Appendix B Flowchart 1, Page 3 B approved EWIS ICA for Are there existing FAA- the zone(s) that you -NO EWIS ICA for the zone(s) you are modifying, you now must Since there are no existing develop applicable and Go to Page 4 of this Flowchart have modified or are effective EWIS ICA inspection proposing to modify? or restoration tasks -YES- Since there are existing EWIS ICA for the zone(s) you At a minimum there will be an existing Zonal GVI for must now determine if these the zone that has been designated as an EWIS ICA. Are there other existing EWIS existing ICA are adequate for The Zonal GVI inspects everything in the zone, so ICA for the zone besides the the modified zone(s), if they anything added or revised by your modification will be Zonal GVI? -YES- need to be revised, or if inspected during the performance of the zonal task. - Stand-alone GVI additional ICA are necessary. Be sure that you use the However, if there are no other EWIS ICA other than the zonal GVI, you must determine if the zonal GVI - DET (detailed inspection) latest FAA-approved EWIS remains applicable and effective for all EWIS in the Restoration (cleaning) ICA for the zone(s) zone after you modification is installed 20A Go to Page 5 of this Flowchart Does the modification Does the modification:
introduce new combustibles or -NO Increases the potential negative safety effects of a contaminants to the zone that can be cleaned?? fire in the zone by introducing flammable vapors or other combustibles where it is not possible to identify an effective and applicable cleaning task? Does the modification:
OR Create a cleaning task to clean the zone at * At (ter tee ANG, or high area carying -NO areas of the zone where prior to Result in wire being installed in an interval not less than the point in the system EWIS to the zone where prior to the the modification there was no existing maintenance program where there modification there were none? wiring?
is planned access. NOTE: If your OR modification introduced the possibility of Install, or modify existing EWIS that will result in the vapors or mist then it is not possible to EWIS being located within 2 in / 50mm of BOTH identify a task to "clean the zone of vapors" primary AND backup hydraulic, mechanical, or for example. However, you can still identify electrical flight controls?
a task to clean any contaminants within the NO zone if your modification has the potential to introduce them to the zone. For example the addition of hydraulic components - if there is an un-shrouded pipe or joints that could leak hydraulic fluid, then the task should be to clean any leaked fluid.
The existing EWIS ICA inspection (DET) for Create a detailed the revised or modified modified EWIS within Create a Stand-alone GVI for the revised or considered as adequate INSPECTIONS can be and no further new or EWIS within the zone the zone at an interval revised EWIS Inspection 3: Refer to the discussion for Step that of the existing at an interval equal to Zonal GVI equal to that of the existing Zonal GVI tasks are necessary. statement to the FAA Submit a compliance 4 and Step 5 of the Appendix A Oversight Office EZAP procedure starting on page A-6 of this AC for guidance in helping you to determine if there are, or likely to be, combustible materials in the zone and defining an effective task to significantly reduce the likelihood of Submit the new EWIS inspection tasks and any cleaning tasks created in Step 22 to the accumulation of combustible FAA Oversight Office for review and approval.
materials. In addition the main Refer to paragraphs 6, 7, and 9 of this AC for guidance on what data the FAA considers body of the AC has more necessary to be included in an EWIS ICA. Remember the EWIS ICA submitted to the FAA discussion on this topic starting at must comply with the identification and documentation requirements of part 25, appendix paragraph 13. B, section H25.5(b).
B-4
Appendix B Flowchart 1, Page 4 29A Create a cleaning task to clean the zone at an interval not less than the point in the From Flowchart, existing maintenance program where there Page 3, Step 17A is planned access. NOTE: If your 29 modification introduced the possibility of Does the modification identify a task to "clean the zone of vapors" vapors or mist then it is not possible to C • introduce new combustibles or YES for example. However, you can still identify contaminants to the zone that can be cleaned?? zone if your modification has the potential to a task to clean any contaminants within the introduce them to the zone. For example the addition of hydraulic components - if there is an un-shrouded pipe or joints that NO could leak hydraulic fluid, then the task should be to clean any leaked fluid.
