Document ID: FAA-2004-18379-0073
Agency: faa
Document Type: Rule
Title: Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/FTS)
Posted Date: 2007-11-08T05:00Z

[Federal Register: November 8, 2007 (Volume 72, Number 216)]
[Rules and Regulations]               
[Page 63363-63414]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08no07-18]                         

[[Page 63363]]

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Part III

Department of Transportation

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Federal Aviation Administration

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14 CFR Parts 1, 21, 25 et al.

 Enhanced Airworthiness Program for Airplane Systems/Fuel Tank Safety 
(EAPAS/FTS); Final Rule

[[Page 63364]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 1, 21, 25, 26, 91, 121, 125, and 129.

[Docket No.: FAA-2004-18379; Amendment Nos. 1-60, 21-90, 25-123, 26-0, 
91-297, 121-336, 125-53, 129-43]
RIN 2120-AI31

 
Enhanced Airworthiness Program for Airplane Systems/Fuel Tank 
Safety (EAPAS/FTS)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule amends FAA regulations for certification and 
operations of transport category airplanes. These changes are necessary 
to help ensure continued safety of commercial airplanes. They improve 
the design, installation, and maintenance of airplane electrical wiring 
systems and align those requirements as closely as possible with the 
requirements for fuel tank system safety. This final rule organizes and 
clarifies design requirements for wire systems by moving existing 
regulatory references to wiring into a single section of the 
regulations specifically for wiring and by adding new certification 
rules. It requires holders of type certificates for certain transport 
category airplanes to conduct analyses of their airplanes and make 
necessary changes to existing Instructions for Continued Airworthiness 
(ICA) to improve maintenance procedures for wire systems. It requires 
operators to incorporate ICA for wiring into their maintenance or 
inspection programs. And finally, this final rule clarifies 
requirements of certain existing rules for operators to incorporate ICA 
for fuel tank systems into their maintenance or inspection programs.

DATES: These amendments become effective December 10, 2007.

FOR FURTHER INFORMATION CONTACT: If you have technical questions about 
the certification rules in this action, contact Stephen Slotte, ANM-
111, Airplane & Flight Crew Interface, Federal Aviation Administration, 
1601 Lind Avenue, SW., Renton, WA 98057-3356; telephone (425) 227-2315; 
facsimile (425) 227-1320, e-mail steve.slotte@faa.gov. If you have 
technical questions about the operating rules, contact Fred Sobeck, 
AFS-308, Aircraft Maintenance Division, Federal Aviation 
Administration, 800 Independence Avenue, SW., Washington, DC 20591; 
telephone: (202) 267-7355; facsimile (202) 267-7335, e-mail 
frederick.sobeck@faa.gov. Direct any legal questions to Doug Anderson, 

Office of Regional Counsel, Federal Aviation Administration, 1601 Lind 
Avenue, SW., Renton, WA 98057-3356; telephone (425) 227-2166; facsimile 
(425) 227-1007, e-mail Douglas.Anderson@faa.gov.

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. Subtitle I, Section 106 
describes the authority of the FAA Administrator. Subtitle VII, 
Aviation Programs, describes in more detail the scope of the agency's 
authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, the FAA is charged with promoting 
safe flight of civil aircraft in air commerce by prescribing minimum 
standards required in the interest of safety for the design and 
performance of aircraft; regulations and minimum standards in the 
interest of safety for inspecting, servicing, and overhauling aircraft; 
and regulations for other practices, methods, and procedures the 
Administrator finds necessary for safety in air commerce. This 
regulation is within the scope of that authority because it 
prescribes--
     New safety standards for the design of transport category 
airplanes, and
     New requirements necessary for safety for the design, 
production, operation, and maintenance of those airplanes, and for 
other practices, methods, and procedures relating to those airplanes.

Contents

I. Executive Summary
II. Background
    A. Summary of the NPRM
    1. The Proposed Rule
    2. Related Activities
    B. Differences Between the NPRM and the Final Rule
    C. Summary of Comments
III. Discussion of the Final Rule
    A. Overview
    B. Design Approval Holder (DAH) Requirements (part 26)
    1. Requirements To Develop ICA
    2. Changes to Location of Design Approval Holder Requirements
    3. Interaction Between New Design Approval Holder Requirements 
and Part 21
    4. Compliance Dates
    5. The Design Approval Holder Compliance Plan
    6. Defining the Representative Airplane
    7. Impact on Operators
    8. EZAPs Already Completed
    9. Wire Inspections
    10. Protections and Cautions
    11. Alignment of EWIS and Fuel Tank ICA
    12. Approval of ICA
    13. Rule Applicability
    14. Non-U.S. Manufacturers
    15. General Comments About Design Approval Holder Requirements
    16. Airplanes Excluded From Design Approval Holder and EWIS 
Operating Requirements
    C. Electrical Wiring Interconnection System (EWIS) Certification 
Rules (part 25 subpart H)
    1. New Subpart for EWIS
    2. The Definition of EWIS (Sec.  25.1701)
    3. Functions and Installation: EWIS (Sec.  25.1703)
    4. Systems and Functions: EWIS (Sec.  25.1705)
    5. System Separation: EWIS (Sec.  25.1707)
    6. System Safety: EWIS (Sec.  25.1709)
    7. Component Identification: EWIS (Sec.  25.1711)
    8. Fire Protection: EWIS (Sec.  25.1713)
    9. Electrical Bonding and Protection Against Static Electricity: 
EWIS (Sec.  25.1715)
    10. Accessibility Provisions: EWIS (Sec.  25.1719)
    11. Protection of EWIS (Sec.  25.1721)
    12. Flammable Fluid Shutoff Means: EWIS (Sec.  25.1727)
    13. Powerplant and APU Fire Detection System: EWIS (Sec.  
25.1731)
    14. Fire Detector Systems, General: EWIS (Sec.  25.1733)
    15. Engine, Nacelle, and APU Wiring
    16. Designated Fire Zones
    17. Goal of the New Wiring Subpart
    18. Harmonization
    D. Instructions for Continued Airworthiness: EWIS (Sec.  25.1729 
and Appendix H)
    1. Requirements for EWIS ICA
    2. ICA as a Single Document
    3. Standard Wiring Practices Manuals
    4. Mandatory Replacement Times
    5. Wire Identification Method Information
    6. Electrical Load Data
    E. Continued Airworthiness and Safety Improvements Subparts for 
Operating Rules (parts 91, 121, 125, 129)
    1. Establishment of New Subparts
    2. Continued Airworthiness Subparts and Airworthiness Directives
    3. Type and Scope of Requirements
    F. Operating Requirements for EWIS (parts 121 and 129)
    1. Requirements for Maintenance and Inspection Program Revisions
    2. ICA Developed by Design Approval Holders
    3. Different Requirements for Existing and Future Designs
    4. ICA for Alterations
    5. Alaska Operations
    6. EWIS Inspections
    7. Non-U.S. Registered Airplanes
    8. Taking Airplanes Out of Service
    9. Training
    10. Reporting Requirements
    G. Operating Requirements for Fuel Tank Systems (parts 91, 121, 
125, and 129)

[[Page 63365]]

    1. Requirements for Maintenance and Inspection Program Revisions
    2. Airplanes Excluded From Fuel Tank System Operating 
Requirements
    3. Change in Operator Compliance Date for Auxiliary Fuel Tank 
ICA
    4. Original Configuration and Auxiliary Fuel Tanks
    5. Inspection and Maintenance Program Terminology
    H. Regulatory Evaluation
    1. Engine Costs
    2. Wiring System Safety Analysis for Engines
    3. Labor Rates
    4. The Regional Airplane Fleet
    5. Measure of Effectiveness
    6. Operational Impacts
    7. Training Costs
    8. Costs for EZAP Analysis and Inspection of Engines
    9. Engine Costs of Sec.  25.1362
    10. Wire Labeling Costs
    11. Additional Certification and Operator Costs
    12. Previous Rulemaking
    13. Relevance to the Current Fleet
    14. Accidents Indirectly Initiated by EWIS
    I. Harmonization Changes to Transport Category Certification 
Rules (Part 25)
    1. FAA/JAA (Joint Aviation Authority) Harmonization
    2. Circuit Protective Devices (Sec.  25.1357)
    3. Precautions Against Injury (Sec.  25.1360)
    4. Electrical Supplies for Emergency Conditions (Sec.  25.1362)
    5. Electrical Appliances, Motors, and Transformers (Sec.  
25.1365)
    J. Additional Certification Rule Changes (part 25)
    1. Rules Changed To Accommodate Subpart H
    2. Electrical Equipment and Installations (Sec.  25.1353)
IV. Regulatory Notices and Analyses
V. The Amendments

I. Executive Summary

    Safety concerns about wiring systems in airplanes were brought to 
the forefront of public attention by a midair explosion in 1996 
involving a 747 airplane. Ignition of flammable vapors in the fuel tank 
was the probable cause of that fatal accident, and the most likely 
source was a wiring failure that allowed a spark to enter the fuel 
tank. All 230 people aboard the airplane were killed. Two years later, 
an MD-11 airplane crashed into the Atlantic Ocean, killing all 229 
people aboard. Although an exact cause could not be determined, the 
presence of resolidified copper on a portion of a wire of the in-flight 
entertainment system cable indicated that wire arcing had occurred in 
the area where the fire most likely originated.
    Investigations of those accidents and later examinations of other 
airplanes showed a collection of common problems. Deteriorated wiring, 
corrosion, improper wire installation and repairs, and contamination of 
wire bundles with metal shavings, dust, and fluids (which would provide 
fuel for fire) were common conditions in representative examples of the 
``aging fleet of transport airplanes.''
    The FAA has concluded that current maintenance practices do not 
adequately address wiring components, wiring inspection criteria are 
too general, and maintenance instructions do not describe unacceptable 
conditions, such as improper repairs and installations, in enough 
detail.
    With this final rule we are introducing new maintenance, 
inspection, and design criteria for airplane wiring to address 
conditions that put transport airplanes at risk of wire failures, 
smoke, and fire. We are adding requirements for type certificate 
holders and applicants for type certificates and supplemental type 
certificates to analyze the zones of their airplanes for the presence 
of wire and for the likely accumulation of contaminant materials. This 
final rule also requires them to develop maintenance and inspection 
tasks to identify, correct, and prevent wiring conditions that 
introduce risk to continued safe flight. We are requiring that these 
tasks be included in new Instructions for Continued Airworthiness for 
wiring and that they be compatible with Instructions for Continued 
Airworthiness for fuel tank systems. The EWIS ICA must not conflict 
with the ICA for fuel tanks, and must avoid duplication and redundancy. 
Too frequent disturbance to electrical wiring by repeated moving, 
pulling, and flexing of the wire bundles will induce unnecessary stress 
on the wiring and its components, which in turn could lead to 
degradation, expedited aging, and failures. Thus it is important that 
redundant tasks and unnecessary disturbances to the electrical wiring 
be minimized. We are amending Title 14 Code of Federal Regulations 
(CFR) parts 91, 121, 125, and 129 operating rules to require operators 
of transport category airplanes to incorporate maintenance and 
inspection tasks for wiring into their regular maintenance programs and 
we are clarifying existing requirements for fuel tanks.\1\ We are 
creating a new subpart of part 25 to contain the majority of the 
certification requirements for airplane wiring, including new rules to 
improve safety in manufacture and modification. Finally, we are 
creating a new part 26 for design approval holder requirements relating 
to continued airworthiness and safety improvements and new subparts in 
parts 91, 121, 125, and 129 for the same types of requirements for 
operators.
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    \1\ We are not amending 14 CFR part 135 because presently there 
are only 20 airplanes with sufficient passenger or payload capacity 
to be affected by this rule that fly in part 135 operations. Should 
part 135 be amended to permit widespread usage of these larger 
transport category airplanes, we may extend the operating 
requirements of today's rule to part 135 at that time.
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    Accompanying this final rule are guidance materials in the form of 
advisory circulars (AC), which present one way, but not the only way, 
to comply with specific parts of these regulations.
    One of the ACs presents a suggested curriculum for electrical 
wiring interconnection system (EWIS) training. Existing Sec.  121.375 
requires that certificate holders or anyone performing maintenance have 
a training program. This requirement ensures that anyone determining 
the adequacy of maintenance work (including inspectors) is fully 
informed about the procedures and techniques involved and is competent 
to perform them. AC 120-94 provides guidance for complying with Sec.  
121.375 as it applies to EWIS maintenance and inspection. In AC 120-94 
we provide a suggested training program to address the informational 
needs of the various people who come in contact with airplane EWIS, and 
we encourage operators to include this training voluntarily. While the 
Aging Transport Systems Rulemaking Advisory Committee (ATSRAC) had 
recommended some form of EWIS training be required for anyone likely to 
come into contact with EWIS, we have determined the associated cost 
would be unduly burdensome. There are 11 other ACs accompanying this 
rule which provide guidance on different requirements contained here. A 
few of them have been revised for clarification. In those instances, 
this will be noted in section III. Otherwise, except for minor 
editorial changes, the guidance accompanying this rule is being 
published in the same form in which it was proposed and will not be 
discussed here.
    Since the Notice of Proposed Rulemaking (NPRM), the National 
Transportation Safety Board (NTSB) has issued Safety Recommendations A-
06-29 through -35 pertaining to fires on one particular model of 
regional jet. In the 6 months between October 2005 and March 2006, 
there were a total of 6 fires on regional jets. A seventh fire occurred 
prior to that 6-month period. The NTSB stated that, in addition to the 
danger posed by the fires, 2 of the incident airplanes temporarily lost 
all flight displays. The NTSB's investigation

[[Page 63366]]

revealed that all of the fires originated from the same electrical 
component--an electrical contactor located in the avionics compartment 
beneath the floor of the captain's seat. The fires were caused by 
moisture-induced short circuits between the electrical terminals of the 
contactors. We have issued airworthiness directives (AD) to correct 
this unsafe condition. However, if the requirements in this final rule 
had been in effect, the type of failure that caused these 7 fires would 
not have occurred. This is because several of the new requirements 
directly address design issues that led to the fires. This final rule 
is meant to proactively address wiring conditions existing in the 
transport airplane fleet that we now know affect safe flight and can be 
detected, corrected, or prevented.
    We express present value benefits and costs using a 7% discount 
rate. The total estimated benefits of this final rule, $801 million 
($388 present value) over a 25-year period, are comprised of 
operational benefits and safety benefits. The operational benefits are 
estimated at $506.3 million ($237.5 million present value). The safety 
benefits are estimated at $294.6 million ($150.6 million present 
value). This final rule will prevent a portion of fatal and non-fatal 
incidents and accidents while decreasing the impact that EWIS 
discrepancies have on airline operations.
    The estimated total cost of this final rule is $416 million ($233 
million present value) over 25 years. The majority of these costs 
($292.2 million, or $147.6 million present value) will be borne by 
operators. The remainder of the projected costs will be borne by 
aircraft and engine manufacturers, and, to a much lesser extent, the 
FAA Oversight Offices.

