Appendix E
• It is also possible that an airplane design could be originally certified with a capacity slightly lower than the minimum specified in this section, but through later design changes, the capacity could be increased above this minimum. The reference to later increases in capacity would ensure that, if this occurs, the design would have to meet the requirements of this section.
Compliance is not proposed for airplanes with a certificated passenger capacity of fewer than 30 passengers, or having a maximum capacity of less than 7500 pounds payload resulting from original certification, because it is not clear at this time that the possible benefits for those airplanes would be proportionate to the cost involved. The FAA intends to evaluate the merits of applying these requirements to those airplanes. We are currently working with ATSRAC to assess how these issues might be addressed in those transport category airplanes. We request comments on the feasibility and benefits of requiring holders of TCs for those airplanes to comply with these requirements.
This proposed rule, as it applies to EWIS, is not applicable to holders of existing (already issued) STCs. Often, the wire design for STC installations of EWIS was based on operator or repair station standard practices and therefore details of the installation are not available. In the cases where such information is available, it would usually indicate that the wiring for the modification follows the same path, or is in the same airplane zone, as the wiring in the original type design. We anticipate that operators would inspect those areas while performing the TC holder’s EZAP program. We also expect that any possible discrepancies will be further mitigated by operators incorporating applicable EWIS maintenance tasks into the maintenance program for that zone. Accordingly, the FAA has decided not to require compliance with this section for existing STCs. However, if an existing STC is amended, this section would apply to the amendment.
TC holders, who design EWIS on airplanes, are the technical experts who possess information about those systems. This proposal would apply to the following:
• TC holders.
• Applicants for TCs and for approval of design changes to existing TCs whose applications are pending when this rule becomes effective.
• Future applicants for approval of design changes to existing TCs.
Section 25.1805(b) would require TC holders to complete a comprehensive assessment of the EWIS of each “representative” airplane for which they hold a TC, develop inspection and maintenance instructions for them, and incorporate those instructions into the airplane’s ICA.
The “representative” airplane is defined as the configuration of each model series airplane that incorporates all the variations of EWIS used on that model, and that includes all TC-holder designed modifications mandated by AD, as of the effective date of this rule.
For example, for the Boeing Model 737, the representative airplane would be the configuration of each of the airplane series, 737-100 through 737-900 that incorporates all the variations of EWIS used in producing each airplane series. The purpose of this definition is to ensure that the TC holder considers the full range of EWIS configurations that may affect the E-15
Appendix E results of the EZAP. Further, AD 99-03-04 applies to all Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. It requires installation of components to provide shielding and separation of the fuel system wiring from adjacent wiring. It also requires installation of flame arrestors and pressure relief valves in the fuel vent system. Boeing would be required to develop ICA for each of those series airplanes as modified by installation of these components and all other modifications mandated by ADs.
The purpose of including these mandated design changes is to ensure that the TC holder’s EZAP addresses the existing configuration of airplanes in the operating fleet, rather than just the configuration produced and delivered by the manufacturer.
Applicants for approval of design changes would be required to evaluate the effect of their proposed change on the EWIS ICA developed by the TC holder for the representative airplane and to develop EWIS ICA to address those effects. For TC holders, this requirement would apply to any design changes that may affect the ICA for the representative airplane. This includes service bulletins describing such design changes. Under § 21.113, these design changes are amendments to the TC.
A description of what must be included in those ICA, and the EZAP that must be used to develop them, is contained in the section of this preamble discussing the proposed revision to Appendix H, part 25.
The requirement for ICA was effective on January 28, 1981. TC holders whose application was dated before that date are not subject to that requirement. This proposal would require TC holders who do not have ICA for specific airplane models to create EWIS ICA for them. As discussed below, air carriers and operators of those airplanes would then be required to revise their maintenance or inspection programs based on the new ICA for EWIS and fuel tank systems.
