1、 MIL-HDBK-525 25 July 2013 DEPARTMENT OF DEFENSE HANDBOOK ELECTRICAL WIRING INTERCONNECT SYSTEM (EWIS) INTEGRITY PROGRAM This handbook is for guidance only. Do not cite this document as a requirement. AMSC N/A AREA SESS DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited
2、. NOT MEASUREMENT SENSITIVE Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 ii FOREWORD 1. This handbook is approved for use by all Departments and Agencies of the Department of Defense. 2. The purpose of this handbook is to establish Me
3、chanical Equipment and Subsystems Integrity Program (MECSIP) tasks for the development, acquisition, modification, operation, sustainment, and service life extension of an aircraft Electrical Wiring Interconnect System (EWIS). This handbook consists of a series of recommendations which, when applied
4、, will promote the continued operational safety, suitability, and effectiveness (OSS or e-mailed to AFLCMC/EN_EZ Engineering Standards. Since contact information can change, you may want to verify the currency of this address information through use of the ASSIST Online database at https:/assist.dla
5、.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 iii CONTENTS Paragraph Page 1 SCOPE 1 1.1 Purpose . 1 1.2 Background 1 1.3 Approach . 2 1.4 Program overview 4 1.5 Applicability 4 2 APPLICABLE DOCUMENTS . 5 2.1 General 5 2.2 Governm
6、ent documents . 5 2.3 Non-Government publications 7 3 DEFINITIONS 8 4. CORE PROCESS TASKS 13 4.1 Core Process Task One . 13 4.2 Core Process Task Two . 14 4.3 Core Process Task Three . 14 4.4 Core Process Task Four . 15 4.5 Core Process Task Five . 15 4.6 Core Process Task Six . 16 4.7 Core ProcessT
7、ask Seven . 16 5 MANAGEMENT METHODS . 16 5.1 General 16 5.2 Policies and guidance 16 5.2.1 Quality . 16 5.3 Training 17 5.4 Technical data 17 6 FAILURE MODES AND LESSONS LEARNED 18 6.1 Wires . 18 6.1.1 Splices . 18 6.1.2 Cables . 19 6.1.3 Fiber optics 19 6.2 Connectors 19 6.3 Relays 20 6.4 Switches
8、20 6.5 Circuit breakers 20 6.6 Pressure seals . 21 6.7 Design and installation . 21 6.8 Maintenance 21 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 iv 6.9 Other electrical and mechanical systems and interfaces that can impact the EWIS
9、 22 6.9.1 Electrical interfaces 22 6.9.2 Flight and throttle controls 22 6.9.3 Interfacing systems, hardware, and software disciplines subsystems 22 6.9.4 Systems without BIT tests (partially tested devices) . 22 7 DETAILED REQUIREMENTS DEVELOPMENT 23 7.1 Appendix A. 23 7.2 Appendix B 23 7.3 Appendi
10、x C 23 7.4 Appendix D 23 7.5 Appendix E 23 7.6 Appendix F. 23 7.7 Appendix G 23 7.8 Appendix H 23 8 NOTES 23 8.1 Intended use 23 8.2 Subject term (key word) listing . 24 APPENDIX A: ELECTRICAL WIRING INTERCONNECTION SYSTEMS (EWIS) MINIMAL INITIAL TRAINING PROGRAM CONTENT 25 A.1 SCOPE 25 A.2 AC 120-9
11、4, APPENDICES A, B, AND C (REMOTE LOCATION) 25 A.3 COURSE OBJECTIVES 25 A.4 INSPECTION ANALYSIS . 26 APPENDIX B: EWIS TASK ONE EWIS DOCUMENTATION 27 B.1 SCOPE 27 B.2 APPLICABLE DOCUMENTS . 29 B.2.1 General 29 B.2.2 Government documents . 29 B.2.3 Non-Government publications 29 B.3 Aircraft Functiona
12、l and Physical Hazard Assessment (AFPHA) 29 B.3.1 Aircraft zone breakdown 29 B.3.2 Zone definition . 29 B.4 EWIS identification . 30 B.4.1 Wire information . 31 B.4.2 Circuit protection device information 31 B.4.3 Relays or switching device information . 32 B.4.4 Connectors 32 B.4.5 LRUs/WRAs and co
