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The need has long existed for a reliable bench test to measure the load carrying properties of multipurpose power transmission fluids for tractors. This paper describes one that meets this need. The test utilizes an SAE Load Machine, modified for oil recirculation and temperature control, and runs under low speed, high torque conditions that simulate final drive operation of tractors. It was used to predict performance of several experimental multipurpose power transmission fluids in actual tractor gear tests, and a good correlation was found. The data provided demonstrate that this test is a valuable tool in formulating improved multipurpose power transmission fluids.

The feasibility of using ceramic materials for advanced airframe and propulsion system structural applications has already been demonstrated. However, their effective use is limited by their relatively high variability in strength. Although it is known that a large number of factors influences the strength of ceramic materials, in the two ceramic composite systems studied here, ZrB2-SiC-B4C and C-ZrB2-SiC, it was apparent that each system had its own strength controlling parameters. It was found that the strength variability could be noticeably decreased by incorporating two engineering techniques: (a) material selectivity, and (b) proof testing. It is shown that at the low probability failure rates normally associated with airframe structure design allowable strengths can be approximately doubled.

A summary is presented of the work conducted during the first 18 months of a 36 month research program to investigate the structural utilization of oxidation-resistant dispersion-strengthened (DS) metals. Dispersion-strengthened metals having the potential for structural use in an uncoated form at temperatures up to 2400 F had previously been developed in material research programs, and the current program was initiated to investigate their use in structures that will experience repeated service at elevated temperatures.

The purpose of this paper is to present principal aerodynamic characteristics of inverting flaps as determined in test flights and wind tunnel tests, and to review applications of this new device, and of its basic kinematic principle, to the V/STOL aircraft field. Two dimensional tests of double slotted inverting flaps show maximum lift coefficients of over four. Flight tests and three dimensional tunnel data show exceptional aerodynamic features for the new flap, including favorable lift-drag ratio and moment characteristics for high lift 90 deg flap position in approach and landing, and direct control of lift-drag ratio with flap position particularly advantageous for wave off and loiter. General considerations on mechanical, structural and operational aspects are reviewed.

The use of numerical control offers a method of reducing cost and assuring a more uniform product. Areas of economic consideration that are directly connected to numerical control include parts selection, machine load, second-source development, tooling, quantity, schedule, engineering product design, and program verification.

Considerable research on large-scale high-performance, lift-engine, V/STOL configurations has been conducted at Ames Research Center. The exhaust gas reingestion characteristics, lift-engine inlet total-pressure recovery and distortion, and engine-airframe induced effects were measured in the 40 × 80 ft wind tunnel both in and out of ground effect over a wide range of transition flight conditions. The results of these investigations show that the lift-engine configurations studied may have severe operational constraints placed upon them during transition.

Work in the industrial setting can be regarded as problem solving activity. Meeting the consumer’s requirements represents the problem to be solved and all persons in a given industry are participants in its solution. Each individual in the organization works at solving his portion of the problem, and he is thereby also working to satisfy some of his personal needs. This paper will show how, by helping others satisfy their needs, the engineer can best reach the objective, the solution of the problem.

The evolution of a successful distributed suction boundary layer control system is described, and an analysis of various high-lift aircraft has been performed to determine the wing lift and the increment of lift due to boundary layer control. Operational problems of distributed suction boundary layer control aircraft are discussed, and a comparison with other means of achieving similar lift coefficients is made.

Basic considerations in the design of clutches are discussed: friction elements during engagement, friction material, single or multiplate design, type of cooling, hardware. After a description of the operation of clutch engagement, each is considered in turn. The author concludes that the heat generated during engagement affects every factor contributing to clutch torque capacity. This heat cannot be eliminated, but can be reduced through design.

This paper describes a program whose first objective was to obtain data on the effect of hydraulic fluid contaminants on the operation of a typical aircraft hydraulic pump from the point of view of contaminant concentration by weight, by particle size, and by type of contaminant. A second objective was to evaluate the methods used to determine contaminant concentration and a method suited to field use was to be recommended. The paper describes the tests performed and gives maximum allowable values for contaminant weight, size, and hardness. Two alternate field contamination test methods are recommended and the weakest point for pump contamination tolerance is discussed.