II. Background

A. Summary of the NPRM

1. The Proposed Rule
    On October 6, 2005 (70 FR 58508), the FAA published in the Federal 
Register the Notice of Proposed Rulemaking (NPRM) entitled Enhanced 
Airworthiness Program for Airplane Systems/Fuel Tank Safety (EAPAS/
FTS), which is the basis of this final rule.
    In that NPRM, we proposed development of Instructions for Continued 
Airworthiness (ICA) for wiring systems and subsequent incorporation of 
those ICA into operators' maintenance programs. We also proposed 
alignment of the compliance times for operators to incorporate wire and 
fuel tank system ICA into their maintenance programs.
    We proposed changes in the certification rules to require more 
attention during the design and installation of airplane systems to 
conditions that could compromise wire safety and accessibility. And we 
proposed a new part 25 subpart that would be dedicated to current and 
new regulations about airplane wiring systems.
    If you would like more details about the proposal, you can get a 
copy by following the instructions under the Availability of Rulemaking 
Documents heading at the end of this preamble.
2. Related Activities
    On July 12, 2005, the FAA published in the Federal Register a 
statement of policy for future management of the shared responsibility 
between design approval holders (DAH) and operators in achieving 
certain types of safety objectives. That stated policy is reflected in 
the requirements of this final rule for DAHs to develop ICA for 
airplane wiring systems.
    Also published in the July 12, 2005 Federal Register was a 
disposition of comments on a previous notice to extend the date for 
operators to comply with special maintenance requirements for fuel tank 
systems. That date was extended from December 6, 2004 to December 16, 
2008.
    On July 7, 2006, we published notice in the Federal Register 
stating that, although we had originally proposed to align compliance 
times for operator incorporation of ICA for wiring and for fuel tanks, 
we later found it impractical to do so. This notice notified operators 
that their compliance date for incorporation of fuel tank ICA is still 
December 16, 2008.
    Twelve draft ACs on different aspects of the rule accompanied the 
NPRM and were made available for public comment at the same time. On 
November 8, 2005, the comment period for the ACs was extended to 
February 3, 2006, so that it would align with the comment period for 
the NPRM.

B. Differences Between the NPRM and the Final Rule

    We have revised the numbering for 14 CFR part 25 subpart H 
Electrical Wiring Interconnection Systems (EWIS). We did this to 
harmonize as much as possible with the planned European Aviation Safety 
Agency (EASA) version of these rules. As discussed later, the design 
approval holder requirements proposed in the NPRM as subpart I are now 
contained in new part 26, again to harmonize more easily with the 
regulatory structure of other national airworthiness authorities. We 
also have made some changes to the compliance planning sections of 
those rules. In response to comments, we have increased the compliance 
time for the design approval holder requirements to 24 months from the 
effective date of this rule. We have increased the time for operator 
compliance with the EWIS requirements to 39 months from the effective 
date of this rule. Because our regulatory process exceeded the time we 
had originally planned for issuance of this rule, it is no longer 
practical to align the operator compliance dates for the EWIS ICA with 
those for fuel tanks. Coordination of the timing of the maintenance 
tasks within those ICA is still desirable and possible, so that aspect 
of our proposal remains unchanged in the final rule. We have, however, 
extended the date for operators to submit ICA for auxiliary fuel tanks 
to the FAA Oversight Office.
    We have removed some airplanes from the exclusion lists of the DAH 
requirements and the operating rules. This was either because they were 
already excluded as a result of the definition of the affected 
airplanes or because we have reconsidered the rationale for certain 
exclusions. We have also made other, minor, changes in wording to the 
proposed rules for the purposes of clarification or harmonization. We 
discuss all of the changes in section III of this preamble.

C. Summary of Comments

    The FAA received 39 comment letters about the proposed rule and 
guidance material. The comments covered a wide spectrum of topics and a 
range of responses, which we discuss more fully below. There was much 
support for the general intent of the rule and the guidance material. 
There were also requests for changes and for clarification.

III. Discussion of the Final Rule

A. Overview

    This rule is a result of years of study, data gathering, and 
collaboration with industry. It has been developed as a solution to the 
problem of wire contamination and wire damage on airplanes, which can 
result in system failures, smoke, and fire, and can threaten continued 
safe flight.
    Examinations by the Aging Systems Task Force of representative 
airplanes from the fleet of aging transports revealed wiring that was 
deteriorated, corroded, improperly installed and repaired, and 
contaminated with materials such as metal shavings, dust,

[[Page 63367]]

and fluids.\2\ The NTSB, as well as working groups of the FAA, 
industry, and other Civil Aviation Authorities, found these conditions 
to be common across the fleet, not just isolated instances of poor 
maintenance. While systems have always been subject to careful scrutiny 
of their safety and reliability during the certification process, the 
wires that connect those systems had been considered appropriately 
cared for when fitted and maintained according to standard industry 
practices.
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    \2\ Transport Aircraft Intrusive Inspection Project final report 
dated December 29, 2000.
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    Now we know that airplane wiring needs more attention. It needs to 
be considered as a discrete system, and given the same careful scrutiny 
as other systems. The design of wiring systems is important for 
creating safe separation from other wires and systems and protecting it 
from damage. Inspection and maintenance is important in uncovering and 
repairing wire damage and preventing buildup of contaminants that can 
cause damage and that also provide fuel for fire. Wire must be 
inspected regularly and contaminant buildup must be prevented.
    In considering the problems found on transport category airplanes, 
we explored various alternatives. One alternative was to do nothing. 
But the result of that approach would be a continuation of incidents 
and accidents caused by deteriorated wiring systems. Once we knew there 
was a problem affecting safe flight, doing nothing was not really an 
option. We could have asked for voluntary support. But voluntary 
programs in the past have not always resulted in complete 
participation, and a voluntary program could not guarantee the level of 
safety we want to ensure. Accordingly, we decided to develop a rule to 
correct potential safety problems with airplane wiring, and to require 
compliance of all those whose participation is necessary to achieve 
that goal.
    This rule enlists the aid of design approval holders in assessing 
the wiring on their airplanes and in developing inspection and 
maintenance tasks that operators can use to maintain wire safety. It 
requires operators to incorporate into their inspection and maintenance 
programs tasks for maintaining wire safety that are based on those 
developed in accordance with requirements. It introduces new 
certification rules for wire separation, identification, system safety, 
protection from damage, access, and other aspects of wire safety. It 
creates a new subpart in the certification rules for wire certification 
so that the many existing requirements are more easily found. It also 
requires that design approval holders align inspection and maintenance 
tasks for wiring with those for fuel tank systems, to avoid duplication 
and to ensure that the most rigorous task is accomplished. As an 
example, if the EWIS ICA calls for a general visual inspection of a 
certain wire and the fuel tank ICA calls for a detailed inspection of 
the same wire, the general visual inspection task would be removed from 
the EWIS ICA and the detailed inspection would be retained in the fuel 
tank ICA, identified as both a fuel tank task and an EWIS task.

B. Design Approval Holder (DAH) Requirements (Part 26)

    For design approval holders this final rule differs from the 
proposal in the following four ways.
     The physical location of the rule has changed, from the 
proposed location in part 25, subpart I, to a new part 26.\3\
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    \3\ Since the comments refer to the NPRM, however, the 
commenters' original references are retained, including references 
to proposed ACs.
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     The compliance date has been changed from December 16, 
2007, to 24 months after the effective date of the rule.
     Two changes were made to the compliance plan requirement.
     The definition of the ``representative airplane'' has been 
clarified.

We have also made minor wording revisions to section 26.11 for 
clarification. They do not change the requirements.
1. Requirements To Develop ICA
    As discussed above, this rule introduces requirements for design 
approval holders (DAH) to assess their airplanes in relation to wiring. 
The assessment must be performed with an enhanced zonal analysis 
procedure (EZAP), which is outlined in a part-25-series advisory 
circular accompanying this rule entitled AC 25-27 ``Development of 
Transport Category Airplane Electrical Wiring Interconnection Systems 
Instructions for Continued Airworthiness Using an Enhanced Zonal 
Analysis Procedure.'' This AC was originally titled AC 120-XX ``Program 
to Enhance Aircraft Electrical Wiring Interconnection System 
Maintenance.'' The material contained in that proposed AC is now 
presented in two separate ACs. Guidance for carrying out an EZAP 
analysis, as required in the new parts 25 and 26 regulations in this 
final rule, is presented in the newly titled No. 25-27 AC named above, 
which will be referred to in the rest of this document as the DAH EZAP 
AC. Guidance for the operator requirements will be presented in a 
separate 120-series AC titled ``Incorporation of Electrical Wiring 
Interconnection System (EWIS) Instructions for Continued Airworthiness 
into the Operator's Maintenance Program.''
    For each zone on the airplane that contains wiring, DAHs must 
develop maintenance and inspection tasks to prevent contaminant buildup 
on that wiring and maintain safety. They must then make those tasks 
available to operators in the form of ICA readily identifiable as 
pertaining to wiring. They must also assess those wiring ICA in 
relation to ICA for fuel tank systems to make sure there are no 
conflicts or redundancies between the two. The rule includes 
requirements for the DAH to submit a compliance plan to the FAA 
outlining how it intends to meet these requirements.
2. Changes to Location of Design Approval Holder Requirements
    In the NPRM, we noted that we had not decided on the final location 
of the continued airworthiness and safety improvements design approval 
holder requirements of part 25, subparts A and I. We requested comments 
on this issue, and received 7 comments on the rule location. Transport 
Canada and British Airways stated that they wanted the requirements in 
part 21. This was to keep the procedural requirements of the new 
subpart with the present procedural requirements of part 21 and out of 
the airworthiness standards parts of the regulations. EASA, Airbus, 
Boeing, Aerospace Industries Association, and the General Aviation 
Manufacturers Association stated that they wanted the requirements in a 
new part or in part 21. EASA said these requirements must be in a 
mandatory part of its system and CS (Certification Specifications) -25, 
its equivalent to our part 25, is not mandatory. Others who commented 
wanted to maintain part 25 as strictly an airworthiness standard.
    Based on these comments and on discussions with Transport Canada, 
EASA, and the Brazilian Agencia Nacional de Aviacao Civil, we decided 
to create a new part 26 and move the enabling regulations out of part 
25 and into part 21--Certification Procedures for Products and Parts. 
We did this for several reasons.
    First, moving these requirements to a new part keeps part 25 as 
strictly an airworthiness standard for new transport category 
airplanes. This is important because it maintains

[[Page 63368]]

harmonization and compatibility among the United States, Canada, and 
the European Union regulatory systems. Second, integrating the 
requirements into part 21 improves the clarity of how the part 26 
requirements will address existing and future design approvals.
    In creating the new part 26, we renumbered the previous sections of 
part 25, subpart I, and we incorporated the changes discussed in this 
preamble. A table of this renumbering follows:

 Table 1.--Relationship of Proposed Subpart I to Final Rules in Part 26
------------------------------------------------------------------------
                  Part 26                        Part 25, Subpart I
------------------------------------------------------------------------
Subpart A--General
    Sec.   26.1 Purpose and Scope.........  Sec.   25.1801(a) Purpose
                                             and definition.
    Sec.   26.3 Definitions...............  Sec.   25.1801(b) and
                                             25.1803.
    Sec.   26.5 Applicability Table.......  New.
Subpart B--Enhanced Airworthiness Program
 for Aging Systems
    Sec.   26.11 Electrical Wiring          Sec.   25.1805 Electrical
     Interconnection Systems (EWIS)          Wiring Interconnection
     Maintenance Program.                    Systems (EWIS) Maintenance
                                             Program.
------------------------------------------------------------------------

