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Mathematical treatise on the recovery from a flat spin

Description: In this mathematical investigation, made in collaboration with Dr. Wilhelm Schmidt, we interpret the temporary change (due to some disturbance) in the quantities which define the position of the airplane while in a flat spin. We further examine the effect of this change, of the means resorted to to produce the disturbance, and thus reveal the expedients available for recovering from a flat spin.
Date: November 1930
Creator: Fuchs, R.
Partner: UNT Libraries Government Documents Department
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Development of Light and Small Airplanes

Description: Memorandum presenting an overview of the development of light and small airplanes. Some of the characteristics explored include the development of airplanes of medium weight, development in countries other than Germany, development of light airplanes, general constructive fiducial lines, safety problems, the economy problem, and some special structural considerations are provided.
Date: July 1926
Creator: Lachmann, G.
Partner: UNT Libraries Government Documents Department
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Accurate Calculation of Multispar Cantilever and Semicantilever Wings With Parallel Webs Under Direct and Indirect Loading

Description: In the present report the computation is actually carried through for the case of parallel spars of equal resistance in bending without direct loading, including plotting of the influence lines; for other cases the method of calculation is explained. The development of large size airplanes can be speeded up by accurate methods of calculation such as this.
Date: March 1932
Creator: Sänger, Eugen
Partner: UNT Libraries Government Documents Department
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Measuring Vibration and Torque With the Oscillograph

Description: "The recent development of technical science demands maximum reliability of functioning, together with maximum utilization of construction materials. For this purpose we must know what stresses are produced during functioning. One cause of great stresses are mechanical vibrations and this report describes a method of using an oscilloscope to measure the stresses of rapidly changing phenomena" (p. 1).
Date: December 1924
Creator: Elsässer, R.
Partner: UNT Libraries Government Documents Department
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Contribution to the Systematic Investigation on Joukowsky Profiles

Description: "This article resulted from the need of showing, in a simple way, how the aerodynamic properties of airfoils are affected by the shape of their profiles. No general solution of this problem could be found, since the profile shapes cannot ordinarily be expressed by simple mathematical formulas. This advantage is possessed only by the Joukowsky profiles and this discussion of the problem is therefore limited to them" (p. 1).
Date: April 1928
Creator: Loew, Gottfried
Partner: UNT Libraries Government Documents Department
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A Few More Mechanical-Flight Formulas Without the Aid of Polar Diagrams

Description: The reliability of the assumption of a parabolic shape of the polar curve is investigated and found satisfactory for all practical purposes. It is further shown that the aerodynamically best possible or "ideal" airplane is produced on this assumption. Lastly, detailed suggestions are given on the possibilities of application of this method of calculation. It especially simplifies the design and evaluation of structural changes and the determination of the limits of technical possibilities. The … more
Date: March 1928
Creator: Schrenk, Martin
Partner: UNT Libraries Government Documents Department
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Kinetographic Determination of Airplane Flight Characteristics

Description: The author's first experiments with a glider on flight characteristics demonstrated that an accurate flight-path measurement would enable determination of the polar diagram from a gliding flight. Since then he has endeavored to obtain accurate flight measurements by means of kinetograph (motion-picture camera). Different methods of accomplishing this are presented.
Date: April 1927
Creator: Raethjen, P.
Partner: UNT Libraries Government Documents Department
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Motive Power Required to Operate a Wind Tunnel

Description: The use of exit cones and different blade configurations to reduce the motive power required in wind tunnels is discussed in this report.
Date: September 1924
Creator: Ziembinski, S.
Partner: UNT Libraries Government Documents Department
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The Mutual Action of Airplane Body and Power Plant

Description: The present report concerns the development of general propeller performance and r.p.m. curves which, combined with the general curve of the power required for level flight, presents a complete picture of the performance. The curve of power required for level flight in this paper is only an approximation for constant profile drag coefficient, meaning that it is not suitable to unconventional wing sections.
Date: April 1932
Creator: Schrenk, Martin
Partner: UNT Libraries Government Documents Department
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Rules and Regulations for Endurance Contest of Aviation Engines: Under the Auspices of the Aero Club of France

Description: Memorandum presenting the rules and regulations of the Endurance Contest of Aviation Engines, which was put on by the Aero Club of France. A description of the rules regarding the aircraft in competition, the characteristics of the tests that were conducted, and information regarding classification of the aircraft is provided.
Date: November 1923
Partner: UNT Libraries Government Documents Department
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Wind Tunnel Tests of Correction Formula for Wings of Large Span

