Balanced and Servo Control Surfaces (open access)

Balanced and Servo Control Surfaces

"Many reports on various control systems are available, but the results cannot be generally applied since the effect of particular changes of surface-form and mounting are subject to variations depending upon airfoil section and influences of airplane layout. This report presents a simple analysis of several control systems in more general use. Elevators, ailerons, and rudders are all discussed" (p. 1).
Date: May 1930
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The De Havilland "Moth Three" Airplane (British): A High-Wing Commercial Monoplane (open access)

The De Havilland "Moth Three" Airplane (British): A High-Wing Commercial Monoplane

Circular describing the De Havilland Moth Three, which is a high-wing commercial monoplane with a steeply sloping windshield, strut-bracing of the wing, and relatively orthodox landing gear. Details of the construction, design, characteristics, performance, drawings, and photographs are provided.
Date: May 1930
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Development of the Junkers-Diesel Aircraft Engine (open access)

Development of the Junkers-Diesel Aircraft Engine

The working process of the Junkers engine has resulted from a series of attempts to attain high performance and to control the necessarily rapid and complete combustion at extremely high speeds. The two main problems of Diesel engines in aircraft are addressed; namely, incomplete combustion and the greater weight of Diesel engine parts compared to gasoline engines.
Date: May 1930
Creator: Gasterstädt
Object Type: Report
System: The UNT Digital Library
Engineering Study of the Seminole Area, Seminole and Pottawatomie Counties, Oklahoma (open access)

Engineering Study of the Seminole Area, Seminole and Pottawatomie Counties, Oklahoma

Report issued by the Bureau of Mines over engineering studies conducted on Oklahoma oil fields. The results of the studies are presented and discussed. This report includes tables, illustrations, and photographs.
Date: May 1930
Creator: Brandenthaler, R. R.; Morris, W. S. & Bopp, C. R.
Object Type: Report
System: The UNT Digital Library
Experimental Research on the Friction of Pivots (open access)

Experimental Research on the Friction of Pivots

In horology the friction between solids is of the greatest importance; one limited, however, to the application of the laws of Coulomb which, do not at all correspond with reality. This report presents a review of the subject and some general conclusions. The choice of lubricant is discussed as well as the pressure between frictional surfaces. The gears in a watch are used extensively as examples.
Date: May 1930
Creator: Jaquerod, A.; Defossez, L. & Mügeli, H
Object Type: Report
System: The UNT Digital Library
Full Scale Drag Tests on Various Parts of Fairchild (FC-2W2) Cabin Monoplane (open access)

Full Scale Drag Tests on Various Parts of Fairchild (FC-2W2) Cabin Monoplane

"The drag due to the various parts of a Fairchild (FC-2W2) cabin monoplane was measured at air speeds varying from 50 to 100 m.p.h., in the Twenty-Foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. It was found that the largest drag was due to the radial air-cooled engine. The measured drag due to the landing gear was also large, being about 4/5 of that due to the engine" (p. 1).
Date: May 1930
Creator: Herrnstein, William H., Jr.
Object Type: Report
System: The UNT Digital Library
The Junkers "G 38" Commercial Airplane (German): A Giant High-Wing Monoplane (open access)

The Junkers "G 38" Commercial Airplane (German): A Giant High-Wing Monoplane

Circular describing the Junkers G 38, which is an airplane designed to minimize fuel consumption and maximize reliability of functioning. A description of the design, construction and equipment, wings, engines, characteristics, drawings, and photographs are provided.
Date: May 1930
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Magnus Effect in Theory and in Reality (open access)

The Magnus Effect in Theory and in Reality

A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.
Date: May 1930
Creator: Ahlborn, F.
Object Type: Report
System: The UNT Digital Library
The National Safety Competition of 1929 (open access)

The National Safety Competition of 1929

Report issued by the U.S. Bureau of Mines on the fifth annual national safety competition. The states represented in the competition are listed. Accident-frequency rates are presented as well. This report includes tables.
Date: May 1930
Creator: Adams, William Waugh
Object Type: Report
System: The UNT Digital Library
Recent Tests of Tailless Airplanes (open access)

Recent Tests of Tailless Airplanes

This report details the advantages and construction of tailless airplanes. Both a glider and a powered model were built and the specifications of both airplanes are listed.
Date: May 1930
Creator: Lippisch, Alexander
Object Type: Report
System: The UNT Digital Library
Refrigerated wind tunnel tests on surface coatings for preventing ice formation (open access)