As discussed earlier, SFAR 88 requires TC holders to develop maintenance and inspection instructions to assure the safety of the fuel tank system. Proposed § 25.1805(b) would require that TC holders align the fuel tank system instructions with the results of the EZAP applied to EWIS to ensure compatibility and minimize redundancies. All EWIS would be subject to review in developing the EWIS ICA, and the appropriate instructions for their maintenance and inspection would be required. But some EWIS are also part of the fuel tank system. The requirements for their maintenance and inspection might be more specific than those for wiring in general, and might contain additional requirements. That is why the two must be reviewed for compatibility.
As discussed later in this section, the ICA for fuel tank system electrical wiring required by SFAR 88 will be determined in accordance with guidance provided by Policy Statement ANM100-2004-1129, “Process for Developing Instructions for Maintenance and Inspection of Fuel Tank Systems Required by SFAR 88” (a copy of which may be found in the docket), or other acceptable process. Compliance with Subpart I will require ICA for the same wire to be determined using an EZAP. While these processes have similarities, they may result in identification of different tasks and intervals. The ICA maintenance tasks and intervals that E-16
Appendix E result from these determinations are expected to be additive. If there is a conflict in the task or interval, for purposes of this section, the FAA Oversight Office will resolve the conflict.
The ICA should be reviewed to ensure that any maintenance tasks for EWIS do not compromise fuel tank system wire requirements, such as separation or configuration specifications. If there is an inspection or maintenance requirement for EWIS and the fuel tank system within the same zone, there must be an effort to align the task interval. In addition, design certificate holder’s existing documents containing EWIS and fuel tank system ICA should be reviewed to either remove or cross-reference redundant information.
The compliance plan required by this proposal must include identification of those common locations in the airplane where EWIS and fuel tank ICA apply. The considerations for compatibility and minimization of redundancy for the two systems will be reviewed and approved by the FAA Oversight Office. The plan for documenting the required ICA for EWIS and fuel tank system will also be reviewed as part of the compliance plan. These documents are critical to the effort that will be required of operators to show compliance with the operational rules contained in this proposal. We intend that the ICA information, both in content and format, will be readily usable by the affected operators for developing proposed changes to their maintenance or inspection programs. Generally, the information contained in the ICA for the fuel tank system required by SFAR 88 would include:
• The location of the fuel tank system components to be maintained or inspected and any access requirements.
• Any unique procedures required, such as special, detailed inspections or dual sign-off of maintenance records.
• Specific task information, such as inspections defined by pictures or schematics.
• Intervals for any repetitive tasks.
• Methods, techniques, and practices required to perform the task.
• Criteria for passing inspections.
• Any special equipment or test apparatus required.
• Critical Design Configuration Control Limitations—for example, wire separation or pump impeller material specifications—that cannot be altered, except in accordance with the applicable limitation.
The information for EWIS ICA would generally include:
• Identification of each zone of the airplane.
• Identification of each zone that contains EWIS.
• Identification of each zone containing EWIS that also contains combustible material.
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Appendix E
• Identification of each zone in which EWIS is in close proximity to both primary and back-up hydraulic, mechanical, or electrical flight controls and lines.
• The location of the EWIS components to be maintained or inspected and any access requirements.
• Any unique procedures required, such as special, detailed inspections, or a dual sign-off of maintenance records.
• Specific task information, such as inspections defined by pictures or schematics.
• Intervals for any repetitive tasks.
• Methods, techniques and practices required to perform the task.
• Criteria for passing inspections.
• Any special equipment or test apparatus required.
• Instructions for protection and caution information that will minimize contamination and accidental damage to EWIS during performance of maintenance, alterations, or repairs.
• Guidelines for identifying wiring discrepancies and assessing what effect such discrepancies, if found, could have on adjacent systems, particularly if these include wiring.
• Critical Design Configuration Control Limitations—for example, wire separation specifications—that cannot be altered, except in accordance with the applicable limitation.
Policy Statement No. PS-ANM100-2004-10029 provides guidance on acceptable processes for developing fuel tank system ICA as required by SFAR 88. The FAA expects that engineers from aircraft certification offices or from the Transport Airplane Directorate will review and approve the results of the EZAP.
The three groups whose compliance with this proposal would be required, and their required compliance dates, indicated in paragraph (c), are as follows:
• Existing TC holders: No later than December 16, 2007.
