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  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Special Report
 Collection: Technical Report Archive and Image Library
An Investigation of the Drag of Windshields in the 8-Foot High-Speed Wind Tunnel

An Investigation of the Drag of Windshields in the 8-Foot High-Speed Wind Tunnel

Date: June 1, 1939
Creator: Robinson, Russell G. & Delano, James B.
Description: The drag of closed-cockpit and transport-type windshields was determined from tests made at speeds from 200 to 440 miles per hour in the NACA 8-foot high-speed wind tunnel. This speed range corresponds to a test Reynolds number range of 2,510,000 to 4,830,000 based on the mean aerodynamic chord of the full-span model (17.29 inches). The shapes of the windshield proper, the hood, and the tail fairing were systematically varied to include common types and a refined design. Transport types varied from a reproduction of a current type to a completely faired windshield. The results show that the drag of windshields of the same frontal area, on airplanes of small to medium size, may account for 15% of the airplane drag or may be reduced to 1%. Optimum values are given for windshield and tail-fairing lengths; the effect, at various radii is shown. The longitudinal profile of a windshield is shown to be most important and the transverse profile, to be much less important. The effects of retaining strips, of steps for telescoping hoods, and of recessed windows are determined. The results show that the drag of transport-type windshields may account for 21% of the fuselage drag or may be reduced ...
Contributing Partner: UNT Libraries Government Documents Department
An Investigation of the Prevention of Ice on the Airplane Windshield

An Investigation of the Prevention of Ice on the Airplane Windshield

Date: November 1, 1939
Creator: Rodert, Lewis A.
Description: An investigation has been completed on several methods for the prevention and removal of ice on an airplane windshield. Tests were made on the use of electric heating, hot-air heating, and an alcohol-dispensing, rotating wiper blade. The results showed that vision through the airplane windshield could be maintained during severe icing conditions by the use of heat. When put in operation prior to the formation of ice on the windshield, the rotating wiper blade prevented the formation of ice. A combination system that employs the use of heated air and a rotating wiper blade would appear to give protection against the formation of ice on the windshield exterior, prevent frost on the interior, and provide for the removal of rainfall.
Contributing Partner: UNT Libraries Government Documents Department
Large-Scale Boundary-Layer Control Tests on Two Wings in the NACA 20-Foot Wind Tunnel, Special Report

Large-Scale Boundary-Layer Control Tests on Two Wings in the NACA 20-Foot Wind Tunnel, Special Report

Date: April 1, 1935
Creator: Freeman, Hugh B.
Description: Tests were made in the N.A.C.A. 20-foot wind tunnel on: (1) a wing, of 6.5-foot span, 5.5-foot chord, and 30 percent maximum thickness, fitted with large end plates and (2) a 16-foot span 2.67-foot chord wing of 15 percent maximum thickness to determine the increase in lift obtainable by removing the boundary layer and the power required for the blower. The results of the tests on the stub wing appeared more favorable than previous small-scale tests and indicated that: (1) the suction method was considerably superior to the pressure method, (2) single slots were more effective than multiple slots (where the same pressure was applied to all slots), the slot efficiency increased rapidly for increasing slot widths up to 2 percent of the wing chord and remained practically constant for all larger widths tested, (3) suction pressure and power requirements were quite low (a computation for a light airplane showed that a lift coefficient of 3.0 could be obtained with a suction as low as 2.3 times the dynamic pressure and a power expenditure less than 3 percent of the rated engine power), and (4) the volume of air required to be drawn off was quite high (approximately 0.5 cubic ...
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Mechanical Properties of Flush-Riveted Joints

Mechanical Properties of Flush-Riveted Joints

Date: January 1, 1940
Creator: Bruggeman, Wm. C. & Roop, Frederick C.
Description: The strength of representative types of flush-riveted joints has been determined by testing 865 single-shearing, double-shearing, and tensile specimens representing 7 types of rivet and 18 types of joint. The results, presented in graphic form, show the stress at failure, type of failure, and d/t ratio. In general, 'dimpled' joints were appreciably stronger than countersunk or protruding-head joints, but their strength was greatly influenced by constructional details. The optimum d/t ratios have been determined for the several kinds of joints. Photomacrographs of each type show constructional details and, in several instances, cracks in the sheet.
Contributing Partner: UNT Libraries Government Documents Department
Method of Determining the Weights of the Most Important Simple Girders

Method of Determining the Weights of the Most Important Simple Girders

Date: December 1, 1931
Creator: Cassens, J.
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. Girders of uniform strength are the lightest girders conceivable, because any girder, all of whose members are stressed to the limit, can not be surpassed by a lighter girder, if the two girders have the same form. The weight G of a member of length l, cross section F and specific gravity gamma is: G = Flgamma.
Contributing Partner: UNT Libraries Government Documents Department
Model tests of a wing-duct system for auxiliary air supply

Model tests of a wing-duct system for auxiliary air supply

Date: January 1, 1941
Creator: Bierman, D. & Corson, B. W., Jr.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
NACA Radio Ground-Speed System for Aircraft, Special Report

NACA Radio Ground-Speed System for Aircraft, Special Report

Date: February 1, 1943
Creator: Hastings, Charles E.
Description: A method that utilizes the Doppler effect on radio signals for determining the speed of an airplane and the distance traveled by the airplane has been developed and found to operate satisfactorily. In this method, called the NACA radio ground-speed system, standard readily available radio equipment is used almost exclusively and extreme frequency stability of the transmitters is not necessary. No complicated equipment need be carried in the airplane, as the standard radio transmitter is usually adequate. Actual flight tests were made in which the method was used and the results were consistent with calibrated air speed indications and stop-watch measurements. Inasmuch as the fundamental accuracy of the radio method is far better than either of the checking systems used, no check was made on the limitations of the accuracy.
Contributing Partner: UNT Libraries Government Documents Department
Notes on Factors Affecting Geometrical Arrangement of Tricycle-Type Landing Gear

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

Date: April 1, 1937
Creator: Wenzinger, Carl J. & Kantrowitz, A. R.
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.
Contributing Partner: UNT Libraries Government Documents Department
Notes on New French Commercial Airplanes

Notes on New French Commercial Airplanes

Date: April 4, 1935
Creator: unknown
Description: This document discusses the types of commercial planes ordered by Air France. Characteristics of the Wibault 670, the Dewoitine D.620, Bloch 300, and the Potez 620 airplanes are included. Pictures and diagrams of these aircraft are also included.
Contributing Partner: UNT Libraries Government Documents Department
Paris Aviation Salon, 1934

Paris Aviation Salon, 1934

Date: November 29, 1934
Creator: unknown
Description: This document reviews the Air show held in Paris in 1934. It includes charts and pictures of the aircraft which were from all parts of Europe.
Contributing Partner: UNT Libraries Government Documents Department