30 Does the modification:
Increases the potential negative safety effects of a fire in the zone by introducing combustibles or contaminants to the zone where before none existed? OR Add power feeder EWIS or other high current carrying EWIS (>16 AWG) or critical airplane system EWIS to the zone where prior to the modification there were none? OR Install, or modify existing EWIS that will result in the EWIS being located within 2 in / 50 mm of BOTH primary AND backup hydraulic, mechanical, or electrical flight controls?
30А Create a detailed inspection (DET) for the revised or modified EWIS within the zone at an interval equal to that of the existing Zonal GVI Designated the existing zonal GVI as an
EWIS ICA -YES- Submit the EWIS ICA to the FAA Oversight Office for review and approval. Refer to paragraphs 6, 7, and 9 of this AC for guidance on what data the FAA considers necessary to be included in an EWIS ICA. Remember the EWIS ICA submitted to the FAA must comply with the identification and documentation requirements of part 25, appendix B, section H25.5(b).
З0B Create a Stand-alone GVI for the revised or modified EWIS within the zone at an interval equal to that of the existing Zonal GVI NO Designated the existing zonal GVI as an
EWIS ICA Submit the EWIS ICA to the FAA Oversight Office for review and approval. Refer to to paragraphs 6, 7, and 9 of this AC for guidance on what data the FAA considers necessary to be included in an EWIS ICA. Remember the EWIS ICA submitted to the FAA must comply with the identification and documentation requirements of part 25, appendix B, section H25.5(b).
B-5
Appendix B Flowchart 1, Page 5 From Page 3 32 Step 20A Is there an existing cleaning tasks designated as an EWIS new combustibles or contaminants Does the modification introduce YES ICA that will effectively clean the new combustibles or -NO to the zone that can be cleaned?? contaminants introduced by the modification?
NO Create a cleaning task to clean the zone at an interval not less than the point in the Since there is a Stand-alone existing maintenance program where there GVI, DET, or both, EWIS is planned access. NOTE: If your inspection tasks for the zone modification introduced the possibility of besides the Zonal GVI, you vapors or mist then it is not possible to need to determine if these, identify a task to "clean the zone of vapors" remain applicable and effective for example. However, you can still identify for all EWIS in the zone after a task to clean any contaminants within the the modification is installed zone if your modification has the potential to introduce them to the zone. For example the addition of hydraulic components - if there is an un-shrouded pipe or joints that could leak hydraulic fluid, then the task should be to clean any leaked fluid Does the modification:
Increases the potential negative safety effects of a fire in the zone by introducing flammable vapors or 35A other combustibles where it is not possible to identify an effective and applicable cleaning task? OR modification is installed, will inspection that, after the Is there an existing DET inspection (DET) for the revised or modified Create a detailed Added power feeder EWIS or other high current EWIS within the zone YES fully inspect the EWIS that NO carrying EWIS (>16 AWG) or critical airplane system EWIS to the zone where prior to the modification there were none? your modification and the EWIS that it was originally was added or revised by that of the existing at an interval equal to Stand-alone or DET OR intended to inspect? inspections Install, or modify existing EWIS that will result in the EWIS being located within 2 in / 50mm of BOTH primary AND backup hydraulic, mechanical, or electrical flight controls?
NO After the modification, will the existing EWIS ICA (other than the zonal GVI) fully The existing EWIS ICA inspect the EWIS that was added or revised by your considered as adequate INSPECTIONS can be Submit the new EWIS inspection tasks and any cleaning tasks created in Step XX to the FAA that it was originally intended modification and the EWIS to inspect? revised EWIS Inspection and no further new or tasks are necessary. guidance on what data the FAA considers necessar Refer to to paragraphs 6, 7, and 9 of this AC for Oversight Office for review and approval.
NO statement to the FAA Submit a compliance Oversight Office. the identification and documentation requirements of EWIS ICA submitted to the FAA must comply with to be included in an EWIS ICA. Remember the part 25, appendix B, section H25.5(b).
