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This paper briefly describes systems effectiveness work currently under way at the Army Missile Command. Two basic types of systems effectiveness analyses performed on Army missile systems are described together with their time phasing during the life cycle of the weapon. The Command conducts major operations research studies at the outset of each major development program and at points where significant changes in system characteristics occur. All system performance parameters are analyzed in the context of a “mix” of weapons in a dynamic battlefield environment. Factors such as mobility, survivability, kill probability, and firepower are considered. Normally, these studies are used to demonstrate the cost effectiveness of proposed systems and to conduct initial parametric design trade-off studies. The second type is that of mission reliability assessment.

Frequently, a choice between system concepts must be made on the basis of something other than a detailed evaluation of the design effectiveness of these systems. This paper develops a rudimentary analysis process for use in addressing this problem.

This paper discusses general and specific requirements of AFSCM 375-5 as applied to control and surveillance systems. The ingredients of the total design concept to achieve operational effectiveness includes specifications, analyses, engineering reviews, and tests. The concepts of utility, acquisition time, effectiveness, and cost are discussed. Model and trade-off considerations are presented. Applications of WSEIAC and AFSCM 375-5 principles and procedures to three complex electronic systems are illustrated.

The purpose of this paper is to identify and discuss some of the principle administrative aspects encountered in the management of systems effectiveness programs. The administrative aspects of the process which are discussed deal with the problem of achieving credibility in the results, from the manager's point of view, by varying the constraints imposed on the study to provide a sensitivity analysis of the effects of the constraints on the results, and with the need for the identification of the point of diminishing returns in each investigation. An example analysis is diagrammed and the administrative task is shown to be that of providing the control, the guidance, and the environment of understanding among all of the technical disciplines involved.

The nacelle design for high bypass ratio turbofan engines installed on high subsonic aircraft is treated in this paper. The high bypass ratio turbofan, with its greater airflow per pound of thrust, presents different problems from those of existing turbojets and low bypass ratio turbofans. For example, there is some bypass ratio, depending upon aircraft payload range and engine geometry, above which the “ short duct” has advantage. The determination of this bypass ratio for a typical case is presented. For a bypass ratio 8 turbofan, the short duct nacelle has 3–4% better airplane direct operating costs than the long duct. With the short duct established as the preferred geometry for high bypass ratio turbofans, the problems of the air inlet, inlet cowl, fan nozzle, fan afterbody, and gas generator afterbody are discussed. Also, the thrust reverser, which affects the nacelle geometry, has been considered.

Both DOD and NASA have established management practices to assure that for each system the mission success requirements are identified, communicated and achieved. Industry contractors who serve these customers must prove that they have the ability to predict and control costs, schedules, and technical performance to the degree required to achieve the potential cost effectiveness of the system. This paper deals with the technical segment of the cost assurance, schedule assurance, and technical assurance triad. It presents a logical system for identifying all activities that experience has shown are critical to achieving system effectiveness. It covers the major techniques for assuring that resources, in the form of documented technology, facilities, and qualified people, are available for each critical activity. Finally, it summarizes program management techniques for assuring that these resources are applied to each project in accordance with cost effectiveness principles.

The present emphasis is on product (system) effectiveness or overall performance and total costs of a product, including costs of development, ownership, and obsolescence. This concept of product value highlights the need to identify and clarify the interrelationships of the acquisition, use, and maintenance elements to achieve product or system requirements within cost limits. The problem is to recognize and assess all the significant elements for trade-offs and to establish the interrelationships with the necessary clarity and visibility for decision making. A product effectiveness program with cost constraints utilizes a basic approach: 1. Defining product purpose and use goals, and applying fixed constraints, such as costs, schedules, and skills. 2. Development and utilization of a checklist to help assure inclusion of all product effectiveness factors, using experience and analysis data. 3.

The use of high bypass ratio engines for future transports presents the opportunity to improve greatly the operational use of thrust reversers. By eliminating the gas generator reverser, or by merely spoiling the thrust of the hot gas stream, the need for reducing power due to hot exhaust ingestion can be alleviated. Engines of the 8:1 bypass ratio class can achieve today's level of reverse thrust effectiveness by reversing only the fan stream. Engines of the 3:1 bypass ratio class require fan stream reversal plus spoiling of the gas generator exhaust. An analysis is presented indicating the desired effectiveness level for the individual fan and gas generator reversers. Design features and model testing of a particularly promising type of fan thrust reverser are discussed in detail. Test results are presented which provide information for the designer and which relate some features of fan thrust reverser geometry to performance.

The progress with the use of deflected thrust in European V/STOL airplanes is reviewed. The difficulties which arise in adopting this concept are examined and commented upon in the light of the practical experience which has been accumulated. Several configurations are discussed: the single sided deflector, a more complex rotating cascade version, the tilting pod-engine configuration, and the vectoring nozzle.

Delivery of high quality fuels to commercial turbine engine aircraft may become more critical for supersonic transport operation. This paper presents high temperature stability test results on current aviation turbine fuel samples taken from refineries and airports throughout the world. Transportation methods involve combinations of tanker, barge, multiproduct pipeline, and truck movements. Data show that, through the application of proper handling techniques, fuels can be transported from refinery to aircraft, through complex distribution systems, with no significant loss in thermal stability. Data also indicate that current aviation turbine fuels are well above the minimum thermal stability specification limits for present subsonic jet aircraft.

