U.S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Incorporation of Electrical Wiring Interconnection Systems Instructions for Continued Airworthiness into an Operator’s Maintenance Program Date: 9/12/12 Initiated by: AFS-300 AC No: 120-102A Change:
On November 8, 2007, the Federal Aviation Administration (FAA) published the Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/FTS) final rule. The intent of the rule is to help ensure the continued safety of commercial airplanes by improving the design, installation, and maintenance of electrical wiring systems. Title 14 of the Code of Federal Regulations (14 CFR) part 121, § 121.1111, and part 129, § 129.111 include requirements for operators to revise their maintenance programs to include instructions for continued airworthiness (ICA), which include inspections and procedures for the electrical wiring interconnection systems (EWIS). This advisory circular (AC) only addresses the EWIS requirements and provides guidance accordingly. The current edition of AC 120-97, Incorporation of Fuel Tank System Instructions for Continued Airworthiness into Operator Maintenance or Inspection Programs, provides guidance for operators to comply with the fuel tank safety (FTS) requirements in the EAPAS/FTS rule.
ORIGINAL SIGNED by /s/ Raymond Towles for
John M. Allen Director, Flight Standards Service
Page iii (and iv)
CONTENTS Paragraph Page
CHAPTER 1. GENERAL1
1-1. Purpose1
1-2. Applicability1
1-3. Background2
1-4. Related CFR Parts3
1-5. Related Reading Materi als (Current Editions)4
1-6. FAA Policy Statements5
CHAPTER 2. ENHANCED AIRWORTHINESS PROGRAM FOR AIRPLANE
SYSTEMS (EAPAS) REQUIREMENTS7
2-1. Requirements7
2-2. Description of EWIS ICA Re quired by 14 CFR Part 26, § 26.117
2-3. EWIS ICA Development Required by § 25.172910
2-4. Description of EWIS ICA Required by § 26.1110
2-5. Why EWIS ICA Approval is Necessary10
2-6. TCH-Developed EWIS Inspect ion and Restoration Tasks11
2-7. STC Holder-Developed EWIS ICA13
2-8. STC Limitation13
2-9. Requirement to Ensure Compatibility Between Fuel Tank System and EWIS ICA14
CHAPTER 3. OPERATIONAL REQUIREMENTS17
3-1. Operator Incorporati on of FAA-Approved Electrical Wiring Interconnection Systems (EWIS) Instructions for Continued Airworthines (ICA) into the
Maintenance Program17
3-2. Operator Changes to EZAP Devel oped EWIS Task or Task Intervals17
3-3. Operator Changes to EWIS ICA De veloped Under 14 CFR Part 25, § 25.172918
3-4. EAPAS Maintenance Training18
3-5. Operator’s Maintenance Progr am Approval under §§ 121.111 and 129.11119
APPENDIX 1. ACRONYMS (2 pages)1
APPENDIX 2. DEFINITIONS (4 pages)1
APPENDIX 3. FAA OVERSIGHT OFFICES BY AIRPLANE
MANUFACTURER (2 pages)1
Par 1-1 Page 1 CHAPTER 1. GENERAL
1-1. PURPOSE. This advisory circular (AC) provides guidance for Title 14 of the Code of Federal Regulations (14 CFR) part 121 certificate holders and 14 CFR part 129 operators (part 129, § 129.14) of U.S.-registered airplanes (hereafter both are referred to as “operators”) regarding compliance with the Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/FTS) rule.
a. Definition. The EAPAS/FTS rule contains new certification and operation requirements for the airplanes’ electrical wiring interconnection systems (EWIS). It requires the development of Federal Aviation Administration (FAA) Oversight Office-approved EWIS instructions for continued airworthiness (ICA). It defines EWIS as including “any wire, wiring device, or combination of these, including termination devices, installed in any area of the airplane for the purpose of transmitting electrical energy, including data and signals, between two or more intended termination points.”
