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| Figure 1. System productivity: number
of systems processed per year versus personnel buildup |
Air University Review, July-August 1969
The U.S. Air Force’s single-point repair activity for inertial guidance systems and for management of the Air Force Calibration Program has recently received a new name and organization. The name has been changed from 2802d Inertial Guidance and Calibration Group to Aerospace Guidance and Metrology Center. The new organization provides four directorates and the necessary supporting staff.
The Aerospace Guidance and Metrology Center (AGMC) has three basic mission responsibilities:
· Accomplish single-point repair inertial guidance systems for aircraft and missiles of the Air Force and other Department of Defense agencies.
· Provide engineering consultant and support services for inertial guidance requested by cognizant engineering activity and to other DOD agencies when required by Inter-Service Support Agreements.
· Manage the Air Force Management Standards Control System and provide technical and procedural direction that assures single integrated Air Force Calibration Metrology Program.
Historically, Newark Air Force Station/ Aerospace Guidance and Metrology Center, located at Heath, Ohio, came into being in August 1961 after Congress approved modification of an excess Air Force plant for this use. This site was selected instead of an active Air Force facility because underground calibration laboratories were desired for temperature and seismic control. The Heath facility already had large and deep underground rooms that were especially designed to be vibration- and shock-isolated from the remainder of the plant. The combination of the geology and the underground construction provided a stability of 10—5 g over a frequency range of .1 to 10. Hz. This was an important factor that could not have been predicted in advance on new construction. The main building of the basic plant covers approximately ten acres and houses one- and two-story highly specialized laboratories and engineering offices. The majority of plant laboratories are devoted to the maintenance and engineering of inertial guidance systems.
The first recognition of the AGMC’S importance came from members of Congress while they were reviewing its military construction program and justification. At that time the House Appropriations Committee stipulated that “maximum use of the resources to be located at Heath, Ohio, would be made by all three Services.”
The production of repaired guidance systems began in October 1962 with the repair of inertial systems used in the Atlas, Titan, and Minuteman missiles. Relocation of the Air Force calibration laboratories from Dayton, Ohio, to Heath and establishment of additional capabilities occurred at approximately the same time.
inertial guidance
The repair concept varies to some degree from weapon to weapon; however, the repair operation is based on a maintenance-to-maintenance repair concept. This means, when a failure occurs, direct shipment to the repair facility, immediate processing, and direct return shipment to the user. This concept is necessary in the processing of such extremely expensive weapon subsystems. To provide timely service to the field commands, the repair facility must be very effective and very flexible between workloads. Inputs from the field are, of course, random in nature. However, the single-point concept for all guidance systems at one location provides a degree of overall stability. The commonality of test equipment for all our inertial guidance systems means a considerable savings when they all are repaired at one place. This is a very important factor in view of the extreme cost of this type of equipment.
To further reduce the high cost of test equipment and also reduce “flow time” and the number of spares required, it has been the practice to work most operations three shifts a day, seven days a week. Another factor in the need for around-the-clock operation is the very long test times involved.
The work force is made up of highly skilled and specialized technicians and engineers. Training for new systems, new techniques, and new processes is a constant and vital part of the total program. Full-time instructors are used, who in turn are being trained and upgraded by factory training programs under the Air Training Command.
Like a subcontractor, the center negotiates for workloads from a number of weapon system managers. It processes guidance systems for almost all the weapon system managers of the AFLC air materiel areas.
The center operates on an industrial funding concept and therefore is keenly aware of its repair costs compared to those of competing contractors. Experience has shown that considerable savings can be obtained for the taxpayer by single-point organic repair of inertial guidance systems rather than repair by dispersed contractual sources. The volume of business at the center is closely comparable to that of a “large business.” At present the acquisition cost of the systems we process each day averages approximately $2,000,000; so the center’s total operational cost of approximately $82,000 per day is about four cents on the dollar.
The buildup of the center’s activities is depicted in Figures 1 through 3. Figure 1 reflects increases in numbers of systems processed per year versus personnel buildup.