Create a Stand-alone GVI to inspect the EWIS that was added or revised by your modification at an interval equal to that of the existing Zonal GVI B-6
Appendix C
Appendix C Definitions
1. Aging Transport Systems Rulemaking Advisory Committee (ATSRAC)—The ATSRAC was an aviation rulemaking committee, chartered under 49 USC § 106(p)(5) and tasked with providing public recommendations to the FAA. The committee was chartered on January 19, 1999, by FAA Order 1110.127, which stated “The committee’s primary task is to propose such revisions to the Federal Aviation Regulations and associated guidance material as may be appropriate to ensure that non-structural systems in transport airplanes are designed, maintained, and modified in a manner that ensures their continuing operational safety throughout the service life of the airplanes.” The FAA sent a formal sunset letter to the ATSRAC on April 11, 2006.
2. Aircraft Evaluation Group (AEG)—Flight Standards Service (AFS) representatives who know the operational and maintenance aspects of a certification project and are responsible for helping to determine their operational suitability. This role includes providing support to the cognizant ACO in the review and approval of the initial ICA and later changes to it related to the safety initiatives referenced in this AC.
3. Aircraft Maintenance Manual (AMM)—A manual developed by the manufacturer of a particular airplane that contains information necessary for the continued airworthiness of that airplane.
4. Arc Tracking—A phenomenon in which a conductive carbon path forms across an insulating surface on electrical wiring. This carbon provides a short circuit path through which current can flow. Arc tracking is normally a result of electrical arcing. Arc tracking is also referred to as “carbon arc tracking,” “wet arc tracking,” or “dry arc tracking.”
5. Auxiliary Tanks—Fuel tanks installed in an airplane that make additional fuel available for increasing the flight range of that airplane. The term “auxiliary” means that the tank is secondary to the airplane’s main fuel tanks. Auxiliary tanks have been installed in various locations, including center wing structure, horizontal stabilizers, wings, and cargo compartments.
6. Combustible—For the purposes of this AC, the term combustible refers to the ability of any solid, liquid, or gaseous material to cause a fire to be sustained after removal of the ignition source. The term is used in place of inflammable/flammable. It should not be interpreted as identifying material that will burn when subjected to a continuous source of heat as occurs when a fire develops.
7. Contamination—For the purposes of this AC, wiring contamination refers to either of the following:
• Presence of a foreign material likely to cause degradation of wiring.
• Presence of a foreign material that is combustible, or capable of sustaining a fire after removal of ignition source.
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Appendix C
8. Design Approval Holder (DAH)—The holder of any design approval, including type certificate, amended type certificate, supplemental type certificate, amended supplemental type certificate, parts manufacturer approval, Technical Standard Order (TSO) authorization, letter of TSO design approval, and field approvals. In particular contexts, the term DAH may also refer to applicants for design approvals.
9. Detailed Inspection (DET)—An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. DET is discussed in greater detail in section 14b(1) of this AC.
10. Effective Task/Task Interval—An “effective” task is an inspection or maintenance task, performed at defined intervals, that will ensure that the desired outcome of the task is achieved.
To be effective the task must reduce the risk of wire failure, to ensure safe operation. For example, a cleaning task to remove contaminants that have accumulated on a wire bundle would be considered effective if it cleaned the bundle sufficiently to minimize the potential of contaminant-induced failure of the bundle, and allow an inspection for wire defects to be performed. The methods and intervals for performing an effective task are developed using a combination of standard industry practices, expert opinion, and engineering judgment from operators, manufacturers, and regulatory authorities. The criteria for the effectiveness of a task should include safety and operational, as well as economic, considerations. Tasks should, at a minimum, be such that they will effectively accomplish all of the following:
• Make identification of failures possible.
• Detect wire degradation with frequent and consistent inspection intervals.
• Reduce the risk of failures.
11. Electrical Wire Interconnection Systems (EWIS)—An EWIS is defined by 14 CFR 25.1701. As defined by that section, EWIS means 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 between two or more intended termination points. The complete regulatory definition appears in appendix E to this AC.
12. Enhanced Airworthiness Program for Airplane Systems (EAPAS)—A broad initiative designed to enhance the continued safety of airplane wiring systems from their design and installation until their retirement. The initiative is a result of an intensive data-gathering effort on airplane wiring systems done in cooperation with industry. It combines a variety of near- and long-term actions into a plan to increase awareness of wiring system degradation, to implement improved procedures for wiring maintenance and design, and to spread that information throughout the aviation community.
