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Determination of desirable lengths of Z- and channel-section columns for local-instability tests

Description: From Summary: "Local-instability tests of 24S-T aluminum-alloy formed Z- and channel-section columns were made in order to determine a length of test specimen that would avoid the increased strength associated with short lengths and also permit the occurrence of a convenient buckling pattern. The effect of column length on the critical compressive stress, on the average stress at maximum load, and on the number of half-waves of the buckling pattern is shown."
Date: October 1944
Creator: Heimerl, George J. & Roy, J. Albert
Partner: UNT Libraries Government Documents Department

Calculation of tab characteristics for flight conditions from wind-tunnel data

Description: Report presenting tail-surface characteristics calculated from wind-tunnel data, which have been reported to not correspond with flight-test measurements. The primary problem under consideration is the calculation of the effect of tab deflection on the free-floating angle of the elevator, as in a servocontrol.
Date: April 1942
Creator: Sears, Richard I.
Partner: UNT Libraries Government Documents Department

Comparative fatigue tests of riveted joints of Alclad 24S-T, Alclad 24S-T81, Alclad 24S-RT, Alclad 24S-T86 and Alclad 75S-T sheet

Description: Report discusses testing performed to determine the fatigue strength of various types of riveted and spot-welded joints in the following aluminum alloys: Alclad 24S-T, 24S-RT, 758-T, 24S-T81, and 24S-T86. Details of the experiment, tensile properties, and information about failure are provided.
Date: August 1945
Creator: Moore, R. L. & Hill, H. N.
Partner: UNT Libraries Government Documents Department

Summary of V-G records taken on transport airplanes from 1932 to 1942

Description: Report presenting an analysis of records of more than 134,000 flying hours, which have been received and evaluated in order to bring the V-G recorder data up to date. The analysis of the records is contained in the report. Results indicate that the maximum effective gust velocities for both the land transport airplanes and the flying boats have approached values of 40 feet per second.
Date: July 1942
Creator: Walker, Walter G.
Partner: UNT Libraries Government Documents Department

Comparison of tightness of 78 degrees machine-countersunk rivets driven in holes prepared with 78 degrees and 82 degrees countersinking tools

Description: Report presenting an investigation to determine whether the use of a 78 degree countersinking tool instead of a 82 degree countersinking tool for riveting would substantially alter the conclusion reached in a previous paper regarding the placement of rivets for maximum strength.
Date: September 1942
Creator: Gottlieb, Robert & Mandel, Merven W.
Partner: UNT Libraries Government Documents Department

A simplified chart for determining Mach number and true airspeed from airspeed-indicator readings

Description: "The determination of flight Mach number from measurements of indicated airspeed and pressure altitude is shown to be relatively simple and leads to direct and accurate computation of true airspeed. A simplified chart is presented for determining flight Mach number and true airspeed for a range of values of indicated airspeed, pressure altitude, and air temperature. A table of standard atmospheric values is included" (p. 1).
Date: March 1943
Creator: Baals, Donald D. & Ritchie, Virgil S.
Partner: UNT Libraries Government Documents Department

The belt method for measuring pressure distribution

Description: "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
Date: February 1943
Creator: Corson, Blake W., Jr.
Partner: UNT Libraries Government Documents Department

The Knock-Limited Performance of Fuel Blends Containing Spiropentane, Methylenecyclobutane, Di-Tert-Butyl Ether, Methyl Tert-Butyl Ether, and Triptane

Description: Tests show that at inlet-air temperatures of 250 deg F and 100 deg F the knock-limited performance of the base fuel of blends, leaded with 4 ml TEL per gallon and containing 20 percent spiropentane, was reduced at fuel/air ratios below 0.085. The 20 percent methylenecyclobutane reduced the knock-limited power of the base fuel at fuel/air ratios below 0.112. Di-tert-butyl ether, methyl-tert-butyl ether, and triptane increased the knock-limited power of the base fuel at all fuel/air ratios and at both temperatures.
Date: May 1946
Creator: Meyer, Carl L.
Partner: UNT Libraries Government Documents Department

Hydrodynamic-stability tests of a model of a flying boat and of a planing surface having a small downward projection (hook) on the planing bottom near the step

Description: Report presenting stability testing of two dynamic models in tank no. 1 in order to investigate the effects of adding a small projection, or hook, on the planing bottom of the forebody near the step of a seaplane. Tests with two different projections had a rather large effect on all of the trim limits and the landing stability.
Date: January 1943
Creator: Benson, James M.
Partner: UNT Libraries Government Documents Department

Flight investigation of a stall-warning indicator for operation under icing conditions

Description: Report presenting an investigation to determine whether some characteristic of the boundary layer could be used to provide warning of the increase in stalling speed of a wing caused by ice formations on the leading edge. Results were analyzed by referring the total pressures at the rake to the free-stream total pressure, static pressure at the rake, free-stream static pressure, and static pressure from wind-tip swiveling head.
Date: July 1942
Creator: Jones, Alun R. & Zalovcik, John A.
Partner: UNT Libraries Government Documents Department

XC-35 gust research project: Preliminary analysis of the lateral distribution of gust velocity along the span of an airplane

Description: Report presenting measurements of the lateral distribution of effective gust velocity along the span of the XC-35 airplane in a variety of weather conditions. Six standard shapes were determined from the distributions: triangular, rectangular, first trapezoidal, second trapezoidal, unsymmetrical, and double triangular.
Date: March 1943
Creator: Moskovitz, A. I.
Partner: UNT Libraries Government Documents Department

