SAE AIR 5317-2006 A Guide to APU Health Management《辅助动力系统(APU)安全管理指南》.pdf

1、_ AIR5317 AEROSPACE INFORMATION REPORT Issued 2006-03 A Guide to APU Health Management RATIONALE This guide was developed to assist Auxiliary Power Unit (APU) operators in identifying the key steps in establishing and maintaining a successful APU health management program that meets both the economi

2、c and the technical requirements of their business. This guide was developed for all APU operators or life-cycle owners, such as commercial operators, Original Equipment Manufacturers (OEM), equipment suppliers, and military transport units. TABLE OF CONTENTS 1. SCOPE 3 1.1 Purpose. 3 2. REFERENCES

3、3 2.1 Applicable Documents 3 2.1.1 SAE Publications. 3 2.1.2 Government Publications 4 2.1.3 Other Publications. 4 2.2 Terminology and Definitions . 4 3. GENERAL DESCRIPTION . 7 3.1 Background. 7 3.2 Current State. 7 4. COSTS AND BENEFITS 8 4.1 Costs . 8 4.2 Benefits . 9 4.3 Reliability. 11 5. TECHN

4、ICAL REQUIREMENTS 11 5.1 Best Practices for Establishing an APU Health Management Program . 12 5.1.1 Detect APU Failures Currently Seen in the Field 12 5.1.2 Detect APU Failures Based on Failure Mode and Effects Analysis . 12 5.2 Recommended Data Collection 14 5.2.1 Measurements 14 5.2.2 Events . 16

5、 5.3 Recommended Communication . 17 5.4 Best Practices for Developing an APU Health Management Program. 17 5.4.1 Symptoms . 18 Reaffirmed 2011-10SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of t

6、his report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabi

7、lized, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or o

8、therwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technic

9、al Report, please visit http:/www.sae.org/technical/standards/AIR5317 SAE AIR5317 - 2 -5.4.2 Diagnostics 185.4.3 Prognostics . 185.4.4 Corrective Action. 265.4.5 Implementation 285.4.6 ETOPS Considerations. 306. EXAMPLES. 317. CONCLUSION 32FIGURE 1 - FOUR ELEMENTS OF APU HEALTH MANAGEMENT. 17FIGURE

10、2 - EGT TRENDING . 21FIGURE 3 - OIL TEMPERATURE TRENDING 22TABLE 1 - TYPICAL APU FUNCTIONAL FMEA 13TABLE 2 - EQUATIONS FOR CORRECTING MEASURED PARAMETERS 20 SAE AIR5317 - 3 -1. SCOPE The SAE Guide to APU health management establishes the foundation for developing a successful APU health management p

11、rogram at any aircraft or APU operator, such as an airline, an OEM, an equipment supplier, or a military transport unit. This guide identifies the best practices for using an APU health management program to improve dispatch reliability and to satisfy Extended Operations (ETOPS) availability require

12、ments. 1.1 Purpose There have been many attempts to institute APU health management programs but most programs were modeled after the pre-existing main engine programs. These models often overlooked special considerations that are necessary to make an APU health management program successful. This r

13、eport will identify the unique characteristics of a successful APU health management program and the best practices for establishing a system. The purpose of this report is to guide the development and use of a successful APU health management effort in a practical, cost effective method. This repor

14、t will: Identify the costs and benefits associated with developing an effective APU health management program Identify the best practices and technologies for developing and implementing an APU health management program Identify the best practices for using APU health management to prevent failures

15、and disruptions to operations Identify a recommended collection of data, including recommended measurements and recommended eventsThe General Description in Section 3 is intended to provide a high level overview of the background and the current state of APU health management. The Costs and Benefits

16、 in Section 4 is intended to provide a high level overview of the costs and benefits associated with establishing an APU health management program. The Technical Requirements in Section 5 is intended to provide detailed information regarding best practices, recommended data collection and monitoring

17、, maintenance correlation, and implementation.2. REFERENCES These references contained useful information that may have been used in this report or may be beneficial in understanding the subject. 2.1 Applicable Documents The following publications form a part of this document to the extent specified