    As noted in the table above, we have added a new Sec.  26.5 to 
provide an applicability table that will facilitate identifying those 
provisions of part 26 that apply to affected persons at any given time. 
As we add subparts to part 26, we will update this table to identify 
the applicability of those new subparts. As with new subpart B of part 
26 in this final rule, we will specify the details of applicability for 
each new subpart in the new subparts themselves.
3. Interaction Between New Design Approval Holder Requirements and Part 
21
    It was our intent to treat those provisions of the requirements 
establishing standards for design changes and revisions to the ICA as 
airworthiness requirements. Adding a statement to the new Sec.  26.1(a) 
that the requirements of part 26 are airworthiness requirements clearly 
integrates these requirements with the procedures specified in part 21. 
The result of treating these requirements as airworthiness requirements 
is that any design changes that may be required by part 26 rulemaking 
become part of the type design of the aircraft. This makes clear that 
the full flexibilities allowed in part 21, such as equivalent level of 
safety findings and special conditions, may be applied. Also, we added 
Sec.  26.1(c) to make a distinction in part 26 between type 
certificates and supplemental type certificates. Typically, for 
interpreting part 21, reference to type certificates includes 
supplemental type certificates unless usage of that term clearly 
indicates otherwise. While the usage of those terms in part 26 is 
contrary to the usage in part 21, we did this to make clear 
distinctions in requirements within part 26.
    To address the change to ``Special retroactive requirements'' 
originally proposed in Sec.  25.2(d) and to fully integrate the new 
rule with part 21, we made four changes to part 21. First, Sec.  21.7 
replaces proposed Sec.  25.2(d) by establishing the applicability of 
continued airworthiness and safety improvement requirements. This 
section establishes the general applicability of part 26 to design 
approval holders, pending and future applicants for design approval, 
and type certificate holders and licensees for newly produced transport 
category airplanes.
    While Sec.  21.7 makes part 26 applicable to pending applications, 
Sec.  21.17(a) clarifies this applicability by adding part 26 to the 
exception list of those requirements of the subchapter that are not 
established by date of application for a type certificate but by date 
that the type certificate is issued.
    For changed products, in the case when the exceptions of Sec.  
21.101(b)(1), (2) or (3) apply, new Sec.  21.101(g) makes clear that, 
even if an applicant may use an early amendment to part 25, the 
applicant must still comply with any applicable provisions of part 26. 
For each applicable part 26 provision, an applicant may elect to comply 
with a corresponding amendment to part 25 that is issued on or after 
the date of the part 26 amendment. Under the normal application of 
Sec.  21.101, if the exceptions of Sec.  21.101(b) do not apply, the 
applicant would be required to comply with the latest amendments of 
part 25 in lieu of the requirements of part 26.
    Sections 21.31 and 21.50 are revised to make it clear that the 
Airworthiness Limitations section of the ICA is part of the type design 
and that changes to the ICA generated under part 26 must be made 
available as part of the total ICA.
    These changes to part 21 do not change or add any new requirements 
to those proposed in the NPRM. Rather, they clarify the relationship 
between existing part 21 and new part 26.
4. Compliance Dates
    Several commenters proposed changes to the DAH compliance dates for 
subpart I (now part 26) requirements. The proposal would have required 
DAHs of existing airplanes to submit ICA for approval to the FAA 
Oversight Office by December 16, 2007. This was based on an expected 
effective date of June 30, 2006 for the final rule, and would have 
allowed DAHs 18 months to complete compliance. The proposed operator 
requirements would have allowed operators 12 months from the date DAHs 
completed their ICA to incorporate EWIS tasks into their maintenance 
program. The compliance date for operators (again based on an expected 
final rule effective date of June 2006) was December 16, 2008.
    Avions de Transport Regional (ATR), Aerospace Industries 
Association and General Aviation Manufacturers Association (AIA/GAMA), 
General Electric (GE), and Boeing requested a longer compliance time 
for the DAH requirements. ATR specifically proposed 30 months because 
it said it will need to review and update all of its maintenance 
documentation. GE requested 36 months. Boeing and AIA/GAMA requested 
the compliance time for DAHs be increased to 24 months. Boeing and AIA/
GAMA noted that industry, through ATSRAC, originally identified 24 
months as the time needed to conduct the EZAP analysis for their 
existing airplane configurations. But the FAA has now proposed 
additional requirements, such as evaluating type certificate (TC) 
holder changes mandated by airworthiness directives (AD) and compliance 
plan activities. The commenters noted that the original schedule and 
resource analysis did not account for these additional activities. 
Additionally, Boeing and FedEx requested that the rule include required 
time periods for FAA review and approval activities involved in the 
compliance plans. Boeing and Airbus noted that the rules do not 
currently limit the amount of time the FAA will take to review and 
approve documents, which will negatively impact their compliance time. 
Boeing stated that most DAHs will require the full 90 days for 
developing a compliance plan, and will not initiate that plan until 
they obtain FAA approval. So to ensure that they have an appropriate 
time for compliance activities, they'll need FAA approval immediately, 
which is impractical.
    Boeing and AIA/GAMA also said that the hard compliance dates and an 
expected final rule issuance in early 2007 will leave DAHs with less 
than 12 months to comply with the subpart I requirements. Along with 
Airbus and GE, they requested that we revise the compliance dates to 
represent a number

[[Page 63369]]

of months after the effective date of the rule, rather than a hard 
date. AIA/GAMA noted that this approach would prevent our process and 
schedule for issuing the final rule from impacting DAH compliance 
dates.
    We agree with the commenters that additional time should be allowed 
for DAH compliance with 26.11. While we understand that ICA for EWIS 
have already been developed for a number of affected airplanes, we also 
understand that not all DAHs have begun this activity. In addition, as 
discussed later, DAHs that have already developed EWIS ICA may not have 
addressed the ``representative airplane'' configurations, as required 
by this rule. However, because DAHs would need to plan and coordinate 
with the FAA anyway, we do not believe the requirements to do so will 
significantly increase the amount of time needed to comply. In 
consideration of these factors, we believe that 24 months will allow 
sufficient time for DAHs to develop and submit the necessary compliance 
plan, draft data and documents, and final data and documents to show 
compliance with today's rule.
    We have made a minor revision to section 26.11(d)(3), (d)(4) and 
(d)(5). This is to clarify that the affected pending or future 
applicants must comply either by a date based on the effective date of 
the rule, or by the date of approval of the related certificate. Even 
though we specifically discussed the intent of these dates in the NPRM 
preamble, we believe that using the term ``approval of the 
application,'' which appeared in the proposal (in proposed Sec.  
25.1805(c)(3), (c)(4), and (c)(5)) indicating dates for compliance, may 
have caused confusion. So, we have replaced the term ``application'' 
with the term ``certificate'' in 26.11(d)(3), (d)(4) and (d)(5).
    We are not including FAA-required time periods for review and 
approval of the required compliance plans. Instead, expectations for 
FAA personnel have been defined in a new FAA order \4\ that directs the 
Aircraft Certification and Flight Standards Services in their roles and 
responsibilities for implementing these initiatives. The order includes 
expected times (6 weeks) for reviewing and approving DAH compliance 
plans, plans to correct deficiencies, and draft and final compliance 
data and documents. To facilitate implementation, we will also train 
affected personnel in their roles and responsibilities and provide in-
depth familiarization with requirements of the regulations and 
associated guidance. The FAA's Aviation Safety organization's recent 
registration as an ISO (International Organization for Standardization) 
-9001-compliant organization will also facilitate standardized and 
timely implementation of the review and approval process.
---------------------------------------------------------------------------

    \4\ Order 8110.26, ``Responsibilities and Requirements for 
Implementing Part 26 Safety Initiatives,'' will be released 
concurrently with this rule.
---------------------------------------------------------------------------

    Several operators also requested revisions to the DAH compliance 
dates, noting the potential adverse impact on them because of the time 
it could take for FAA review and approval. Air Transport Association 
(ATA) recommended that Sec.  25.1805(c)(1) (now 26.11(d)(1)) be 
rewritten to provide a reasonable period of time (90 days) for the 
necessary FAA review and approval activities. ATA noted that the amount 
of time the FAA will take to review and approve TC holders' EWIS/FTS 
ICA could reduce operator compliance time significantly. FedEx made 
similar comments and noted that compliance dates should acknowledge 
time for approval of compliance documents, distribution of those 
documents, operator planning for addressing the requirements, and final 
release of the changes in the operator's program. Royal Dutch Airlines 
(KLM) was also concerned about FAA review and approval impacting 
operators' compliance time and requested that the operator compliance 
date be one year after ICA are approved. Boeing, ATR and U.S. Airways 
also stated that the compliance time for the operational rules should 
be based on availability of needed data.
    Continental requested that operators be allowed 18 months rather 
than 12 months to comply. It said a thorough training program would be 
needed for maintenance personnel not familiar with wiring and its 
components. This would require additional effort by the operator not 
contemplated by simply having ICA incorporated into a maintenance task 
or inspection program. Additionally, Continental stated that contract 
maintenance personnel must also be trained for systems they maintain.
    The National Air Carrier Association (NACA) requested that 
operators have two years for compliance, dependent on DAHs complying 
with their requirements on time.
    Based on rationale the ATA provided for requesting the change, we 
infer that ATA would like additional time (90 days) added to the 
operator's compliance time rather than to the DAH's compliance time. 
While it is inappropriate to put requirements for the FAA in a rule 
applicable to DAHs, we have, as discussed previously, identified 
expectations for FAA review and approval (including timeframes) in an 
internal FAA order. The length of time to review plans, data, and 
documents depends largely on the quality of the submittals. Acceptable 
documents will take less time to review.
    We have structured the requirements of the DAH rule and developed 
complementary guidance to facilitate timely review and approval of DAH 
submittals (compliance planning, draft document reviews, etc.). We do 
agree, however, that a modest increase in operator compliance time 
would help ensure that operators are not impacted by the FAA review and 
approval process. We have revised the EAPAS compliance date for 
operators from 12 months to 15 months.
    Regarding the NACA request for a two-year compliance time, in the 
past we have imposed numerous maintenance program revision requirements 
through operational rules and ADs. Twelve months has been the typical 
compliance time for these changes and has been sufficient for operators 
to comply. The maintenance actions described in the maintenance program 
changes would be accomplished sometime later, as specified in the 
maintenance program. So operators will have sufficient time to plan and 
conduct the necessary EWIS training.
    On July 30, 2004, (69 FR 45936), we extended the Fuel Tank Safety 
Operational Rule compliance dates to December 16, 2008, for reasons 
outlined in that final rule. Because of the similar timelines for 
operator incorporation of the FTS and EAPAS maintenance actions into 
their programs, we had determined that aligning the compliance dates 
for the FTS and EAPAS maintenance program changes would allow operators 
to revise their maintenance program once to address both safety 
initiatives. However, given delays in issuing the EAPAS rulemaking 
proposal and the expectation for industry to have the FTS ICA developed 
for compliance with the EASA rule (December 2007) and the FAA rule 
(December 2008), we have determined that the benefits of aligning the 
FTS and EAPAS compliance dates are not substantial enough to justify 
further delay in implementing FTS maintenance actions. As previously 
discussed, we are not extending the FTS operational rule compliance 
date in this final rule.

[[Page 63370]]

5. The Design Approval Holder Compliance Plan
    As noted above, in the NPRM we contemplated submission of a 
proposed means of compliance, identifying all required submissions to 
the FAA. The NPRM proposed submission of--
     A project schedule identifying all major milestones.
     A detailed explanation of how the proposed means of 
compliance would be shown to comply if it differed from that described 
in advisory material.
     A proposal for submitting a draft of all compliance items 
no less than 60 days before the compliance due date.
     A proposal for how the approved ICA would be made 
available to affected persons (operators and others required to comply 
with this rule).
    The proposal stated that if the FAA notified the DAH of 
deficiencies in its proposed compliance plan or in its implementation 
of that plan, the DAH must submit a corrected plan to the FAA Oversight 
Office within 30 days. All of these compliance plan requirements were 
contained in proposed Sec.  25.1805(d) and (e).
    Airbus requested that Sec.  25.1805(d) and (e) be removed because, 
it said, these requirements are unnecessary. Airbus believes the only 
important compliance date is the final date for DAHs to submit the data 
and documents necessary to support operator compliance. Boeing 
recommended we remove the Sec.  25.1805(d)(3) requirement to identify 
deviations to methods of compliance identified in FAA advisory material 
because it does not agree that proposed methods of compliance should be 
compared to other methods. Instead, it said, they should be evaluated 
on their own merits.
    The FAA agrees that some provisions of proposed Sec.  25.1803(d) 
and (e) could be removed without adversely affecting our ability to 
facilitate TC holder compliance. Specifically, proposed paragraph 
(d)(3) would require TC holders to identify intended means of 
compliance that differ from those described in FAA advisory materials. 
While this is still a desirable element of any compliance plan, we have 
concluded that an explicit requirement is unnecessary and it is not 
included in this final rule. As with normal type certification 
planning, we expect that TC holders will identify differences and fully 
discuss them with the Oversight Office early in the compliance period 
to ensure that these differences will ultimately not jeopardize full 
and timely compliance. Because we believe that timely review and 
approval is beneficial and will save both DAH and FAA resources, the 
advisory material recommends that if the DAH proposes a compliance 
means differing from that described in the advisory material, the DAH 
should provide a detailed explanation of how it will demonstrate 
compliance with this section. The Oversight Office will evaluate these 
differences on their merits, and not by comparison with FAA advisory 
material.
    Similarly, proposed paragraph (e) contains provisions that would 
have authorized the Oversight Office to identify deficiencies in a 
compliance plan or the TC holder's implementation of the plan and 
require specific corrective actions to remedy those deficiencies. While 
we anticipate that this process will still occur in the event of a 
potential non-compliance, we have concluded that it is unnecessary to 
adopt explicit requirements to correct deficiencies and have removed 
them from the final rule. Ultimately, TC holders are responsible for 
submitting compliant EWIS ICA by the specified date. This section 
retains the requirements to submit a compliance plan and to implement 
the approved plan. If the Oversight Office determines that the TC 
holder is at risk of not submitting compliant EWIS ICA by the 
compliance date because of deficiencies in either the compliance plan 
or the TC holder's implementation of the plan, the Oversight Office 
will document the deficiencies and request TC holder corrective action. 
Failure to implement proper corrective action under these 
circumstances, while not constituting a separate violation, will be 
considered in determining appropriate enforcement action if the TC 
holder ultimately fails to meet the requirements of this section.
    Additionally, in reviewing the comment, we realized that the rule 
text could more clearly state our intent to allow DAHs flexibility to 
modify their approved plan if necessary. So the final text of proposed 
Sec.  26.11(f) has been modified to read ``each affected person must 
implement the compliance plan, or later approved revisions * * *.'' In 
response to Airbus' comment that the only important compliance date is 
the final date for DAHs to submit the data and documents, we must 
reiterate that we believe a compliance plan is important. The purpose 
of a 90-day compliance date for the compliance plan is to allow all 
parties to be informed about how the DAH will be meeting its 
requirements and to ensure that the all necessary data will be provided 
to the operators on time. Early development of a compliance plan will 
give assurance of development of all the necessary data in time for the 
operators to comply with their requirements.
6. Defining the Representative Airplane
    Boeing requested that we define in advance of the final rule which 
TC holder configuration changes mandated by ADs should be considered in 
the EZAP. Boeing and AIA/GAMA noted that the DAH must consider airplane 
configurations representative of each airplane model plus DAH-developed 
modifications mandated by AD. Boeing stated that because ADs are 
applicable to operators and not DAHs, and because most ADs are not 
applicable to all airplanes within a specific model range, it is 
difficult to define a representative airplane. Boeing does not believe 
the proposed Sec.  25.1805 (now Sec.  26.11) compliance time allows 
enough time to properly define the representative configuration.
    As previously discussed, we have increased the proposed DAH 
compliance time for a number of reasons, one of which was to allow 
sufficient time for the DAH to identify the representative 
configuration for each affected airplane model.
    As discussed in the NPRM, the purpose of the requirement to address 
all TC-holder-developed modifications mandated by AD is to make the 
EZAP as complete and accurate as possible. It would serve no purpose to 
require the TC holder to analyze an airplane configuration no longer in 
service because an AD has mandated its modification. Therefore, TC 
holders must assess all these modifications to determine whether they 
affect the results of the EZAP. Because TC holders own the design data 
for both the original configurations and these modifications, they are 
the only entities capable of performing these assessments. When TC 
holders develop AD-mandated modifications for airplanes still in 
production, they normally incorporate these same modifications into new 
airplanes. So this requirement imposes little additional burden for 
these airplanes. At the same time, we recognize that it would be 
unreasonable to require the TC holder to analyze modifications 
developed by third parties. Accordingly, this requirement is limited to 
TC-holder-developed modifications.
    In reviewing Boeing's comment, we recognized that the proposed 
definition of ``representative airplane,'' i.e., ``the configuration of 
each model series airplane that incorporates all variations of EWIS 
used on that series airplane * * *,'' could be interpreted in different 
ways. It could be interpreted as applying to all post-production

