurs. Some suggestions are made to prevent its occurrence such as carrying an air speed instrument in the airplane.
Data on the Design of Plywood for Aircraft
"This report makes available data which will aid the designer in determining the plywood that is best adapted to various aircraft parts. It gives the results of investigations made by the Forest Products Laboratory of the United States Forest Service at Madison, Wisconsin, for the Army and Navy Departments, and is one of a series of reports on the use of wood in aircraft prepared by the Forest Products Laboratory for publication by the National Advisory Committee for Aeronautics. The object of the study was to determine, through comprehensive tests, the mechanical and physical properties of plywood and how these properties vary with density, number, thickness, arrangement of the plies and direction of grain of the plies" (p. 109).
Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade
In order to determine the maximum and the most favorable pitch for a propeller, it was found desirable to investigate the dependence of propeller efficiency on the angle of attack of the propeller blade. The results of a few experiments are given to show that propeller blades conduct themselves just like airplane wings with reference to the dependence of their efficiency on their angle of attack.
Design of Wind Tunnels and Wind Tunnel Propellers, 2
Report presenting a continuation of a previous study in order to supply further data to the designers of wind tunnels. Particular emphasis was placed on the study of directional variation in the wind stream. The results indicated that placing radial vanes directly before the propeller actually increased the efficiency of the tunnel to a considerable extent.
Design of Wind Tunnels and Wind Tunnel Propellers 2
This report is a continuation of National Advisory Committee for Aeronautics report no. 73. The variations in velocity and direction of the wind stream were studied by means of a recording air speed meter and a recording yawmeter. The work was carried on both in a 1-foot diameter model tunnel and in a 5-foot full-size tunnel, and wherever possible comparison was made between them. It was found that placing radial vanes directly before the propeller in the exit cone increased the efficiency of the tunnel to a considerable extent and also gave a steadier flow.
Destructive Distillation of Mixtures of Oil and Coal
Report issued by the U.S. Bureau of Mines on the characteristics and behavior of oil and coal distillation processes. The effectiveness of the distillation processes and the properties of the oil and coal mixtures are presented. This report includes tables, graphs, and illustrations.
The determination of downwash
It is obvious that, in accordance with Newton's second law, the lift on an aerofoil must be equal to the vertical momentum communicated per second to the air mass affected. Consequently a lifting aerofoil in flight is trailed by a wash which has a definite inclination corresponding to the factors producing the lift. It is thought that sufficient data, theoretical and experimental, are now available for a complete determination of this wash with respect to the variation of its angle of inclination to the originating aerofoil and with respect to the law which governs its decay in space.
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