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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. The present paper attempts to summarize the most promising results obtained to date. Topics covered include ordinary ailerons, external ailerons, floating ailerons, upper-surface ailerons, and spoilers. Although the external ailerons above the trailing edge of the wing and the spoilers at the rear of the wing appear quite promising, it would seem that probably the most satisfactory immediate solution of the problem, including the obtaining of light and smoothly graduated control forces, would in most cases be obtained by the use of the arrangement in which the flap is retracted ahead of ordinary narrow-chord ailerons and is deflected to the rear as well as downward when in use.
Date: August 1933
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

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 th wing forward of th ailerons. When the flap is retracted, the arrangement is as sketched in figure 1(a). If a simple form of split flap were used, hinged at its forward edge, the appearance when deflected would be as shown in figure 1(b). The flap if deflected with its leading edge remaining in this forward position would give somewhat less than three fourths of the lift increase of the same flap in the usual rear position. (See reference 1.). If, as shown in figure 1(c), the split flap ahead of th aileron is moved to the rear as the trailing=edge portion is deflected downward, a double advantage is obtained. The deflected flap can be located in the most effective region for high lift (reference 1), and the force required to deflect the flap is reduced. This is the arrangement used in the present tests.
Date: December 1933
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

The Behavior of Conventional Airplanes in Situations Thought to Lead to Most Crashes

Description: Simple flight tests were made on ten conventional airplanes for the purpose of determining their action in two situations, which are generally thought to precede and lead to a large proportion of airplane crashes. These situations are when in an attempt to stretch the glide in a forced landing, the airplane is stalled, and when while taking off, particularly if taking off steeply, the engine fails at a low altitude.
Date: February 1931
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Navy Propeller Section Characteristics as Used in Propeller Design

Description: "This report contains artificial aerodynamic characteristics of a set of propeller sections to be used in designing propellers by means of the blade element theory. Characteristics computed from model propeller tests for a single section are extended to cover sections of Navy propeller sections at high Reynolds Number in the variable density tunnel of the NACA" (p. 1).
Date: August 1926
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Propeller Design: Extension of Test Data on a Family of Model Propellers by Means of the Modified Blade Element Theory 2

Description: This report is the second of a series of four on propeller design, and describes the method used to extend the data obtained from tests on a family of thirteen model propellers to include all propellers of the same form likely to be met in practice. This necessitates the development of a method of propeller analysis which when used to calculate the powers and efficiencies gives results which check the tests throughout their range.
Date: May 1926
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Propeller Design 4: A Simple Method for Determining the Strength of Propellers

Description: "The object of this report, the last of a series of four on propeller design, is to describe a simple method for determining whether the strength of a propeller of a standard form is sufficient for safe operation. An approximate method of stress analysis is also given" (p. 1).
Date: June 1926
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Propeller Design: Practical Application of the Blade Element Theory 1

Description: "This report is the first of a series of four on propeller design and contains a description of the blade elements or modified Drzewiecke theory as used in the Bureau of Aeronautics, U.S. Navy Department. Blade interference corrections are used which were taken from R.& M. NO. 639 of the British Advisory Committee for Aeronautics. The airfoil characteristics used were obtained from tests of model propellers, not from tests of model wings" (p. 1).
Date: May 1926
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Drag and Cooling With Various Forms of Cowling for a Whirlwind Engine in a Cabin Fuselage

Description: An investigation on the cowling of radial air-cooled engines was conducted in the 20-foot Propeller Research Tunnel at Langley Field. Cooling and drag tests were made with each form of cowling. The propulsive efficiency was found to be practically the same with all forms of cowling.
Date: November 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

The Effect of Reduction Gearing on Propeller-Body Interference as Shown by Full-Scale Wind-Tunnel Tests

