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The Ultimate GD&T Pocket Guide explains the most common rules, symbols, and concepts used in geometric dimensioning and tolerancing. ...This one-of-a-kind reference guide includes over 100 detailed drawings to illustrate concepts, more than 40 charts for quick reference, explanations of each GD&T symbol and modifier and much more...Written by standards expert Alex Krulikowski, this valuable on-the-job reference clarifies how to interpret standard-compliant technical drawings that use ASME Y14.5-2009.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of this base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

The intent of this specification is for the procurement of the material listed on the QPL and, therefore, no qualification or equivalency threshold values are provided. Users that intend to conduct a new material qualification or equivalency program shall refer to the Quality Assurance section of this base specification, AMS3961. All material qualification and equivalency data has been archived and is available for review upon request. Contact the CMH-17 Secretariat (www.cmh17.org) for additional information.

In the course of CRYOSYSTEM phase B (development phase) financed by the European Space Agency, AIR LIQUIDE (France) and Astrium Space Infrastructure (Germany) have developed an optimized design of a −183°C freezer to be used on board the International Space Station for the freezing and storage of biological samples. The CRYOSYSTEM facility consists of the following main elements: - the CRYORACK, an outfitted standard payload rack (ISPR) accommodating up to three identical Vial Freezers - the Vial Freezer, a dewar vessel capable of fast and ultra-rapid freezing, and storing up to approximately 900 vials below −183°C; the dewar is cooled by a Stirling machine producing > 6 W at 90 K. The Vial Freezer is operational while accommodated in the CRYORACK or attached to the Life Science Glovebox (LSG). One CRYORACK will remain permanently on-orbit for several years while four Vial Freezers and two additional CRYORACKs support the cyclic upload/download of samples.

In the frame of the CRYOSYSTEM A-phase study financed by the European Space Agency, AIR LIQUIDE (France) and ORBITAL HYDRAULIC-BREMEN (Germany) have been studying a -183°C freezer to be used on-board the International Space Station for freezing and storing biological samples.

As humans move into outer space, need for air, clean water and food require that green plants be grown within all planetary colonies. The complexities of ecosystems require a sophisticated understanding of the interactions between the atmosphere, all nutrients, and life forms. While many experiments must be done to find the relationships between mass flows and chemical/energy transformations, it seems necessary to develop generalized models to understand the limitations of plant growth. Therefore, it is critical to have a robust modelling capability to provide insight into potential problems as well as to direct efficient experimentation. Last year we reported on a simple leaf model which focused upon the mass transfer of gases, radiation/heat balances, and the production of photosynthetically produced carbohydrate. That model indicated some of the plant processes which had to be understood in order to obtain parameters specific for each species.

A number of specimen life performance tests were conducted on three test lubricants selected to demonstrate their gross ranking capabilities. The results indicated that the test rigs should be used only for gross ranking. A large difference in magnitude of life values were obtained even though agreement in gross ranking was obtained by three out of the five participating laboratories. Further testing is recommended under preselected test conditions and lubricants.

In the design of fluid systems plumbing for aircraft engines, the designer is continually challenged by the problem of component location and routing. In order to achieve accessibility and maintainability, and to avoid physical interferences, plumbing design is accomplished through extensive graphical projection and mockups. The solution to this problem must also satisfy tubing stress limits, resonant frequencies, bracket or clamping positions available and future space requirements. To facilitate and expedite this design procedure a digital computer technique has been developed which determines the clearances between tubing and other engine components. Though not a substitute for graphical projection, this program provides a means for accurate checking for interference. It also serves a valuable purpose in the storage of previous or alternate plumbing routing arrangements for comparison.

The Shuttle orbiter currently uses hydrazine-powered APU’s for powering its hydraulic system pumps. To enhance vehicle safety and reliability, NASA is pursuing an APU upgrade where the hydrazine-powered turbine is replaced by an electric motor pump and battery power supply. This EAPU (Electric APU) upgrade presents several thermal control challenges, most notably the new requirement for moderate temperature control of high-power electronics at 132 °F (55.6 °C). This paper describes how the existing Water Spray Boiler (WSB), which currently cools the hydraulic fluid and APU lubrication oil, is being modified to provide EAPU thermal management.

The system that will be presented consists of a Crawling Portable Robot (CPR) for drilling large air frame components as a part of the whole assembly process of fuselage or wing type sub-structures. Currently, the drilling of such components is massively fulfilled manually in a very labour intensive and “craft-based” manner. The operations are conducted in cramped, dangerous conditions and often involve unhealthy postures. The alternative to this situation consists in the use of large fixed-base multi-axis machines mounted upon a foundation on the shop floor. These machines are quite expensive, and also have a number of operational limitations. Because of their large working envelope, it is difficult for these machines to hold close tolerances over the entire range of all movement axes of the machine. Hence, there is a need to probe and calibrate the machine to the workpiece one or more times during work operations with the consequent negative impact in productivity.