Figure 1. System productivity: number
of systems processed per year versus personnel buildup
During the buildup from July 1962 to June 1966 it was necessary to develop the skills and proficiencies of personnel in addition to accomplishing the workloads. A leveling out of personnel (reflected by the solid black line) is now taking place as the volume of workload still increases and random inputs of the various systems tend to provide an overall smoothing of total input. Figure 2 reflects the increased value of systems processed each year. Figure 3 reflects the increase in value of the test equipment used in processing inertial guidance systems (IGS). The types of systems being processed or to be processed through the center are as follows:
Present
Future
NS-10 guidance for
Minuteman IN-16 guidance for FB-111 NS-17 guidance for
Minuteman IIKT-70 guidance for SRAM LGM-25 guidance for
TitanKT-70 guidance for A-7 LN-7 guidance for
RC-135CKT-70 guidance for F-105 LN-12 guidance for F-4C FLIP guidance for C-5 LN-14 guidance for
F-111ANS-20 guidance for
MM-III
LN-15 guidance for B-52
Figure 2. Acquisition cost of items processed: increased value of systems processed each year
The heart of any effective maintenance program is maintainability and reliability. It is most important that every action be taken to see that new systems are designed to provide maximum reliability under field operating conditions, and that they remain serviceable the required number of hours after repair and are easily maintained upon failure. It is equally important that any weakness in design be properly analyzed and fixes provided to upgrade the system and its meantime-between-failures. To do these things, a definite program must exist at repair activities to gather detailed, factual data and to analyze such data not only to develop engineering design fixes but also to ensure that experience gained on active inventory is considered during the development phase of future systems. The center has a highly specialized engineering staff to accomplish this important function. These engineers work closely with the design and development groups and weapon system managers so as to input experience gained at the depot. The single-point concept makes it feasible to consolidate engineering data and indicate the strong and weak points of all systems processed during the review of anyone new system. An early logistics interface also exists with personnel of the System Program Office (SPO) and System Manager/Inventory Manager (SM/IM) to provide information of logistics experience. In keeping with DOD policy, the engineering staff of the center is supporting other government agencies by providing IGS engineering assistance.
The AGMC engineering analysis staff operates a Central Data Acquisition and Analysis System, through the use of a central computer and analysis programs. The purpose of the analysis capability is to determine the most probable cause of malfunctions in guidance systems returned to the center for repair. The results of the data analysis are used to direct repair actions and/or additional testing for further confirmation or identification of the malfunctions.
To summarize the service engineers’ responsibilities, one might say that during the conceptual and acquisition phases the service engineers assist in providing the necessary maintenance support concepts, plans, and maintenance experience data to be used in developing technical requirements for maintenance of new inertial guidance systems. The service engineers participate in design reviews and evaluation of test results to reduce the need for maintenance support. Thus, effective engineering participation can significantly influence technical requirements in design, which, in general, dictate initial and future support investment and operating costs associated with new hardware.
calibration program
The USAF single integrated calibration program had its beginning in 1954 with approval of a study by Dayton Air Force Depot (DAFD). In 1957 a follow-on study was approved, providing for the establishment of Precision Measurement Equipment Laboratories (PMEL). In 1958 a DAFD study outlined many deficiencies that existed in calibration laboratories throughout the Department of Defense and industry. An area considered very serious was the lack of traceability of standards used by industry to those of the National Bureau of Standards. The DAFD study provided a definition of the “measurement gap” which existed throughout industry and government. Those involved in measurement standards in DOD and industry, as well as the NBS and professional societies such as the Instrument Society of America, made great strides in the next few years in closing the gap and establishing firm ground rules for acceptable standards.
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The number of precision measurement laboratories was increased in 1959 and by late 1960 had reached 163 throughout the world. In 1962 the new laboratories at Heath, Ohio, were completed, providing many new and highly specialized capabilities. One such capability resulted from establishment of an Advanced Weapons Laboratory, whose purpose is to review highly specialized calibration requirements peculiar to new and advanced weapon systems and to provide engineering “laboratory type” evaluation of weapon hardware. An additional responsibility of this group is to develop “standards” for measurement in the advanced areas. The laboratory was equipped with stable test platforms capable’ of reducing accelerations in the frequency range of .1 to 10. Hz to less than 10—5 g. These test platforms are used for support of accelerometer and gyro test equipment and isolate the test equipment from influences of temperature, magnetic fields, humidity, earth motion, and culture “noise,” while at the same time remaining perpendicular to true vertical. The Advanced Weapons Laboratory also includes infrared, ultraviolet, laser, and visible light measuring capabilities and standards. Laboratory test equipment is available to allow testing under laboratory conditions of most types of gyros, accelerometers, and guidance platforms.