b. Requirements. The EWIS ICA have been developed using an enhanced zonal analysis procedure (EZAP). Refer to Appendix 2, Definitions, for the definition of EZAP. The requirements to develop these EWIS ICA are contained in 14 CFR part 25, § 25.1729, and part 26, § 26.11. These sections refer to EWIS ICA requirements contained in part 25 appendix H, § H25.5(a)(1) and (b). This AC provides guidance for EWIS ICA that have been developed in accordance with § 26.11 and the current edition of AC 25-27, Development of Transport Category Airplane Electrical Wiring Interconnection Systems Instructions for Continued Airworthiness Using an Enhanced Zonal Analysis Procedure.
1-2. APPLICABILITY. This AC applies to operators of transport category turbine-powered airplanes with a type certificate (TC) issued after January 1, 1958 that, as a result of original type certification or later increase in capacity, have a maximum type-certificated passenger capacity of 30 or more, or a maximum payload capacity of 7,500 pounds or more. This AC can also be used as a method of compliance for any transport category airplane that has § 25.1729 in its certification basis.
NOTE: The phrase “original type certification or later increase in capacity” addresses two situations. In the past, some designers and operators avoided applying requirements mandated only for airplanes over a specific capacity by receiving a design change approval for a slightly lower capacity. By referencing the capacity resulting from original certification, the rule removes this means of avoiding compliance. Also, the FAA could have originally certified an airplane design with a capacity slightly lower than the minimum specified in the rule, but through later design changes, the capacity could be increased above this minimum. The reference to later increase in capacity in the rule ensures that, if this occurs, the design would have to meet the requirements of the rule.
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1-3. BACKGROUND.
a. TWA Flight 800. Since 1959, there have been 18 fuel tank explosions. Most notably, on July 17, 1996, a 25-year-old Boeing 747-100 series airplane was involved in an in-flight breakup after takeoff from Kennedy International Airport in New York, resulting in 230 fatalities. The National Transportation Safety Board (NTSB) determined that the probable cause of the TWA Flight 800 accident was an explosion of the center wing fuel tank (CWT) resulting from ignition of the flammable fuel and air mixture in the tank. The NTSB could not conclusively determine the source of ignition energy for the explosion, though the most likely cause was a wiring failure outside the CWT. This failure allowed excessive electrical energy to enter the CWT through electrical wiring associated with the fuel quantity indicator system (FQIS).
b. Swissair Flight 111. Two years after the TWA accident, in September 1998, an MD-11 airplane, Swissair Flight 111, crashed into the Atlantic Ocean off the coast of Nova Scotia, Canada. In its final accident report, The Transportation Safety Board of Canada (TSB) determined that there was smoke and a fire above the ceiling in the cockpit. In the report, the TSB could not identify the exact cause of the fire; however, the TSB stated that “a segment of in-flight entertainment network power supply unit cable… exhibited a region of resolidified copper on one wire that was caused by an arcing event.” The TSB determined that this resolidified copper was located in the area where the fire most likely originated.
c. Investigation. Investigation of these two accidents, and subsequent examinations of many other airplanes, showed that deteriorated wiring, corrosion, and improper wire installation and repairs were common conditions in the EWIS. In addition, wire bundles contaminated with metal shavings, dust, and fluids were also common conditions in representative examples of transport airplanes. These contaminants could damage EWIS and also provide fuel for an electrical fire.
d. FAA’s Conclusions.
(1) The FAA concluded that the following ICA for the EWIS are too general, and not described in enough detail in maintenance manuals:
(a) Wiring maintenance practices,
(b) Wiring components,
(c) Wiring inspection criteria, and
(d) Wiring repair and installation instructions.
