Search

This report examines current and anticipated acquisition management policies/practices, as they will be applied to advancing technologies, and attempts to forecast those shortfalls which require attention by those personnel involved in the Naval Systems Command material acquisition cycle.

This report examines current and anticipated acquisition management policies/practices, as they will be applied to advancing technologies, and attempts to forecast those shortfalls which require attention by those personnel involved in the Naval Air Systems Command material acquisition cycle. (Author), Revision 1 to rept. no. NAFI-TR-2183 dated 2 May 77, AD-B018 391L.

Several types of insulated electrical wire purchased to MIL-W-22759, MIL-W-81044, and MIL-W-81381, along with a new fluoropolymer insulated wire, were immersed in solvents purchased to MIL-C-43616 and TT-R-248. The ability of the insulation to withstand degradation by the solvents was determined by subjecting the conditioned wire to a dielectric withstand voltage test. This testing differs from previous testing in that the fluids were maintained at 75 C during immersion of the wire specimens. (Author), Includes Appendices A and C. Entire report including Appendix B available in AD-B022 023L. See also Part 2, AD-A043 942.

Several types of insulated electrical wire purchased to MIL-W-81044 were immersed in cleaners purchased to MIL-C-43616. The ability of the insulation to withstand degradation by the cleaners was determined by subjecting the conditioned wire to a dielectric withstand voltage test. The electrical insulation DC resistance was also determined. (Author), See also Part 1, AD-B013 842L.

This report evaluates the performance characteristics of a thin layer thermoelectric device, developed for use in special cooling applications. Test results, conclusions, and recommendations are included. (Author)

Several types of insulated electrical wire purchased to MIL-W-5086, MIL-W-81044 and MIL-W-81381 were immersed in solvents purchased to MIL-C-43616 and TT-R-248. The ability of the insulation to withstand degradation by the solvents was determined by subjecting the conditioned wire to a dielectric withstand voltage test. On some wire types the electrical insulation DC resistance was also determined. (Author), See also AD-B013 842.

A test for determining the ionic contaminants on printed-wiring assemblies was proposed, defined, and found feasible. The basis of the test is the change in electrical resistivity of the solvent with which the chemist washed the printed-wiring assembly. The solvent was 75% by volume, ACS Reagant Grade isopropyl alcohol. The resistivity is lowered when contaminants, such as flux residues, are dissolved. Establishing acceptance criteria for clean printed-wiring assemblies was beyond he scope of this investigation. (Author), Revision of report dated 25 May 72.

This report discusses methods of fabrication for a sandwich structured photoconductor. Test results from various cells are presented. The development of a thin film phototransistor is discussed. (Author), Revision of Rept. no. NAFI-TR-2148.

This report summarizes the SEM Exploratory Development module packaging studies accomplished by NAFI and NWSC, Crane during FY 1976. The primary outputs of these studies are the criteria and background data to be used in the definition of a SEM conceptual module, or family of modules, compatible with higher level electronic functions. (Author)

This report provides a narrative and details to supplement the 200 Series PRediction and Optimization of Failure Rates (PROF 200) computer program user's manual. PROF 200 was designed to be used by engineers for predicting failure rate and reliability of systems according to the methods of MIL-HDBK-217 and others. The program version described herein is as of 31 May 74.

A cooperative investigation was conducted by Rogers Corp. (hereafter called the Vendor) and NAFI to evaluate test procedures used in determining dielectric constant and dissipation factor of sheet laminate material. The need for this became apparent when inter-laboratory tests revealed serious inconsistencies in results. It was found that test procedures which employ a gap between electrodes and the specimen do not give accurate determinations of dissipation factor, but that with a proper gap choice accurate dielectric constant determinations are possible. One test procedure of those considered was chosen as preferred since it produced the most accurate and reproducible results in determining both dielectric constant and dissipation factor. (Author)

Progress is reported on the design, developmentAND DELIVERY SCHEDULES FOR THE FOLLOWING EQUIPMENT: Transmitter - unit 1; receiver - unit 2; indicator, radar display - unit 3; control, radar set - unit 4; control, radar set, auxiliary - unit 8; power supply-azimu h sweep unit - unit 5; and antenna - unit 6.