[[Page 63371]]

modifications, not just those mandated by AD and those DAH-developed 
modifications introduced into production. It could also refer to 
variations used for post-production modifications, as well as those 
used in production. Boeing correctly understands that we intended to 
require evaluation only of variations used in production and those 
post-production modifications mandated by AD. Section Sec.  26.11(b) 
has been revised to clarify this. For those design changes made in 
production for which the TC holder has issued service bulletins 
describing post-production equivalents, the ICA should identify those 
service bulletins with the corresponding production configurations. 
This will enable operators that have incorporated these service 
bulletins to determine that the ICA for the production modification 
also applies to them.
7. Impact on Operators
    Boeing asked that we separate the operational rule from DAH 
requirements, with a separate comment period, so that defined service 
information and associated costs can be evaluated by the operators. 
Boeing contended that consolidating DAH and operational requirements 
into one rulemaking action with one comment period prevents the FAA 
from obtaining accurate cost estimates and prevents operators from 
determining the true impact of the proposal on their operations. NACA 
also expressed concern that operators cannot know the full impact of 
this rule until DAHs develop the required ICA.
    We have decided against separating the operational rules from the 
DAH requirements. Separating the rules would not change the technical 
requirements contained in this final rule but would substantially delay 
implementation of the EAPAS safety initiative. Thus, it is essential to 
include both certification and operational requirements in the final 
rule to ensure maximum safety benefits to the flying public.
    In addition to issues of timeliness, we note that while some 
operators will not know the precise effects of the ICA developed by TC 
holders on their maintenance programs, they should have a good 
understanding of the nature and scope of the program from the NPRM and 
the guidance material provided in the DAH EZAP AC (AC No. 25-27). As 
discussed, both of these were derived from ATSRAC's recommendations, 
which operators played a major role in developing. In addition, since 
2004, multiple operators have been involved with several airplane 
manufacturers in developing EWIS ICA using the EZAP analysis described 
in the DAH EZAP AC. This has been accomplished by integrating EWIS ICA 
development into the airplane manufacturer's normal maintenance 
development program. Operators of the airplane model for which a 
maintenance program is being developed (or revised) are always involved 
in the development of that program. Therefore, these operators do know 
the impact of integrating these new EWIS ICA into their maintenance 
programs.
8. EZAPs Already Completed
    Boeing asked that we include a statement in the final rule 
indicating that EZAP analyses conducted prior to the effective date of 
the final rule, and resultant ICA, comply with subpart I (now part 26) 
requirements. Boeing questioned the statement that the proposed time 
frames are supported by experience gained by EZAPs already performed, 
when the NPRM did not discuss the acceptability of those analyses. It 
noted that several EZAP analyses were conducted using MSG-3 \5\ 
methods, which differ slightly from those contained in proposed AC 120-
XX (now the DAH EZAP AC, No. 25-27). Boeing noted that, for those 
cases, it must show the FAA Oversight Office how the previous analyses 
were conducted, make any necessary changes, obtain industry agreement, 
and have the FAA approve the resulting ICA.
---------------------------------------------------------------------------

    \5\ Air Transport Association (ATA) Maintenance Steering Group 3 
(MSG-3) is a document containing a logic process used by the 
airlines and manufacturers to develop scheduled maintenance programs 
for an airplane.
---------------------------------------------------------------------------

    We believe that work done before adoption of the rule will reduce 
the level of effort required for DAHs to comply with the rule. But we 
also recognize that some additional work may be necessary for DAHs to 
show compliance. For example, EWIS ICA may not have been aligned with 
FTS ICA or may not have been developed for the ``representative 
airplane'' as defined in the rule. Therefore previous work cannot 
automatically be considered compliant. Because we cannot say with any 
confidence that no more work will be required, we are not adopting 
Boeing's recommendation.
9. Wire Inspections
    The National Air Traffic Controllers Association (NATCA) called the 
proposal inadequate because it relies on enhanced zonal inspections to 
detect latent failures in the wiring system, and it said that zonal 
inspections detect only visible deteriorated wire.
    The commenter said that without periodic or real-time monitoring of 
airplane wiring, there is no way to predict a degraded state and 
prevent future wire failures. NATCA recommended that we include 
requirements for either continuous on-board detection of airplane 
wiring faults, such as that provided by system self-test features, or 
periodic maintenance tasks, to detect both visible and hidden 
degradation in the wiring system.
    The requirements adopted today do not prevent use of wire 
monitoring or fault detection technology. Multiple non-destructive 
inspection (NDI) tools and real-time monitoring techniques are being 
developed for use in aircraft wiring inspection. However, current NDI 
reflectometry technology is not yet mature enough for its use to be 
mandated by the FAA. Although real-time monitoring technology, such as 
arc fault circuit breaker technology, is further along in development, 
it too is not yet mature enough to address all circuit types. We expect 
that these technologies, when available, may be relatively more 
expensive than conventional methods, so the need for visual inspection 
of EWIS would remain even if this technology were widely available. We 
made no change based on this comment.
10. Protections and Cautions
    Boeing requested that we remove from subpart I (now part 26) the 
requirement to include ICA instructions for protection and caution 
information to minimize contamination and accidental damage during 
maintenance activities. It suggested this language should be added to 
the operating rule. Boeing considers the methods of protecting wiring 
during maintenance to be best determined by the maintenance provider 
and dependent on the type of maintenance activity underway. Boeing also 
noted that operators who have already developed protection schemes 
based on their experience will be required by the operational rules to 
replace this with the one provided by the TC holder. Boeing does not 
believe this is a positive step towards increased protection of EWIS.
    United Airlines stated its support for requiring airplane 
manufacturers to include specific recommendations for when and how to 
protect wire bundles from damage during different phases of 
maintenance.
    We infer that Boeing is referring to the requirement in 
H25.5(a)(1)(vi). That requirement applies both to new type certificates 
complying with Sec.  25.1729

[[Page 63372]]

(proposed as Sec.  25.1739) and existing type certificates complying 
with part 26. The requirement is consistent with ATSRAC's 
recommendations. These recommendations were based on recognition that 
the TC holder will have the best understanding of EWIS material 
properties and vulnerabilities, and will be in the best position to 
identify what protection and caution measures are needed. If operators 
have developed their own instructions, they may be used as alternatives 
or as supplements to those provided by the TC holder, if approved by 
their Principal Inspector (PI). We have provided guidance to the FAA 
field offices to allow for consideration of an operator's alternative 
to that approved by the FAA Oversight Office. We made no rule change 
based on this comment.
11. Alignment of EWIS and Fuel Tank ICA
    AIA/GAMA and GE requested that the last sentence of proposed Sec.  
25.1805(b) (now Sec.  26.11(b)), requiring minimization of redundant 
requirements between EWIS and fuel tank ICA, be deleted. The commenters 
stated that this is an economic and customer service issue beyond the 
scope of the FAA's safety interest.
    Boeing requested we include, within proposed Sec.  25.1805(b), the 
levels of alignment of FTS and EWIS maintenance actions that will be 
acceptable for compliance. While Boeing sees the benefit of eliminating 
redundant maintenance activities, it considers itself unable to 
determine how to show compliance with this requirement.
    Minimizing redundant requirements is not just an economic issue for 
operators. One of ATSRAC's findings is that repeated disturbance of 
EWIS during maintenance is itself a source of safety problems. 
Therefore, while ensuring that all necessary maintenance is performed, 
it is also our objective to minimize disturbance by eliminating 
redundant requirements. Too frequent disturbance to electrical wiring 
by repeated moving, pulling, and flexing of the wire bundles will 
induce unnecessary stress on the wiring and its components, which in 
turn could lead to degradation, expedited aging, and failures. Thus it 
is important that redundant tasks and unnecessary disturbances to the 
electrical wiring be minimized. Operators will review their maintenance 
tasks and coordinate with the DAHs to ensure that tasks are 
incorporated into their maintenance program for the highest level of 
safety and performed in the manner most suitable for their operation.
    As discussed earlier, Boeing and other TC holders have been 
required to develop ICA since 1981, and maintenance manuals even before 
that. In developing ICA, TC holders routinely review individual tasks 
to align them with other tasks being developed. This is done both to 
avoid redundancy and to eliminate confusing or conflicting instructions 
that could inadvertently lead to improper maintenance with unsafe 
consequences. The purpose of the requirement to align the ICA is no 
different. The intended ``levels of alignment'' are the same as would 
be expected for ICA developed in connection with original type 
certification. The MSG-3 and Maintenance Review Board (MRB) processes, 
with which Boeing and other affected TC holders are familiar, have the 
same objectives. The DAH EZAP AC, ``Development of Transport Category 
Airplane Electrical Wiring Interconnection Systems Instructions for 
Continued Airworthiness Using an Enhanced Zonal Analysis Procedure,'' 
No. 25-27, describes means of compliance that will achieve these 
objectives. It provides a step-by-step process to assist applicants in 
compliance with the electrical wiring interconnection system (EWIS) 
maintenance requirements. This process includes a step requiring an 
analysis of the related maintenance tasks to ensure that they are 
consolidated and/or aligned to maximize effectiveness and eliminate 
redundancies and duplications between the EWIS and fuel tank ICA.
    The airplane manufacturer will align the ICA requirements to the 
greatest extent possible. No change to the final rule is necessary.
12. Approval of ICA
    Boeing and AIA/GAMA requested further clarification of proposed 
Sec. Sec.  25.1739 (now Sec.  25.1729) and 25.1805(b) (now Sec.  
26.11(b)) requirements that ICA prepared in accordance with paragraph H 
25.5 of Appendix H be submitted to the FAA Oversight Office for 
approval. AIA/GAMA, Airbus, and FedEx recommended that EWIS ICA be 
accepted by the FAA, rather than approved, with the exception of any 
applicable airworthiness limitation items (ALI), which should be 
approved. The commenters were concerned that the proposed requirements 
are not consistent with the current requirement in Sec.  25.1529 that 
ICA be found acceptable to the FAA (except for ALI, which must be 
approved). FedEx also stated that creation of separate ``FAA-approved'' 
ICA will lead to confusion and fragmentation of what should be an 
integrated inspection program.
    As discussed earlier, one of the primary objectives of these DAH 
rules is to ensure that operators have at least one source of FAA-
approved data and documents that they can use to comply with 
operational requirements. This objective would be defeated if the 
required data and documents were not, in fact, approved. Only by 
retaining authority to approve these materials can we ensure that they 
comply with applicable requirements and can be relied upon by operators 
to comply with operational rules. We believe that there are differences 
between EWIS ICA and other ICA that necessitate approval of EWIS ICA:
     EWIS ICA are the means for compliance with some of the 
technical requirements of new subpart H (Sec.  25.1707 relating to 
system separation and Sec.  25.1711, component identification).
     EWIS ICA contain highly technical information such as 
electrical loads data and wiring practices standards that are more 
complex than typical maintenance instructions.
     EWIS ICA require a degree of consistency and 
standardization that may not be necessary for other ICA.
    We agree that further clarification is needed regarding FAA 
Oversight Office approval of EWIS ICA. We do not intend to approve all 
documents that contain EWIS ICA details, such as the airplane 
maintenance manual. We do intend to review references in all documents 
that are referred to in the EWIS ICA source documents. We have made 
changes to the AC guidance information (AC 25.1701-1) to clarify 
exactly what documents the FAA Oversight Office will approve. No change 
to the final rule is necessary.
13. Rule Applicability
    Today's rule is applicable to airplanes with a passenger capacity 
of 30 or more passengers or a payload capacity of at least 7,500 pounds 
operating in parts 121 and 129. NATCA requested that we consider 
revising the rule applicability to address all transport airplanes 
regardless of size or type of operation. It stated that all transport 
airplanes are subject to the same aging safety concerns, and passengers 
should have one level of safety.
    The FAA has used these size criteria for the applicability of other 
rulemakings because they capture the airplanes carrying the vast 
majority of passengers and cargo. Similarly, by limiting applicability 
of the EAPAS operational rules to parts 121 and 129, we focus these 
requirements on the

[[Page 63373]]

airplanes that transport most passengers and cargo. Based on our 
analysis, the additional safety benefit of extending the operational 
requirements to all transport airplanes would not justify the 
additional costs of doing so. We will continue to review this issue 
and, as this rule is implemented, if we can demonstrate that it can be 
applied cost effectively to smaller airplanes or other operators, we 
may consider further rulemaking.
    Several commenters requested revisions and clarification of 
applicability with respect to supplemental type certificates (STC). 
EASA requested we revise the applicability of Sec.  25.1805 (now Sec.  
26.11(d)) to include STCs that significantly affect EWIS.\6\ British 
Airways stated its support for the existing applicability, agreeing 
that the analysis performed by the DAH would cover the EWIS they are 
responsible for as well as the wiring changed or added by others. FedEx 
requested clarification on means of compliance for STCs.
---------------------------------------------------------------------------

    \6\ EASA plans to address STCs in its NPA.
---------------------------------------------------------------------------

