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Technical Paper

EVA Design Integration for Space Station Assembly

1988-10-01
881542
EVA (extravehicular activity) will be a major aspect of the on-orbit assembly of the US Space Station “Freedom”. Under the auspices of NASA's Johnson Space Center, an EVA assembly integration plan has been developed. This plan provides a comprehensive approach to defining all the EVA assembly tasks and validating the systems and equipment designs for accomplishing these tasks on orbit. EVA tasks are traded off against the use of robotics devices. Task description sheets are used to compile pertinent data on all significant EVA tasks. An EVA task checklist is used to ensure consideration of all access and support equipment requirements. Evaluations of all EVA tasks are planned and scheduled, using the WETF (Weightless Environment Training Facility) at JSC or other test facilities as appropriate. This comprehensive approach provides confidence in the successful EVA assembly of the Space Station.
Technical Paper

Automation: Revisiting the Basics

1988-10-01
881548
There have been some air carrier concerns that basic aviator skills are atrophying due to the increasing use of automation in all phases of airline operation. We will examine three systems where automation has greatly influenced crew activity, outline our concerns, and discuss how we are addressing those concerns.
Technical Paper

Report of the SAE A-9 Act Hoc Committee on Flotation Platforms

1988-10-01
881538
1.0 Abstract This paper documents the activities, meetings, and conclusions of the SAE S-9 Ad Hoc Committee on Flotation Platforms from its formation in late 1986 through the submittal of this paper to the S-9 Cabin Safety Committee. The Ad Hoc Committee was charged with the development of an Aerospace Information Report (AIR) on the integration of the flotation platform concept into a redefined commercial airline overwater safety environment. This paper is offered in lieu of the AIR as the product of the Ad Hoc Committee. Its intent is to summarize the significant issues, points of view, and concerns surrounding the flotation platform concept, and its application in redefining commercial airline overwater safety equipment requirements. An Aerospace Recommended Practice (ARP No. 1830) defining flotation platforms has previously been drafted by the S-9 Committee, but is being held pending the AIR that would define the use of such equipment.
Technical Paper

Flight Crew Displays for Space Station Proximity Operations

1988-10-01
881540
Proximity operations aboard Space Station Freedom involve a number of complex operations including: piloting of unmanned space vehicles in the vicinity of the Space Station; docking and berthing of unmanned space vehicles; control of the mobile transporter; Space Station RMS and the FTS; and monitoring of extravehicular activities. Display hardware is required aboard the Space Station to provide information to the crew. This information takes the form of full color text and graphics as well as full motion, full color video. Other display requirements include: readability in high ambient light conditions; low power, weight and size; and ability to adjust the angle and distance from the crew. A number of display technologies exist to meet these requirements. CRTs are the standard in display technology; however, they may not be able to meet the sunlight readability requirements and they consume considerable weight, volume and power.
Technical Paper

Design and Development of a Software Engineering Training Program

1988-10-01
881514
Software has become a major portion of the products developed by Avionics Group, Rockwell International. As such, the need to develop software in a cost effective and productive manner is of increasing importance. The Avionics Group Software Engineering Training Program (SETP) was developed in response to the need to increase our personnel's knowledge of software engineering, particularly with respect to real-time, embedded systems development. This paper describes some of the highlights of the efforts to design and implement the SETP. Program definition, curriculum development, and implementation concerns are discussed.
Technical Paper

Evaluation of Ada Environments

1988-10-01
881510
Software development technology has currently reached a state where there is a proliferation of software for almost any purpose. However, technology has a long way to go before it can provide an effective method for evaluating all this software. This paper discusses current research aimed at advancing the technology for evaluating an Ada Programming Support Environment (APSE) and its components. The development of a decision support system, providing a framework for analyzing current Ada software evaluation efforts and determining elements which still need to be evaluated, can provide a comprehensive and consistent method for Ada software evaluation.
Technical Paper

U.S. Light Duty Vehicle Fleet Emissions Performance and The Emissions Impact of Technology Changes

1988-10-01
881681
This paper determines the level of improvement in Federal Test Procedure (FTP) exhaust emissions realized by typical in-use vehicles over the last twenty years as emission standards have become increasingly stringent. Furthermore, this paper explores the likelihood that in-use emission performance improvements will continue now that emission standards have stabilized.
Technical Paper

Enhancing Low-Temperature Phase Stability of a 50/50 Methanol/Hydrocarbon Blend

1988-10-01
881680
Separation of roughly equal volume mixtures of methanol and gasoline into two phases at low temperature may cause problems for vehicles that are designed to operate on these mixtures. Cosolvent alcohols (C2-C12) and surfactants were evaluated as additives for enhancing phase stability at -25°C of a blend containing SO volume percent methanol, 40 percent isooctane, and 10 percent toluene (simulating a 50/50 methanol/gasoline mixture). For alcohol cosolvents, the amount required decreased with increasing carbon number (number of carbon atoms per molecule) from about 50 percent with C2 to about 6 percent for C8 through C12 A simple cost analysis indicated that decanol (C10) provided the minimum treatment cost for preventing separation at -25°C: $0.13/galloπ. Of the various commercial nonionic surfactants and various anionic fatty acid surfactants evaluated, only palmitic acid (C16) showed good effectiveness.
Technical Paper