13. Environmentally Sealed Splice—A wire splice that ensures that moisture or fluid will not penetrate the spliced area.
14. Enhanced Zonal Analysis Procedure (EZAP)—A logical process for developing maintenance and inspection instructions for Electrical Wiring Interconnection Systems (EWIS).
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Appendix C
15. FAA Oversight Office—The FAA oversight office is defined by 14 CFR 26.3 as “the aircraft certification office or office of the Transport Airplane Directorate with oversight responsibility for the relevant type certificate, supplemental type certificate, or manufacturer, as determined by the Administrator.”
16. Flammable Fluid Leakage Zone—Any area where flammable liquids or vapors are not intended to be present, but where they might exist due to leakage from flammable-fluid-carrying components (for example, leakage from tanks, lines). These zones are typically identified by the airplane manufacturer. Examples of such areas include:
• Wing leading and trailing edges (including any adjacent compartment such as the strut)
• Farings located below the fuel tanks
• Wheel wells
• Fuel pump enclosures
• Unpressurized areas of the fuselage surrounding fuel tanks
• Areas containing flammable fluid lines or tanks
17. Flight Standards Service (AFS) Offices—Offices located in FAA headquarters responsible for developing guidance and policy for Aircraft Evaluation Group (AEG) personnel and AFS field personnel (maintenance, avionics, and operations aviation safety inspectors) in the conduct of their responsibilities.
18. Fuel Tank Safety (FTS)—FTS, as used in the context of the EAPAS/FTS rule, refers to the operational requirements of 14 CFR parts 91, 121, 125, and 129 that were first issued in the 2001 FAA final rule “Transport Airplane Fuel Tank System Design Review, Flammability Reduction, and Maintenance and Inspection Requirements,” Docket No. FAA-1999-6411. The EAPAS/FTS final rule revised and renumbered these requirements.
19. Functional Failure—Failure of an item to perform its intended function within specified limits.
20. General Visual Inspection (GVI)—A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.
21. Instructions for Continued Airworthiness (ICA)—The information documented in accordance with 14 CFR 25.1529, 25.1729, or 26.11 that includes the applicable methods, C-3
Appendix C inspections, processes, procedures, and airworthiness limitations required to keep the airplane airworthy throughout its operational life.
22. Lightning/High Intensity Radiated Field (L/HIRF) Protection—The protection of airplane electrical systems and structure from induced voltages or currents by means of shielded wires, raceways, bonding jumpers, connectors, composite fairings with conductive mesh, static dischargers, and the inherent conductivity of the structure; may include airplane specific devices, for example, radio frequency (RF) gaskets.
23. Maintenance—As defined in 14 CFR 1.1, “maintenance means inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.” For the purposes of this advisory circular, maintenance also includes preventive maintenance, as described in both § 1.1 and paragraph (c) of appendix C to 14 CFR part 43. Section 1.1 of 14 CFR provides the following definition: “Preventive maintenance means simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations.” Paragraph (c) of appendix A to 14 CFR part 43 lists the tasks that are considered preventive maintenance.
24. Maintenance Instructions—Information that provides recommended periods for cleaning, inspection, adjustment, testing, lubrication, degree of inspection, applicable wear tolerances, and recommended work necessary for each part of the airplane and its engine auxiliary power units, propellers, accessories, instruments, and equipment to provide for continued airworthiness of the airplane. Recommended overhaul periods and necessary cross-references to the Airworthiness Limitations section of the maintenance manual are also included.
25. Maintenance Significant Item (MSI)—Items (system or component) identified by the manufacturer whose failure could have one or more of the following results or characteristics:
• Could affect safety (on ground or in flight).
• Is undetectable during operations (on ground or in flight).
• Could have significant operational impact.
• Could have significant economic impact.
26. Maintenance Review Board Report (MRBR)—A report intended for use by air carriers that contains the initial minimum scheduled maintenance and inspection requirements for a particular transport category airplane maintenance program. Air carriers use the MRBR and its associated requirements to develop maintenance programs. See AC 121-22A, Maintenance Review Board Procedures, for more information.
