UNT Libraries Government Documents Department - 111 Matching Results

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Suggestions for Popularizing Civil Aviation

Description: The public generally is taking very little interest in the progress of Civil Aviation, and the time has come to educate the public in aeronautics and to make them realize the far-reaching importance of air transport. Briefly, the whole problem resolves itself into discovering and applying means for bringing some of the many aspects and effects of civil aviation into the everyday lives of the public. The report suggests three principal groups of methods: (1) Bring aviation into daily contact with the public. (2) Bring the public into daily contact with aviation. (3) General publicity.
Date: January 1926
Creator: Eliott-Lynn

Estimated Effect of Ring Cowl on the Climb and Ceiling of an Airplane

Description: From Summary: "Although the application of a ring cowl to an airplane with an air-cooled engine increases the maximum L/D and the high speed to an appreciable extent, the performance in climb and ceiling is not increased as much as one would expect without analyzing the conditions. When a ring cowl is installed on an airplane, the propeller is set at a higher pitch to allow the engine to turn its rated r.p.m. at the increased high speed. V/nD is increased and the propeller efficiency at high speed is increased slightly. The ratio of r.p.m. at climbing speed, V(sub c) , to the r.p.m. at maximum speed, V (sub m) is dependent upon the ratio of V(sub c) to V(sub m)."
Date: June 1931
Creator: Louden, F. A.

Method of Determining the Weights of the Most Important Simple Girders

Description: "This paper presents a series of tables for the simple and more common types of girders, similar to the tables given in handbooks under the heading "Strength of Materials," for determining the moments, deflections, etc., of simple beams. Instead of the uniform cross section there assumed, the formulas given here apply only to girders of "uniform strength," i.e., it is assumed that a girder is so dimensioned that a given load subjects it to a uniform stress throughout its whole length. This principle is particularly applicable to very strong structures" (p. 1).
Date: December 1931
Creator: Cassens, J.

Statistics of the Bureau Veritas

Description: "Statistics are indispensable factors for the amelioration of safety. Through the reconciliation of accidents which may appear isolated to interested parties, they permit tracking of typical causes of accidents; conversely, they can prevent, after a serious accident due to some fortuitous cause, the taking of incautious measures under the pressure of public opinion, which always inclines to gauge the gravity of the causes by that of the results. Lastly, they permit appraisal of the efficacy of rules in force. We should add that statistics provide an agency of prevention for future accidents" (p. 1).
Date: March 1932
Creator: Volmerange, André

Present Status of Lateral-Control Devices for Use With Split Flaps, Special Report

Description: "The increased use of split flaps for the dual purpose of reducing the landing speed and shortening the landing glide of airplanes has established as acute the problem of obtaining satisfactory lateral control to be used in conjunction with the flaps with out the sacrifice of any of the effectiveness of the flaps. A large amount of work is being done on this problem by various organizations and individuals. Several of the devices developed seem usable, some of them unquestionably so" (p. 1).
Date: August 1933
Creator: Weick, Fred E.

Flight Tests on the Lateral Control of an Airplane having a Split Flap which Retracts Ahead of Conventional Ailerons, Special Report

Description: "Since the recent more or less extensive adoption of high-lift flaps on airplane wings, the problem of providing satisfactory lateral control without sacrificing a part of the span of the flaps has become one of some importance. The difficulties have been largely a matter of obtaining satisfactory rolling moments with a smoothly graduated action, together with sufficiently small control forces throughout the entire speed range. As part of an investigation including several different lateral-control arrangements to be used with split flaps, the tests reported in this paper were made on one arrangement in which conventional ailerons of narrow chord are used, and a split flap is retracted into the under surface of the wing forward of the ailerons" (p. 1).
Date: December 1933
Creator: Weick, Fred E.

Resume of Present Data on Load Distribution on Slots and Flaps, Special Report

Description: This report covers a study of the generally available data on load distribution on slots and flaps. The study was made by the National Advisory Committee for Aeronautics at the request of the Material Division, Army Air Corps to furnish information applicable to design criteria for slots and flaps of various types. The data are presented in three main sections: slots (Handley page type), auxiliary airfoils (fixed), and flaps.
Date: April 1934
Creator: Wenzinger, Carl J.

Preliminary Wind-Tunnel and Flight Tests of a Balanced Split Flap, Special Report

Description: One disadvantage that has been apparent in the operation of split flaps as used to date is the time and effort required to operate them. In this communication an investigation is being made of possible means for balancing them aerodynamically to make their operation easier. Several arrangements have been tested in the 7 by 210 foot wind tunnel, and the results of the wind-tunnel tests as well as preliminary flight tests on one of the more promising forms are given in this paper.
Date: August 1934
Creator: Weick, Fred E. & Thompson, Floyd L.

The Effect of Lateral Inclination of the Thrust Axis and of Sweepback of the Leading Edge of the Wing on Propulsive and Net Efficiencies of a Wing-Nacelle-Propeller Combination

Description: "This report describes and gives the results of tests made to determine the effect of lateral inclination of the propeller thrust axis to the direction of flight. A wing-nacelle-propeller combination with the nacelle axis located successively parallel to and at 15 degrees to the perpendicular to the leading edge of a wing was tested with the combination at several angles of yaw. Tests of the wing alone at the same angles of yaw were also made" (p. 1).
Date: April 1935
Creator: Wood, Donald H. & Windler, Ray

The Relative Hydrodynamic Resistance of Various Types of Rivet Heads from Tests of Planning Surfaces, Special Report

Description: The Committee was requested to investigate the effect of various types of rivet heads on hydrodynamic resistance. The proposal was made to obtain the resistance of the various types of rivets by tests of planing surfaces on which the full size rivets would be arranged. The testing methods, results and conclusions are given.
Date: July 1935
Creator: Truscott, Starr & Parkinson, John B.