Description: The theory (wing experiments in an artificial air stream are subject to error, due to the fact that the wing is not situated in an unlimited body of air) by means of which the given drag correction was obtained, was based on various assumptions (e.g., elliptical distribution of lift) which do not always hold true. For this reason it was desirable to test the equation for the additional drag in regard to its reliability and range of application.
Date: May 1924
Creator: Wieselsberger, C.
Partner: UNT Libraries Government Documents Department
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Pressure Distribution on Fuselage of Airplane Model

Description: Memorandum describing the method of determining the pressure distribution on the fuselage, with special attention to how it is affected by the presence of the wings.
Date: February 1925
Partner: UNT Libraries Government Documents Department
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Investigation of the Variations in the Velocity of the Air Flow About a Wing Profile

Description: Memorandum presenting an investigation to determine the variations in the velocity of the air when it was obliged to flow about a wing profile. Special interest was paid to the determination of velocity as compared with that of the undisturbed flow and of the velocity drop in successive planes perpendicular to the flow direction at increasing distances from the wing profile.
Date: July 1930
Creator: Repenthin, Walter
Partner: UNT Libraries Government Documents Department
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Graetzin Special Carburetor

Description: Corresponding to practical requirements, this carburetor (especially the smaller sizes) may be regarded as the smallest form of a float carburetor and is adapted for use with all small engines, including auxiliary bicycle and similar engines.
Date: February 1923
Partner: UNT Libraries Government Documents Department
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Experiments With Airplane Brakes

Description: This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at u… more
Date: September 1931
Creator: Michael, Franz
Partner: UNT Libraries Government Documents Department
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Distant-Compass

Description: Report presenting a description of fluid compasses that are being used in aircraft, including why magnetic compasses are not usable. Details of the distant compass are provided, which is an improved form of the compass that has a practical application in seaplanes.
Date: June 1921
Creator: Friedensburg, Walter & Miner, D. M.
Partner: UNT Libraries Government Documents Department
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Elmira Soaring Contest, 1930

Description: This report details the Elmira, New York soaring contest of 1930 and provides up-current maps, experiences in piloting, distance flights, and a few details on glider design.
Date: March 1931
Creator: Hirth, Wolfram K. E.; Schempp, Martin H. & Herrick, Jack
Partner: UNT Libraries Government Documents Department
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Combating Airplane Fires

Description: This report provides a summary of the important steps to be taken in combating airplane fires. Some considerations and ways of preventing fires from developing are provided.
Date: January 1930
Creator: Brunat, Henri
Partner: UNT Libraries Government Documents Department
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Effect of Viscosity in Speed Measurements With Double-Throat Venturi Tubes

Description: In order to clarify the viscosity effect some experiments were made in the Gottigen low-pressure tunnel with the Bruhn double-throat Venturi tube. This type of tunnel makes it possible to vary the pressure and thereby the density within wide limits and consequently, to examine the viscosity effect. This, however, did not impair the results because pressure and temperature were determined at different periods.
Date: August 1931
Creator: Peters, H.
Partner: UNT Libraries Government Documents Department
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Spindled and Hollow Spars

Description: "The most usual method of arriving at the maximum amount of spindling or hollowing out permissible in the case of any particular spar section is by trial and error, a process which is apt to become laborious in the absence of good guessing - or luck. The following tables have been got out with the object of making it possible to arrive with certainty at a suitable section at the first attempt" (p. 1).
Date: October 1926
Creator: Blyth, J. D.
Partner: UNT Libraries Government Documents Department
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Rules and Regulations of the 1923 Rhon Soaring-Flight Contest

Description: Memorandum describing the rules and regulations of the 1923 Rhön Soaring-Flight Contest. The requirements of the aircraft, pilot and competitor requirements, and prizes are provided.
Date: May 1923
Partner: UNT Libraries Government Documents Department
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Supplement to Comparison of Automatic Control Systems

Description: "This analysis deals with the indirect regulator, wherefrom the behavior of the direct regulator is deduced as a limiting case. The prime mover is looked upon as "independent of the load": a change in the adjusting power (to be applied) for the control link (as, for example, in relation to the adjusting path (eta) with pressure valves or the rudder of vessels) does not modify the actions of the prime mover. Mass forces and friction are discounted; "clearance" also is discounted in the transmiss… more
Date: August 1941
Creator: Oppelt, W.
Partner: UNT Libraries Government Documents Department
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