    Additionally, the ATA requested we revise proposed Sec.  
25.1805(c)(4) (now Sec.  26.11(d)) to clarify its applicability only to 
new STCs issued after the effective date of the final rule and not to 
existing STCs that may be modified after the effective date of the 
rule. The ATA noted that some STCs are modified to expand the STC 
effectivity as an operator's fleet grows and should not be evaluated 
for compliance with Sec.  25.1805(c)(4).
    Section 26.11 will apply to future applicants for STCs and to 
existing TCs. As explained in the NPRM, we decided not to include 
existing STCs in this section for two reasons. First, most existing 
STCs do not provide detailed instructions for wiring installation, 
relying on the judgment and expertise of the individual installer. In 
most cases it would not be possible for the current STC holder to 
evaluate these wiring installations. Second, in most cases, installers 
have followed the TC holder's wire routing and installed STC wiring in 
or adjacent to existing wiring. In these cases, implementing the 
maintenance programs developed by the TC holder should adequately 
address the safety issues identified in this rule that may exist in the 
STC wiring. Our conclusion here is consistent with ATSRAC's 
recommendations.
    However, we will not revise Sec.  26.11 to exclude modifications to 
existing STCs. As discussed, one reason we are not applying this rule 
to existing STCs is that in many cases existing STCs do not include 
data for EWIS that can be evaluated. As discussed in the NPRM, we 
believe it is important that EWIS ICA be provided for all future STCs, 
including changes to existing STCs. We have revised Sec.  26.11(d) to 
clarify that ``if an existing STC is amended, this section would apply 
to the amendment.''
    The extent of the review required for changes to existing STCs 
would be limited to the newly proposed changes. Applicants would not be 
required to evaluate the entire design change approved under their 
existing STC. For example, if an applicant proposed to add additional 
monitors to an existing in-flight entertainment STC, only the EWIS 
supporting the additional monitors would need to be evaluated for the 
impact to the ICA. If an applicant were merely adding airplane models 
of the same configuration to an existing STC, they would not need to 
evaluate their STC.
    Boeing Wichita asked whether it would be required to evaluate EWIS 
for an entire airplane in order to comply with requirements of Sec.  
25.1805 (now Sec.  26.11) when applying for an STC.
    We do not intend to require applicants for design changes approval 
to evaluate the EWIS of the entire airplane. Rather, these applicants 
must evaluate whether their proposed design change would require 
revision of the ICA developed by the TC holder (and any previous STC 
applicants) in compliance with Sec.  26.11 to correctly address the 
design change. An example would be if an STC applicant proposed to add 
EWIS to a zone that did not previously have EWIS. The applicant would 
need to develop an ICA revision providing for any maintenance actions 
within that zone that may be necessary to comply with Appendix H to 
part 25. We have revised Sec.  26.11 by adding a new paragraph (c) to 
clarify this requirement.
14. Non-U.S. Manufacturers
    Airbus also commented that proposed Sec.  25.1805 paragraphs (b), 
(d), and (e) (now Sec.  26.11(b) and (e)) fail to acknowledge that non-
U.S. manufacturers will likely have to comply with similar regulations 
issued by their own authorities. Airbus said that discussion of the 
compliance plan and review of the compliance items should be delegated 
to the relevant foreign authority, as far as permitted by existing 
Bilateral Aviation Safety Agreements.
    We recognize the important role other national authorities are 
likely to play in implementation of this rule. In addition to the on-
going efforts to harmonize these requirements, we have been working 
closely with the other national authorities to define appropriate 
roles, responsibilities, and relationships among all affected 
authorities. As discussed in the NPRM, the compliance planning 
provisions are equally important for foreign TC holders, and we expect 
to have mutually agreeable arrangements with their authorities on how 
this planning will be overseen.
15. General Comments About Design Approval Holder Requirements
    We received a number of general comments responding to the concept 
of DAH requirements rather than to the DAH requirements in this 
specific rulemaking. We responded to these types of comments in the 
comment disposition document accompanying our policy statement titled 
``Safety--A Shared Responsibility--New Direction for Addressing 
Airworthiness Issues for Transport Airplanes.'' Both were published in 
the Federal Register on July 12, 2005. As a result, we will not respond 
to such comments again here. We have included them, and our responses, 
in a separate document in the docket. That document is titled ``General 
Comments about DAH Requirements Sent to Docket Number 18379.''
    Boeing and AIA/GAMA did not agree with our assessment that DAH 
rules are necessary to support this initiative. They requested we 
remove proposed Sec.  25.1805 (now Sec.  26.11) from the rule. They 
contended that
     The required material is neither complex nor limited to 
the DAH,
     Operators have the option of developing an enhanced zonal 
inspection program without participation of the DAH, and
     Operators will not be required to adopt maintenance 
programs developed by the DAH.
    Both commenters stated that developing EWIS ICA is not complex. 
They noted the EZAP process is based on MSG-3 maintenance program 
development procedures, which are neither complex nor limited to the 
DAH. They believe that the DAH type design data needed for development 
of maintenance tasks is also available to operators.
    Boeing and AIA/GAMA also said that use of the MSG-3 process by the 
DAH alone will only account for airplane configurations certified by 
the DAH and some, but not all, AD-mandated modifications. Unique 
configurations that evolved after delivery will not be considered by 
the DAH. Boeing contended that operators are capable of assessing their 
airplane configurations using proposed AC 120-XX (now the DAH EZAP AC) 
and developing an

[[Page 63374]]

enhanced zonal inspection program without DAH involvement. 
Additionally, Boeing stated that operators could develop ICA more 
efficiently because they could concurrently address the baseline 
configuration and any configuration changes made in service.
    As discussed previously, the policy statement provides criteria for 
deciding when DAH regulations are necessary.
    Appendix H paragraph H25.5(a)(1) identifies information required to 
perform the analysis and develop maintenance tasks. While some of this 
information may be available to operators without assistance from the 
DAH, operators would not have access to all of it.
    Also, the methodology described in the AC may appear to be 
relatively simple, but applying it properly requires considerable 
expertise and judgment and can be quite complex. DAH involvement is 
necessary to ensure it is applied properly. We believe that DAH 
regulations are necessary for this safety initiative to ensure all of 
the representative type design configurations are addressed in a timely 
manner. 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.
    Existing regulations regarding ICA as adopted in Amendments 21-50 
and 25-54 require DAHs to provide ICA for the airplane as a whole. This 
rule simply applies that same policy to EWIS, which were not 
specifically addressed by those amendments.
    We note that in the form in which the rules were proposed, 
operators would be required to implement EWIS ICA based on those 
``developed by the type certificate holder.'' That statement did not 
clearly articulate our intent and we have corrected that language in 
the final rule to reference ``in accordance with the provisions of 
Appendix H of part 25 of this chapter applicable to each affected 
airplane * * *.''
    Both Boeing and AIA/GAMA requested that we establish, within the 
final rule, all requirements for the DAHs regarding consistency, 
standardization of process and requirements, and technical guidelines. 
They do not believe the rule or guidance material is comprehensive 
enough to enable DAHs to comply. Boeing stated that the root cause of 
past difficulties with voluntary compliance lies with unclear 
regulatory requirements and lack of appropriate guidance. Boeing noted 
that the FAA attempted to address this problem in the proposed rule, 
but said those attempts have fallen short of what is needed. It quoted 
draft AC 25-XX: ``* * * the Compliance Team, as soon as possible after 
issuance of the safety initiative rule, will provide the DAHs with our 
expectations for the required analysis content [and] describe to the 
DAHs our expectations for the content and format of their data * * * 
.'' Boeing contends that visibility of requirements, expectations, and 
technical requirements would ensure uniformity of application and 
inform operators of what information they would receive from DAHs.
    We partially agree. The program plan for the aging airplane rules 
was to release associated guidance and policy for public comment upon 
release of the NPRMs. We believe this approach should have helped 
clarify our expectations of what is considered an acceptable approach 
to compliance.
    For this initiative, both the performance standards and guidance 
materials were developed by ATSRAC, which had representatives from the 
affected industry. We must presume that industry, in helping to develop 
these materials, understood what would be expected for new TCs. We 
consider these same materials to be sufficient for application to 
existing TCs.
    The comprehensiveness and level of detail of requirements and 
related advisory material is at least equivalent to that for other ICA 
currently in Appendix H, which DAHs have successfully complied with for 
25 years. The purpose of compliance planning provisions is to ensure 
that DAHs work closely with the FAA, as they do for initial 
certification, in developing compliant data and documents. We made no 
change to the rule due to this comment. However, we will clarify in AC 
26-1 that the compliance team will meet with DAHs as soon as possible 
after issuance of the final rule to ensure that guidance materials and 
expectations related to rule implementation are clear.
16. Airplanes Excluded From Design Approval Holder and EWIS Operating 
Requirements
    The DAH requirements and the EWIS requirements for operators do not 
apply to the following airplane models:
(1) Lockheed L-188
(2) Bombardier CL-44
(3) Mitsubishi YS-11
(4) British Aerospace BAC 1-11
(5) Concorde
(6) deHavilland D.H. 106 Comet 4C
(7) VFW-Vereinigte Flugtechnische Werk VFW-614
(8) Illyushin Aviation IL 96T
(9) Bristol Aircraft Britannia 305
(10) Handley Page Herald Type 300
(11) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(12) Airbus Caravelle
(13) Lockheed L-300

    The airplanes excluded from these rules are not currently operating 
under parts 121 or 129, so there is no need for DAHs to develop data to 
support the operational rules for these airplane models. The Vickers 
Viscount airplane appeared on this exclusion list in the NPRM. But 
since the Vickers Viscount was originally type certificated before 
January 1, 1958, this airplane is not subject to these rules because of 
the general exclusion of airplanes type certificated before that date. 
Thus it has been removed from the exclusion list. Similarly, the 
Convair and DC-3 models that have been modified to incorporate turbine-
powered engines are also covered by this general exclusion, so they too 
have been removed from the originally proposed exclusion list. The 
Lockheed L-300 has been added to the exclusion list. There is only one 
qualified aircraft, which was modified, used, and later retired by the 
National Aeronautics and Space Administration (NASA) in 1995. It would 
not be cost effective to bring it into 121 operations. Thus it has been 
excluded from the requirements of these rules.

C. Electrical Wiring Interconnection System (EWIS) Certification Rules 
(Part 25 Subpart H)

1. New Subpart for EWIS
    This final rule creates a new subpart H within part 25 of 14 CFR 
addressing electrical wiring interconnection systems (EWIS). Its 
purpose is to be the single place in the regulations where the majority 
of certification rules pertaining to transport airplane wiring can be 
found. Many of the rules contained in this new subpart are previously-
existing requirements that have been moved from different parts of the 
regulations. Some have been reworded to make it clear that they apply 
to wiring. Several of the rules in subpart H are new. As a whole, the 
rules in subpart H are meant to improve the safety of transport 
airplane wiring by making sure that it is designed to be safe. 
Individually, the rules address different aspects of wiring design 
safety, and they are discussed individually below.
    To better harmonize with foreign airworthiness authorities, the 
numbers of many of the rules in subpart H have been changed from those 
originally proposed. The following table indicates the revised numbers. 
Since commenters referred to the proposal when they

[[Page 63375]]

wrote to the FAA, however, their references below are the originally 
proposed rule numbers. Similarly, if a commenter references a proposed 
AC, the original draft AC number is retained, as used by the commenter. 
Several of the proposed subpart H rules received no comments and remain 
unchanged except for their numbers. Those will not be discussed here. 
The following table indicates the rule number changes.

                  Table 2.--Subpart H Rule Renumbering
------------------------------------------------------------------------
                                                 Final rule      NPRM
              Title in subpart H                  section      section
------------------------------------------------------------------------
Definition....................................      25.1701      25.1701
Functions and Installation: EWIS..............      25.1703      25.1703
Systems and Functions: EWIS...................      25.1705      25.1719
System Separation: EWIS.......................      25.1707      25.1709
System Safety: EWIS...........................      25.1709      25.1705
Component Identification: EWIS................      25.1711      25.1711
Fire Protection: EWIS.........................      25.1713      25.1713
Electrical Bonding and Protection against           25.1715      25.1717
 Static Electricity: EWIS.....................
Circuit Protective Devices: EWIS..............      25.1717      25.1721
Accessibility Provisions: EWIS................      25.1719      25.1725
Protection of EWIS............................      25.1721      25.1727
Flammable Fluid Protection: EWIS..............      25.1723      25.1729
Powerplants: EWIS.............................      25.1725      25.1731
Flammable fluid shutoff means: EWIS...........      25.1727      25.1733
Instructions for Continued Airworthiness--EWIS      25.1729      25.1739
Powerplant and APU fire detector system: EWIS.      25.1731      25.1737
Fire detector systems, general: EWIS..........      25.1733      25.1735
[Reserved]....................................      deleted      25.1707
[Reserved]....................................      deleted      25.1715
Instruments using a power supply: EWIS........      deleted      25.1723
------------------------------------------------------------------------

2. The Definition of EWIS (Sec.  25.1701)
    Section 25.1701 is a new requirement. It defines electrical wiring 
interconnection systems (EWIS). The final rule differs from the 
proposal in the addition of the words ``and external wiring of 
equipment,'' discussed below.
    Boeing commented that EWIS is not limited to the numbered items in 
Sec.  25.1701(a). EWIS components might also include terminal blocks, 
circuit protective devices, and contactors. Boeing requested we 
indicate that EWIS may include these and other items as well.
    We agree with Boeing that the EWIS components listed in Sec.  
25.1701(a) are not a comprehensive list. There may be other devices 
that would be considered part of an EWIS, as indicated by the phrase in 
the lead-in sentence to the list of Sec.  25.1701(a)(1)-(13); ``* * * 
this includes:'' A determination of whether a component is considered 
to fall under the definition of EWIS must be made on specific design 
details of a certification program.
    Airbus commented that the phrase ``and external wiring of 
equipment'' should be added to the list in proposed Sec.  25.1701(b) of 
components covered by the EWIS definition. Airbus stated that for 
completeness and consistency, external wiring of equipment should be 
considered, since it can be part of the aircraft installation (e.g., 
galley connection wiring and seat connection wiring). Continental asked 
if wire installed in seats is covered by the proposal.
    We have added the phrase ``and external wiring of equipment'' to 
the list of equipment in Sec.  25.1701(b). We consider this a 
clarification of what constitutes an EWIS component and not an increase 
in scope over the proposal. If an airplane component, such as a galley 
or a seat, is manufactured with connection cables external to it, then 
the external connection cables would be considered an EWIS component.
    An individual commenter stated that the word ``interconnection'' in 
the phrase ``electrical wiring interconnection systems'' is redundant 
and should be eliminated. This commenter also requested that we cite 
the numerous examples of airplane electrical wiring systems that are 
not a part of the EWIS. This commenter further requested that we define 
the term EWIS in the definition section and cite examples of components 
included in and excluded from the system.
    We do not concur with the request to remove ``interconnection'' 
from the term ``electrical wiring interconnection system'' (EWIS). The 
EWIS certification and operational requirements in the final rule apply 
to wires that ``interconnect'' airplane systems, as opposed to wiring 
located solely within the enclosure of a piece of avionics equipment, 
for example. Thus the word interconnection is integral and important in 
describing what electrical wiring interconnection system means.
    The definition of EWIS contained in Sec.  25.1701 does include 
examples of airplane wiring and its associated components that are not 
part of the EWIS. We believe that these examples are sufficient to 
adequately articulate the regulatory definition of EWIS and that 
further examples are unnecessary. We made no change due to this 
comment.
    We do not agree with the commenter's proposal to define EWIS in the 
definition section. Although not specifically identified by the 
commenter, we are assuming that he wants the definition to appear in 14 
CFR part 1. Section 25.1701 contains the EWIS definition and clearly 
states that the definition applies to ``The Chapter.'' This includes 
all applicable certification and operational subchapters such as parts 
25, 121, and 129 where the EWIS requirements are located. We have 
revised the final rule to include a reference to Sec.  25.1701 in Sec.  
1.2.
    Continental Airlines quoted Sec.  25.1701 (definition) and the 
preamble discussion to emphasize the following statements:

    The term EWIS means any wire, wiring device, or combination of 
these, including termination devices, installed in the airplane for 
transmitting electrical energy between two or more termination 
points * * *
    * * * but any electrical connection used to support power and/or 
signal transmission that is part of the airplane TC, and that is 
used for the laptop or other carry-on items, is covered by the 
proposed definition.