13、nnected devices 33 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 v B.4.6 Wire harness information . 33 B.5 EWIS separation identification . 34 B.6 EWIS Physical Failure Impact 35 B.6.1 Aircraft-Level Physical Failure 35 B.6.1.1 Common
14、Cause Assessment . 35 B.6.1.2 Catastrophic physical failure assessment 36 B.6.1.3 EWIS physical failure analysis results 36 B.7 Aircraft system and subsystem engineering assessments . 37 B.7.1 Identify catastrophic failure modes for critical EWIS components . 39 APPENDIX C: EWIS TASK TWO DATA ANALYS
15、IS 40 C.1 SCOPE 40 C.2 OVERVIEW 40 C.3 GENERAL 42 C.3.1 Visual observation 42 C.3.2 Comparative analysis . 42 C.3.3 Statistical analysis 42 C.3.4 Analysis process 42 C.4 Data mining process 42 C.4.1 Field, Depot, and Engineering Surveys 43 C.4.2 Goals for filtering of data 43 C.4.3 Maintenance datab
16、ases . 43 C.4.4 Identify available data 43 C.4.5 Keyword search . 44 C.4.6 Keyword supplement . 45 C.4.7 Data selection 45 C.5 Data review 45 C.5.1 Tier #1 data review. 46 C.5.2 Tier #2 data review. 46 C.6 Data analysis . 46 C.6.1 Analysis techniques . 47 C.6.2 Partitioning of data . 47 C.6.3 Data f
17、itting 47 C.6.4 Examples . 47 C.7 Data analysis questionnaire . 50 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 vi APPENDIX D: EWIS TASK THREE PHYSICAL AIRCRAFT INSPECTION. 52 D.1 SCOPE 52 D.2 APPLICABLE DOCUMENTS . 52 D.2.1 General 5
18、2 D.3 Background 55 D.4 Causes of wire and other EWIS component degradation . 55 D.4.1 Vibration. 55 D.4.2 Moisture . 55 D.4.3 Maintenance 55 D.4.4 Metal shavings and debris . 55 D.4.5 Repairs 55 D.4.6 Indirect damage . 56 D.4.7 Contamination 56 D.4.8 Heat . 57 D.4.9 Cold . 57 D.4.10 Severe Wind And
19、 Moisture Prone (SWAMP) areas 57 D.5 General EWIS maintenance guidance . 57 D.5.1 Levels of inspection applicable to EWIS . 58 D.5.2 General Visual Inspection 58 D.5.3 Detailed inspection (DET) 58 D.5.4 Zonal inspection . 59 D.5.5 EWIS-related guidance for zonal inspections . 59 D.6 Wiring installat
20、ions and areas of concern . 61 D.6.1 Wiring installations . 61 D.6.2 Clamping points . 61 D.6.3 Connectors 61 D.6.4 Terminations 61 D.6.5 Backshells 62 D.6.6 Sleeving and conduits 62 D.6.7 Grounding points 62 D.6.8 Harness protection . 62 D.6.9 Pressure seals . 62 D.6.10 Splices . 62 D.6.11 Areas of
21、 concern . 63 D.6.11.1 Wire raceways and bundles . 63 D.6.11.2 Wings . 63 D.6.11.3 Engine, pylon, and nacelle area . 63 D.6.11.4 Accessory compartment and equipment bays 63 D.6.11.5 Auxiliary power unit (APU) . 63 D.6.11.6 Landing gear and wheel wells 63 D.6.11.7 Electrical panels and LRUs/WRAs . 63
22、 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 vii D.6.11.8 Batteries 63 D.6.11.9 Power feeders 63 D.6.11.10 Under galleys, lavatories, and cockpit 64 D.6.11.11 Fluid drain plumbing . 64 D.6.11.12 Fuselage drain provisions 64 D.6.11.13
23、 Cargo bay underfloor . 64 D.6.11.14 EWIS subject to movement 64 D.6.11.15 Access panels 64 D.6.11.16 Under doors . 64 D.6.11.17 Under cockpit sliding windows . 64 D.6.11.18 Areas where EWIS is difficult to access . 64 D.6.11.19 Severe Wind And Moisture Prone areas 64 D.6.11.20 Separation distance f
24、rom structure and hydraulic/fuel lines 64 D.6.11.21 Separation from other components 65 D.6.11.22 EWIS component identification 65 D.7 Selection of aircraft 65 D.8 Selection of EWIS components for inspection 65 D.9 Electrical characterization 65 D.10 Inspection report 65 D.11 Skills of personnel per
