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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

Tests of 10 inch 24S-T aluminum-alloy shear panels with 1-1/2 inch holes 2 : panels having holes with notched edges

Description: Report discusses the results of testing of 10-inch 24S-T aluminum alloy shear panels with 1.5 inch holes with notched edges to determine if a notch decreases the strength of the panel and if reinforcements can overcome the negative effects of the notch. The notch did appear to increase the stress concentration around the holes, but the lack of applicability to real-world scenarios is discussed.
Date: April 1944
Creator: Kuhn, Paul & Levin, L. Ross
Partner: UNT Libraries Government Documents Department

Tests of beams having webs with large circular lightening holes

Description: From Summary: "Strength tests were made on two sets of beams having webs with large circular lightening holes. The main conclusion drawn from the tests is that allowable web stressed derived from pure shear tests and allowable flange stresses derived from compression tests cannot be applied in the design of beams without making corrections for interaction." Pure shear tests and beam tests were performed and the circumstances of failure were investigated.
Date: February 1944
Creator: Levin, L. Ross
Partner: UNT Libraries Government Documents Department

Tests of hydraulically expanded rivets

Description: Report discusses the results of an investigation into the tightness, shear strength, tensile strength, and life under pulsating loads of hollow, hydraulically expanded rivets made of 17S-T aluminum alloy. The countersunk-head rivets with inserts had a much higher maximum load in shear than the modified-roundhead rivets, which did not have inserts.
Date: March 1944
Creator: Mandel, Merven W.; Crate, Harold & Schuette, Evan H.
Partner: UNT Libraries Government Documents Department

Tests of 10-inch 24S-T aluminum-alloy shear panels with 1-1/2-inch holes

Description: Report discusses the results of testing on "10-inch shear panels of 24S-T aluminum alloy with 1.5 inch holes to determine the stress concentration at static rupture and the deformation characteristics" (from Summary). The strength of the perforated specimens is compared to the solid specimens and the critical stresses are computed. The stress at which permanent set occurs was also measured.
Date: June 1943
Creator: Kuhn, Paul & Levin, L. Ross
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

The use of geared spring tabs for elevator control

Description: Report discussing the use of two types of geared spring tabs for elevator control: ordinary (or ungeared) spring tabs and geared spring tabs. Their use in airplanes of various sizes and in comparison to conventional control systems is described.
Date: February 1945
Creator: Phillips, William H.
Partner: UNT Libraries Government Documents Department

XC-35 gust research project analysis of gust measurements

Description: Report discusses measurements of gust size and intensity during the spring and summer of 1941 and 1942 under a variety of weather conditions and various altitudes up to 34,000 feet. Information about average gust-gradient distance, gust velocities, and gust frequency is included.
Date: April 1944
Creator: Moskovitz, A. I.
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

XC-35 gust research project characteristics of vertical drafts and associated vertical gust velocities within convective type clouds

Description: Report discusses the results of measurements made via an XC-35 airplane to determine the relation between the velocities of vertical drafts and associated gusts within convective-type clouds. Information about vertical-draft velocity and maximum vertical true gust velocity is included.
Date: January 1945
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

Wind-tunnel tests of a piston-type control booster on an airfoil and aileron model

Description: From Summary: "Measurements of control moments were made in the NACA stability tunnel to determine the operational characteristics of a piston-type control booster on an aileron. The booster was so constructed and installed that pressures picked up from the air stream below the wing acted on a pair of pistons. The data are presented in the form of curves of pressure coefficients acting on the pistons, hinge-moment coefficients, and booster coefficients plotted against aileron deflection."
Date: November 1943
Creator: Bird, J. D. & Mendelsohn, Robert A.
Partner: UNT Libraries Government Documents Department

Use of stagnation temperature in calculating rate of heat transfer in aircraft heat exchangers

Description: From Summary: "Theoretical and experimental investigations of the effect of frictional heat on the rate of heat transmission at high fluid velocities are briefly reviewed. On the basis of these investigations, calculations are made which show that the use of the stagnation temperature of the cooling air as the effective temperature for heat transfer in an aircraft heat exchanger is sufficiently accurate."
Date: October 1943
Creator: Wood, George P.
Partner: UNT Libraries Government Documents Department

Variation of hydrodynamic impact loads with flight-path angle for a prismatic float at 12 degree trim and with a 22-1/2 degree angle of dead rise

Description: Report discusses the results of testing "to determine the relationship between impact normal acceleration and flight-path angle for seaplanes landing on smooth water" (from Summary). The tests were performed at 12 degrees trim, 22.5 degree angle of dead rise, and a total weight of 1100 pounds. The effect on the maximum impact normal acceleration and the effects of immersion on acceleration are described.
Date: February 1946
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department

Variation of hydrodynamic impact loads with flight-path angle for a prismatic float at 3 degree trim and with a 22 1/2 degree angle of dead rise

Description: Report discusses the results of testing "to determine the relationship between impact normal acceleration and flight-path angle for seaplanes landing on smooth water" (from Summary). The testing was done with a model at high and low forward speeds at 3 degrees trim, a dead-angle rise of 22.5 degrees, and consistent weight.
Date: February 1945
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department