Description: This report presents the results of full-scale tests made on a 10-foot 5-inch propeller on a geared J-5 engine and also on a similar 8-foot 11-inch propeller on a direct-drive J-5 engine. Each propeller was tested at two different pitch settings, and with a large and a small fuselage. The investigation was made in such a manner that the propeller-body interference factors were isolated, and it was found that, considering this interference only, the geared propellers had an appreciable advantage in propulsive efficiency, partially due to the larger diameter of the propellers with respect to the bodies, and partially because the geared propellers were located farther ahead of the engines and bodies.
Date: March 20, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Drag and Cooling With Various Forms of Cowling for A "Whirlwind" Radial Air-Cooled Engine - 2

Description: "This report gives the results of the second portion of an investigation in the twenty-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics, on the cowling and cooling of a "Whirlwind" J-5 radial air-cooled engine. The first portion pertains to tests with a cabin fuselage. This report covers tests with several forms of cowling, including conventional types, individual fairings behind the cylinders, individual hoods over the over the cylinders, and the new N. A. C. A. complete cowling, all on an open cockpit fuselage. Drag tests were also made with a conventional engine nacelle, and with a nacelle having the new complete cowling" (p. 191).
Date: December 17, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Drag and Cooling With Various Forms of Cowling for A "Whirlwind" Radial Air-Cooled Engine - 1

Description: "This report presents the results of an investigation undertaken in the 20-foot Propeller Research Tunnel at Langley Field on the cowling of radial air-cooled engines. A portion of the investigation has been completed, in which several forms and degrees of cowling were tested on Wright "Whirlwind" J-5 engine mounted in the nose of a cabin fuselage. The cowlings varied from the one extreme of an entirely exposed engine to the other in which the engine was entirely inclosed. Cooling tests were made and each cowling modified, if necessary, until the engine cooled approximately as satisfactorily as when it was entirely exposed" (p. 165).
Date: October 5, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full Scale Tests on a Thin Metal Propeller at Various Tip Speeds

Description: "This report describes an investigation made in order to determine the effect of tip speed on the characteristics of a thin-bladed metal propeller. The propeller was mounted on a VE-7 airplane with a 180-HP E-2 engine, and tested in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics. It was found that the effect of tip speed on the propulsive efficiency was negligible within the range of the tests, which was from 600 to 1,000 feet per second (about 0.5 to 0.9 the velocity of sound in air)" (p. 465).
Date: June 20, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

The Drag of a J-5 Radial Air-Cooled Engine

Description: This note describes tests of the drag due to a Wright "Whirlwind" (J-5) radial air-cooled engine mounted on a cabin type airplane. The tests were made in the 20-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. The drag was obtained with three different types of exhaust stacks: Short individual stacks, a circular cross section collector ring, and a streamline cross section collector ring.
Date: July 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full Scale Investigation of the Drag of a Wing Radiator

Description: Tests were made on the 1927 Williams racer in order to determine the effect of the wing radiator on the airfoil characteristics. It was found that the radiator doubled the minimum drag of the portion of the wing it covered, and also reduced the lift somewhat.
Date: September 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full-Scale Wind-Tunnel Tests of a Series of Metal Propellers on a VE-7 Airplane

Description: "An adjustable blade metal propeller was tested at five different angle settings, forming a series varying in pitch. The propeller was mounted on a VE-7 airplane in the twenty-foot propeller research tunnel of the National Advisory Committee for Aeronautics. The efficiencies were found to be from 4 to 7 per cent higher than those of standard wood propellers operating under the same conditions. The results are given in convenient form for use in selecting propellers for aircraft" (p. 521).
Date: July 13, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full-Scale Wind-Tunnel Tests on Several Metal Propellers Having Different Blade Forms

Description: "This report gives the full-scale aerodynamic characteristics of five different aluminum alloy propellers having four different blade forms. They were tested on an open cockpit fuselage with a radial air-cooled engine having conventional cowling. The results show that (1) the differences in propulsive efficiency due to the differences in blade form were small; (2) the form with the thinnest airfoil sections had the highest efficiency; (3) it is advantageous as regards propulsive efficiency for a propeller operating in front of a body, such as a radial engine, to have its pitch reduced toward the hub" (p. 123).
Date: March 18, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full-Scale Wind-Tunnel Tests With a Series of Propellers of Different Diameters on a Single Fuselage