The dollars-and-cents aspects of on-site power systems are evaluated by examining the economic and operating performance data of some on-stream total energy systems. Field experience with 420 cps high frequency fluorescent lighting are discussed. Some evolving technology is making the combination total energy-high frequency lighting systems more attractive economically and performance-wise, and these developments are discussed.

Multiple lead enables electrical discharge machining to compete as a production method with conventional machining methods, provided proper tooling is used. In this paper, the electrical discharge power supply, the machine, the work and electrode holding fixtures, the electrodes, and the dielectric are all considered as tools. Each has its individual function in obtaining an efficient EDM cut which is essential for multiple-lead operation. The power supply must be capable of producing discharges that are compatible with the electrodes and workpieces being used. Machines must furnish the servo function and auxiliary cycling equipment. Work and electrode holding fixtures must hold precision relationship between electrodes and workpieces as well as eliminate electrode vibration and direct dielectric flow. The electrodes must be suitable to the application, and because they are expendable, must be economically produced.

Synchronized pulsed flushing is described as a method for controlling wear on electrodes during the EDM process, which uses electrical energy to remove material in machining. Background is provided on EDM phenomena. The attributes of wear are specified, and the method of synchronized pulsed flushing is contrasted with continuous flushing.

The dynamic behavior of the dielectric fluid and fluid contaminants, and some of the effects of the dielectric fluid behavior on the electrical discharge machining process variables are described. High speed photomicrographic records showing the dispersion of debris accompanying a single EDM discharge and the removal of the debris by the dielectric fluid flow are presented. Dielectric flushing effectiveness is discussed and curves of volume flow rate for deep cavities are presented. The volume flow rate data suggest that dielectric flushing pressure, the flushing parameter which is usually monitored during the EDM process, is not a very meaningful indication of flushing effectiveness.

Recent advances in forging techniques make possible the fabrication of aircraft-quality gears with improved bending fatigue strength. This paper presents the results of several recent test programs sponsored by the U. S. Army Aviation Materiel Laboratories (U. S. AVLABS) to evaluate the comparative fatigue strength of gears with integrally-forged teeth and gears made from conventional pancake forgings with cut and ground teeth. Included in this presentation are single-tooth fatigue test data on spur gears manufactured by several high-energy forging techniques and gears made from conventional pancake forgings.

Features, specifications, and some of the major design requirements for the new John Deere 570 hydraulic motor grader are presented in this paper. This grader is maneuverable, versatile, it is comfortable and safe to operate, it is easy to service since currently available parts are used when possible, and it has a precise and nondrifting control system.

After stating all advantages of the new Wankel engine design, the development status of small, air cooled, rotary combustion engines from 6-20 hp is reported. These engines are now completely competitive with conventional reciprocating piston engines. The housing is cooled by air and the piston by the fuel mixture. Specific fuel consumption is comparable to that of a 4-stroke reciprocating engine of equal size. Lubrication is done by mixing oil and fuel in a ratio of 1: 50. A metering oil pump can be provided for separate tanking of fuel and oil. Some typical applications are specified.

An all electric governor is described for constant speed applications, especially engine-generator sets. The various parts of the electric governor are described. An analysis of the transient characteristics of this governor system on a particular engine is presented. General application of this governor is described.

There are several “generally accepted accounting practices” which can be applied in the development of manufacturing costs. However, most of these techniques are developments of, or modifications of, “distribution accounting” methods. As a result, although they are legal and ethical from a tax and financial point of view, they do not offer a basis for “precision” in cost estimating, cost control or inventory valuation. The “total absorption standard cost” technique provides a basis for “precision costing” at all stages of manufacture and distribution. This technique also simplifies the application of computer technology to cost extimating, performance simulation, and automated design engineering. The heart of this precision costing concept lies in the application of a matrix type “code language,” the development of a “landed cost of sales” approach to inventory valuation, and a “building block” element cost technique.

In speed control of prime movers, precise steady-state and transient control of frequency and close control of electrical load division among paralleled generators are a challenge to the control designer. The inherent adaptability of an electrical device to control these electrical characteristics, makes it a good choice for this type of application. The electrical speed-control system discussed in this paper fulfills these requirements. Components include electrical circuits for sensing speed and load and an electrohydraulic actuator which converts electrical signals from the amplifier into useful mechanical motion for operation of an engine fuel control. This system has been used with all type engine-generator sets. It is also readily adaptable to high speed compressors and pumps. Reliability is a proved feature as its design is very conservative and all components being used are well within their ratings.