• Current applicants for TCs and amendments to TCs (including service bulletins describing design changes) whose applications are pending and future applicants for TC amendments: No later than December 16, 2007, or the date of approval of their application, whichever is later.
• Pending and future applicants for STCs: No later than June 16, 2008, or the date of the approval of their application, whichever is later.
Future applicants for changes to TCs that comply with proposed § 25.1739 would not be required to comply with this section. As discussed previously, under § 21.101, applicants for E-18
Appendix E “significant” changes that meet certain criteria must comply with the latest airworthiness requirements. If this NPRM is adopted as a final rule, such a future applicant would have to comply with § 25.1739. Because the proposed requirements of that section are more extensive than the proposed requirements of § 25.1805, requiring compliance with this section would be redundant.
In determining the compliance schedules for the requirements covered in this proposal, the FAA balanced the safety-related reasons for the rule against the need to give industry enough time to comply with it. Therefore, before setting the proposed compliance times for the TC holders to complete their analysis of their representative type design, the FAA considered the following:
• Input from industry.
• Current or planned compliance periods of several aging-related rulemakings, such as the pending Aging Airplane Safety proposed rule, Fuel Tank System safety initiatives (69 FR 45936, 66 FR 23086), and the pending Widespread Fatigue Damage proposal.
• Safety improvements that will result from compliance with this rule.
• Industry’s current efforts to incorporate some of these safety initiatives.
ATSRAC recommended a compliance time of 24 months for TC holders to develop these ICA. To align this proposal with other rules in the aging airplane program, the FAA has adjusted the time frame to that of other rules discussed earlier, so that operators can more efficiently comply with requirements to revise their maintenance programs. To support this realignment, compliance dates that allow an 18-month time frame for TC holders to develop the EWIS ICA and 12 months for operators to implement them were determined to be appropriate and were included in this proposal. We believe these time frames are supported by the experience gained from the EZAPs already performed. Since ATSRAC made its recommendation, several manufacturers have applied an EZAP to their type design airplanes and have completed those reviews.
When we initially drafted this proposal, we assumed the final rule would be adopted by mid-2006. As a result, we set the compliance dates in the proposal using the mid-2006 time frame as the baseline. However, the proposed rulemaking process took longer than we had anticipated. Consequently, we expect that the time frame for adoption of the final rule will be sometime after mid-2006. We recognize that this delay will adversely impact the compliance dates we propose for TC holders and operators and we may need to adjust them. Therefore, we request and will consider your comments on revising the proposed compliance dates. Once the ICA are approved by the FAA Oversight Office, the submitter must make the ICA available to affected persons as required by § 21.50.
Because this proposal sets a precedent in introducing part 25 requirements for holders of existing TCs, it is the FAA’s expectation that they will work closely with the FAA Oversight Office in putting together a compliance plan for developing the required ICA. Proposed section E-19
Appendix E
25.1805(d) would require that the compliance plan be approved by the FAA Oversight Office as sufficient basis for showing compliance with the proposed § 25.1805.
Development of a compliance plan is necessary to ensure that TC holders thoroughly understand the requirements of this proposal and produce on time appropriate ICA that are acceptable in content and format in addressing the maintenance and inspection tasks for EWIS and the fuel tank system. Integral to the compliance plan will be the inclusion of procedures to allow the FAA to monitor progress towards compliance. These aspects of the plan will help ensure that the expected outcomes will be acceptable and on time for incorporation by the affected operators in accordance with the operational rules contained in this proposal.
To help ensure that TC holders are fully informed of what is necessary to show compliance with these requirements, as previously discussed, we are issuing AC 120.XX, and have issued a policy statement that describes an acceptable means, but not the only means, of complying with these requirements for developing EWIS ICA and the fuel tank system ICA required by SFAR 88. AC 120-XX, “Program to Enhance Transport Category Airplane Electrical Wiring Interconnection System Maintenance,” provides an enhanced zonal analysis procedure (EZAP) for completing a review of the representative airplane covering all areas, including the flight deck (or cockpit), electrical power center, fuel tank wiring, and powerfeeder cables. Policy Statement ANM100-2004-10029, “Process for Developing Instructions for Maintenance and Inspection of Fuel Tank Systems Required by SFAR 88,” provides guidance for identifying ICA, including any airworthiness limitations, as a result of the fuel tank system review required by SFAR 88 and compliance with Amendment 102 to part 25 Appendix H and § 25.981.