End-zone water injection as a means of suppressing knock in a spark-ignition engine

Description: Report discusses the results of an investigation into the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. The injection angle was found to be very important for obtaining maximum results. The results of various angles and amounts of water were examined.
Date: September 1944
Creator: Brun, Rinaldo J.; Olsen, H. Lowell & Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Use of Internal Coolant as a Means of Permitting Increase in Engine Take-Off Power

Description: Engine tests, together with estimates made at Langley Memorial Aeronautical Laboratory, indicate that a 25-percent increase in take-off power can be obtained with present-day aircraft engines without increasing either the knock limit of the fuel or the external cooling requirements of the engine. This increase in power with present fuels and present external cooling is made possible through the use of an internal coolant inducted through the inlet manifold. Estimates on aircraft indicate that this 25-percent increase in power will permit an approximate usable increase of 8.5 percent in the take-off load of existing military airplanes. This increase in load is equivalent to an increase in the weight of gasoline normally carried of between 30 and 65 percent.
Date: January 1944
Creator: Rothrock, Addison M.
Partner: UNT Libraries Government Documents Department

An analysis of the fatigue life of an airplane wing structure under overload conditions

Description: From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."
Date: February 1946
Creator: Putnam, Abbott A. & Reisert, Thomas D.
Partner: UNT Libraries Government Documents Department

Tables and Charts for the Evaluation of Profile Drag From Wake Surveys at High Subsonic Speeds

Description: Report presents tables and charts for the evaluation of profile drag from wake surveys at high supersonic speeds. Two methods of evaluation are presented: an exact method that can be used on a wake of any shape and a simple approximate method that can be used when the variation of total-pressure loss across the wave has a typical form.
Date: July 1945
Creator: Block, Myron J. & Katzoff, S.
Partner: UNT Libraries Government Documents Department

A Positive-Replica Technique for Examining Finished Metal Surfaces and Its Application to Aircraft Engine Cylinders

Description: Report discusses a method of replica creation and testing of the surface-finish variation of aircraft engine parts subject to wear. In this report, a positive replica is created, the surface is treated, the replica is tested to make sure the fidelity is high enough, and a series of ring-sticking tests are conducted on the replicas. A summary of the results of the testing is also included.
Date: September 1944
Creator: Clark, Thomas P.
Partner: UNT Libraries Government Documents Department

The Preparation of 2, 2, 4, 4-Tetramethylpentane

Description: Report presenting seven distinct operations in the preparation of 2,2,4,4-tetramethylpentane, including the preparation of di-isobutylene hydrochloride, preparation of dimethylzinc, reaction of dimethylzinc in dry benzene with di-isobutylene hydrochloride, preliminary distillation of the reaction products, treatment of the first distillate with sodium and alcohol, final distillation after appropriate washing of the products, and recovery of the iodine in the zinc residues of II as methyl iodide.
Date: May 1942
Creator: Drake, N. L.
Partner: UNT Libraries Government Documents Department

Progress Summary Number 1: Mechanical Properties of Flush-Riveted Joints Submitted by Five Airplane Manufacturers

Description: Summary presenting information on flush-riveted joints for aircraft construction, including the strength, occurrence of defects, and effect of the angle of rivet head. The current tests covers specimens from 15 manufacturers of which 5 series have been completed and are described in this report.
Date: February 1942
Creator: Brueggeman, William Charles
Partner: UNT Libraries Government Documents Department

Effect of Normal Pressure on the Critical Compressive Stress of Curved Sheet

Description: Results are presented of tests of two specimens tested to study the effect of normal pressure on the critical compressive stress for thin curved sheets. These specimens are designated by their respective rib spacings of 10 inches and 30 inches. The relationship between compressive stress and normal pressure at which buckles disappeared is independent of whether the buckles were made to disappear by increase of normal pressure or decrease of compressive stress. (author).
Date: August 25, 1942
Creator: Rafel, Norman
Partner: UNT Libraries Government Documents Department

Tests of a Stressed-Carrying Door in Shear

Description: Bulletin presenting testing of a monocoque box with a stress-carrying door made and tested in torsion. The results indicate that if a stress-carrying door and its frame are made sufficiently heavy, the torsional stiffness of the box with the door can be made greater than the torsional stiffness of the box without the cut-out" (p. 1).
Date: August 1942
Creator: Gottlieb, Robert
Partner: UNT Libraries Government Documents Department

Tests of a Stress-Carrying Door in Compression

Description: Bulletin presenting the results of bending tests on a monocoque box with the door on the compression side. The results indicate that the effectiveness of a stress-carrying door depends on the intended function of the door.
Date: September 1942
Creator: Gottlieb, Robert
Partner: UNT Libraries Government Documents Department

A Description of the Ju 88 Airplane Anti-Icing Equipment

Description: Bulletin presenting an examination of a part of the anti-icing equipment for a Ju 88 airplane, including exhaust-air heat exchangers, control valves, air duct system, and air-heated wing panels. Testing was performed on the components and indicated that the thermal ice-prevention equipment can maintain the outer-wing panel free from ice.
Date: September 1942
Creator: Rodert, Lewis A. & Jackson, Richard
Partner: UNT Libraries Government Documents Department

The Fatigue Strengths of Some Wrought Aluminum Alloys

Description: Report presenting an exploration of fatigue stresses of some wrought aluminum alloys, including charts that cover different ranges of stress and number of cycles.
Date: June 1942
Creator: Stickley, G. W.
Partner: UNT Libraries Government Documents Department