The digital Computer Aided Radar Design program is a general radar system analysis tool that has been specifically designed for ease of operation, accuracy, and completeness. CARD allows the user to implement target and radar flight characteristics, antenna gain patterns, automatic weather, sea, or land clutter models, signal processing, and automatic maximum range calculations. The user input data sheet, FORTRAN IV listing, sample runs, and instructions for implementation on other computer systems are presented. In addition, the basic radar theory and equations used in the CARD program are given. (Author)

The report describes the integrated circuit (IC) read-only memories (ROMs) with regard to characteristics and application for the purpose of acquainting the systems engineers with these circuit elements. In addition, some old and new aspects to be considered in the development and design of ROM SHP modules are presented to encourage and stimulate creative thinking by the SHP module design engineers. (Author)

The report presents models of commonly used electrical and electronic components that can be used with the CODED (Computer Oriented Design of Electronic Devices) computer circuit analysis programs. These models will also be useful to the engineer doing manual design or analysis. Each model is presented in identical format which includes a schematic of the model, equations to convert data sheet values to model parameters, discussions of limitations and uses, assumptions that can be used in special cases, and a typical example. (Author)

Content: Design considerations and methods using advanced electronic fabrication techniques; A survey of microelectronic technology; Vacuum technology; Guidelines for design and layout of thin-film circuits; Functional design using microelectronic techniques; Common materials encountered in microelectronics; Heat transfer design considerations for microelectronic modules; Microelectronic electrical connection techniques; Microelectronic packaging techniques. (Author)

Optical metrology: techniques in microinterferometry, cylindrical reference lenses, interferometric measurements of imperfections in gyro tilt bearings, construction of a monochromatic light source, interference bibliography, interference gaging, and surface replication. MIL-STD-206 TORQUE TESTER: Data analyzer problems, strain gage amplifier, torque tester problems, stringing of torque tester strain gage wires, torsional pendulum investigation, importance and influence of shoulder dimensions of bearing spindles, torque chart characteristics, and operational repeatability. AIR BEARINGS: Air supported lubrication test spindles and research spindles. LUBRICATION, PACKAGING AND PRESERVATION: Disassembly and reassembly techniques for helicopter rotor stack bearings, lubricants for use in electromechanical components over 200 C, semi-annual status report on bearing research bearing cleaning solution, plastic film for bearing packaging, and evaluation of high temperature greases. MISCELLANEOUS: Load deflection curves and stacking of matched pairs, and technical specifications for bearing procurement.

This report explains the purpose, background, and applications of the Computer Oriented Design of Electronic Devices program (CODED) for avionic power transformers. It also describes the purpose, need, and techniques of the transformer component standardization effort. The report is intended to acquaint the reader with the CODED project and provide enough information so that a transformer designer may use the program successfully. It is also intended to illustrate the benefits of using digital methods as a tool in the solution of engineering design problems. (Author)

A functionally designed model of the doppler navigator AN/APN-137(XAN-1) is described which features a Ka-band radar for minimum size and weight. The equipment design, the derivation of the doppler and computer equations, and the results of the flight tests are presented. The flight test program showed that the Ka-band frequencies are feasible for use in doppler navigators. The obvious advantage of this band is the small size and light weight of the antenna and microwave components. There are inherent disadvantages to Ka-band, but the APN-137 system design techniques minimize the disadvantages. A program for developing a navigator using the small components typical of Ka-band, together with the design techniques to minimize the disadvantages, would result in an all-weather device, which would exceed the present state of the art. (Author)

The state-of-the-art is in such a turmoil that it is impossible, at this time, to predict the ultimate form it will assume. No one concept should be generally accepted at this time - at least by the military. In the interest of industrial preparedness, all concepts should be carefully followed and understood by responsible military representatives. Great strides are being taken forward and more are inevitable as scientists learn more about physics of the solid state. For purposes of discussion and reference in this report, microelectronics concepts have been arbitrarily classified as follows: (1) Packaging; (2) Integrated Circuit (ceramic substrate); (3) Integrated Circuit (semiconductor substrate); and (4) Functional Blocks. The microcard concept is a reality now and is gaining acceptance. A list of microcomponent suppliers appears in Appendix A. There is considerable optimism about the others.