25、forming inspection . 66 APPENDIX E: EWIS TASK FOUR COMPONENT ASSESSMENT . 70 E.1 SCOPE 70 E.2 APPLICABLE DOCUMENTS . 70 E.2.1 General 70 E.3 OVERVIEW . 71 E.4 EWIS devices to be considered for assessment 73 E.5 Device assessment methods . 73 E.5.1 General assessment techniques 73 E.5.2 Visual Inspec
26、tion 73 E.5.3 Corrosion . 73 E.5.4 Contact resistance . 73 E.5.5 Wire insulation and conductor integrity . 74 E.5.5.1 Aromatic polyimide insulations (common name, Kapton) 74 E.5.5.2 XL-ETFE (common name, Tefzel) 74 E.5.5.3 Composite insulations (common name, Teflon-KAPTON-Teflon(TKT) . 74 E.5.5.4 Fi
27、ber optic cable 74 E.5.5.5 Coax cables . 74 E.5.6 Protective harness materials 74 E.5.7 Shield and ground terminations 74 E.5.8 Connector contact integrity and shield effectiveness 75 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 viii
28、E.5.9 Circuit breaker contact integrity and the trip curve verification 75 E.5.9.1 Pull force 75 E.5.9.2 Thermal degradation 75 E.5.9.3 Corrosion . 75 E.5.9.4 Contact resistance . 75 E.5.9.5 Trip curve and response time . 76 E.5.10 Relay contact integrity and actuation performance . 76 E.5.11 Switch
29、 contact integrity and actuation performance . 76 E.5.12 Electrical distribution panels . 76 E.5.13 Terminal boards, ground studs, and connector back shells 76 E.6 Compare condition of components with new (unused) components . 77 E.7 Component selection . 77 E.8 Aircraft selection 77 E.8.1 Selection
30、 factors 77 E.8.1.1 Availability 77 E.8.1.2 Accessibility . 77 E.8.1.3 Age 77 E.8.1.4 Service locations 77 E.8.2 Sample size . 78 E.9 Test performance . 78 E.10 Test results. 78 E.11 Task report 78 APPENDIX F: EWIS TASK FIVE RISK ASSESSMENT 79 F.1 SCOPE 79 F.2 Documentation of EWIS results . 81 F.2.
31、1 Assignment of failure probability 81 F.2.2 Maintenance data numeric assignment 81 F.2.3 Degradation assessment numeric assignment . 82 F.2.4 Degradation forecast 82 F.2.5 Combine degradation assessment with maintenance data . 83 F.3 Failure severity 84 F.4 Assessment of mitigation . 84 APPENDIX G:
32、 EWIS TASK SIX ACTION PLAN 85 G.1 SCOPE 85 G.2 Determination of actions to be taken 87 G.2.1 Design changes . 87 G.2.2 Reduction of physical failure risk 87 G.2.3 Reduction of functional failure risk . 88 G.2.4 Replacement 88 Provided by IHSNot for ResaleNo reproduction or networking permitted witho
33、ut license from IHS-,-,-MIL-HDBK-525 ix G.2.5 Forecasting replacement 88 G.2.6 Maintenance changes 88 G.3 EWIS Enhanced Zonal Analysis Program Development. 88 G.3.1 Enhanced Zonal Analysis Procedure 89 G.3.2 Guidance for a General Visual Inspection 89 G.3.3 Protections and cautions 89 G.3.4 “Protect
34、 and Clean as You Go” philosophy . 89 G.3.5 Consolidation with fuel tank requirements 89 G.3.6 Enhanced Zonal Analysis Proceduregeneral guidance . 90 G.3.6.1 STEP 1: Identify aircraft zones, including boundaries. . 92 G.3.6.2 STEP 2: List details of zone. . 92 G.3.6.3 STEP 3: Does zone contain wirin
35、g? 92 G.3.6.4 STEP 4: Are there, or are there likely to be, combustible materials in zone? . 92 G.3.6.5 STEP 5: Is there an effective task to reduce significantly the likelihood of accumulation of combustible materials? . 93 G.3.6.6 STEP 6: Define the task and assign an interval for its performance.
