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The Engineering Analysis SYstem (EASY) computer program is summarized in this report. It provides techniques for analysis of steady-state and dynamic (transient) environmental control system (ECS) performance, control system stability, and for synthesis of optimal ECS. General uses of a transient analysis computer program for ECS design and development, and general features of EASY relative to these uses, are presented. This report summarizes the nine analysis options of EASY, EASY program organization for analyzing ECS, data input to the program and resulting data output, and a discussion of EASY limitations. Appendices provide general definitions for dynamic analysis, and samples of input and output for EASY.

This document considers the cooling of equipment installed in equipment centers, which usually consist of rack-mounted equipment and panel mounted equipment in the flight deck. In instances where these two locations result in different requirements, these are identified. For purposes of this document, the cooled equipment is referred to generally as E/E equipment, denoting that both electrical and electronic equipment is considered, or as an E/E equipment line-replaceable-unit (LRU). The majority of cooled equipment takes the form of LRUs. This document primarily relates to E/E equipment which is designed to use forced air cooling in order to maintain the equipment within acceptable environmental limits, in order to maintain equipment operating performance (within acceptable tolerances), and to maintain reliability. Cooling may be applied internally or externally to the case of the item of E/E equipment.

This document considers the cooling of equipment installed in equipment centers, which usually consist of rack-mounted equipment and panel mounted equipment in the flight deck. Instances where these two locations result in different requirements are identified. This document generally refers to the cooled equipment as E/E equipment, denoting that both electrical and electronic equipment is considered, or as an E/E equipment line-replaceable-unit (LRU). The majority of cooled equipment takes the form of LRUs. The primary focus of this document is E/E equipment which uses forced air cooling to keep the equipment within acceptable environmental limits. These limits ensure the equipment operates reliably and within acceptable tolerances. Cooling may be supplied internally or externally to the E/E equipment case. Some E/E equipment is cooled solely by natural convection, conduction, and radiation to the surrounding environment.

This AIR is intended as a status report on the work of E.C.S. to date in dealing with the problem of equipment cooling in present and immediate future civil transport aircraft. Subsequent revisions to this AIR will follow as more information is gathered on this subject.

This report contains background information on life cycle cost elements and key ECS cost factors. Elements of life cycle costs are defined from initial design phases through operational use. Information on how ECS designs affect overall aircraft cost and information on primary factors affecting ECS costs are discussed. Key steps or efforts for comparing ECS designs on the basis of LCC are outlined. Brief descriptions of two computer programs for estimating LCC of total aircraft programs and their use to estimate ECS LCC, are included.

The Environmental Control Analysis SYstem (EASY) computer program is summarized in this report. Development of this computer program initially was sponsored by the U.S. Air Force Flight Dynamics Laboratory. (See References 1, 2, 3, and 4.) It provides techniques for determination of steady state and dynamic (transient) ECS performance, and of control system stability; and for synthesis of optimal ECS control systems. The program is available from the U.S. Air Force, or as a proprietary commercial version. General uses of a transient analysis computer program for ECS design and development, and general features of EASY relative to these uses, are presented. This report summarizes the nine analysis options of EASY, EASY program organization for analyzing ECS, data input to the program and resulting data output, and a discussion of EASY limitations. Appendices provide general definitions for dynamic analysis, and samples of input and output for EASY.

This document supplements and in some cases supersedes the recommendations presented in ARP 85D, which refers to subsonic civil transports.

This publication outlines general design concepts considered the minimum acceptable standards for use in electrical and electronic equipment. The objective is increased reliability of the equipment without penalizing the aircraft performance.

This section relates the engineering fundamentals and thermophysical property material of the previous sections to the airborne equipment for which thermodynamic considerations apply. For each generic classification of equipment, information is presented for the types of equipment included in these categories, and the thermodynamic design considerations with respect to performance, sizing, and selection of this equipment.

This SAE Aerospace Information Report (AIR) covers the design parameters for various methods of humidification applicable to aircraft, the physiological aspects of low humidities, the possible benefits of controlling cabin humidity, the penalties associated with humidification, and the problems which must be solved for practical aircraft humidification systems. The design information is applicable to commercial and military aircraft. The physiological aspects cover all aircraft environmental control applications.

This section relates the engineering fundamentals and thermophysical property material of the previous sections to the airborne equipment for which thermodynamic considerations apply. For each generic classification of equipment, information is presented for the types of equipment included in these categories, and the thermodynamic design considerations with respect to performance, sizing, and selection of this equipment.

The purpose of this section is to provide methods and a set of convenient working charts to estimate penalty values in terms of take-off fuel weight for any given airplane mission. The curves are for a range of specific fuel consumption (SFC) and lift/drag ratio (L/D) compatible with the jet engines and supersonic aircraft currently being developed. A typical example showing use of the charts for an air conditioning system is given. Evaluation of the penalty imposed on aircraft performance characteristics by the installation of an air conditioning system is important for two reasons: 1 It provides a common denominator for comparing systems in the preliminary design stage, thus aiding in the choice of system to be used. 2 It aids in pinpointing portions of existing systems where design improvements can be most readily achieved.

The purpose of this section is to provide methods and a set of convenient working charts to estimate penalty values in terms of take-off fuel weight for any given airplane mission. The curves are for a range of specific fuel consumption (SFC) and lift/drag ratio (L/D) compatible with the jet engines and supersonic aircraft currently being developed. A typical example showing use of the charts for an air conditioning system is given. Evaluation of the penalty imposed on aircraft performance characteristics by the installation of an air conditioning system is important for two reasons: 1 It provides a common denominator for comparing systems in the preliminary design stage, thus aiding in the choice of system to be used. 2 It aids in pinpointing portions of existing systems where design improvements can be most readily achieved.

It is intended that the scope of this information report be limited to electrical heating of passenger, crew, and cargo compartments only. No attempt has been made to develop the complete electrical circuitry associated with the electrical heating components; however, the electrical circuitry required for heating component operation, safety, and monitoring will be included as available. Specific design information is given for various modern aircraft utilizing electrical heating. Each aircraft discussed will be identified by alphabetical letter designation and included in the appropriate appendix.

It is intended that the scope of this information report be limited to electrical heating of passenger, crew, and cargo compartments only. No attempt has been made to develop the complete electrical circuitry associated with the electrical heating components; however, the electrical circuitry required for heating component operation, safety, and monitoring will be included as available. Specific design information is given for various modern aircraft utilizing electrical heating. Each aircraft discussed will be identified by alphabetical letter designation and included in the appropriate appendix.

This ARP covers the basic criteria for the design of cabin pressure control systems (CPCS) for general aviation, commercial and military pressurized aircraft.

This SAE Aerospace Information Report (AIR) provides information on aircraft cabin air quality, including: Origins of chemical airborne contaminants during routine operating and failure conditions. Exposure control measures, including design, maintenance, and worker training/education. This AIR does not deal with airflow requirements.

This SAE Aerospace Information Report (AIR) covers airbone particulate contaminants that may be present in commercial aircraft cabin air during operation. Discussions cover sources of contaminants, methods of control and design recommendations. Air quality, ventilation requirements and standards are also discussed.

This SAE Aerospace Information Report (AIR) covers airbone particulate contaminants that may be present in commercial aircraft cabin air during operation. Discussions cover sources of contaminants, methods of control and design recommendations. Air quality, ventilation requirements and standards are also discussed.