This report presents, in unclassified form, the mathematical theory of aircraft fire control as developed in the present state of the art. It is intended that this book will serve as a basic text for use by schools or individuals desiring background theory in the field of aircraft fire control.

The solderless wrapped connection (or wire wrap connection) is finding extensive use in both commercial and military electrical and electronic equipments. Wire wrapping is a technique for electrically and mechanically connecting a solid conductor to a terminal by wrapping a specified number of turns of wire, under tension, around a terminal having two or more sharp edges. The increasing use of the solderless wrapped connection as a wiring technique is accompained by an increasing need for a comprehensive evaluation of the wrapped connection to determine its performance capabilities under a wide spectrum of environmental states, including those encountered under both ground and aerospace conditions. As a step infulfilling this need an exploratory environmental evaluation program was conducted to establish environmental capabilities of wire wrap connections with respect to temperature, vibration and salt spray exposures, and to provide designers and users with some guidelines for wire wrap application in military systems. Although basic test procedures and environmental limits were developed around existing military specifications, the severity of these tests, both in duration and environmental extremes, was extended well beyond the requirements of these specifications. This was done in an effort to explore wire wrap characteristics under conditions far more extreme than those presently specified for wrapped connections and to possibly establish ultimate capabilities., IDEP-570.90.55.50-X2-01.

The system for torque chart analysis is based on the theoretically ideal chart, which is uniform, level, has a low magnitude, a low bandwidth, no torque peaks, and a low frequency of variation for the instantaneous torque. The median torque line, in gram-centimeters times 100, provides the basic demerit number and is the ase from which all deviations are identified for the application of demerit points.

An Al powder alloy was produced with a linear coefficient of expansion of 9.0 to 9.9 x 10-6 in./in./F (68 to 212F) and other physical properties equal to that of Vanasil. However, the machinability was superior to that of Vanasil. The alloy was produced by ball milling a mixture of 13% Si(-325 mesh)-3.5% Ni(-325 mesh) and -100 mesh atomized Al under methyl alcohol in a porcelain jar for 20 hr with porcelain cylinders as a grinding medium. The test bars which were compacted at 80,000 psi were sintered at 1000, 1020, and 1040 for 1 and 2 hr in an H atmosphere with a -43F dew point. The breaking strengths were 182 to 234 lb. A reduction in the section size of Vanasil castings decreased the Si segregation by increasing the freezing rate. Test data for 2 trail computers build on A-132 base castings showed satisfactory performance before and after temperature cycling from -60 to 165F. Further tests are planned to determine the use of A-132 castings instead of Vanasil for low-expansion instrument castings.

Results of Teflon bearings showed that they were not suitable for instrument bearing applications in their present state of development. Sapphire bearing were subject to friction oxidation of the shaft and chipping where vibration was present; they should not be used as a ball substitute.

Tables are given for the conversion of knots to miles/hour to feet/second; feet/second to miles/hour to knots; degrees to milliradians; and milliradians to degrees. Tables are included of the speed of sound vs temperature, the speed of sound vs altitude, various constants, ballistic relative air density vs the altitude of the NACA standard atmosphere, NACA altitude vs ballistic relative air density, and firing table angles. A graph of air speed vs altitude is included.

The report presents a study of the stability problem (tendency for unwanted oscillation) of a servo amplifier driving a servomotor. Servo amplifier stability is affected by the servomotor impedance being reflected back into the amplifier internal feedback loop. The servo amplifier/servomotor modeling techniques used for stability evaluation are considered. The study develops techniques for evaluating, testing, and specifying servo amplifier/servomotor combinations with respect to stability. Recommendations are made to modify present specifications to include parameters which will insure stable operation of amplifier/motor combinations. A limited number of commercially available servo amplifiers with standard servomotors are evaluated and results are summarized.