SITUATIONAL AWARENESS IN THE COMMERCIAL FLIGHT DECK: DEFINITION, MEASUREMENT, AND ENHANCEMENT

1988-10-01
881508
This paper provides an indepth examination of the concept of pilot situational awareness. A detailed definition of the concept is provided, examining both the components that make up situational awareness and its dynamic aspects. We then describe what we consider to be the benefits of enhanced situational awareness. These include: improved safety, reduced workload, enhanced pilot performance, expanded range of pilot operations, and improved decisionmaking. The question of measurement is next considered. Both the direct measurement of situational awareness and the measurement of pilot performance are addressed. The paper ends with a discussion of methods for enhancing situational awareness.
Technical Paper

Properties, Performance and Emissions of Medium Concentration Methanol-Gasoline Blends in a Single-Cylinder, Spark-Ignition Engine

1988-10-01
881679
Methanol-gasoline blends containing 30 to 70 percent by volume methanol have potential to eliminate, or at least alleviate, major technical problems with the use of neat methanol such as safety, cold start and the reduced vehicle range. However, little information exits on their properties, performance and emissions. Experiments were carried out in a spark-ignited, single-cylinder, variable compression ratio, Waukesha RDM engine with primarily commercial grade unleaded gasoline, commercial grade methanol, M30, M50 and M70 methanol-gasoline blends to compare efficiency, performance and emissions characteristics. The fuels were compared at their knock-limited compression ratios and MBT spark-timing. In addition, fuel properties, such as research and motor octane qualities, volatility, heating values and cloud points of methanol-gasoline blends were determined.
Technical Paper

X-29A Subsystems Integration - An Example for Future Aircraft

1988-10-01
881504
The X-29A is the first X-series experimental aircraft developed in the United States since the mid-sixties. The X-29A is a technology demonstrator aircraft that integrates several different-technologies into one airframe. Among the technologies demonstrated are the aeroservoelastically tailored composite forward swept wings, close coupled canards, discrete variable camber wing, triplex digital flight control system with analog backup, thin supercritical wing, three surface pitch control, large negative static margin and the integration of these technologies into the X-29 airframe. This paper deals with the issue of technology integration of five of the X-29A subsystems and the early design decision to use existing aircraft, components whenever and wherever possible. The subsystems described are the X-29 aircraft Hydraulics System, the Electrical Power System, the Emergency Power System, the Aircraft Mounted Accessory Drive and the Environmental Control System.
Technical Paper

On Board Dimethyl Ether Generation to Assist Methanol Engine Cold Starting

1988-10-01
881678
Dimethyl ether has high vapor pressure and wide flammability limits, which make it an excellent fuel for cold starting methanol engines. We have investigated the catalytic dehydration of methanol to produce dimethyl ether on board methanol-fueled vehicles. We tested four methanol dehydration catalysts in a microcatalytic plug flow reactor and found that a fluorinated γ-alumina was very active and selective for methanol dehydration in the 250-350°C (482-662°F) temperature range. We also tested the fluorinated γ- alumina catalyst with a 15% gasoline/85% methanol mixture (M85) and found that the catalyst activity decreased in proportion to the gasoline content but that no catalyst deactivation occurred. Data from the catalyst testing were used to design an electrically-heated methanol dehydration reactor ‘that could be used on board a methanol fueled vehicle.
Technical Paper

TestGen-Testing Tool for Ada Designs and Ada Code

1988-10-01
881513
This paper describes a software program, TestGen, that assists in the testing both of executable Ada code as well as assisting in the testing of high level descriptions of Ada designs using Ada/PDL pseudo-code. The TestGen program provides three distinct capabilities: 1. The Design Review Expert Assistant- Allows Ada designs to be thoroughly reviewed, insuring that all paths have been evaluated, and that alt possibilities have been covered. 2. The Unit Test Strategy Generator- Assists in the definition of unit test procedures using a “white box” testing technique. 3. The Test Coverage Analyzer- Determines the extent of coverage (the percentage of the total numbers of paths, branches and statements that were actually executed during a given test sequence). The TestGen tool is one of the AISLE (Ada/ADADL Integrated Software Lifecycle Environment) toolset, an integrated set of tools that assist the developers of Ada software through the development lifecycle.
Technical Paper

