UNT Libraries Government Documents Department - 36 Matching Results

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Airplane inspection guide.

Description: "The purpose of this manual is to furnish to mechanics, inspectors, and other personnel, ..., the necessary information relative to the inspection of airplanes, airplane engines, and auxiliary equipment."
Date: August 17, 1943
Creator: United States. War Department.

Bearing strengths of some wrought-aluminum alloys

Description: From Introduction: "Although a number of investigations of the bearing strength of aluminum alloys have been made, the problem remains one of considerable interest to the aircraft industry. For this reason it has seemed advisable to make additional tests of the commonly used aircraft alloys in an effort to establish a better basis for the selection of allowable bearing values. Current design practice does not recognize the effect of edge distance upon bearing strengths, and for this reason edge distance was one of the principal variables considered in this investigation. The increasing emphasis being placed upon permanent set limitations makes it essential that more information on bearing yield phenomena be obtained."
Date: August 1943
Creator: Moore, R. L. & Wescoat, C.

The effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum alloy

Description: An experimental study was made to determine the effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum-alloy sheet material. The results of the tests show that certain combinations of aging time and temperature cause a marked increase in the yield strength and a small increase in the ultimate strength; these increases are accompanied by a very large decrease in elongation. A curve is presented that shows the maximum yield strengths that can be obtained by aging this material at various combinations of time and temperature. The higher values of yield stress are obtained in material aged at relatively longer times and lower temperatures.
Date: August 1943
Creator: Kotanchik, Joseph N.; Woods, Walter & Zender, George W.

The Effect of Mass Distribution on the Lateral Stability and Control Characteristics of an Airplane as Determined by Tests of a Model in the Free-Flight Tunnel

Description: The effects of mass distribution on lateral stability and control characteristics of an airplane have been determined by flight tests of a model in the NACA free-flight tunnel. In the investigation, the rolling and yawing movements of inertia were increased from normal values to values up to five times normal. For each moment-of-inertia condition, combinations of dihedral and vertical-tail area representing a variety of airplane configurations were tested. The results of the flight tests of the model were correlated with calculated stability and control characteristics and, in general, good agreement was obtained. The tests showed the following effects of increased rolling and yawing moments of inertia: no appreciable change in spiral stability; reductions in oscillatory stability that were serious at high values of dihedral; a reduction in the sensitivity of the model to gust disturbances; and a reduction in rolling acceleration provided by the ailerons, which caused a marked increase in time to reach a given angle of bank. The general flight behavior of the model became worse with increasing moments of inertia but, with combinations of small effective dihedral and large vertical-tail area, satisfactory flight characteristics were obtained at all moment-of-inertia conditions.
Date: August 1943
Creator: Campbell, John P. & Seacord, Charles L., Jr.

Fission Spectrum

Description: Measurements of the spectrum of the fission neutrons of 25 are described, in which the energy of the neutrons is determined from the ionization produced by individual hydrogen recoils. The slow neutrons producing fission are obtained by slowing down the fast neutrons from the Be-D reaction of the Stanford cyclotron. In order to distinguish between fission neutrons and the remaining fast cyclotron neutrons both the cyclotron current and the pusle amplifier are modulated. A hollow neutron container, in which slow neutrons have a lifetime of about 2 milliseconds, avoids the use of large distances. This method results in much higher intensities than the usual modulation arrangement. The results show a continuous distribution of neutrons with a rather wide maximum at about 0.8 MV falling off to half of its maximum value at 2.0 MV. The total number of netrons is determined by comparison with the number of fission fragments. The result seems to indicate that only about 30% of the neutrons have energies below .8 MV. Various tests are described which were performed in order to rule out modification of the spectrum by inelastic scattering.
Date: August 18, 1943
Creator: Bloch, F. & Staub, H.

Improved baffle designs for air-cooled engine cylinders

Description: Report presenting an investigation to determine methods for improving the cooling of air-cooled engine cylinders by means of baffle modifications. Testing was conducted using a Pratt & Whitney R-1830-43 engine mounted on a ground test stand. Results regarding temperature data for variations in atmospheric conditions, temperature measurements at various points along the cylinder, and some of the implied effects of baffle modifications are provided.
Date: August 1943
Creator: Kinghorn, George F.

A method for determining the column curve from tests of columns with equal restraints against rotation on the ends

Description: The results are presented of a theoretical study for the determination of the column curve from tests of column specimens having ends equally restrained against rotation. The theory of this problem is studied and a curve is shown relating the fixity coefficient c to the critical load, the length of the column, and the magnitude of the elastic restraint. A method of using this curve for the determination of the column curve for columns with pin ends from tests of columns with elastically restrained ends is presented. The results of the method as applied to a series of tests on thin-strip columns of stainless steel are also given.
Date: August 1, 1943
Creator: Lundquist, Eugene E.; Rossman, Carl A. & Houbolt, John C