Proposed § 25.1805(d) is intended to provide TC holders, applicants with pending TC-amendment or STC applications, and the FAA with assurance that they understand what means of compliance are acceptable and have taken necessary actions, including assigning sufficient resources, to achieve compliance with this section. This paragraph is based substantially on “The FAA and Industry Guide to Product Certification,” which describes a process for developing project-specific certification plans for type certification programs. A copy of this guide may be found in the docket. This planning requirement would not apply to future applicants for TC amendments or STCs because, as described in the guide, this type of planning routinely occurs at the beginning of the certification process.
The guide recognizes the importance of ongoing communication and cooperation between applicants and the FAA. Section 25.1805, while regulatory in nature, is intended to encourage establishment of the same type of relationship in the process of complying with this section. In particular, in addition to other necessary information, paragraph (d)(3) makes it clear that, to the extent that they intend to use means of compliance different from those already identified as acceptable by the FAA, it is imperative that they identify those differences at the earliest possible stage so any compliance issues can be resolved without risk of unnecessary expenditure of resources or, ultimately, noncompliance.
Proposed § 25.1805(d) would require TC holders and applicants to submit to the FAA Oversight Office the following within 90 days after the effective date of the rule:
E-20
Appendix E
• A proposed project schedule, identifying all major milestones, for meeting the compliance dates of this rule.
• A proposed means of compliance with this section, identifying all required deliverables, including all compliance items and all data to be developed to substantiate compliance. If any affected person has already initiated compliance, the FAA Oversight Office will review the results of those efforts to ensure that the results are acceptable.
• A detailed explanation of how the proposed means will be shown to comply with this section if the affected person proposes a means of compliance that differs from that described in FAA advisory material.
• A proposal for how the approved ICA will be made available to affected persons.
It should be noted that this section applies not only to domestic TC holders and applicants, but also to foreign TC holders and applicants. In this sense, this section is different from most type certification programs, where foreign applicants typically work with their responsible certification authority, and the FAA relies on that authority’s findings of compliance under bilateral airworthiness agreements. Since this rulemaking is not harmonized in all cases, the FAA will make all the necessary compliance determinations, and where appropriate we may accept findings of compliance made by the appropriate foreign authorities using procedures developed under the bilateral agreements. The compliance planning provisions of this section are equally important for domestic and foreign TC holders and applicants, and we will work with the foreign authorities to ensure that their TC holders and applicants perform the planning necessary to comply with the requirements of this section.
One of the items required in the plan is, “If the proposed means of compliance differs from that described in FAA advisory material, a detailed explanation of how the proposed means will comply with this section.” FAA advisory material is never mandatory because it describes one means, but not the only means of compliance. In the area of type certification, applicants frequently propose acceptable alternatives to the means described in advisory circulars. But when an applicant chooses to comply by an alternative means, it is important to identify this as early as possible in the certification process to provide an opportunity to resolve any issues that may arise that could lead to delays in the certification schedule.
The same is true for this requirement. As discussed earlier, TC holder compliance with this section on time is necessary to enable operators to comply with the operational requirements of this NPRM. Therefore, this item in the plan would enable the FAA Oversight Office to identify and resolve any issues that may arise with the TC holder's proposal without jeopardizing the TC holder's ability to comply with this section by the compliance time.
As of the date of this proposal, certain TC holders have voluntarily started to develop the EWIS EZAP that would be required by proposed § 25.1805. An EZAP has been completed on certain transport category airplanes. Although the EZAP used by those TC holders may not be the version outlined in AC120-XX, it is similar. The FAA would expect that after issuance of the final rule, these TC holders would either submit a plan proposing revisions to the EZAP for those model airplanes to be consistent with the guidance given in AC120-XX, or use the E-21
Appendix E planning process to show that their EZAP complies with this section. The FAA Oversight Office will then review the results of those efforts to ensure that the results are acceptable for compliance with this section.
