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A Methodology for Quantifying the Performance of an Engine Monitoring System
- Aerospace Standard
- AIR4985
- Reaffirmed
Downloadable datasets available
Annotation ability available
Sector:
Issuing Committee:
Language:
English
Scope
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:
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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).
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2
Facilitate trade studies during the design process in order to compare performance versus cost for various EMS design strategies, and
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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 techniques used for this methodology borrow from those used for testability analysis and are modified to apply to the unique aircraft supportability definitions in item 1 above. While the discussion and examples in this document focus on aircraft engines and their components, the methods and terms in this AIR are applicable to other systems. For example starting systems can be considered to be within the scope of the document.
It will be noted that many of the terms and measures used in the document reflect a military bias. It is anticipated that the methods described will either apply directly to commercial aviation measures or can be readily adapted.
Rationale
AIR4985 has been reaffirmed to comply with the SAE Five-Year Review policy.
Recommended Content
Topic
Data Sets - Support Documents
| Title | Description | Download |
|---|---|---|
| TABLE 1 | Sample Calculation of FDR% | |
| TABLE 2 | Component Descriptions | |
| TABLE 3 | Sample FDR% Analysis Logic | |
| TABLE 4 | Sample Calculation of FIR% | |
| TABLE 5 | Sample FIR% Analysis Logic | |
| TABLE 6 | Mean Time for Troubleshooting Methods | |
| TABLE 7 | Sample Calculation of MTTD | |
| TABLE 8 | Sample MTTD Analysis Logic | |
| TABLE 9 | Sample Calculation of EMS on IFSD Rate |
Issuing Committee
E-32 Aerospace Propulsion Systems Health Management
Background
Engine condition monitoring and rotorcraft HUMS(Health and Usage Monitoring Systems)can be used as a tool to track and restore engine performance, improve problem diagnosis, suggest solutions, promote better commercial and military aircraft operation, minimize in-flight failures, and reduce costs of engine maintenance. Because of these and other continuing objectives, the need for consolidated action by a group of experts to promote engine monitoring and rotorcraft condition monitoring know-how and standards was identified. It was deemed appropriate by the SAE Propulsion Division to assign this task to a special committee designated as Committee E-32. The committee has existed for over 40 years and has 26 active members. Purpose / Charter E-32 Committee serves as a forum to gather, record, and publish expert information in the discipline of aerospace propulsion system health management. The Committee gathers and analyzes requirements for propulsion system health management for the various types of air vehicle propulsion systems and develops standards and recommendations for the adoption of aerospace propulsion system health management devices that affect the operation of propulsion systems. Objectives Identifies potential propulsion system parameters suitable for sensing (pressure, temperature, vibration, etc.) and considerations involved in selecting parameters (potential problems, accuracy, cost, etc.), Analyzes the various approaches to aerospace propulsion system health management (e.g., airborne vibration health management systems, fault prediction capabilities, ground software interfaces, etc.) and establishes criteria for cost effective systems, and guidance regarding best practices for designing propulsion health management systems, Develops appropriate standards for aerospace propulsion system health management equipment and techniques; e.g., types of sensors, identification of signals which should be led to common diagnostic connectors, etc., Develops new requirements and uses for aerospace propulsion system health management to promote sustainable and cost effective operation of air vehicles, and Hosts technical conferences related to health management of propulsion systems. Provide a means to gain regulatory approval for utilizing EHM data in a range of maintenance activities.Reference
| Number | Title |
|---|---|
| AIR1872 | GUIDE TO LIFE USAGE MONITORING AND PARTS MANAGEMENT FOR AIRCRAFT GAS TURBINE ENGINES |
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