(2) Therefore, the FAA determined that to correct these deficiencies, future ICA developed for the EWIS must define:
(a) What has to be done,
(b) When it has to be done,
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(c) How it will be accomplished, and
(d) That EWIS ICA must be FAA-approved.
e. EAPAS/FTS Final Rule. On November 8, 2007, the FAA published the EAPAS/FTS rule. This rule helps ensure the continued safety of commercial airplanes by improving the design, installation, and maintenance of the airplanes’ EWIS. The rule also includes new certification (§ 26.11 and § 25.1701 through § 25.1733) and operation (14 CFR part 121, § 121.1111, and § 129.111) requirements. Part 26 subpart A establishes design approval holder (DAH) requirements for support of the continued airworthiness and safety improvements for turbine-powered transport category airplanes.
NOTE: For the purposes of this AC, a DAH refers to the TC and Supplemental Type Certificate (STC) holder when used in context.
NOTE: For the purposes of this AC, the FAA Oversight Office is defined in § 26.3 as the Aircraft Certification Office (ACO) or the office of the Transport Airplane Directorate with oversight responsibility for the relevant TC, STC, or manufacturer as determined by the Administrator.
f. New 14 CFR Subparts. Section 121.1101 subpart AA, and § 129.101 subpart B requires operators to support the continued airworthiness of each airplane. These new requirements may include revising the maintenance or inspection program, incorporating design changes, incorporating revisions to ICA, and making necessary documentation available to affected persons (refer to Appendix 2). These new subparts will also improve the reader’s ability to readily identify rules pertinent to continued airworthiness.
1-4. RELATED CFR PARTS. The Regulatory and Guidance Library (RGL) is a set of searchable databases that contain regulatory, guidance, and aviation product information. The RGL contains certain Federal aviation regulations and Special Federal Aviation Regulations (SFAR) from 14 CFR in their current versions as well as historical versions. The current editions of the following sections of 14 CFR apply:
• Part 21, § 21.50, Instructions for Continued Airworthiness and Manufacturer’s Maintenance Manuals Having Airworthiness Limitation Sections.
• Part 25, § 25.1529, Instructions for Continued Airworthiness.
• Part 25, § 25.1729, Instructions for Continued Airworthiness: EWIS.
• Part 25 Appendix H, Electrical Wiring Interconnection Systems (EWIS).
• Part 26 Subpart A, Continued Airworthiness and Safety Improvements for Transport Category Airplanes.
• Part 26, § 26.11, Electrical Wiring Interconnection Systems (EWIS) Maintenance Program.
• Part 43, § 43.13, Performance Rules (General).
• Part 121 Subpart AA, Continued Airworthiness and Safety Improvements.
• Part 121, § 121.1111, Electrical Wiring Interconnection Systems (EWIS) Maintenance Program.
• Part 129 Subpart B, Continued Airworthiness and Safety Improvements.
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• Part 129, § 129.111, Electrical Wiring Interconnection Systems (EWIS) Maintenance Program.
1-5. RELATED READING MATERIALS (Current editions).
a. ACs. You can locate each of the following ACs at http://www.faa.gov/regulations_policies/advisory_circulars.
(1) AC 25-8, Auxiliary Fuel System Installations.
(2) AC 25-19, Certification Maintenance Requirements.
(3) AC 25-27, Development of Transport Category Airplane Electrical Wiring Interconnection Systems Instructions for Continued Airworthiness Using an Enhanced Zonal Analysis Procedure.
(4) AC 25.981-1, Fuel Tank Ignition Source Prevention Guidelines.
(5) AC 25.981-2, Fuel Tank Flammability.
(6) AC 25.1701-1 Certification of Electrical Wiring Interconnection Systems on Transport Category Airplanes.
(7) AC 25.981.2A, Fuel Tank Flammability Reduction Means.
(8) AC 26-1, Part 26, Continued Airworthiness and Safety Improvements.
(9) AC 120-16, Air Carrier Maintenance Programs.
(10) AC 120-94, Aircraft Electrical Wiring Interconnection Systems Training Program.
(11) AC 120-97, Incorporation of Fuel Tank System Instructions for Continued Airworthiness into the Operator Maintenance or Inspection Program.
(12) AC 121-22, Maintenance Review Board Report Maintenance Type Board, and OEM/TCH Inspection Program Procedures.