27. Maintenance Steering Group 3 (MSG-3)—MSG-3 is a document issued by the ATA that addresses the development of scheduled maintenance using an analytical procedure contained within the document. As stated in the document, its objective is “. . . to present a means for developing the scheduled maintenance tasks and intervals which will be acceptable to the regulatory authorities, the operators, and the manufacturers. The scheduled maintenance task and interval details will be developed by coordination with specialists from the operators, C-4
Appendix C manufacturers, and the regulatory authority of the country of manufacture. Specifically, this document outlines the general organization and decision processes for determining scheduled maintenance requirements initially projected for the life of the aircraft and/or powerplant.”
28. Needling—The puncturing of a wire’s insulation to make contact with the core to test the continuity and presence of voltage in the wire segment.
29. Special Federal Aviation Regulation No. 88 (SFAR 88)—SFAR 88 was issued in 2001 as part of FAA final rule “Transport Airplane Fuel Tank System Design Review, Flammability Reduction, and Maintenance and Inspection Requirements,” Docket No. FAA-1999-6411.
SFAR 88 requires the design approval holder to perform a safety review of the fuel tank system to show that fuel tank fires or explosions will not occur on airplanes of the approved design. In conducting the review, the design approval holder must demonstrate compliance with the new standards adopted for § 25.981(a) and (b) and the existing standards of § 25.901.
30. Source Document (SD)—A single document required by paragraph H25.5(b) to appendix H of 14 CFR part 25, which identifies all of the components comprising the EWIS ICA. The SD must either contain all of the required EWIS ICA, or reference other documents that contain that information.
31. Stand-Alone GVI—A general visual inspection that is not performed as part of a zonal inspection. Even in cases where the interval coincides with the zonal inspection, the stand-alone GVI remains an independent step on the work card.
32. Structural Significant Item (SSI)—Any detail, element, or assembly that contributes significantly to carrying flight, ground, pressure, or control loads and whose failure could affect the structural integrity necessary for the safety of the airplane.
33. Swarf—British term used to describe the metal particles generated from drilling and machining operations. Such particles may accumulate on and between wires within a wire bundle.
34. Standard Wiring Practices Manual (SWPM) (may also be known as the Electrical Standards Practice Manual (ESPM))—A manual (either in book or electronic form) produced by an airplane manufacturer containing information detailing procedures and practices for the universal repair and maintenance of electrical wire, cable bundles, and coaxial cables. Standard practices include procedures and practices for the inspection, installation, and removal of electrical systems components or other EWIS components, including methods of bundle attachment, wire splices, connectors and electrical terminal connections, and bonding/grounding.
35. Transport Airplane Directorate (TAD)—The FAA’s directorates (Engines and Propellers, Rotorcraft, Small Airplanes, and Transport Airplane) develop and implement national regulatory requirements, policy and procedures for continued operational safety, and type, production, and airworthiness certifications for their designated products. Each directorate also has responsibility for overseeing certification activities (field office operations, certification programs, and projects) within its geographic area. TAD has oversight responsibility for transport category airplane design approvals and modifications worldwide, as well as oversight responsibility for C-5
Appendix C over 900 production approval holders. TAD works closely with other FAA offices throughout the country and with foreign regulatory authorities to accomplish this mission.
36. Zonal Inspection—A collective term comprising selected general visual inspections and visual checks that are applied to each airplane zone, defined by access and area, to check system and power plant installations and structure for security and general condition. Zonal inspections are discussed in greater detail in section 10 of this AC.
37. Zonal Inspection Program (ZIP)—A part of an airplane model’s overall maintenance program where the whole of the airplane is divided into zones. For each zone of the airplane, applicable maintenance instructions are identified.
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Appendix D Appendix D
1. FAA Oversight Offices for the Purposes of Part 26. Table 1 lists the FAA oversight offices, as currently determined by the Administrator, that oversee issuance of type certificates and amended type certificates for manufacturers of transport category airplanes with a passenger capacity of 30 passengers or a payload capacity of 7,500 pounds or greater.