Refrigerated wind tunnel tests on surface coatings for preventing ice formation

"This investigation was conducted to determine the effectiveness of various surface coatings as a means for preventing ice formations on aircraft in flight. The substances used as coatings for these tests are divided into two groups: compounds soluble in water, and those which are insoluble in water. It was found that certain soluble compounds were apparently effective in preventing the formation of ice on an airfoil model, while all insoluble compounds which were tested were found to be ineffective" (p. 1).
Date: May 1930
Creator: Knight, Montgomery & Clay, William C.
Object Type: Report
System: The UNT Digital Library
Some effects of air and fuel oil temperatures on spray penetration and dispersion (open access)

Some effects of air and fuel oil temperatures on spray penetration and dispersion

Presented here are experimental results obtained from a brief investigation of the appearance, penetration, and dispersion of oil sprays injected into a chamber of highly heated air at atmospheric pressure. The development of single sprays injected into a chamber containing air at room temperature and at high temperature was recorded by spray photography equipment. A comparison of spray records showed that with the air at the higher temperature, the spray assumed the appearance of thin, transparent cloud, the greatest part of which rapidly disappeared from view. With the chamber air at room temperature, a compact spray with an opaque core was obtained. Measurements of the records showed a decrease in penetration and an increase in the dispersion of the spray injected into the heated air. No ignition of the fuel injected was observed or recorded until the spray particles came in contact with the much hotter walls of the chamber about 0.3 second after the start of injection.
Date: May 1930
Creator: Gelalles, A. G.
Object Type: Report
System: The UNT Digital Library
Sweet Potato Certification Program and List of Authorized Growers of Certified Sweet Potato Plants (open access)

Sweet Potato Certification Program and List of Authorized Growers of Certified Sweet Potato Plants

Agriculture bulletin describing the sweet potato certification project, with a listing of authorized growers and certified sweet potato plants.
Date: May 1930
Creator: Del Curto, J. M., 1897- & Crozier, E. T.
Object Type: Pamphlet
System: The Portal to Texas History
Dynamic and flight tests on rubber-cord and oleo-rubber-disk landing gears for an F6C-4 airplane (open access)

Dynamic and flight tests on rubber-cord and oleo-rubber-disk landing gears for an F6C-4 airplane

The investigation described in this report was conducted for the purpose of comparing an oleo-rubber-disk and a rubber-cord landing gear, built for use on an F6C-4 airplane. The investigation consisted of drop tests under various loading conditions and flight tests on an F6C-4 airplane. In the drop tests the total work done on each gear and the work done on each of the shock-absorbing units were determined. For both drop tests and flight tests the maximum loads and accelerations were determined. The comparative results showed that the oleo gear was slightly superior in reducing the ordinary landing shocks, that it had a greater capacity for work, and that it was very superior in the reduction of the rebound. The results further showed that for drops comparable to very severe landings, the rubber-cord gear was potentially more effective as a shock-reducing mechanism. However, due to the construction of this chassis, which limited the maximum elongation of the cords, this gear was incapable of withstanding as severe tests as the oleo gear. The action of the oleo gear was greatly inferior to the action of an ideal gear. The maximum accelerations encountered during the flight tests for severe landings were 3.64g for …
Date: May 20, 1930
Creator: Peck, William C.
Object Type: Report
System: The UNT Digital Library
Pressure Fluctuations in a Common-Rail Fuel Injection System (open access)

Pressure Fluctuations in a Common-Rail Fuel Injection System

This report presents the results of an investigation to determine experimentally the instantaneous pressures at the discharge orifice of a common-rail fuel injection system in which the timing valve and cut-off valve were at some distance from the automatic fuel injection valve, and also to determine the methods by which the pressure fluctuations could be controlled. The results show that pressure wave phenomena occur between the high-pressure reservoir and the discharge orifice, but that these pressure waves can be controlled so as to be advantageous to the injection of the fuel. The results also give data applicable to the design of such an injection system for a high-speed compression-ignition engine.
Date: May 20, 1930
Creator: Rothrock, A. M.
Object Type: Report
System: The UNT Digital Library
Pressure Distribution Over a Thick, Tapered and Twisted Monoplane Wing Model-N.A.C.A. 81-J (open access)

Pressure Distribution Over a Thick, Tapered and Twisted Monoplane Wing Model-N.A.C.A. 81-J