(13) AC 129-4, Maintenance Programs for U.S.-Registered Aircraft Operated Under 14 CFR Part 129.
b. FAA Orders.
(1) Order 8110.54, Instructions for Continued Airworthiness Responsibilities, Requirements, and Contents.
(2) Order 8110.104, Responsibilities and Requirements for Implementing Part 26 Safety Initiatives.
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c. Industry References. The Air Transport Association of America (ATA) Operator/Manufacturer Scheduled Maintenance Development, Maintenance Steering Group— 3rd Task Force (MSG-3) and later revisions. The ATA is now the Airlines 4 America (A4A).
1-6. FAA POLICY STATEMENTS (Available for download at http://rgl.faa.gov).
a. PS-ANM110-7-12-2005, Safety—A Shared Responsibility—New Direction for Addressing Airworthiness Issues for Transport Airplanes.
(1) On July 12, 2005, the FAA issued policy statement PS-ANM110-7-12-2005. The policy states, in part:
“Based on our evaluation of more effective regulatory approaches for certain types of safety initiatives…the FAA has concluded that we need to adopt a regulatory approach recognizing the shared responsibility between design approval holders (DAHs) and operators. When we decide that general rulemaking is needed to address an airworthiness issue, and believe the safety objective can only be fully achieved if the DAHs provide operators with the necessary information in a timely manner, we will propose requirements for the affected DAHs to provide that information…”
(2) To implement this policy, the FAA established a new § 26.11 in the EAPAS/FTS rule. The new § 26.11 requires the DAH to develop ICA for EWIS for certain existing transport category airplanes and submit them to the FAA Oversight Office for approval.
b. PS-AIR-100-2009-05-27, Adding Part 26 to Type Certificate Data Sheets and Supplemental Type Certificates. On October 22, 2007, 14 CFR adopted a new part 26, Enhanced Airworthiness Program for Airplane Systems (EAPAS). Since its issuance, part 26 has been amended twice.
c. PS-AIR-100-2007-12-27A, Enhanced Airworthiness Program for Airplane Systems (EAPAS) Supplemental Type Certificate (STC) Limitation. On July 7, 2008, the FAA issued policy statement PS-AIR-100-2007-12-27A (refer to paragraph 2-7 of this AC for a detailed discussion).
d. PS-AIR-100-2007-12-27B, Enhanced Airworthiness Program for Airplane Systems (EAPAS) Supplemental Type Certificate (STC) Limitation. On June 10, 2009, the FAA issued revised policy statement PS-AIR-100-2007-12-27B. This revision adds part 26 to type data sheets and STCs.
e. PS-ANM-08-113-001, Clarification of Maximum Payload Capacity Definition in Design Approval Holder Rules. On September 12, 2008, the FAA issued policy statement PS-ANM-08-113-001. The maximum payload capacity criterion is used, along with other criteria, to determine whether a rule is applicable to a DAH. However, there has been confusion on the use and definition of the term. This policy memorandum clarifies the maximum payload capacity criterion when used with regard to these DAH rules and their corresponding operational rule.
Par 2-1 Page 7 CHAPTER 2. ENHANCED AIRWORTHINESS PROGRAM FOR AIRPLANE
SYSTEMS (EAPAS) REQUIREMENTS
2-1. REQUIREMENTS. This advisory circular (AC) provides guidance to support operator compliance with the electrical wiring interconnection system (EWIS) maintenance program requirements contained in the Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/FTS) rule. Title 14 of the Code of Federal Regulations (14 CFR) part 121, § 121.1111 and part 129, § 129.111 require operators to incorporate Federal Aviation Administration (FAA) Oversight Office-approved EWIS instructions for continued airworthiness (ICA) into their maintenance program. The ICA consists of inspection and restoration tasks, task intervals, procedures to accomplish those tasks, and “protections and caution” instructions/information for the EWIS. The design approval holder (DAH) develops and revises the ICA using the current edition of AC 25-27, Development of Transport Category Airplane Electrical Wiring Interconnection Systems Instructions for Continued Airworthiness Using an Enhanced Zonal Analysis Procedure. (For more information on enhanced zonal analysis procedure (EZAP), refer to Appendix 2.)
