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Aviation History
1964
1964 - 1959.PDF
1080 FLIGHT International, 25 June 1964 Inside the assembly building at Boeing-operated Air Force Plant 77 at Ogden, Utah. This is the only place at which it is possible to see an assembled fAinuteman until the "bird" flies, because the rest of its life is spent sealed in an SSCBM container or in its silo Missiles and Spaceflight sides of the nozzle, each unit with two hydraulically-actuated valves which inject liquid Freon at any of four locations spaced 90° apart around the nozzle. Opening the appropriate valve therefore pro- duces deflections in pitch and yaw that control the missile's flight. Each valve is capable of a maximum flow of about 601b/sec. Since such a large quantity of Freon must be carried to ensure control under the most difficult flight conditions, the flight-control system continuously monitors Freon usage, compares the quantity remain- ing with what is necessary for the rest of the flight of the second stage, and dumps the excess overboard. In Minuteman LGM-30F, the flight-control unit for each stage is located right in the nozzle area, and connected by cable to the control system in the guidance and control section between the third-stage motor and the re-entry vehicle. Stage-one and stage- three rockets have nozzle control units directed from the guidance and control section, and the second stage has the Freon injectors. In each of these three units, the electronic assemblies are constructed from discrete microminiature components encapsulated in epoxy resin to give protection from nozzle heat. Most of the electronics of the F-model Minuteman, and all of the power supply for the control system, are found in the amplifier assembly of the guidance and control section. Included are servo- amplifiers that drive four hydraulic actuators on each of the three stages, as well as semi-conductor power switches capable of delivering 10A to activate engine ignition, staging and thrust- termination. The use of microminiature circuits in four of the five major electronic assemblies in the flight-control system has resulted in a weight and volume reduction of more than 10 :1 over comparable circuits of the flight-control system in Minuteman LGM-30A. This has made it possible to relocate most of the flight-control functions in the guidance and control section, rather than in the appropriate primary stages of the missile, without incurring any significant penalty in range or payload. The effect is greatly to reduce field- maintenance problems, since the guidance and control section can be replaced without withdrawing the missile from its silo. Largely through the use of integrated circuits, the number of parts and fabrication processes for the flight-control system has been cut in half in Minuteman LGM-30F, and reliability has been improved. According to Dr Enthoven, the development cost of LGM-30F is of the order of $85Om. Although a considerable sum, he empha- sized that this extension of the Minuteman programme was a good example of Pentagon cost/effectiveness, since the improved missile is "adaptable to far more targets." Approximately 350 Minuteman silos have so far become operational, the first 150 housing LGM-30A and the next 200 being equipped with LGM-30B. The new F model does not come into service until 1965-66, but it is significant that all three models of Minuteman can be launched from the same design of silo, and it is generally believed by Boeing and the other industry members of the Air Force Systems Command team that all Minuteman silos will ultimately be loaded with LGM-30F. In conclusion, it is appropriate to note that on June 10 Boeing announced remarkable success with their "Minutemiser" cost- improvement programme. A year ago the company and its suppliers set a target of lopping |60m off total programme cost in the 1964 fiscal year. The actual saving exceeded $100m. According to Lysle A. Wood, v-p and general manager of Boeing's Aero-Space Division, "The Air Force has created a very satisfactory business environment in which to conduct a cost reduction programme. We have had stability in terms of top Air Force support, technical Zft "Flight International" drawing Comparative scale drawings of (from left) Minuteman LGM-30A, LGM-30& and LCM-30F. A, first stage; 6. second stage; C third stage; D, guidance and control section; £, re-entry vehicle continuity, excellent teamwork among associate contractors and military agencies, incentive contracts and a common belief in the need and soundness of the Minuteman weapon system." Wood noted that the company had reduced weapon system costs with no loss of reliability or performance. "Most of the reductions have been achieved through ahead-of-schedule deliveries, increased application of management controls, and greater application of value engineering techniques."
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