Table 1. FAA Oversight Offices for Issuance of TCs and Amended TCs Airplane Manufacturer FAA Oversight Office Aerospatiale Transport Airplane Directorate, International Branch, ANM-116 Airbus Transport Airplane Directorate, International Branch, ANM-116 BAE Transport Airplane Directorate, International Branch, ANM-116 Boeing Puget Sound Seattle Aircraft Certification Office Boeing Long Beach Los Angeles Aircraft Certification Office Bombardier New York Aircraft Certification Office CASA Transport Airplane Directorate, International Branch, ANM-116 deHavilland New York Aircraft Certification Office Dornier Transport Airplane Directorate, International Branch, ANM-116 Embraer Transport Airplane Directorate, International Branch, ANM-116 Fokker Transport Airplane Directorate, International Branch, ANM-116 Lockheed Atlanta Aircraft Certification Office McDonnell-Douglas Los Angeles Aircraft Certification Office SAAB Transport Airplane Directorate, International Branch, ANM-116 D-1
Appendix E Appendix E
1. Applicable Regulations and Relevant Preamble Discussion.
a. The text of the regulations referred to in this AC is reproduced here for easy reference.
This information is provided as reference only. If any deviation exists between the reference material provided here and the regulations contained in the Code of Federal Regulations (CFR), it is the regulations in the CFR that must be complied with. We have also included here the applicable preamble discussions from the EAPAS/FTS Notice of Proposed Rulemaking (NPRM) issued on October 5, 2005 (70 FR 58508). The preamble discussion for a particular regulation follows the text of that regulation. You should refer to the NPRM and the final rule for a complete discussion of the requirements. Only the most relevant text from those discussions has been reproduced here.
b. Comments received about the NPRM are summarized and discussed in the final rule.
You can download a copy of the Final Rule from the Internet at http://www.gpoaccess.gov/cfr/.
Mail, telephone, and fax request information is given in appendix G.
2. Part 25
a. Section 25.1701.
Ҥ 25.1701 Definition.
(a) As used in this chapter, electrical wiring interconnection system (EWIS) means 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. This includes:
(1) Wires and cables.
(2) Bus bars.
(3) The termination point on electrical devices, including those on relays, interrupters, switches, contactors, terminal blocks and circuit breakers, and other circuit protection devices.
(4) Connectors, including feed-through connectors.
(5) Connector accessories.
(6) Electrical grounding and bonding devices and their associated connections.
(7) Electrical splices.
(8) Materials used to provide additional protection for wires, including wire insulation, wire sleeving, and conduits that have electrical termination for the purpose of bonding.
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Appendix E
(9) Shields or braids.
(10) Clamps and other devices used to route and support the wire bundle.
(11) Cable tie devices.
(12) Labels or other means of identification.
(13) Pressure seals.
(14) EWIS components inside shelves, panels, racks, junction boxes, distribution panels, and back-planes of equipment racks, including, but not limited to, circuit board back-planes, wire integration units, and external wiring of equipment.
(b) Except for the equipment indicated in paragraph (a)(14) of this section, EWIS components inside the following equipment, and the external connectors that are part of that equipment, are excluded from the definition in paragraph (a) of this section:
(1) Electrical equipment or avionics that are qualified to environmental conditions and testing procedures when those conditions and procedures are—
(i) Appropriate for the intended function and operating environment, and
(ii) Acceptable to the FAA.
(2) Portable electrical devices that are not part of the type design of the airplane. This includes personal entertainment devices and laptop computers.
(3) Fiber optics.”
b. Section 25.1729.
(1) Regulation.
Ҥ 25.1729 Instructions for Continued Airworthiness: EWIS.
The applicant must prepare Instructions for Continued Airworthiness applicable to EWIS in accordance with Appendix H sections H25.4 and H25.5 to this part that are approved by the FAA.”
(2) NPRM Preamble Discussion (70 FR 58526, October 6, 2005). (§ 25.1729 was proposed as § 25.1739).
“Section 25.1739 Instructions for Continued Airworthiness: EWIS.
Proposed § 25.1739 would require that applicants prepare EWIS ICA in accordance with the requirements of Appendix H to part 25. The proposed EWIS ICA requirements are discussed in the next section of this document.”
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