18、 herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. No

19、thing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside US

20、A), www.sae.orgAIR1828A Guide to Oil System Monitoring AIR1839B A Guide to Aircraft Turbine Engine Vibration Monitoring AIR4061A Guidelines for Integration of Engine Monitoring Functions with On-board Systems SAE AIR5317 - 4 -AIR4175 A Guide to Development of a Ground Based Station for Engine Condit

21、ion Monitoring AIR4176 Cost versus Benefits of Engine Monitoring Systems AIR4985 A Methodology for Quantifying the Performance of an Engine Monitoring System ARP1587B Aircraft Gas Turbine Engine Monitoring System Guide AS4831 Software Interfaces for Ground-Based Monitoring Systems 2.1.2 Government P

22、ublications Available from http:/www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/FAA AC 120.42 Extended Operations (ETOPS) of Multi-Engine Airplanes 2.1.3 Other Publications Richard A. Wade, “A Need-focused Approach to Air Force Engine Health Management Research”, US Ai For

23、ce Research Laboratory, Wright-Patterson Air Force Base, OH2.2 Terminology and Definitions AMBIGUITY GROUP: A group of two or more components that are identified as the potential cause of an APU failure.APU: Auxiliary Power Unit - A small gas turbine engine on the aircraft that provides auxiliary el

24、ectrical power on the ground and in-flight. Most APUs also provide pressurized air to operate Environmental Control Systems (ECS) and pneumatic systems for icing and main engine starting.ACARS: Aircraft Communications Addressing and Reporting System ARINC: Aeronautical Radio, Incorporated. AVAILABIL

25、ITY: A measurement of how often an APU is capable of performing its full functionality. An APU whose performance has degraded may not be capable of providing sufficient electrical power or pressurized air to the aircraft; hence, the APU is not available.BASELINE: A quantifiable physical condition or

26、 level of performance from which changes are measured. BCV: Bleed Control Valve - An internal APU valve used to regulate the airflow extracted from the APU to supply the airplane pneumatic system. BIT: Built-in Test - A self-initiated test performed by the APU controller software to validate interna

27、l circuits, input/outputsignal conditioning, and external interface circuits. DEGRADATION: The mechanism by which the performance and ability of the APU system reduces as a function of time or usage. DIAGNOSTICS: The process of using data and other measurements to determine the cause of an APU malfu

28、nction or discrepancy. The second element of health management; the active process to undertake analysis of a symptom to understand its cause. SAE AIR5317 - 5 -DOD: Domestic Object Damage - Damage caused by an APU system component. ECS: Environmental Control System - The aircraft system which regula

29、tes the pressure and temperature in the cabin, cockpit, and cargo compartments. The ECS also regulates the air supplied to the aircraft exterior surfaces to control ice buildup.EHM: Engine Health Management - The general process of evaluating the overall health of a gas turbine engine by comparing m

30、easurements during normal operations to a model of the expected values or to a baseline. The process includes identifying trends that indicate pending failures that may impact the availability of the engine in near future operations.EGT: Exhaust Gas Temperature - The temperature measured at a specif

31、ic point in the APU gas path aft of the combustor. ETOPS: Extended Operations - An International Civil Aviation Organization (ICAO) rule adopted by regulating authorities permitting multi-engine commercial air transports to fly routes in which the distance to the nearest diversion airfield is greate

32、r than 60 flying minutes. Additional deviations of 207 minutes have been granted to some aircraft and longer deviations are being evaluated. Historically, ETOPS referred to twin-engine aircraft but has since been extended to include multi-engine aircraft. ETOPS drives additional APU reliability and

33、availability constraints. FAULT ISOLATION MANUAL: An controlled manual that provides operators with a set of recommended maintenance procedures for determining the root cause of an APU failure.FAILURE EFFECTS: The effect an APU failure has on operations and/or on revenue.FAILURE MODE: A way in which