Corona and breakdown voltage information is presented for use in the design of printed wiring boards for high altitude applications. The complete mass of raw data is published in addition to the recommended conductor spacings, because of requests by design engineers who prefer to review the raw data and set their own safety factors for each particular design application. Recommended spacings between the conductors on printed wiring boards were established. The corona discharge and dielectric breakdown voltages were measured for each of ten different spacings: .010, .015, .022, .025, .032, .062, .093, .125, .187, and . 250 inches.

INERTIAL NAVIGATION EMPLOYS AN INERTIAL INPUT, OUTPUT SYSTEM COMPOSED OF A COMPUTER AND A GIMBALLED PLATFORM CONTAINING GYROS AND ACCELEROMETERS MOUNTED ALONG THE AXES OF THE MEASUREMENT SYSTEM. The accelerometers constantly measure acceleration in this system of axes, which is required to have a known orientation with respect to inertial space. The computer is usually referenced to earth's longitude and latitude, or to some other reference frame having known space and time orientation with respect to measurement axes system. Mathematical expressions for each of nine platforms are derived for the acceleration components, angular rates, and linear and ground velocities. The most important problem in inertial navigation is the establshment of the level plane through a point above the Earth, which is represented approximately by an Earth reference ellipsoid. Platform level is defined by the choice of the normal or vertical, which may be geocentric, running through the center of the reference ellipsoid or non-geocentric, intercepting the polar axis out of center. The directional coincidence of the normal with the mass attraction is called the mass attraction vertical. The vertical taken normal to the surface of the reference ellipsoid is called the geodetic vertical.

The effectiveness of various electrical filters in simultaneous smoothing and differentiating azimuth-angle data was analyzed to determine the optimum method of eliminating noise, N(t), superimposed on the signal, A(t). Two types of signals were used; one was associated with a target on a straight-line path at an angle beta from the ownership course, and the other was associated with the target on a pure pursuit course (parabolic path) relative to the ownship. The noise function was assumed to have a typical form of the autocorrelation function R(t) = sigma squared eta sub minus a/tl, where sigma squared = R (theta) gives the mean square value of the noise amplitude N(t). Evaluation criteria based on the resulting signal distortion and the value of N(t) in the output of the filter were selected and brief derivation is included of the Zadeh-Ragazzini (Z-R) theoretical expressions for filtering (J. Appl. Phys. 21 7:645-655, 1950) which are based upon the assumption that the signal is representable as a polynomial P(t) of degree not higher than a specified number n. The comparative evaluation of various RC filters on the basis of the Z-R theory and the criteria indicated an optimum filter network transfer function which resulted in a mean square noise output less than 25 sq yd/sec/sec for a 37-ft-long attacking plane. An experimental approach was suggested for future investigations.

Research is reported on the development of a small lightweight attachment to modern attack radar systems which will provide essential navigation information. Conventional Doppler navigators are too large, too heavy, and too expensive for many applications. By utilizing radar equipment already present in an aircraft, the proposed attachment can be made small, light inexpensive, and easy to maintain. Research has 2 main objectives: (1) to modify the design of the present drift angle attachment as necessary for use at K band and adapt it for use with radar set AN/APQ-89(XAN-1); and (2) to develop a technique for extracting ground speed information from the radar signal.

The report provides a work form and rationale to perform hand calculations of the radar range equation. The techniques described cover the conventional geometric aspects of the radar equations as well as the effects of rain clutter, rain attenuation, atmospheric attenuation, sea and land clutter, and pulse integration for both conventional pulse and chirp clutter. It is complete, requiring no further texts, tables, references or slide rules.

This report presents a set of tables which give the minimum sample size required to accept a small lot with the probability of acceptance less than or equal to beta for a given LTPD. The tables are based on the hypergeometric probability distribution for lot sizes N of 10(5) 100; beta of 0.01, 0.025, 0. 05, 0.10(0.10) 0.90, 0.95, 0.975 and 0.99; and acceptance numbers a of 0(1)3.

