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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.

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.

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.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: (a) Functional considerations. (b) Weight considerations. (c) Environmental performance factors. (d) End fitting types. (e) Additional considerations.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: (a) Functional considerations. (b) Weight considerations. (c) Environmental performance factors. (d) End fitting types. (e) Additional considerations.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: a Functional considerations. b Weight considerations. c Environmental performance factors. d End fitting types. e Additional considerations. A quick-disconnect coupling as used in this AIR is one that can be rapidly and repetitively connected and disconnected without excessive fluid loss. The relative importance of the design factors depends upon the fluid medium of the particular system in which quick-disconnect is to be used. The effect of the fluid media on each factor is discussed in this report where applicable.

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.

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).

Lubricants used in space mechanisms must be thoroughly tested prior to their selection for critical applications. Traditionally, two types of tests have been used: accelerated and full-scale. Accelerated tests are rapid, economical, and provide useful information for gross screening of candidate lubricants. Although full-scale tests are more believable because they mimic actual spacecraft conditions, they are expensive and time consuming. The spiral orbit tribometer compromises between the two extremes. It rapidly determines the rate of tribochemically induced lubricant consumption, which leads to finite test times, under realistic rolling/pivoting conditions that occur in angular contact bearings.

Best fit assembly is now a widely spread assembly technique that consists in finding an optimal position of measured components in order to get an assembly that fits its tolerance specifications. The rigid body assumption does not apply for compliant assemblies that can be slightly deformed and for which the geometrical variations are cleared by the flexibility of components to be assembled. We are proposing a best assembly process that takes into account through simulation the flexibility of components. Thanks to this more realistic simulation, the best fit application scope can be enlarged and confidently applied. It leads to reduced fitting times for over-constrained parts or interchangeable items, like doors, during assembly integration and in service replacements.

CONTINUOUS increase in the power output of aircraft engines introduces from time to time lubricating problems including excessive wear and scuffing, excessive oxidation of the oil, and ring sticking. The one problem of ring sticking was chosen and the discussion is limited to the testing of lubricating oils to compare their abilities to prevent this type of failure. Although the best answer as to the ring-sticking tendencies of a lubricant rests with the full-scale engine in service, a simple test is needed during the development period. The development work which led up to the selection of an L-head CFR engine for a ring-sticking test is discussed. Various criteria used for detecting incipient ring sticking are mentioned and a method for direct measurement of incipient ring sticking is described.

The new type of fluid device described in this paper is closely analogous to a vacuum tube cathode follower amplifier. It provides an output pressure equal to an input control pressure, but with a high input impedance and low output impedance providing a power gain. A string of balls moving in response to pressures acting on the ball surfaces provides the basic valve action. Because of its structure and the use of balls as the control elements, this device is relatively easy to manufacture, does not require a lubricating fluid and can be operated at high temperatures.

A novel normal measurement device for robotic drilling and countersinking has been developed. This device is mainly composed of three contact displacement sensors and a spherically compliant clamp pad. The compliance of the clamp pad allows it to be perpendicular to the part when the Multi-Function End Effector (MFEE) drives it to clamp the part surface prior to drilling, while the displacement sensors are used to measure the movement of the clamp pad relative to the MFEE. Once the sensors’ position is calibrated, the rotation angle of the clamp pad can be calculated by the displacement of the sensors. Then, the normal adjustment of MFEE is obtained, and the adjustment process can be achieved by the Rotation Tool Center Point (RTCP) function of robot. Thus, an innovative method based on laser tracker to identify the position of sensors is proposed.

There has been a recent upsurge in interest from the media concerning the quality of the environment within aircraft cabins and cockpits especially in the commercial world1-4. This has included (although by no means been limited to) the air quality, with particular reference to the alleged effects of contamination from the aircraft turbine lubricant. Possible exposure to ‘organophosphates’ (OPs) from the oil has raised special concerns from cabin crew. Such is the concern that government organisations around the world, including Australia, USA and UK, have set up committees to investigate the cabin air quality issue. Concern was also voiced in the aviation lubricants world at the way in which OP additives in turbine lubricants were being blamed in some reports for the symptoms being experienced by air crew and passengers. SAE Committee E-34 therefore decided that it should gather as much available information on the subject as possible.

There has been a recent upsurge in interest from the media concerning the quality of the environment within aircraft cabins and cockpits especially in the commercial world. This has included (although by no means been limited to) the air quality, with particular reference to the alleged effects of contamination from the aircraft turbine lubricant. Possible exposure to 'organophosphates' (OPs) from the oil has raised special concerns from cabin crew. Such is the concern that government organisations around the world, including Australia, USA and UK, have set up committees to investigate the cabin air quality issue. Concern was also voiced in the aviation lubricants world at the way in which OP additives in turbine lubricants were being blamed in some reports for the symptoms being experienced by air crew and passengers. SAE Committee E-34 therefore decided that it should gather as much available information on the subject as possible.

An automated system drills the outer moldline holes on a military aircraft wing. Currently, the operator manually checks countersink diameter every ten holes as a process quality check. The manual method of countersink inspection (using a countersink gauge with a dial readout) is prone to errors both in measurement and transcription, and is time consuming since the operator must stop the automated equipment before measuring the hole. Machine vision provides a fast, non-contact method for measuring countersink diameter, however, data from machine vision systems is frequently corrupted by non-gaussian noise which causes traditional model fitting methods, such as least squares, to fail miserably. We present a solution for circle measurement using a statistically robust fitting technique that does an exceptional job of identifying the countersink even in the presence of large amounts of structured and non-structured noise such as tear-out, scratches, surface defects, salt-and-pepper, etc.

One of the more subtle problems that has haunted the space and missle industry from its inception has been the selection of a separable tubing connector (fitting) that would be acceptable for the severe service condition characteristic of this type of program. Many of the unknowns have to be eliminated by the costly method of “in service” trial and error. Methods of testing to determine fitting limitations had to be developed from the results of our failures because we learned that the established test methods of the past, although adequate for their intended use, were not adequate for this type of program. It shall be our purpose to present possible approaches in design and development procedures that would contribute to the production of a reliable tubing fitting for the various pressure systems of the Aero Space and Missile Industry.