[[Page 63376]]

    The commenter requested that the phrase ``signal transmission'' be 
defined.
    As used in the context of the proposal, signal transmission refers 
to data transmitted through wired means, as opposed to wireless signal 
transmission.
    GE and AIA/GAMA commented that proposed Sec.  25.1701(c), which 
provides for exceptions to the definition of an EWIS, means that the 
equipment inside shelves, panels, etc. will have to show compliance 
with EWIS requirements even if they are qualified to the standards of 
Radio Technical Commission for Aeronautics (RTCA) document number RTCA/
DO-160. These commenters believe this would be the opposite of the 
rule's intended meaning. They request that the following phrase be 
deleted from the final rule: ``Except for the equipment indicated in 
paragraph (b) of this section''.
    As discussed in the NPRM, the definition of EWIS includes 
electrical wiring interconnection system components inside shelves, 
panels, racks, junction boxes, distribution panels, back-planes of 
equipment racks including circuit board back-planes, and wire 
integration units. This EWIS, unlike wiring within avionics equipment, 
is typically designed and made for a particular airplane model or 
series of models. Avionics components must be sent back to their 
manufacturer or a specialized repair shop for service. But this type of 
equipment is maintained, repaired, and modified by the same personnel 
who maintain, repair, and modify the other EWIS in the airplane. In an 
electrical distribution panel system, for example, separation must be 
designed and maintained within the panel just as in the EWIS leading up 
to that panel. Identification of components inside the panel is just as 
important as for those outside the panel since the wiring inside the 
panel is treated much the same. We have retained the first sentence of 
proposed Sec.  25.1701(c).
3. Functions and Installation: EWIS (Sec.  25.1703)
    Section 25.1703 (whose number is unchanged from that in the 
proposal), is essentially derived from requirements of existing Sec.  
25.1301. It requires that applicants select EWIS components that are of 
a kind and design appropriate to their intended function. Factors such 
as the components' design limitations, functionality, and 
susceptibility to arc tracking and damage from moisture must be 
considered in selecting EWIS components.
    The final rule differs from the proposal in that words were changed 
to clarify meaning and words inadvertently left out of the proposal 
were put back in. We also removed the word ``adequately'' in response 
to a comment from Boeing, as noted in the discussion elsewhere under 
the heading System Separation (Sec.  25.1707).
    Boeing commented that proposed Sec.  25.1703(a)(3) states that EWIS 
must ``function properly when installed.'' Boeing proposed the final 
rule be rewritten to say that EWIS must ``perform the function for 
which it was intended without degrading the airworthiness of the 
airplane.''
    The commenter stated that it has had difficulty in the past with 
the term ``function properly'' when applied to complex or non-essential 
systems. It stated the suggested revision will help clarify the 
regulation's intent.
    We agree that in the past the term ``function properly'' has been 
applied to complex or non-essential systems in a nonstandardized 
manner. We have revised the final rule text as proposed.
    Airbus, Boeing, General Electric, and Honeywell requested that we 
add the words ``in the fuselage'' to Sec.  25.1703(c) so it is 
consistent with the original regulation, Sec.  25.869 (a)(3). They said 
that this will ensure that the requirements of Sec.  25.1703(c) are 
consistent with the original requirement.
    We agree. We mistakenly omitted the phrase ``in the fuselage'' in 
the proposed wording. We have revised the final rule to include it.
    EASA and Airbus commented that ATSRAC recommended that Sec.  
25.1703 include the following requirement:

    Electrical wiring interconnection system modifications to the 
original type design must be designed and installed to the same 
standards used by the original aircraft manufacturer or other 
equivalent standards acceptable to the Administrator (for 14 CFR)/
authorities (for JAR).

    EASA stated that this requirement will be included in the EASA 
notice of proposed amendment (NPA) that will propose to adopt ATSRAC's 
recommendations. Airbus said such a requirement is consistent with the 
proposal's preamble and advisory material (reference proposed AC 
25.17XX, paragraph 5.b.(8)(b)). Airbus said that including this 
language in the final rule will ensure EWIS minimum compatibility for 
modifications made after an airplane is delivered.
    Similarly, the International Aviation Safety Association (IASA) 
commented that airplane and wiring manufacturers should be required to 
approve the type of wiring used in modifications to an approved type 
design.
    To add this additional requirement would essentially delegate to 
the type certificate holder authority to establish standards that go 
beyond the minimum safety standards required by part 25. The FAA does 
not have legal authority to make such a delegation. As with other 
airworthiness standards, an applicant who shows compliance with our 
standards is entitled to design approval (reference Sec.  21.117). The 
rationale for this is that our standards provide an acceptable level of 
safety, so exceeding them is not necessary for safety. However, the 
referenced advisory material does contain the following statement:

    Only the components listed in the applicable manual or approved 
substitutes should be used for the maintenance, repair, or 
modification of the aircraft. EWIS modifications to the original 
type design should be designed and installed to the same standards 
used by the original aircraft manufacturer or other equivalent 
standards acceptable to the FAA. This is because the manufacturer's 
technical choice of an EWIS component is not always driven by 
regulatory requirements alone. Sometimes specific technical 
constraints would result in the choice of a component that exceeds 
the minimum level required by the regulations.

We believe such a statement meets the intent of the ATSRAC 
recommendation. Therefore, we made no changes based on this comment.
    Airbus requested that the term ``hazard'' replace ``hazardous 
effects'' in proposed Sec.  25.1703(d). Airbus said this would 
eliminate ambiguous interpretation due to inappropriate use of what is 
a system safety classification term in Sec.  25.1309(b). Airbus stated 
that the effect on the component itself needs to be covered instead of 
the effect on the function.
    We infer from this comment that Airbus objects to the phrase 
``hazardous effects'' because it believes this phrase implies that a 
numerical probability analysis would be necessary to show that moisture 
on EWIS components in known areas of moisture accumulation would not 
create a hazard not shown to be improbable. A numerical probability 
analysis is not necessary when demonstrating compliance with Sec.  
25.1703(d). The intent is that good engineering and manufacturing 
judgment be used when designing and installing EWIS components in areas 
of known moisture accumulation to minimize potential for moisture to 
cause an EWIS component failure. Such a failure could in turn lead to a 
functional failure of the system it is associated with. Or it could 
lead to accelerated

[[Page 63377]]

degradation of the component and localized electrical arcing could 
occur. This in itself could lead to a hazardous condition. It is 
important to protect the EWIS component from moisture damage. But it is 
the possible safety hazard from failure of the component that the rule 
is addressing, and not strictly the effect on the component, or its 
function. The advisory material for Sec.  25.1703(d) states, in part, 
the following:

    This section requires that EWIS components located in areas of 
known moisture build-up be adequately protected to minimize 
moisture's hazardous effects. This is to ensure that all practical 
means are used to ensure damage does not occur from fluid contact 
with components.

We believe that this statement prevents confusion about whether or not 
a numerical probability analysis is required for demonstrating 
compliance with this requirement. It is not. We made no changes due to 
this comment.
    Boeing and AIA/GAMA commented that the preamble discussion of Sec.  
25.1703(d) states that the rule proposes to ensure that ``all practical 
means'' are used to prevent damage due to fluid contact. They noted 
that one could interpret this guidance to mean that multiple means must 
be used. Another interpretation could be that all practical means must 
be considered and the most appropriate method used to address potential 
for fluid impinging on wiring. For purposes of clarification, Boeing 
requests that the term ``used'' be changed to ``considered.''
    This rule is meant to require that all practical means be 
considered and the most appropriate method used to address potential 
damage from fluid contact with EWIS components. The advisory material 
for this requirement has been clarified to state this.
4. Systems and Functions: EWIS (Sec.  25.1705)
    Section 25.1705 was proposed as Sec.  25.1719. This section adds to 
the regulations the concept that EWIS associated with systems required 
for type certification or by operating rules must be considered an 
integral part of those systems and considered in showing compliance 
with all applicable requirements. In addition to this general 
requirement, the rule lists other specific certification rules (for 
example Sec.  25.773 Pilot compartment view and Sec.  25.981 Fuel tank 
ignition prevention) for which the applicant must include consideration 
of the EWIS that is part of the subject system in demonstrating 
compliance.
    There are two differences between the proposal and the requirement 
as adopted: The section number has been changed, and a reference to 
Sec.  25.1331(a)(2) (as discussed below) has been added.
    EASA and Airbus requested that Sec.  25.1723 be deleted and 
references to Sec. Sec.  25.1303(b) and 25.1331(a)(2) be moved to Sec.  
25.1719 (now Sec.  25.1705).
    We partially agree to this request. There is no need to list both 
rules in Sec.  25.1705(b). It is necessary to refer to Sec.  
25.1331(a)(2) because that requirement specifically applies to 
instruments required by Sec.  25.1303(b). To list both Sec. Sec.  
25.1303(b) and 25.1331(a)(2) would be redundant. Therefore we have 
revised Sec.  25.1705(b) to include 25.1331(a)(2) and we have deleted 
proposed Sec.  25.1723 from the final rule.
    EASA suggested that references to Sec. Sec.  25.854 and 25.858 be 
included in Sec.  25.1719 (now Sec.  25.1705). The subjects of these 
two requirements are lavatory fire protection and cargo or baggage 
compartment smoke or fire detection systems, respectively. EASA stated 
that if we add Sec. Sec.  25.854 and 25.858 to Sec.  25.1719(b), Sec.  
25.1735 can be deleted, because its intent would be addressed in Sec.  
25.1719(a) and (b).
    Requirements of Sec.  25.1705(a) apply to EWIS associated with 
systems required for type certification or by operating rules. This is 
slightly different from those in Sec.  25.1735, which apply to EWIS 
associated with any installed fire protection system, whether or not it 
is required for type certification or by operating rules. Therefore, we 
cannot delete Sec.  25.1735. We have revised it, however, to include 
references to Sec. Sec.  25.854 and 25.858. We included these two 
requirements in the preamble discussion for the proposed Sec.  25.1735 
and to avoid future confusion we believe they should be referenced 
within the final rule.
5. System Separation: EWIS (Sec.  25.1707)
    Section 25.1707 System Separation: EWIS was proposed as Sec.  
25.1709. This rule requires applicants to design EWIS with appropriate 
separation to minimize possibility of hazardous effects upon the 
airplane or its systems.
    Aside from the section number change, the difference between the 
proposal and this final rule is that word changes have been made to 
clarify meaning, and the reference in paragraph (a) has been changed.
    EASA commented that proposed Sec.  25.1709 (now Sec.  25.1707) uses 
the phrase ``any EWIS component failure'' in several places throughout 
the requirement. EASA believes this implies that an exhaustive list of 
possible EWIS component failures not related to the design under review 
would have to be produced. It believes this goes beyond the intent of 
the rule, and states that the equivalent EASA requirement will use the 
wording ``an EWIS component failure * * *'' as was recommended by 
ATSRAC. EASA recommended that the final rule language be revised to 
adopt ATSRAC's recommended wording.
    We have made the change EASA requested. The intent of the 
requirement is that applicants assess all EWIS components that could 
have a reasonable likelihood of failing in such a manner as to create a 
hazardous condition. We believe the revised rule language is clearer 
and will not cause an applicant to unreasonably consider EWIS component 
failures that could not adversely impact required separation.
    Boeing requested that the words ``adequately'' be removed from the 
text of proposed Sec.  25.1703(d) (rule number unchanged) and 
``adequate'' from Sec.  25.1709 (a), (c), (d), (e), (f), (g), (k), and 
(l) (Sec.  25.1709 is now Sec.  25.1707). Boeing contends that 
inclusion of these terms does not enhance interpretation of the rules. 
It requested that we either delete them or add performance criteria 
that define the term ``adequate.''
    We believe the word ``adequate'' is necessary to the intent of 
Sec.  25.1707. Paragraph (a) of that section provides objective 
criteria outlining how adequate physical separation must be achieved. 
We have also described various means of providing adequate physical 
separation in the associated advisory material. Because each system 
design and airplane model can be unique, and because manufacturers have 
differing design standards and installation techniques, Sec.  25.1707 
does not mandate specific separation distances. The advisory material 
provides the criteria each airplane manufacturer should consider when 
developing adequate physical separation for EWIS. These criteria 
include the following factors:
     The electrical characteristics, amount of power, and 
severity of failure condition of the system functions performed by the 
signals in the EWIS and adjacent EWIS.
     Installation design features, including the number, type, 
and location of support devices along the wire path.
     The maximum amount of slack wire resulting from wire 
bundle build tolerances and other wire bundle manufacturing 
variabilities.
     Probable variations in the installation of the wiring and 
adjacent wiring, including position of wire support devices and amount 
of wire slack possible.

[[Page 63378]]

     The intended operating environment, including amount of 
deflection or relative movement possible and the effect of failure of a 
wire support or other separation means.
     Maintenance practices as defined by the airplane 
manufacturer's standard wiring practices manual and the ICA required by 
Sec.  25.1529 and Sec.  25.1729.
     The maximum temperature generated by adjacent wire/wire 
bundles during normal and fault conditions.
     Possible electromagnetic interference, high intensity 
radiated fields, or induced lightning effects.

Although not related to this comment, we believe that the requirements 
of Sec.  25.1707(c) could be stated more clearly. We have revised Sec.  
25.1707(c) in the final rule to state that

    * * * damage to circuits associated with essential functions 
will be minimized under fault conditions.

    We have removed the word ``adequately'' from Sec.  25.1703(d). As 
used in proposed Sec.  25.1703(d), that word does not add clarity to 
the requirement's intent and is therefore unnecessary.
    GE suggested that for clarification we revise proposed Sec.  
25.1709(l) (now Sec.  25.1707(l)) to read as follows:

    Sec.  25.1709(l) Each EWIS must be designed and installed so 
there is adequate separation between it and other aircraft 
components, in order to prevent abrasion/chafing, vibration damage, 
and other types of mechanical damage.