Section 25.1805(e) requires that TC holders and applicants correct a deficient plan, or deficiencies in implementing the plan, in a manner identified by the FAA Oversight Office.
Before the FAA formally notifies a TC holder or applicant of deficiencies, however, we will have communicated with them to try to achieve a complete mutual understanding of the deficiencies and means of correcting them. Therefore, the notification referred to in this paragraph should document the agreed corrections.
Because operators’ ability to comply with the applicable operational rules will be dependent on TC holders’ and applicants’ compliance with § 25.1805, the FAA will carefully monitor their compliance and take appropriate action if they fail to achieve compliance. Failure to comply within the specified time would constitute a violation of the requirements and may subject the violator to certificate action to amend, suspend, or revoke the affected certificate in accordance with 49 U.S.C. § 44709. In accordance with 49 U.S.C. § 46301, it may also subject the violator to a civil penalty of not more than $25,000 per day per TC until § 25.1805 is complied with.”
3. Operating Requirements.
a. Part 119.
(1) § 119.3 Definitions Maximum payload capacity means:
(1) For an aircraft for which a maximum zero fuel weight is prescribed in FAA technical specifications, the maximum zero fuel weight, less empty weight, less all justifiable aircraft equipment, and less the operating load (consisting of minimum flightcrew, foods and beverages, and supplies and equipment related to foods and beverages, but not including disposable fuel or oil).
(2) For all other aircraft, the maximum certificated takeoff weight of an aircraft, less the empty weight, less all justifiable aircraft equipment, and less the operating load (consisting of minimum fuel load, oil, and flightcrew). The allowance for the weight of the crew, oil, and fuel is as follows:
(i) Crew—for each crewmember required by Federal Aviation Regulations— (A) For male flight crewmembers—180 pounds.
(B) For female flight crewmembers—140 pounds.
(C) For male flight attendants—180 pounds.
E-22
Appendix E (D) For female flight attendants—130 pounds.
(E) For flight attendants not identified by gender—140 pounds.
(ii) Oil—350 pounds or the oil capacity as specified on the Type Certificate Data Sheet.
(iii) Fuel—the minimum weight of fuel required by the applicable Federal Aviation Regulations for a flight between domestic points 174 nautical miles apart under VFR weather conditions that does not involve extended overwater operations.
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Appendix F
Appendix F
1. Background.
a. Over the years there have been a number of in-flight smoke and fire events where contaminants ignited by electrical faults allowed the fire to be sustained and spread. The FAA and the National Transportation Safety Board (NTSB) have conducted aircraft inspections and found wiring contaminated with items such as dust, dirt, metal shavings, lavatory waste water, coffee, soft drinks, and napkins. Sometimes wire bundles and surrounding areas have been found to be completely covered with dust.
b. In recent years Federal government and industry groups have realized that current maintenance practices may not be enough to address aging non-structural systems. Over time, insulation can crack or breach, thus exposing the conductor. While age is not the sole cause of wire degradation, the likelihood of EWIS damage from inadequate maintenance, contamination, improper repair, or mechanical damage increases over time. Examples include the practice of needling wires to test the continuity or voltage, and using a metal wire or rod as a guide to feed new wires into an existing bundle. These practices could cause a breach in the wiring insulation that can contribute to arcing.
c. Research has shown that maintenance work on other aircraft systems can cause collateral damage to nearby wiring. Normal maintenance actions, even using acceptable methods, techniques, and practices, can, over time, contribute to wire degradation. A person inspecting an electrical power center or avionics compartment, for example, may inadvertently cause damage to wiring in a nearby area. Zones of an airplane subject to a high level of maintenance activity display more deterioration of wiring insulation. Undisturbed wiring will have less degradation than wiring that is disturbed during maintenance.
d. Typical analytical methods used for developing maintenance programs have not provided a focus on wiring. As a result, most operators have not adequately addressed EWIS deterioration in their programs. We have reviewed current inspection philosophies to identify improvements that could lead to a more consistent application of inspection requirements, whether for zonal, stand-alone GVI, or DET inspections, as they relate to airplane wiring.
e. We believe it would be valuable to provide guidance on the type of deterioration a person performing a GVI, DET, or zonal inspection could expect to discover. Though it may be assumed that all operators provide such guidance to their affected personnel, it is evident that significant variations exist, and a significant enhancement to wiring inspection could be obtained if standardized guidance material existed. Achievement of the objectives of this AC is dependent on each operator conducting GVI and DET inspections as defined in this document.