Air Force policy provides for a single integrated measurement system based on national standards. System engineering, technical direction, and program management are administered by the Aerospace Guidance and Metrology Center. At this time, 15 Air Force commands operate some 160 base PMEL’S, following technical direction provided by AGMC.
The Air Force has a system in which all measurements are traceable from national standards maintained by the National Bureau of Standards to the center’s laboratories and thence to the base PMEL’S. Weapon system contractors also maintain measurement references with the NBS, thus ensuring a common basis for operational measurement requirements.
Periodic calibration of standards and precision measurement equipment is required at prescribed intervals to ensure continued accuracy and reliability. Calibration intervals are based on stability characteristics of the measurement device.
Base Precision Measurement Equipment Laboratories are established at selected bases depending upon mission requirements. Every effort is made by the three services, through joint DOD conferences, to prevent duplication of engineering projects and maximize use of common resources in providing area calibration support.
To ensure support of weapon measurement requirements at the base PMEL level, AGMC manages the calibration work much as a weapon or support system is managed by a system program office/system manager. The first step in this process is to work with the SPO/SM and the using command on calibration and measurement problems during all development phases, starting with the conceptual phase and continuing through the definition, acquisition, and operational phases.
When a new standard is required in support of a weapon system, it is programmed by AGMC into the budget buy cycle for acquisition, acceptance, calibration, and delivery to the PMEL having support responsibility. These standards, as well as others, are returned to the center at specified intervals for recalibration. New calibration technical orders are written and disseminated through the regular TO distribution system to the PMEL’S.
The center determines the competence of each PMEL on an annual basis by evaluating its personnel, equipment, and facility resources against specified standards of excellence. This results in certification of the PMEL or imposing measurement restrictions until the standards are met.
The laboratory complex below ground has four floors, descending in a tier, the lowest level at a depth of 65 feet. The underground laboratory is operated as a high-quality clean room and employs the very strict environmental controls necessary for precise measurements.
A Look into the future shows that the requirements for accuracy in measurements and standards will increase by a considerable amount. This will mean that new materials and other technical breakthroughs must be devised in order to meet the challenge. Among the new measurement areas that will require a great deal of specialized attention will be lasers, blackbodies, ultraviolet and infrared radiation, solar and stellar simulators inertial reference systems, high vacuum, submillimeter microwaves, microminiature length measurements, cryogenics, ultra high and ultra low temperatures, nuclear radiation detectors, photometry, propagation of sound, plasmas, high-velocity micrometeorite particles, nerve gas detectors, biological agent detectors, and ultra precise time synchronization.
In the future, emphasis will shift to providing selected PMEL’S with high-cost calibration capabilities in special areas of measurement.
As advances are made in weapons technology, the metrology problem becomes more demanding and sophisticated. Oftentimes “measurement gaps” exist until the required standards can be developed and produced. The diminishing reaction time in which to produce new measurement standards was graphically stated in a recent NBS bulletin:
It is well known that the lag time between the discovery and application of major developments is swiftly decreasing: a. Over 50 years for electric power generation. b. About 4 years for the transistor. c. About 19 months for the laser. A consequence of this acceleration is that new standards are required barely moments after discovery.
Newark Air Force Station, Ohio
Wallace L. Horton has been Technical Director, Aerospace Guidance and Metrology Center, Newark Air Force Station, Ohio, since its inception in 1961. He was previously Deputy Director of Maintenance-Engineering, Dayton Air Force Deport, and has served in management and engineering supervisory positions with the Air Force for over 26 years. He has received the Air force Association Management Award (1961) and the Air Force Exceptional Civilian Service Award (1966). He has written several technical articles which have been published by the Instrument Society of America, and in Proceedings of the IEEE Automatic Support System Symposium.
Disclaimer
The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.
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