Ice Prevention on Aircraft by Means of Impregnated Leather Covers, Special Report

Description: "The National Advisory Committee for Aeronautics is testing the effectiveness of a method to prevent the formation of ice on airplanes. The system makes use of a leather cover that is attached to the leading edge of the wing. A small tube, attached to the inner surface of the leather, distributes to the leading edge a solution that permeates throughout the leather and inhibits the formation of ice on the surface. About 25 pounds of the liquid per hour would be sufficient to prevent ice from forming on a wing of 50-foot span" (p. 1).
Date: August 1935
Creator: Clay, William C.

Tank Tests of the Effect of Rivet Heads, etc., on the Water Performance of a Seaplane Float, Special Report

Description: "A 1/3.5 full-size model of the Mark V float of the Bureau of Aeronautics, Navy Department, was tested in the NACA tank both with smooth painted bottom surfaces and with roundhead rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. The augmentation in water resistance due to the added roughness was found to be from 10-12% at the hum speed and from 12-14% at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high trims" (p. 1).
Date: June 4, 1936
Creator: Parkinson, J. B. & Robertson, J. B., Jr.

Relative Efficiencies and Design Charts for Various Engine-Propeller Combinations, Special Report

Description: "The relative efficiencies of various engine-propeller combinations were the subject of a study that covered the important flight conditions, particularly the take-off. Design charts that graphically correlate the various propeller parameters were prepared to facilitate the solution of problems and also to clarify the conception of the relationships of the various engine-propeller design factors. It is shown that, among the many methods for improving the take-off thrust, the use of high-pitch, large-diameter controllable propellers turning at low rotational speeds is probably the most generally promising" (p. 1).
Date: September 1936
Creator: Biermann, David

Accelerations in Landing with a Tricycle-Type Landing Gear

Description: "In connection with the application of stable tricycle-type landing gears to transport airplanes, the question arises as to whether certain passengers may not experience relatively great accelerations in an emergency landing. Since the main landing wheels are behind the center of gravity in this type of gear, a hard-braked landing will cause immediate nosing down of the airplane and, when this motion is stopped due to the front wheel striking the ground, there will be some tendency for the rearmost passengers to be thrown out of their seats, The provided rough calculations are designed to show the magnitudes of the various reactions experienced in a severe landing under these circumstances" (p. 1).
Date: February 1937
Creator: Jones, Robert T.

Energy Loss, Velocity Distribution, and Temperature Distribution for a Baffled Cylinder Model, Special Report

Description: Report discusses the important principles involved in the operation of a baffle for an engine cylinder and how using a correctly designed baffle can improve cooling. The baffle-exit radius and width and exit-duct length were found to be the most important parts of the baffle and a baffle that gave a relatively uniform temperature distribution was designed.
Date: April 1937
Creator: Brevoort, Maurice J.

Notes on Factors Affecting Geometrical Arrangement of Tricycle-Type Landing Gears

Description: The effects of the geometrical arrangement of tricycle landing gears on various characteristics of an airplane equipped with such landing gear is discussed. The characteristics discussed include directional stability, overturning tendencies, steering and ground handling, shimmy, takeoff, and porpoising. The conclusions are summarized in a table.
Date: April 1937
Creator: Wenzinger, Carl J. & Kantrowitz, A. R.

A Study of Transparent Plastics for use on Aircraft, Special Report

Description: "Various transparent organic plastics, including both commercially available and experimental materials, have been examined to determine their suitability for use as flexible windshields on aircraft, The properties which have been studied include light transmission, haziness, distortion, resistance to weathering, scratch and indentation hardness, impact strength, dimensional stability, resistance to water and various cleaning fluids, bursting strength at normal and low temperatures, and flammability" (p. 1).
Date: May 12, 1937
Creator: Axilrod, Benjamin M. & Kline, Gordon M.

Supplement to A Study of Transparent Plastics for use on Aircraft

Description: This supplement to a NACA study issued in May 1937 entitled "A Study of Transparent Plastics for Use on Aircraft", contains two tables. These tables contain data on bursting strengths of plastics, particularly at low temperatures. Table 1 contains the values reported in a table of the original memorandum, and additional values obtained at approximately 25 C, for three samples of Acrylate resin. The second table contains data obtained for the bursting strength when one surface of the plastic was cooled to approximately -35 C.
Date: August 1937
Creator: Axilrod, Benjamin M. & Kline, Gordon M.

Tandem Air Propellers

Description: Report discussing tests of 2-blade, adjustable-pitch, counterrotating tandem model propellers, adjusted to absorb equal power at maximum efficiency. The characteristics at several pitch settings and diameter spacings were compared with 2-blade and 4-blade propellers. Tandem propellers were found to have an advantage over single propellers at higher pitch settings.
Date: August 1937
Creator: Lesley, E. P.