These definitions should be incorporated in operators’ training material and in the introductory section of maintenance planning documentation.
F-1
Appendix G
Appendix G
1. Related Regulations and Documents.
a. Title 14, Code of Federal Regulations (14 CFR) parts and specific regulations.
(1) You can download an electronic copy of 14 CFR from the Internet at http://www.gpoaccess.gov/cfr/. A paper copy can be ordered by sending a request to the U.S.
Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402-0001, or by calling telephone number (202) 512-1800; or by sending a request by facsimile to
(202) 512-2250.
(2) Part 21—Certification Procedures for Products and Parts.
(a) Special Federal Aviation Regulation No. 88—Fuel Tank System Fault Tolerance Evaluation Requirements
(3) Part 25—Airworthiness Standards: Transport Category Airplanes.
(a) Subpart H—Electrical Wiring Interconnection Systems (EWIS)
(b) Appendix H to Part 25—Instructions for Continued Airworthiness
(4) Part 43—Maintenance, Preventive Maintenance, Rebuilding, and Alteration.
(a) § 43.13 Performance rules (general).
(5) Part 119—Certification: Air Carriers and Commercial Operators.
b. Advisory Circulars (ACs).
(1) The following advisory circulars also provide information that may support the method of compliance established by this AC. They are stored on the Internet in the FAA’s Regulatory & Guidance Library (RGL), a set of searchable databases containing 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.
(2) You can download an electronic copy of the latest version of the following ACs and policy from the Internet at http://www.faa.gov/regulations_policies/advisory_circulars/.
• 25-8, Auxiliary Fuel System Installation
• 25-16, Electrical Fault and Fire Prevention and Protection
• 25.981-1B, Fuel Tank Ignition Source Prevention Guidelines G-1
Appendix G
• 25.1701-1, Certification of Electrical Wiring Interconnection Systems on Transport Category Airplanes
• 26-1, Part 26, Continued Airworthiness and Safety Improvements
• 43-12A, Preventive Maintenance
• 43.13-1B, Acceptable Methods, Techniques, and Practices—Aircraft Inspection and Repair
• 43-204, Visual Inspection for Aircraft
• 43-206, Inspection, Prevention, Control, and Repair of Corrosion on Avionics Equipment
• 65-15A, Airframe & Powerplant Mechanics Airframe Handbook, Chapter 11, Aircraft Electrical Systems
• 120-16D, Air Carrier Maintenance Programs
• 120-94, Aircraft Electrical Wiring Systems Training Program
• 120-97, Incorporation of Fuel Tank System Instructions for Continued Airworthiness into Operator Maintenance or Inspeciton Program
• 120-99, Incorporation of Electrical Wiring Interconnection System (EWIS) Instructions for Continued Airworthiness into the Operator’s Maintenance Program (EAPAS AC 120-99 was not yet final at the time this AC was issued.)
• 121.22A, Maintenance Review Board Procedures
c. Policy and Orders.
(1) You can download an electronic copy of the latest version of the following policy and order from the Internet at http://www.faa.gov/regulations_policies/orders_notices/:
• FAA Policy Statement ANM112-05-001, “Process for Developing SFAR 88-related Instructions for Maintenance and Inspection of Fuel Tank Systems” (69 FR 60170)
• FAA Order 8110.104, “Responsibilities and Requirements for Implementing Part 26 Safety Initiatives”
d. Reports.
• “Transport Aircraft Intrusive Inspection Project, (An Analysis of the Wire Installations of Six Decommissioned Aircraft), Final Report,” The Intrusive Inspection Working G-2