2-2. DESCRIPTION OF EWIS ICA REQUIRED BY 14 CFR PART 26, § 26.11.
a. Overview. EWIS ICAs required by § 26.11 are inspection and restoration tasks, procedures, and instructions to keep EWIS Airworthy throughout its operational life and are described below. The EWIS ICA required by § 26.11 are developed in accordance with 14 CFR part 25 Appendix H, § H25.5(a)(1) and (b).
(1) The inspection can be a zonal General Visual Inspection (GVI), stand-alone GVI, detailed inspection (DET), or a combination of these as required for a design change.
(2) Restoration tasks are usually cleaning tasks such as replacing an air filter in order to reduce the likelihood of contamination build-up within a zone.
NOTE: The type certificate holder (TCH) or applicant develops the inspection and restoration tasks using the Airlines for America (A4A), operator manufacturer scheduled maintenance development, Maintenance Steering Group – 3rd Task Force (MSG-3), and later revisions, and the EZAP described in the current edition of AC 25-27. A Supplemental Type Certificate (STC) holder or applicant does not utilize the Maintenance Review Board (MRB) process, but uses the guidance contained in the current edition of AC 25-27 to develop new or revise EWIS ICA as required for a design change.
(3) In addition to the inspection and restoration tasks, EWIS ICA can also include:
(a) A revised standard wiring practices/electrical standards manual that is presented in a standardized format using the guidance in AC 25-27 (refer to § H25.5(a)(2)).
(b) Wire separation requirements (refer to § H25.5(a)(3)).
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(c) Information explaining the EWIS identification method and requirements for identifying any changes to EWIS (refer to § H25.5(a)(4)).
(d) Electrical load data (i.e. electrical load analysis) and instructions for updating that data (refer to § H25.5(a)(5)).
NOTE: The source document requirements only apply to EWIS inspection and restoration tasks.
(4) The DAH or applicant develops the EWIS ICA using the MSG-3 and the current edition of AC 25-27. An STC holder or applicant does not utilize the MSG-3, but can use guidance contained in the current edition of AC 25-27 to develop new or revise EWIS ICA as required for a design change.
b. Multiple Components. EWIS ICA can be, and almost always are, comprised of several different components. All of these components define a particular EWIS ICA. These components are located in multiple DAH-produced documents.
(1) As an example, EWIS ICA components can be located in one or more of the following documents:
• Document required by § H25.5(b) (commonly referred to as a “source document”);
• Maintenance Review Board Report (MRBR);
• Maintenance Planning Document (MPD);
• Maintenance implementation document (MID);
• Airplane Maintenance Manual (AMM);
• Standard Wiring Practice Manual (SWPM);
• Electrical Standard Practices Manual (ESPM) (a term used by some TCH); or
• Stand-alone ICA document produced by an STC applicant.
(2) These components include such items as:
• Type of task (restoration/cleaning, stand-alone GVI, DET, or standard zonal GVI as identified in the MRBR or MID.)
• Task interval (e.g., every 16,000 flight cycles or 3,000 days).
• Airplane zone identification for airplanes with a zonal program (e.g., Zone 201).
• Task description as described in the MRBR and MID (e.g., Inspect (General Visual) all exposed EWIS in the wheel well.)
NOTE: The gear is extended with the handle down and gear locked in the down position and doors in open position.
• Airplane applicability as identified in the source document. Some models within the same family of airplanes may have differing maintenance requirements based on available options (e.g., freighter versus passenger version engine types).
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• Task procedure(s) as described in the referenced AMM or other documents that contain the procedure(s). These are the actual instructions on how to perform the GVI, DET, and restoration/cleaning tasks that support the task description listed in the MRBR and MID.