    We agree with GE that the wording of this rule could be improved to 
help clarify its requirements. We have revised Sec.  25.1707(l) to 
state that

    * * * EWIS must be designed and installed so there is adequate 
physical separation between it and other aircraft components and 
aircraft structure, and so that the EWIS is protected from sharp 
edges and corners, to minimize potential for abrasion/chafing, 
vibration damage, and other types of mechanical damage.

    Boeing requested that the reference to Sec.  25.1309(b)(1) and 
(b)(2) in Sec.  25.1709(a) (now Sec.  25.1707(a)) be deleted. It 
commented that the applicable guidance material does not include a 
numerical probability analysis. EASA commented that proposed Sec.  
25.1709(a) limits applicability of Sec.  25.1309 to EWIS addressed by 
subparagraphs (b)(1) and (b)(2). EASA believes that for administrative 
purposes the final Sec.  25.1709(a) should simply reference Sec.  
25.1309 because Sec.  25.1309 could be revised in the future or the 
requirements of those paragraphs could be moved to a different 
paragraph within Sec.  25.1309, making it necessary to also change 
Sec.  25.1709. It stated that the equivalent EASA requirement will just 
reference Sec.  25.1309.
    We agree with Boeing's request to delete the reference to Sec.  
25.1309(b)(1) and (b)(2) and do not agree with EASA's request to modify 
the reference. The intent of the reference to failure conditions as 
defined by Sec.  25.1309(b)(1) and (b)(2) was to require that an EWIS, 
under normal and failure conditions, would not create an unsafe 
condition. The failure conditions we were intending to reference are 
``hazardous'' or ``catastrophic,'' used in EASA CS-25.1309 and in Sec.  
25.1709. In reviewing the text of the proposal, however, we realized 
that this reference could cause confusion as to the intent of the 
requirement and that the reference to the ``catastrophic'' failure 
condition is not necessary for the purposes of this requirement. To 
better align the requirement of paragraph (a) with the requirements of 
paragraphs (e) through (j), and to ensure adequate separation between 
EWIS and other airplane systems not specifically addressed by those 
paragraphs and paragraph (k), we have revised the first sentence of 
25.1707(a). That sentence now reads: ``Each EWIS must be designed and 
installed with adequate physical separation from other EWIS and 
airplane systems so that an EWIS component failure will not create a 
hazardous condition.'' We discuss the term ``hazardous condition'' in 
our response to the next two comments.
    General Electric and Honeywell commented that the wording of Sec.  
25.1709 (now Sec.  25.1707) should be revised to clarify the meaning of 
``hazardous conditions,'' so that a contained and detectable engine 
nacelle or auxiliary power unit (APU) enclosure fire is clearly 
distinguished from a fire within the pressurized fuselage as not being 
hazardous. In a similar comment, Airbus requested that the language for 
Sec.  25.1709(b) (now Sec.  25.1707(b)) be revised to reflect the 
original ATSRAC recommendation as follows:

    Each EWIS must be designed and installed so that any electrical 
interference likely to be present in the airplane will not result in 
hazardous effects upon the airplane or its systems unless shown to 
be extremely remote.

    Airbus stated that the ATSRAC-proposed words ``unless shown be to 
extremely remote,'' should not be removed unless it can be interpreted 
that the word ``likely'' excludes cases that are extremely remote and 
this is expressed in the advisory material.
    In our NPRM preamble discussion of this issue, we said that the 
phrase ``hazardous condition'' in Sec.  25.1709 (now Sec.  25.1707) is 
used in a different context than it is when associated with the EWIS 
safety analysis requirements of Sec.  25.1705 (now Sec.  25.1709.) 
While that statement remains true, we now realize that framing the 
discussion around what a hazardous condition means in different rules 
may have caused confusion. The meaning of the term ``hazardous 
condition'' remains the same, whether used in Sec.  25.1707, in Sec.  
25.1709, in current Sec.  25.1353, or in CS 25.1309. Here is the 
definition for a hazardous failure condition, and also for a 
catastrophic failure condition.
    Hazardous Failure Condition:
    Failure condition that would reduce the capability of the airplane 
or the ability of the flightcrew to cope with adverse operating 
conditions to the extent that there would be, for example:
     A large reduction in safety margins or functional 
capabilities; or
     Physical distress or excessive workload such that the 
flightcrew cannot be relied upon to perform their tasks accurately or 
completely; or
     Serious or fatal injuries to a relatively small number of 
persons other than the flightcrew.
    Catastrophic Failure Condition:
    Failure condition that would result in multiple fatalities, usually 
with the loss of the airplane.
    Hazardous and catastrophic failure conditions are descriptive terms 
for situations that could occur in the airplane because of failures 
(safety margins reduced, the flightcrew unable to perform accurately 
because of adverse operating conditions, injuries to passengers, etc.). 
These are situations that result from unsafe conditions and must be 
avoided. Therefore, when an airplane is certified, the applicant must 
show that the kinds of failures that could result in these kinds of 
situations have been considered, and measures put in place to prevent 
them.
    In the System Separation rule, Sec.  25.1707, separation distances 
or a barrier must be used to ensure that none of the types of failures 
described in the rule will create a situation that would fit the 
definition of a hazardous condition. The operative term in this rule is 
that such failures will not create a hazardous condition. To show that 
a given failure, such as fuel leakage onto EWIS components, will not 
create a hazardous condition, the applicant may use a qualitative 
analysis, consisting of expert engineering judgment, manufacturing 
judgment, and an assessment of any relevant service history.
    In the EWIS System Safety rule, Sec.  25.1709, the applicant must 
show that each EWIS system is designed and installed so that each 
hazardous failure

[[Page 63379]]

condition is extremely remote. The definition of a hazardous failure 
condition remains the same. In this rule, however, a numerical 
probability is required to demonstrate that the possibility for such an 
occurrence is extremely remote.
    Section Sec.  25.1709 uses both the terms ``hazardous'' and 
``catastrophic'' and says that the applicant must not only show that 
each hazardous failure condition is extremely remote, but that each 
catastrophic failure condition is extremely improbable and does not 
result from a single failure. This would normally require a combination 
of qualitative and quantitative analyses to demonstrate compliance.
    The requirements of Sec.  25.1707 do not preclude use of valid 
component failure rates if the applicant chooses to use a probability 
argument in addition to the design assessment to demonstrate 
compliance. It also does not preclude the FAA from requiring such an 
analysis if the applicant cannot adequately demonstrate that hazardous 
conditions will be prevented solely by using the qualitative design 
assessment. However, we did not include the words ``unless shown to be 
extremely remote'' in Sec.  25.1707 because we did not want to imply 
that a numerical probability assessment was required to comply with 
this rule.
    The engine nacelles and APU enclosures are designated as fire zones 
and this is taken into account in the design and installation of EWIS 
in those areas. But we do not agree with GE and Honeywell that a fire 
in the engine nacelle or APU enclosure could never create a hazardous 
condition. There is always the possibility that the fire could not be 
suppressed and could result in a safety hazard. We made no changes 
because of these comments.
    The National Air Carrier Association (NACA) commented that the 
proposed EWIS system separation requirements in Sec.  25.1709 (now 
Sec.  25.1707) are necessary for new aircraft. However, it said that 
imposing these requirements and those of Sec.  25.1711 on existing 
airplanes would be a significant economic burden.
    The separation and identification requirements of Sec. Sec.  
25.1707 and 25.1711 are applicable to new designs and do not apply to 
previously certified products.
    In a comment relating to proposed Sec.  25.1709 (now Sec.  
25.1707), IASA requested that specific mention be made of wiring that 
is required to regularly flex in position (such as that in doors and 
hatches).
    We agree that designers and installers should address the 
additional stresses placed on wires and cables that are required to 
regularly flex, such as those in doors and hatches. We have revised the 
advisory material for Sec. Sec.  25.1703 and 25.1709 to reflect this. 
However we do not concur that a change to Sec.  25.1707 is necessary. 
As stated, these requirements are performance based. Applicants would 
have to demonstrate that any wiring required to regularly flex in 
operation would be able to maintain its designed separation distance 
from other EWIS, components, or airplane structure as applicable.
    Boeing and GE requested that we clarify Sec.  25.1709(d) (now Sec.  
25.1707(d)). They asked whether an ``independent airplane power 
source'' is considered to be an airplane level power source as is 
related to an APU, battery, etc., or whether it is any power source 
that transmits power. If it is the latter, they recommended that there 
be some differentiation in the associated guidance material for the 
differences between ground blocks and ground studs, and for the 
differences between static grounds terminating at ground blocks and 
ground studs. The commenters did not consider ground blocks ``a common 
terminating location'' for non-redundant grounds.
    As used in Sec.  25.1707(d), ``independent airplane power sources'' 
means a general source of power for the whole of the airplane or for 
major subsystems (such as the permanent magnet generators that provide 
power for fly-by-wire systems ). Examples include engine-or APU-driven 
generators, batteries, and ram air turbines. We have revised the AC to 
reflect this.
    GE requested that the word ``physical'' be deleted from the text of 
Sec.  25.1709(d) (now Sec.  25.1707(d)). It stated that adequate 
separation should be all that is required and that using physical 
separation is only one means of achieving this.
    The FAA believes that the word ``physical'' is necessary, as 
recommended by ATSRAC, to ensure that necessary separation is not 
achieved solely by electrical isolation and use of control logic via 
hardware or software implementation. We made no changes due to this 
comment.
    Airbus requested that the phrase ``will not create a hazardous 
condition'' be replaced by the phrase ``will not create a hazard'' in 
proposed Sec.  25.1709 (e), (f), (g), (h), (i), and (j) (proposed Sec.  
25.1709 is now Sec.  25.1707). Airbus commented that this would 
eliminate ambiguous interpretation from inappropriate use of what is a 
system safety classification term used in Sec.  25.1309(b).
    We believe the word ``hazard'' is ambiguous and could cause 
confusion in the context of the requirement. We believe that the 
preamble discussion in the NPRM (which refers to this rule as Sec.  
25.1709), the additional clarification given in this final rule, and 
the advisory material for final Sec.  25.1707 clearly articulate what 
is meant by the term ``hazardous condition.''
6. System Safety: EWIS (Sec.  25.1709)
    This rule requires applicants to perform a system safety assessment 
of the EWIS on their airplane. The current regulation requiring system 
safety assessment for certification is Sec.  25.1309. But current Sec.  
25.1309 only covers systems and equipment that are ``required by this 
subchapter,'' and wiring for non-required systems is sometimes ignored. 
The objective of new Sec.  25.1709 is to apply the concepts of Sec.  
25.1309 to all wiring.
    The safety assessment required by Sec.  25.1709 must consider 
effects that both physical and functional failures of EWIS would have 
on the airplane's safety. Based on that safety assessment, the 
applicant must show that each EWIS failure considered to be hazardous 
is extremely remote. Each EWIS failure considered to be catastrophic 
must be shown to be extremely improbable and may not result from a 
single failure.
    This rule was proposed as Sec.  25.1705. That number has been 
changed to Sec.  25.1709, to harmonize with foreign airworthiness 
authorities. With the exception of that number change, this rule 
remains unchanged from the form in which it was proposed.
    Airbus suggested that use of the words ``extremely remote'' and 
``extremely improbable'' should be avoided. It pointed out that the 
preamble discussion for Sec.  25.1705 (now Sec.  25.1709) is based on a 
qualitative approach and this was the basis of ATSRAC's recommendation. 
Airbus said that no calculated number should be necessary for 
compliance with this rule. It also said, with reference to the NPRM 
preamble discussion, that ``jamming'' cannot be a justification for 
creating Sec.  25.1705 because an EWIS cannot cause flight control 
surface or pilot controls jamming.
    The analysis required by Sec.  25.1709 is not purely a qualitative 
assessment of the effects of EWIS failures. Nor was this the basis of 
the ATSRAC recommendation. The analysis required by Sec.  25.1709 is 
based on a qualitative and quantitative approach to assessing EWIS 
safety, as opposed to a purely numerical, probability-based 
quantitative analysis. This is consistent with existing Sec.  25.1309 
assessments, where a qualitative analysis is always necessary, and the 
quantitative

[[Page 63380]]

probability analysis is a means of compliance for the hazardous and 
catastrophic failure conditions.
    Section 25.1709 is based on the recommendation from ATSRAC. The 
Sec.  25.1709 safety assessment must consider effects that both 
physical and functional failures of EWIS would have on airplane safety. 
The physical analysis is meant to be a qualitative assessment and its 
results are to be integrated into the analysis required by Sec.  
25.1309 (or other required assessments such as Sec.  25.671 as 
applicable), which is both a qualitative and quantitative assessment.
    In response to Airbus's comment that creation of EWIS requirements 
should not be predicated on flight control surface or pilot controls 
jamming, the NPRM preamble reference is in the context of explaining 
that certain airplane systems are exempt from Sec.  25.1309. EWIS 
associated with those exempt systems are thus also excluded, even 
though those EWIS could create hazardous conditions in the same way as 
any other EWIS. As a result, there is a need for a requirement to 
address all the EWIS on an airplane. We made no changes based on these 
comments.
    While acknowledging that the aim of proposed Sec.  25.1705 (now 
Sec.  25.1709) is to make the requirements of Sec.  25.1309 more 
explicitly applicable to EWIS, Airbus requested that the text of this 
rule be revised to read as follows:

    Each EWIS must be designed and installed so it does not lead to 
a catastrophic failure condition as a consequence of a single EWIS 
failure. EWIS failure should be understood as failure affecting from 
one to all EWIS components within a single bundle.