To keep pace with man's increased scope of space exploration in the future, it is imperative that fluid power system technology continue to expand its methods and techniques to be able to meet the severe environments indicated on the various planets. Support equipment industries have a prime new field to develop in the maintenance of vehicles in space. Various investigations have discovered basic data that will prove valuable in projecting effective fluid power support for space craft outside the Earth's atmosphere.

The Air Force Space Systems Division's continued development of equipments for the space program is producing problems in engineering for transportability that are even more challenging than those faced in the development of the missile family. The large solid rocket motor (SRM) program's experience in 120-156 in. solid motor transportation and handling will be outlined in this paper. The current state-of-the-art and the anticipated requirements for the future will be discussed as well as emphasizing the impact of transportability resolutions upon program management. The measures implemented in the Air Force Systems Command's 375 Series Manuals to integrate the Engineering for Transportability Program into the design engineering process will be summarized.

The integrate-transfer-launch (ITL) concept of assembly, checkout, transport, and launch of the Titan III vehicle at Cape Kennedy requires a unique facility and special handling and transportation equipment. The launch facility incorporates an entirely new concept for preparing a vehicle for launch. The handling and transportation equipment designed for use in the ITL system includes some that is common to the aerospace industry and some that is entirely new. This paper presents a description of the ITL facility and the ground handling and transportation equipment required to support the Titan III system.

This is a summary of fuel related problems encountered with fuel systems particularly during the past 5 years. The combined efforts of systems engineers and fuel technologists to overcome them are stressed. Problems associated with chemical impurities such as sulfur and chlorine compounds are discussed and comments made upon the effects of particulate matter and free water. Further problems associated with lubricity of fuels are included and some reference to fuel additives. The effects of some hydrogen treated fuels on synthetic rubber is outlined, also the development of equipment to operate at high fuel temperatures and on a wide range of petroleum distillates.

The poor performance of some high purity jet fuels appears to be related to polar compounds in the fuel and not to viscosity, volatility, or sulfur and nitrogen compounds. Surface active additives such as corrosion inhibitors markedly improve lubricity. Results of laboratory tests correlate well with the field experience, where sticking fuel controls and pump wear at high temperatures have been reported. Highly refined fuels developed to meet new standards of thermal stability or purity are generally poor in lubricity compared with conventionally refined fuels and may require a lubricity additive to satisfy advanced fuel systems.

The effect of the flight environment on the severity of the lubrication requirements of the Pratt & Whitney candidate SST engine is reviewed and compared with current commercial turbofan engines. The characteristics of currently available lubricants are examined. The deisgn features of the SST engine aimed at reducing lubricant system stress are discussed. The conclusion is drawn that several type II oils currently available will meet the requirements established by the P & WA SST engine.

The use of pyrotechnic devices in missiles and space vehicles creates a hazardous environment for equipment. Several reported flight anomalies concurrent with the separation event prompted Lockheed Missiles & Space Co. to devote considerable effort to establish methods of treating pyrotechnic shock. An extensive ground testing program included activation of the vehicle’s pyrotechnic systems and subsequent measurement of the shock. Several methods of improving confidence in equipment performance during pyrotechnic shock by means of electrical modifications, shock mounting, and testing were investigated. In addition to treatment of present shock problems, a program was initiated to reduce the pyrotechnic shock levels in the vehicle by redesigning the booster separation joint. Several methods of achieving a qualification testing system for equipments is included in the discussion of the system and specification which LMSC presently uses.

As an alternative to the normal mode approach to the dynamics and controls analysis of flexible aerospace vehicles, the analysis of bending vibration is being studied in terms of the distributed system concepts of propagation and reflection. A relationship is developed between the vibration equation of motion and the propagating wave equation. Transmission matrices, including the effects of shear compliance and rotary inertia, are developed for uniform beam segments. Through a transformation technique, the local state variables are changed to characteristic variables of the beam permitting factorization of the solution into propagation and end-effect matrices. The technique is applied to a cascaded or step beam structure and a beam structure combined with a damped spring mass sloshing model. The advantages and disadvantages of the distributed parameter transmission matrix approach are investigated and the use of this approach for the dynamic analysis of aerospace vehicles is evaluated.

An understanding of the errors associated with the measurement equipment is essential to making correct conclusions about the characteristic of the physical process being measured. This paper discusses the errors associated with analog data reduction equipment. The specific items covered are ordinary and cross-spectral density analyzers; auto-and cross-correlation analyzers; and ordinary and joint probability density analyzers.

This paper discusses the future of systems effectiveness and cost effectiveness analysis in the sequential phases of the life cycle of a weapon or support system. System and cost effectiveness analysis should be developed to be a useful aid to decision making by all participants to a program. Models and supporting data must present total system effectiveness which will cover the operational period of the weapon and total cost analysis which will embrace the acquisition period as well. Also discussed is the application of cost effectiveness analysis by program phases such as during conceptual formulation, contract definition, and during the acquisition period of the weapon system. Cost effectiveness and system effectiveness analysis is an evaluation tool which is an aid to decision making by the government and contractor throughout the life cycle of a weapon or support system.