Description: "Aerodynamic tests were made with four geometrically similar metal propellers of different diameters, on a Wright "Whirlwind" J-5 engine in an open cockpit fuselage. The results show little difference in the characteristics of the various propellers, the only one of any importance being an increase of efficiency of the order of 1 per cent for a 5 per cent increase of diameter, within the range of the tests" (p. 107).
Date: March 12, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full Scale Drag Tests on Various Parts of Sperry Messenger Airplane

Description: "The drag of a Sperry Messenger airplane with the wings removed, and also the drag of its various component parts, was measured in the 20-foot air stream of the N.A.C.A. propeller research tunnel at air speeds from 50 to 100 m.p.h. It was found that the three-cylinder radial air-cooled engine nearly doubled the drag of the bare fuselage, and the drag of the landing gear was about the same as that of the fuselage and engine combined" (p. 1).
Date: January 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Working Charts for the Selection of Aluminum Alloy Propellers of a Standard Form to Operate With Various Aircraft Engines and Bodies

Description: "Working charts are given for the convenient selection of aluminum alloy propellers of a standard form, to operate in connection with six different engine-fuselage combinations. The charts have been prepared from full-scale test data obtained in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics. An example is also given showing the use of the charts" (p. 3).
Date: March 25, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

A Comparison of Propeller and Centrifugal Fans for Circulating the Air in a Wind Tunnel

Description: The tests described in this paper afford a direct comparison of the efficiency and smoothness of flow obtained with propeller fan and multiblade centrifugal fan drives in the same wind tunnel. The propeller fan was found to be superior to the centrifugal fan in that the efficiency was about twice as great, and the flow much smoother.
Date: March 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Study of Open Jet Wind Tunnel Cones

Description: "Tests have been made by the National Advisory Committee for Aeronautics on the air flow in an open jet wind tunnel with various sizes, shapes, and spacings of cones, and the flow studied by means of velocity and direction surveys in conjunction with flow pictures. It was found that for all combinations of cones tested the flow is essentially the same, consisting of an inner core of decreasing diameter having uniform velocity and direction, and a boundary layer of more or less turbulent air increasing in thickness with length of jet. The energy ratio of the tunnel was obtained for the different combinations of cones, and the spilling around the exit cone causing undesirable air currents in the experiment chamber was noted" (p. 1).
Date: August 1927
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Tests of Four Racing Type Airfoils in the Twenty-Foot Propeller Research Tunnel

Description: Tests were made on four racing type airfoils, the N-9, N-38, C-62, and N-46, in order to determine the high speed characteristics of the wings. The results indicate that the N-46 has about 12 percent lower minimum drag than the regular C-62 section, and that both the N-38 and N-46 have the same exceptionally low minimum drag coefficient.
Date: September 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Determination of Propeller Deflection by Means of Static Load Tests on Models

Description: "This note describes a simple and inexpensive method for determining the deflection of propeller blades under operating loads. Both the centrifugal force and air force loads are applied statically as a number of concentrated loads by means of weights and wires. Two methods of attaching the wires to the propeller blades have been tested, both giving approximately the same deflections. The method is considered useful for studying the deflections of propellers of different shapes under various operating conditions" (p. 1).
Date: January 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Full Scale Tests of Wood Propellers on a VE-7 Airplane in the Propeller Research Tunnel

Description: "The investigation described in this report was made primarily to afford a comparison between propeller tests in the new propeller research tunnel and flight tests and small model tests on propellers. Three wood propellers which had been previously tested in flight on a VE-7 airplane, and of which models had also been tested in a wind tunnel, were tested again on a VE-7 airplane in the propeller research tunnel. The results of these tests are in fair agreement with those of the flight and model tests" (p. 445).
Date: June 18, 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department