An important current engineering problem in the aviation field involves the providing of increasingly effective lubricating oil filtration for today's more advanced aircraft engines. The critical demands of the higher powered reciprocating engines and the new gas turbine engines, together with the strong desire to reduce aircraft operating and maintenance costs require considerable refinement and improvement in oil filtration methods. This paper discusses some recent developments in scavenge oil filtration and describes a basic, new filter design.

A dynamic simulation model has been developed for a vapor-cycle cooling system designed for aircraft applications using the latest technology developments. The heat exchanger models use multiple-, lumped-parameter, fixed-length elements based on coupled thermal and mass storage effects, and flow equations that incorporate the effects of thermal expansion and contraction. This model is developed to include the two-phase constant pressure temperature gradient unique to refrigerant mixtures. The full system model incorporates global mass conservation which is essential for accurate pressure levels and, thus, dynamic response and steady state performance. Phase boundary-based coordinate transformations on the nonazeotropic refrigerant mixture property data result in improved accuracy and computation efficiency. The simulation is developed with modular components with causality defined to minimize connection states and thus execution time.

This paper is a review of the literature covering the history of the use of lubricants. The uses of oils derived from animals, vegetables and minerals are placed in perspective from ancient times to the Wright Brothers' flight in 1903. After that period, the discussion is confined largely to the lubrication of aircraft piston engines. The paper attempts to explain the preference for castor oil in European and British engines and the more general, but by no means exclusive, use of petroleum-based mineral oils in the United States. The British Air Ministry, in 1929, reached a decision to abandon castor oil due to availability and cost of petroleum-based oils. The simultaneous U.S. Army Air Corps recognition of the advantages of the very flat viscosity-temperature curve of Pennsylvania oils for hot running engines and for cold starting led to the world-wide use of these lubricating oils.

Cooling detectors down to 0.1K will be of great importance for future far infra red and submillimeter space telescopes during the next few years. This objective can be reached using a Stirling Cryocooler and a Joule Thomson (JT) expansion stage to precool to 4K. The low temperatures are then obtained by an open cycle dilution refrigerator circulating 3He and 4He. This system does not need any cryogenic reservoir and can be launched at room temperature. In this paper, we present the characteristics and performances of the two parts of the refrigerator measured separately, showing the feasibility of such a system. Expected performances of the complete system are a base temperature of 100mK with 100nW heat load and a life time of 5 years with a reasonable gas storage weight (20-50 kg).

Specifications describing performance characteristics for lubricating oils are examined. The author describes the engine performance requirements, and physical and chemical tests required by the military and by the leading automobile manufacturers. Specifications for passenger car automatic transmission fluids are also examined, as are synthetic aircraft lubricants for commercial and military use.

Laboratory, component, and engine tests have been conducted by the General Electric Co. to evaluate the various lubricant properties important to the J79 jet engine. Such properties as elastomer volume swell, oxidation-corrosion, coking characteristics, and lubricity were evaluated. The effects of these various properties on engine performance and how the laboratory results relate to the component results and engine test results are discussed.

The purpose of this SAE Aerospace Information Report (AIR) is to present a quantitative approach for evaluating the performance and capabilities of an Engine Monitoring System (EMS). The value of such a methodology is in providing a systematic means to accomplish the following: 1 Determine the impact of an EMS on key engine supportability indices such as Fault Detection Rate, Fault Isolation Rate, Mean Time to Diagnose, In-flight Shutdowns (IFSD), Mission Aborts, and Unscheduled Engine Removals (UERs). 2 Facilitate trade studies during the design process in order to compare performance versus cost for various EMS design strategies, and 3 Define a “common language” for specifying EMS requirements and the design features of an EMS in order to reduce ambiguity and, therefore, enhance consistency between specification and implementation.

The purpose of this SAE Aerospace Information Report (AIR) is to present a quantitative approach for evaluating the performance and capabilities of an Engine Monitoring System (EMS).

This paper describes the development of a packaging technique using the new dual in-line package. Part one tells why this package was developed and gives some advantages this technique has over present trends in packaging. Part two gives a complete explanation and description of the component parts of the package. The third part elaborates on the heart of the package, namely the interconnection matrix. Details are given on converting from a systems logic diagram to a graphic format used in the development of the matrix layout. Part four explains the step by step procedure used in manufacturing the dual in-line module on both the prototype and production level. The fifth and final part of the paper tells of other packaging techniques using as a basic building block, the internal parts of the dual in-line module.

A CELSS has been defined based on current or near-term technology. The CELSS was sized to support the metabolic load of four people on the Moon for ten years. A metabolic load of 14 MJ/person/day is assumed, including an average of 2.6 hr of EVA/person/day. Close to 100% closure of water, and oxygen, and 85% closure of the food loop is assumed. With 15% of the calories supplied from Earth, this should provide adequate dietary variety for the crew along with vitamin and mineral requirements. Other supply and waste removal requirements are addressed. The basic shell used is a Space Station Freedom 7.3 m (24 ft) module. This is assumed to be buried in regolith to provide protection from radiation, meteoroids, and thermal extremes. A solar dynamic power system is assumed, with a design life of 10 years delivering power at 368 kWh/kg. Initial estimates of size are that 73 m2 of plant growth area are required, giving a plant growth volume of about 73 m3.