An investigation was made of the alignment of an inertial navigation system by gyrocompassing. The method of gyrocompassing is developed and the effects of initial tilt, gyro drifts, reference velocity error and noise on the accuracy of alignment is studied. Gyrocompassing is defined in this report as the method of aligning a system to north by detecting the presence of a component of earth rate (W sub IE) cos L sin psi, on its misaligned east axis. The following conclusions are drawn from the report: (1) the basicACCURACY OF THE ALIGNMENT IS DETERMINED BY THE ACCURACY OF THE REFERENCE VELOCITY AND THE DRIFT RATE OF THE EAST GYRO; (2) the system should be leveled before it is gyrocompassed; and (3) the noise present in the reference velocity limits the natural frequency of the system and hence the time required to align. (Author)

This report is a user's manual for MECA 74, a user oriented nonlinear network analysis program which uses less computer time on large networks than its predecessor MECA 68. MECA 74 is capable of finding operating points, driving point characteristics, and transfer characteristics of resistive nonlinear networks containing controlled sources, and two terminal nonlinear resistors characterized by piecewise-linear voltage-current curves.

This report is a 'User Instruction Manual' which outlines the procedure for using the PRediction and Optimization of Failure Rates, 200 Series (PROF) computer program. Included with the necessary instructions is a 'sample' prediction on a system. The PROF 200 program can be used to predict failure rate and reliability by a user having little or no computer experience.

The report describes a radar that utilizes a sample function from a random process as its transmitted signal. The basic theory of operation of a random signal radar is summarized and then applied to the task of designing and constructing a random signal radar system. This system includes modes for PPI, B-scope, A-scope, and selected range segment displays. System photographs, display photographs, and test results are presented. A brief outline of recent research at Purdue University is also presented. (Author)

This paper presents the results of a study concerning the confidence limits applicable to the HF (high frequency) propagation prediction techniques presently available for predicting the performance of communications systems operating in the sky-wave mode in the 3-30 megacycle frequency band. The paper also discusses the independence of HF paths in terms of the diversity techniques required to obtain reliable HF communications systems. An example of a communications link designed by the use of HF prediction and diversity techniques is presented. (Author)

A method is proposed for determining the performance sensitivity of a Kalman filter with respect to small variations in the parameters of both a 'real world' reference model and an assumed filter model. It is shown that a sizable reduction in computational effort may be achieved using the adjoint method presented here to calculate the local performance sensitivities for a large number of parameters rather than using more direct methods. In the report, equations for the covariance functions of the combined filter and reference system are found and adjoint equations corresponding to the linear perturbation equations of the system covariance functions determined. An expression is found for the change in a performance index in terms of the adjoint functions and small, possibly time-varying, changes in the parameters of the combined system. (Author)

The report lists the fundamental requirements for shipboard antenna to operate with the various meteorological satellites planned for the 1972 time period. (Author)

For adequate control of an aircraft during an automatic terrain following flight, certain feedback loops may be required. In this report, the characteristics of several feedback configurations are discussed on an individual basis. (Author)

This report presents a design release reliability prediction for the Test Set, Guided Weapon, AN/DSM-77A. The data and methods used to arrive at this prediction are included. (Author)

The primary purpose of the Practice Guided Weapon (PGW) is to train pilots on target acquisition and launch sequence procedures. In addition, the PGW, because of its similarity to the Guided Weapon Mk 1 Mod 0, is an ideal training device for aircraft handling, loading and maintenance crews. On a typical training flight using the PGW, the pilot is given a flight plan and targets are designated. The pilot makes simulated launches against these targets while his maneuvers are recorded on video tape inside the PGW. After the flight, the pilot and instructor view the video tape recording. In addition to the visual display of the flight, audio tones are present, indicating Lock-On, Intent-to-Launch, and azimuth/elevation tracking error. The video playback machine, supplied as associated equipment, has features for augmenting tape splicing and for sound dubbing. The sound dub feature facilitates recording of training tapes or recording the pilots' and instructors' comments on practice flight tapes during playback after the flight., Supersedes Rept. no. NAFI-TR-1429 dated 1 Jun 69.

The report evaluates several types of three layer thin films for compatibility with standard microelectronic interconnection techniques. Specifically, it was determined if any of the materials used as intermediate layers were capable of functioning as a diffusion barrier at the elevated temperatures required for eutetic die mounting and thermocompression wire bonding. (Author)