• Supporting task procedure(s), if any, necessary to perform the task procedure in any other document referenced by the task procedure.
• Instructions for protections and caution information that will minimize contamination and accidental damage to EWIS (these can appear in different places, such as in the AMM or in the SWPM/ESPM). This information, if contained in the SWPM/ESPM (or other similar documents), should be in its chapter 20. Sometimes, this information is repeated in the standard practices chapter 20 of the AMM. In any case, it is general protections and caution information and it is not expected that unique procedures will be developed for individual EWIS ICA for a particular airplane model or models produced by the same manufacturer. The AMM or SWPM/ESPM will reference any protections and caution information specific to EWIS ICA.
c. EWIS Source Document. Section H25.5(b) states that the EWIS ICA developed in accordance with the requirements of § H25.5(a)(1) must be in the form of a document appropriate for the information provided, and must be easily recognizable as EWIS ICA or specifically reference other sections of the EWIS ICA that contain this information. This document is referred to as the source document. Section H25.5(b) does not prescribe a specific data form. The form is at the discretion of the DAH, as long as it meets the requirements of § H25.5(b). The entire EWIS ICA can be in the source document, or the source document can point to a series of other documents, such as the MRBR, MPD, MID, AMM, or SWPM/ESPM, which contain the EWIS ICA.
NOTE: The source document referenced above is FAA Oversight Office approved. The operational rules require operators to incorporate EWIS ICA into their maintenance program that have been FAA Oversight Office approved. The source document provides the information necessary for the operator to comply with §§ 121.1111 and 129.111.
d. Controlling Reference Numbers. Controlling reference numbers for the individual EWIS ICA tasks are listed in the MRBR, MPD, MID, or other maintenance documents. An example of a controlling reference number in an MRBR is “MM/MPD ref. 20-XXX-XX.” This number correlates to a cross reference number in the source document and the AMM, which is the actual maintenance task with all associated instructions to accomplish it. The DAH may refer to these reference numbers as MRB reference, AMM/MPD reference, Maintenance Significant Items (MSI) reference, task number, etc. It can vary. The TCH may consider one or all of the reference numbers part of the EWIS ICA. The DAH will identify all reference numbers necessary to fully track and identify the EWIS ICA. All reference numbers considered necessary to fully identify and track the EWIS ICA should be considered part of the EWIS ICA.
e. DAH Revisions to EWIS ICA. The DAH will revise the source document in order to account for any new or revised EWIS inspection or restoration procedures developed due to production changes, or designated changes mandated by AD. They will provide the revised
Page 10 Par 2-2 source document to operators after the document has been approved by the FAA Oversight Office.
2-3. EWIS ICA DEVELOPMENT REQUIRED BY § 25.1729. In addition to EWIS ICA that are required and developed under § 26.11 for existing in service airplanes, there will also be EWIS ICA developed under § 25.1729 for new airplane type certificates (TC), or when 14 CFR part 21, § 21.101, Designation of Applicable Regulations, requires the holder of an amended TC or an STC to comply with a corresponding amendment to part 25 that was issued on or after the date of the applicable part 26 provision. Section 21.101 is referred to as the Changed Product Rule. The EWIS ICA required by § 25.1729 are developed under § H25.5(a)(1) through (5), and
(b). Simply stated, an operator can have airplanes that have EWIS ICA developed under § 26.11 and EWIS ICA developed under § 25.1729 which include all of § H25.5.
2-4. DESCRIPTION OF EWIS ICA REQUIRED BY § 26.11. The DAH is required to develop ICA for the “representative airplane’s” EWIS according to § 26.11, as follows:
a. TCH. The TCH is required to develop EWIS ICA for the “representative airplane” in accordance with § 26.11(b). The purpose was to ensure that all variations of EWIS used in production were reviewed and appropriate ICA were developed. These EWIS ICA were developed in accordance with H25.5(a)(1) and (b), in effect on December 10, 2007 for each affected type design. The TCH submits those ICA for review and approval by the FAA Oversight Office.