"This reports presents the results of pressure distribution tests on a thick, tapered and twisted monoplane wing model. The investigation was conducted for the purpose of obtaining data on the aerodynamic characteristics of the new wing and to provide additional information suitable for use in the design of tapered cantilever wings. The tests included angles of attack up to 90 degrees. The span loading over the wing was approximately of elliptical shape, which gave rise to relatively small bending moments about the root" (p. 97).
Date: May 21, 1930
Creator: Wenzinger, Carl J.
Object Type: Report
System: The UNT Digital Library
Maneuverability investigation of the F6C-3 airplane with special flight instruments (open access)

Maneuverability investigation of the F6C-3 airplane with special flight instruments

"This investigation was made for the purpose of obtaining information on the maneuverability of the F6C-3 airplane. It is the first of a series of similar investigations to be conducted on a number of military airplanes for the purpose of comparing the abilities of these airplanes to maneuver, and also to establish a fund of quantitative data which may be used in formulating standards of comparison for rating the maneuverability of any airplane. A large part of this initial investigation was necessarily devoted to the development and trial of methods suitable for use in subsequent investigations of this nature" (p. 117).
Date: May 23, 1930
Creator: Dearborn, C. H. & Kirschbaum, H. W.
Object Type: Report
System: The UNT Digital Library
Chalcid control in alfalfa-seed production. (open access)

Chalcid control in alfalfa-seed production.

Describes the damage that the chalcid can cause to an alfalfa seed crop, and various measures that a farmer can take to control it.
Date: May 1931
Creator: Wildermuth, V. L.
Object Type: Book
System: The UNT Digital Library
Christmas trees as a cash crop for the farm. (open access)

Christmas trees as a cash crop for the farm.

Provides steps for planting, cultivating, and marketing Christmas trees.
Date: May 1931
Creator: Eyre, F. H. (Francis Howlett), 1898-
Object Type: Book
System: The UNT Digital Library
Coal-Mine Fatalities in April, 1931 (open access)

Coal-Mine Fatalities in April, 1931

Report issued by the U.S. Bureau of Mines on the coal mine related deaths during the month of April, 1931. The number of fatalities and the causes are presented. This report includes tables and graphs.
Date: May 1931
Creator: Adams, William Waugh & Chenoweth, L.
Object Type: Report
System: The UNT Digital Library
Combined Pitching and Yawing Motion of Airplanes (open access)

Combined Pitching and Yawing Motion of Airplanes

This report treats the following problems: The beginning of the investigated motions is always a setting of the lateral controls, i.e., the rudder or the ailerons. Now, the first interesting question is how the motion would proceed if these settings were kept unchanged for some time; and particularly, what upward motion would set in, how soon, and for how long, since therein lie the dangers of yawing. Two different motions ensue with a high rate of turn and a steep down slope of flight path in both but a marked difference in angle of attack and consequently different character in the resultant aerodynamic forces: one, the "corkscrew" dive at normal angle, and the other, the "spin" at high angle.
Date: May 1931
Creator: v. Baranoff, A. & Hopf, L.
Object Type: Report
System: The UNT Digital Library
Comparison of Weights of 17ST and Steel Tubular Structural Members Used in Aircraft Construction (open access)

Comparison of Weights of 17ST and Steel Tubular Structural Members Used in Aircraft Construction

Although the strong aluminum alloys have proved themselves to be very efficient in aircraft construction there is a growing competition from the high-strength steels for certain parts, especially for tubular members. This tendency is being reflected in research work carried on at the Bureau of Standards. This study will be based largely on data given in Technical Note No. 307 of the NACA.
Date: May 1931
Creator: Hartmann, E. C.
Object Type: Report
System: The UNT Digital Library
Definition of Method of Measurement of Supporting and Control Surface Areas (open access)

Definition of Method of Measurement of Supporting and Control Surface Areas

Definitions of methods of measurements of supporting and control surface areas are presented. Methods for measuring the supporting surface, i.e., the wing area, and the control surfaces, i.e., the horizontal tail area, the vertical tail area, and the trailing control surface areas are defined. Illustrations of each of the areas are included.
Date: May 1931
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Determination of Resistance and Trimming Moment of Planing Water Craft (open access)

Determination of Resistance and Trimming Moment of Planing Water Craft

This report presents a new theory which makes it possible to interpret the resistance and the trimming moment for any loading of a planing aircraft when these values are given for one load. This application of the new theory forms the basis of the present paper. Derivations of various conversion formulas are given as well as numerous examples.
Date: May 1931
Creator: Schröder, P.
Object Type: Report
System: The UNT Digital Library