36、 . 93 G.3.6.7 STEP 7: Is wiring close to both primary and backup hydraulic, mechanical, or electrical flight controls? . 93 G.3.6.8 STEP 8: Does the zone contain EWIS supporting safety-critical CAT 1 failure severity systems? 94 G.3.6.9 STEP 9: Does the zone contain EWIS components that showed degra
37、dation but no actions were taken for replacement? . 94 G.3.6.10 STEP 10: Select wiring inspection level and interval. 94 G.3.6.10.1 Inspection level 94 G.3.6.10.1.1 Zone identification 94 G.3.6.10.1.2 Zone size . 94 G.3.6.10.1.3 Zone density 94 G.3.6.10.1.4 Failure severity 95 G.3.6.10.2 Selecting a
38、n inspection interval 96 G.3.6.10.3 Inspection-level guidance . 96 G.3.6.11 STEP 11: Consider consolidation with existing inspection tasks in systems and power plant and/or zonal programs. 97 APPENDIX H: EWIS TASK SEVEN ITERATIVE EWIS ASSESSMENT 101 H.1 SCOPE 101 H.2 EWIS monitoring 101 H.2.1 EWIS c
39、omponent reassessment 101 H.2.2 Develop assessment metrics . 101 H.2.3 Action plan implementation assessment 101 H.3 Periodic reassessment . 101 H.3.1 Change in risk tolerances . 101 H.3.2 Design life review . 101 H.3.3 System upgrades . 102 H.3.4 Mission change 102 Provided by IHSNot for ResaleNo r
40、eproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 x TABLES TABLE I. Joint Services Manual cross-reference21 TABLE B-I. Example breakpoints for zone environmental conditions .30 TABLE B-II. Example of gathered wire data 31 TABLE B-III. Example of gathered circuit protectio
41、n data 31 TABLE B-IV. Example of gathered switching data 32 TABLE B-V. Example of gathered connector data .32 TABLE B-VI. Example of gathered harness data 34 TABLE B-VII. Example physical failure analysis on selected bundle sections .35 TABLE B-VIII. Example assessment of arc damage on nearby system
42、 components .36 TABLE B-IX. Severity Categories .38 TABLE C-I. Sample keywords for EWIS maintenance search 44 TABLE C-II. Example database keyword search result .45 TABLE F-I. Maintenance action category assignment .81 TABLE F-II. Degradation forecast numerical assignment .82 TABLE F-III. Example de
43、gradation forecast for three example devices .83 TABLE F-IV. Degradation assessment categories combined with maintenance data analysis categories 83 TABLE F-V. Risk assessment matrix 84 FIGURES FIGURE 1. Process flow for risk assessment . 3 FIGURE B-1. Process flow for risk assessment 28 FIGURE B-2.
44、 Example system diagram for CAT 1 component 39 FIGURE C-1. Process flow for risk assessment 41 FIGURE C-2. Example of Pareto analysis of turbofan EWIS maintenance issues .48 FIGURE C-3. Example Pareto analysis of TR subsystem maintenance actions 48 FIGURE C-4. Example Pareto analysis of engine TR sw
45、itch maintenance actions .49 FIGURE C-5. Example of maintenance items categorized by system and device type .49 FIGURE D-1. Process flow for risk assessment 54 FIGURE E-1. Process flow for risk assessment 72 FIGURE E-2. Circuit breaker pull tests 75 FIGURE E-3. Test results of circuit breaker trip t
46、ests 76 FIGURE F-1. Risk assessment process flow 80 FIGURE G-1. Risk assessment process flow 86 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-525 1 1 SCOPE 1.1 Purpose. This handbook provides weapons systems program offices a systematic pr
47、ocess to assess an aircraft Electrical Wiring Interconnect System (EWIS) for overall condition, service life extension, and continued airworthiness. It aligns with the Mechanical Equipment and Subsystems Integrity Program (MECSIP) (see MIL-STD-1798) and makes extensive use of lessons learned from EW
48、IS-related military, industry, and Federal Aviation Administration (FAA) Advisory Circulars (ACs) concerned with maintaining aircraft airworthiness. It contains a framework to achieve and maintain the physical and functional integrity of the EWIS. This process should be tailored to meet specific platform, program office, system and/or subsystem requirements or constraints. The process and core tasks should also be tailored relative to platform status: whether in de