Garrett Multipurpose Small Power Unit (MPSPU)-Program Status

1988-10-01
881502
The Garrett Auxiliary Power Division's Multipurpose Small Power Unit (MPSPU), Contract DAAJ02-86-C-0006, sponsored by the Aviation Applied Technology Directorate, Ft. Eustis, Virginia, has progressed through detail design and analysis to component and power unit development testing. The MPSPU Advanced Development program is structured to provide advanced technology for current and future United States Army and other Department of Defense auxiliary power unit/secondary power system applications for aircraft, combat vehicles, and mobile tactical shelters. The MPSPU has been designed for low specific fuel consumption, low weight and volume, low acquisition and life cycle costs and high reliability and durability. This paper discusses the design and current developmental status of the Garrett GTP50 MPSPU.
Technical Paper

T-100 Multipurpose Small Power Unit: Technology for the Next Generation Auxiliary Power Units

1988-10-01
881501
This paper describes the features and capabilities of the T-100 Multipurpose Small Power Unit (MPSPU), an advanced technology gas turbine engine demonstrator sponsored by the U.S. Army. The MPSPU technology is intended to provide an improved acquisition outlook for users of small turbine power units for airborne and vehicular auxiliary power and ground power applications. This will be accomplished by applying the newest existing component technologies for improved performance and designing for versatility so a wide range of applications can be derived from the same frame.
Technical Paper

A Study on Three Way Conversion Catalyst Thermal Deactivation and improvement

1988-10-01
881684
Abstract A study was made into thermal deactivation of Pt/Rh/Ce three way conversion (TWC) catalyst by the use of aging engines, as well as the changes in catalytic properties developed by thermal deactivation. As a result, crystallization of Pt and CeO2 and the accompanied decrease in O2 storage capacity were found as factors resulting from the thermal deactivation. To minimize the thermal deactivation of the catalyst, CeO2 became a focus of the study and a method to inhibit CeO2 crystallization was pursued. The results of engine high temperature durability testing on improved catalysts employing the new technique confirmed inhibition effects of thermal deactivation. The study successfully resulted in a new TWC catalyst minimizing thermal deactivation.
Technical Paper

Emergency Power Combined With An Auxiliary Power Unit

1988-10-01
881500
Todays aircraft, especially fighters, are becoming smaller, faster, and highly sophisticated. This results in a requirement for emergency power at extreme altitudes with little volume available for secondary power. In addition, the fly-by-wire technology requires immediate power with engine flameout at altitude. The traditional auxiliary power unit (APU) does not satisfy this requirement. The APU cannot provide rapid power initiation and does not start well at extreme altitudes. An emergency power unit (EPU) provides rapid power initiation at all altitudes but, requires additional volume and the use of exotic fuels. The optimum power supply can be used on the ground for engine starting and emergency power in the air, even at high altitudes. Combining an APU and an EPU into a single unit will minimize aircraft volume needed for a secondary power system while providing quick reaction to power loss at any altitude.
Technical Paper

In-Use Performance of U.S. Emission Concept Vehicles in Europe

1988-10-01
881683
Although further testing is still required, this paper demonstrates that U.S. emission concept vehicles can be operated in Europe and can be expected to comply longterm with U.S. 49 state emission standards. Further, there is a growing amount of data which suggests that, from a manufacturer's standpoint, it is an economic necessity to call for the discussion of a single emission standard and certification procedure to be employed throughout Europe, and possibly the world, as opposed to the collection of standards and test procedures that face our industry today.
Technical Paper

Alternative Methods of Dynami Model Verification for Ascent

1988-10-01
881529
Of particular concern to most spacecraft programs is the verification of the finite element model used to predict launch loads. The verification process requires a test-to-model correlation of the high loads producing modes. Presently, this usually requires building/using a test fixture to simulate the spacecraft-booster interface fixity conditions. This method, usually referred to as fixed-base modal testing, introduces significant uncertainties to the test results in the form of test stand flexibility, friction at the interface, etc. To avoid this myriad of problems and possibly reduce the overall structural test program duration significantly, alternative test programs have been developed. These test programs couple a standard modal test of a freely suspended structure with modified modal tests designed to highlight the character of the payload-booster interface without the need of simultaneously constraining all the interface degrees of freedom (DOF's).
Technical Paper

GM's In-Use Emission Performance Past, Present, Future

1988-10-01
881682
EPA and GM test programs have quantified the in-use emission performance of the GM closed-loop emission control systems. In-use exhaust emission levels, adjusted to the 50,000 mile point, show averages under the standards for the 1986 model year cars. In-use evaporative emission levels are under the standard, on average, for the 1985 and 1986 model year cars. Fuel injection systems have inherent evaporative emission performance advantages over carburetor systems. Average exhaust emission levels for the national fleet will continue to decrease as the closed-loop fleet replaces the older models. Predictions of future inventories are lower if the GM data reflecting the 1981+ emission improvements are used instead of the estimates currently in the MOBILE3 model.
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