NOTE: TCH with § 25.1729 in their certification basis will develop EWIS ICA in accordance with § H25.5(a) and (b).
b. STC/ATC Holders. STC/ATC holders are only required to develop EWIS ICA in compliance with § 26.11(c) or, if required or elected, in compliance with § 25.1729 if the application date for the STC or change to an existing STC was before December 10, 2007, and the FAA issued the certificate on or after December 10, 2007. New STC or amended applications filed after the effective date of the rule (December 10, 2007) are also required to develop FAA Oversight Office-approved EWIS ICA in compliance with § 26.11 or, if required or elected, in compliance with § 25.1729.
NOTE: STC/ATC holders with § 25.1729 in their certification basis will develop EWIS ICA in accordance with § H25.5(a) and (b).
2-5. WHY EWIS ICA APPROVAL IS NECESSARY. While the FAA accepts ICAs, the cognizant FAA Oversight Office must approve EWIS ICA. The development of EWIS ICA requirements can be complex, requiring qualitative engineering and maintenance assumptions.
Approval will help ensure standardized application of these assumptions (e.g., zone density, zone size, potential effects of tire, environmental effects, etc.) and ensure that important information such as wire identification requirements and EWIS separation requirements developed during airplane certification are correctly and logically documented in the airplane’s ICA documents.
FAA approval also ensures that operators will be provided with the EWIS ICA and able to use the data/documents to comply with their operational requirements. It will also ensure that the
Par 2-5 Page 11 data/documents delivered to the operators will be standardized to the extent required by the EWIS ICA requirements.
2-6. TCH-DEVELOPED EWIS INSPECTION AND RESTORATION TASKS. The TCH can develop EWIS ICA in accordance with § H25.5(a)(1) and (b), which are invoked either by § 25.1729 or § 26.11(b) or (c), by utilizing the MSG-3 logic contained in the Air Transport Association Operator/Manufacturer Scheduled Maintenance Development Document (MSG-3) Revision 2005.1 and later revisions, and the current edition of AC 25-27. The EWIS ICA will be identified as EWIS ICA as required by § H25.5(b) in the source document developed by the TCH. As stated earlier in this AC, the TCH will:
• Develop a source document that contains all required EWIS ICA data;
• Develop a source document that references other maintenance documentation that contains the required EWIS ICA data; or
• Utilize an existing document, such as the MRBR, MPD, or MID.
NOTE: With reference to TCH Service Bulletins (SB) that affect EWIS, the FAA expects that the TCH will identify protections and caution information in a manner or form that conveys the information to the operator. For example, one TCH states in every SB that affects the EWIS this cautionary statement: keep the work area, wires, and electrical bundles clean of metal particles or contamination when you use tools. Unwanted material, metal particles, or contamination caught in wire bundles can cause damage to the bundles. Damaged wire bundles can cause sparks or other electrical damage.
a. Overview. EWIS ICA developed from application of the EZAP should be located in the systems and powerplant section under ATA 20, and the zonal inspection program section of the airplane’s MRBR, maintenance planning document, maintenance implementation document, or a source document. They consist of inspection and restoration tasks, task intervals, and instructions/procedures to accomplish the tasks. The inspection can be a zonal GVI, stand-alone GVI, DET, or a combination of these. The TCH selects the task intervals to ensure that operators properly maintain the EWIS, while still allowing flexibility for the operators to schedule maintenance tasks within their maintenance programs. The FAA Oversight Office approves the EWIS ICA.
b. Location.
(1) All EWIS ICA will be in the source document, or the source document will reference other document locations.
(2) Operators must incorporate the FAA Oversight Office-approved EWIS ICA into their maintenance program.
c. Instructions and Procedures.
(1) The FAA Oversight Office-approved instructions/procedures to carry out the EWIS tasks will be contained in the AMM or SWPM/ESPM.