34、 an APU may become unavailable to perform its full functionality.FMEA: Failure Modes and Effects Analysis - A means of ranking the APU system failures using numerical assignments for severity of effects, for probability of occurrence of a cause, and for the ability to detect a loss before it is enco

35、untered.A failure mode may be severe only if it impacts the operation or results in a loss of revenue. The cause of the failure mode may be associated with a particular APU model. The cause of some failure modes may be preventable through normal practices while other modes are not preventable. The c

36、ause of some failure modes may be easily detected while others are not predictable. Each failure mode implies a different risk to the continued successful operation of the aircraft. FOD: Foreign Object Damage - Damage caused by an object that is not an APU system component. GSE: Ground Support Equip

37、ment - (1) Owned or rented equipment that supports operations while aircraft are on the ground, such as electrical generators. (2) Ground-based software used to support data analysis.IGV: Inlet Guide Vane - An internal vane in an APU that controls airflow through the APU and into the aircraft pneuma

38、tic system. LRU: Line Replaceable Unit - Equipment attached to, or functionally associated with, an APU, which can be replaced by maintenance personnel within the operational schedule of the aircraft. MEL: Minimum Equipment List - The Federal Airworthiness Regulations require that equipment installe

39、d on an aircraft required for compliance with the Airworthiness Standards and the Operating Rules must be operative. However, the rules also permit the publication of an MEL where compliance with certain equipment requirements is not necessary. Experience has shown that with various levels of redund

40、ancy designed into the aircraft, operation of every system or installed component may not be necessary when the remaining operative equipment can provide an acceptable level of safety. The MEL authorizes the release of aircraft for flight with inoperative equipment. In order to maintain an acceptabl

41、e level of safety, restrictions in the form of placards, maintenance procedures, and crew operating procedures are specified in the MEL. SAE AIR5317 - 6 -MES: Main Engine Start - The process of starting the main engines with pneumatic air supplied by the APU. MSA: Maintenance Service Agreement - A c

42、ontractual agreement between a commercial operator and the APU manufacturer where the operator pays the manufacturer a fixed price per hour of APU operation in lieu of a maintenance charge for labor and materials. An MSA is commonly referred to as a Power-by-the-Hour agreement. MTBUR: Mean Time Betw

43、een Unscheduled Removals - A reliability measurement typically calculated as the total flying hours during the time period, divided by the number of unscheduled removals that occurred during the same period. NFF: No Fault Found - The finding noted by licensed personnel when an APU or an LRU is teste

44、d to a specific test procedure and no defects are found. Also referred to as No Trouble Found (NTF). NVM: Non-Volatile Memory - The space allocated in a data acquisition unit or an APU controller for storing measurements and fault information.OEM: Original Equipment Manufacturer - The OEM is the ori

45、ginal manufacturer of a piece of equipment, such as an APU or an aircraft, who completed the development, testing, and certification of the equipment. PCMCIA: PERSONAL COMPUTER MEMORY CARD INTERNATIONAL ASSOCIATION - A small memory device used for data storage. POR: POINT OF REGULATION - The physica

46、l location in the generation system where the demand is controlled. PROBABLE CAUSE: A probable cause is a known cause that is likely to result in an identified failure mode. For example, worn starter motor brushes is a probable cause of a “Fail to Crank” fault. PROGNOSTICS: The process of predicting

47、 the future condition and availability of an APU, using the current condition and a model of a failure mode. The third element of health management; the determination of where the cause or condition is leading and in what time frame. RTL: Ready To Load - The point in which an operational APU is capa

48、bility of providing electrical power or pressurized air to the aircraft. SATCOM: Satellite Communications. SITA: Societe Internationale Telecommunications Aeronautiques - An aviation community owned organization that manages the worlds largest telecommunications system, provides the ground transfer

49、of aircraft communications between ARINC and the airlines, and provides direct communication between the aircraft and the airlines. SMOOTHING: An algorithm intended to reduce the scatter in trended data due to normal variations in the raw data. A widely used smoothing algorithm is the 95% weighting of “old data” and 5% weighting of new data. Another widely used smoothing algorithm is the 30-day rolling average.SYMPTOMS: Th