Airbus's rationale for this change is based on the originally estimated 
32.8 accidents that adoption of the proposed rules will prevent over 
the next 25 years. When combined with the number of airplanes projected 
to be in service and their combined operating hours, the probability of 
an EWIS causing a hazardous or catastrophic failure condition will be 
less than is required to demonstrate compliance with Sec.  25.1709. The 
commenter contended that if this rationale is accepted by the FAA, then 
all an applicant should have to do is show in a qualitative manner that 
an airplane's EWIS will not be the cause of a catastrophic event.
    The purpose of Sec.  25.1709 is to ensure that the same analytical 
rigor applied to other systems for compliance with Sec.  25.1309 is 
applied to EWIS. That is why the proposal specified the same criteria 
as Sec.  25.1309(b). Airbus's request would impose lesser criteria for 
analysis of EWIS, even though the consequences of EWIS failures may be 
just as severe as any other system failures. Airbus's justification for 
its request relies on the estimated numbers of incidents in the initial 
regulatory evaluation and an apparent assumption that this number would 
meet the computed risk threshold required by Sec.  25.1309. This is not 
the case. The analytical methods used for an economic evaluation are 
very different from methods required for risk assessment by Sec.  
25.1309 (or Sec.  25.1709). The regulatory evaluation is a projected 
incident rate based on historical data. Estimating possible failures 
for compliance requires a detailed evaluation of the modes and effects 
of potential failures in a specific system design. We made no change 
because of this comment.
    Boeing requested that proposed Sec.  25.1705 (now Sec.  25.1709) be 
included as a reference within Sec.  25.1309(b) as previously proposed 
by industry. Boeing stated that duplicating the regulations leaves open 
the possibility of deviations in application. GE commented that 
proposed Sec.  25.1705 is not acceptable. It said the discussion of 
this proposal, and the accompanying AC, contain several misstatements 
regarding current use and means of compliance with Sec.  25.1309. 
According to GE, this misunderstanding of Sec.  25.1309 has led to a 
perception by the FAA that a new rule is needed, when in fact, Sec.  
25.1309 already addresses the area of concern. The NPRM preamble states 
that Sec.  25.1309 does not address single wire chafing or arcing as a 
cause of failure: ``the physical portion has been neglected in past 
system safety analyses.'' GE contended this is not true, because Sec.  
25.1309 safety assessments have addressed wiring failures as sources of 
fire. GE recommended that proposed Sec.  25.1705 be removed. It 
suggested that the AC material for proposed Sec.  25.1705 be provided 
to ARAC for incorporation into the Sec.  25.1309 AC.
    As stated in the preamble discussion of the NPRM, and in its 
related draft advisory material, the Sec.  25.1709 analysis may be 
accomplished in conjunction with Sec.  25.1309 assessments. Having a 
separate requirement for EWIS safety assessments will ensure that all 
airplane EWIS are assessed for potential impact on safe operation. This 
cannot be accomplished if Sec.  25.1709 is simply included as a 
reference in Sec.  25.1309. Nor can we delete Sec.  25.1709 and 
incorporate its means of compliance into future versions of advisory 
material for Sec.  25.1309, as GE suggests. As discussed in the NPRM, 
the requirements of Sec.  25.1709 are necessary. Current safety 
analysis practice has been proven--by accidents and service history--to 
be insufficient with respect to safety assessments of wire designs and 
installations, including wire failures that can cause fires. The 
requirements of Sec.  25.1709 are such that they complement those of 
Sec.  25.1309 and address its shortcomings when it comes to safety 
assessments of EWIS. Section 25.1309 does not allow any single failure 
to result in catastrophic consequences, regardless of the failure 
probability. The requirements of Sec.  25.1709 are consistent with 
those of Sec.  25.1309. We made no changes due to these comments.
    Federal Express referred to this statement in the preamble 
discussion of proposed Sec.  25.1705 (now Sec.  25.1709):

    If this information [what systems and functions the other wires 
in the same and surrounding bundles support] is not available to the 
modifier, then the EWIS system must be designed to accommodate this 
lack of knowledge * * *.

FedEx said this would typically mean that wire being added for the 
modification would need to be routed separately from existing airplane 
wiring. It requested that, prior to adoption of this concept into any 
advisory material or design standard, detailed guidance on separation 
in confined areas such as equipment racks or breaker panels be 
developed.
    We believe that the advisory material for post-TC modifications 
provides clear guidance for the case cited by Federal Express. When 
separation cannot be maintained because of physical constraints (in 
terminal strips and connectors, for instance), the applicant should 
conduct the appropriate analysis to show that no adverse failure 
conditions result from sharing the common device. This analysis 
requires knowledge of the systems or system functions sharing that 
device (again, the example would be terminal strips and connectors). If 
a modifier cannot identify the systems or system functions in the 
congested area, then the new EWIS would have to be routed through a 
different area if an acceptable alternative method of providing 
adequate separation is not provided. We made no changes to the final 
rule because of this comment. However, we have expanded the final 
advisory material for this requirement to provide clear guidance on the 
specific scenario contained in FedEx's comment.
    Boeing commented on the part of the Sec.  25.1705 (now Sec.  
25.1709) discussion in the NPRM that states that an in-flight 
entertainment (IFE) system installed on an airplane with subpart H as 
part of its type certification basis would be subjected to a more 
rigorous safety

[[Page 63381]]

assessment. Boeing noted its understanding that subpart H is applied to 
applicants for type certificates, amended type certificates, and 
supplemental type certificates. It asked whether it is correct that 
``an application for that or another IFE system to be installed on any 
airplane following the implementation of subpart H would be subjected 
to a more rigorous safety assessment.''
    Boeing asked whether an existing STC applicable to an existing 
airplane model, applied to a new airplane of the same model but with 
subpart H as part of its certification basis, would be subjected to 
requirements of subpart H. It referred to the statement in the NPRM 
that post-type certificate modifications have repeatedly introduced 
wiring safety problems. Boeing asked for clarification of whether an 
existing amended or supplemental type certificate would be subjected to 
subpart H requirements prior to installation on an airplane with or 
without subpart H as its basis of certification.
    In the case of a previously certified IFE system being considered 
for installation on an airplane model with subpart H in its 
certification basis, the answer is yes. The IFE system would have to be 
certified to the EWIS requirements of subpart H. To do otherwise could 
compromise the safety of the airplane by applying a lesser 
certification standard to the IFE system. After the effective date of 
the final rule, if a modification is proposed for an existing airplane 
model without subpart H in its certification basis, whether or not the 
modification will need to have subpart H in its certification basis 
will be decided on a case-by-case basis, and the requirements of Sec.  
21.101, Designation of applicable regulations, will apply.
7. Component Identification: EWIS (Sec.  25.1711)
    This rule requires applicants to identify EWIS components using 
consistent methods that facilitate easy identification of the 
component, its function, and its design limitations. For EWIS 
associated with flight-essential functions, identification of the EWIS 
separation requirement is also required.
    The number of this rule remains unchanged from its number as 
proposed. In response to comment, we have revised wording to clarify 
its intent, as discussed below.
    Boeing requested that we clarify Sec.  25.1711(a) by revising it as 
follows:

    EWIS components must be labeled or otherwise identified using a 
consistent method that facilitates identification of the wire EWIS 
component, its function, and its design limitations, if any.

GE requested we revise the same paragraph to read as follows:

    EWIS components must be labeled or otherwise identified using a 
consistent method that facilitates identification.

    Boeing and GE also requested that we remove the requirement in 
Sec.  25.1711(b) that, for systems requiring redundancy, components 
must be identified with component part number, function, and separation 
requirement for bundles. They stated that all wiring should be treated 
with the same level of care. The commenters contended that as the 
proposed requirement was written, the regulation was impractical to 
implement, since there are many redundancy separation categories in the 
aircraft. A given bundle might have different separation requirements 
from multiple other bundles, from hydraulic systems, and from air 
ducts, and the requirement could vary with axial distance along the 
fuselage. There would not be room to add all this data to the bundle 
label.
    We have clarified Sec.  25.1711(a) as requested by Boeing. It is 
the intent of this rule to require identification of all EWIS 
components and not just the wire (which is one component of an EWIS). 
We have revised that section by replacing the word ``wire'' with the 
phrase ``EWIS component.''
    We have decided against deleting the phrase ``of the wire, its 
function, and its design limitations, if any'' from Sec.  25.1711(a). 
It is important that the EWIS component's function and design 
limitation information be easily and readily available to maintainers 
and future modifiers. Labeling components with this information will 
help ensure that the level of safety provided by the original design is 
not degraded. It will also prevent potential safety hazards from 
improper maintenance and from replacement of original parts with parts 
not designed or intended for that particular use.
    We have also decided against deleting Sec.  25.1711(b). We agree 
that all wiring must be treated with care. But we are especially 
concerned that wires and other EWIS components associated with flight-
essential or flight-critical systems be easily identifiable by those 
designing and installing modifications, as well as by technicians 
performing maintenance or repair. If a wire bundle has different 
separation requirements as it is routed throughout the airplane, then 
those varying separation requirements must be identified on the bundle 
at the appropriate location where a particular separation requirement 
is applicable. It would not be necessary to have each label on the 
bundle contain all the differing separation requirements.
    IASA suggested that using a color-coding approach to identifying 
critical systems would help post-TC modifiers easily identify critical 
airplane systems. We agree with the need to help ensure easy 
identification of these systems so that post-TC modifications and 
repairs do not inadvertently introduce unintended failure modes. 
However, the EWIS identification requirements of Sec.  25.1711 do not 
prescribe the means by which EWIS is identified. It only requires that 
the identification scheme be consistent throughout the airplane and 
that modifications follow the same scheme. Color coding of EWIS may be 
an acceptable means to comply with the requirements. We made no changes 
because of this comment.
    US Airways stated that mandating identification for all terminals, 
switches, connectors, or any component mounted in an area with limited 
space could cause tags or something similar to be used. These would in 
turn become contaminants.
    We agree that some EWIS components may be so small that it would be 
impractical to label the component directly with textual data, and that 
excessive use of tags could become a source of future contamination. 
However, Sec.  25.1711 states that other means of identification can be 
used if the component cannot be physically marked. For example, the 
manufacturer's consistent marking scheme may be such that a color code 
is used to mark these types of components. Applicants will have to 
collaborate with their FAA Aircraft Certification Office to work out 
the details. The method of identification is not mandated by the rule. 
It is left up to the applicant to propose a method of identification. 
We made no changes based on this comment.
8. Fire Protection: EWIS (Sec.  25.1713)
    This rule requires that EWIS components meet the applicable fire 
and smoke protection requirements of Sec.  25.831(c). It further 
requires that EWIS located in designated fire zones be fire resistant. 
Insulation on electrical wires and cables is required to be self-
extinguishing when tested in accordance with the applicable portions of 
Appendix F, part 1, of part 25. Section 25.1713 is adopted as proposed, 
except that we removed the phrase ``at least'' that preceded ``fire 
resistant.''
    EASA and Airbus commented that Sec.  25.1713(a) should also 
reference Sec.  25.863. Airbus stated that this reference is common 
practice for fire

[[Page 63382]]

protection compliance demonstration for EWIS components. EASA stated 
that the equivalent EASA requirement, CS 25.1713, will reference CS 
25.863.
    Because Sec.  25.1723 already requires EWIS components to meet 
requirements of Sec.  25.863, it is not necessary to state the same 
requirement in Sec.  25.1713.
    Boeing commented that proposed Sec.  25.1713(c) repeats and 
replaces Sec.  25.869(a)(4), except with the change underlined below:

    (c) Insulation on electrical wire and electrical cable, and 
materials used to provide additional protection for the wire and 
cable, installed in any area * * *

Boeing requested that we change Sec.  25.1713(c) and/or Appendix F to 
Part 25 to clarify which test article configurations (test components 
individually or test components installed on the wire), and which 
flammability tests are required for ``materials used to provide 
additional protection for the wire and cable.''
    Boeing noted that Appendix F only refers to electrical conduit. It 
said the rule is clear on how electrical conduit and insulation on wire 
must be tested, but not on how to test the ``materials used to provide 
additional protection for the wire and cable.''
    Boeing said that the rules should make clear what testing is 
required for materials such as tight-fitting protective sleeve ( heat 
shrinkable material, for example), loose-fitting protective sleeve 
(such as spiral wrap or Varglas), or, for that matter, clamps, grommets 
installed in holes, or other devices used to protect wire and cable.
    We have not revised Sec.  25.1713(c) and/or Appendix F because we 
believe the requirements of Sec.  25.1713(c) are clear and unambiguous. 
A material used to protect wire such as heat shrinkable material, or 
loose fitting protective sleeving such as spiral wrap or Varglas, must 
be tested in accordance with the requirements of part 25, Appendix F, 
part I, in the same manner as electrical wire is tested. As stated in 
Appendix F, Part 1(a)(v), it is not necessary to test small parts such 
as clamps and grommets because they would not contribute significantly 
to the propagation of a fire.
9. Electrical Bonding and Protection Against Static Electricity: EWIS 
(Sec.  25.1715)
    Section 25.1715 requires that EWIS used for electrical bonding and 
protection against static electricity meet the requirements of Sec.  
25.899. It requires that EWIS components used for any electrical 
bonding purposes (not just those used for protection against static 
electricity) provide an adequate electrical return path under both 
normal and fault conditions.
    Section 25.1715 was proposed as Sec.  25.1717. Its number was 
changed to better harmonize with foreign airworthiness authorities. In 
response to comments, we have revised the wording of Sec.  25.1715 and 
expanded it to clarify meaning, as discussed below.
    Boeing stated that the term ``adequate electrical return path'' as 
used in Sec.  25.1717 (now Sec.  25.1715) is difficult to define, and 
should be replaced with performance criteria, such as the following:

    On airplanes having grounded electrical systems, electrical 
bonding provided by EWIS components must provide an electrical 
return path capable of carrying both normal and fault currents 
without creating a shock hazard.

GE requested clarification of what constitutes a fault condition for 
compliance with proposed Sec.  25.1717. It asked if a fault condition 
includes failure of the bonding path, such as physical breakage.
    We have revised Sec.  25.1715 as requested by Boeing but have added 
the phrase ``or damage to the EWIS components, other airplane system 
components, or airplane structure.'' to the end of the suggested 
revision.
    In response to GE's comment, the intent of the requirement is to 
ensure that the current return paths are sized so they can accommodate 
fault currents due to component failure. One example would be shorted 
integrated drive generator power feeder cables where electrical bonding 
is used for the fault current path.
10. Accessibility Provisions: EWIS (Sec.  25.1719)
    This rule requires access be provided to allow for inspection of 
EWIS and replacement of their components, as necessary for continued 
airworthiness.
    Section 25.1719 was proposed as Sec.  25.1725. Its number has been 
changed to facilitate harmonization. No other changes have been made.
    EASA and Airbus commented that the wording of proposed Sec.  
25.1725 (now Sec.  25.1719) is slightly different from that recommended 
by ATSRAC. ATSRAC recommended that it state:

    Means must be provided to allow for inspection of EWIS and the 
replacement of its components as necessary for continued 
airworthiness.

The NPRM proposed Sec.  25.1725 to read as:

    Access must be provided to allow inspection and replacement of 
any EWIS component as necessary for continued airworthiness.

    Airbus said that the word ``access'' is ambiguous. For example, it 
said, it is almost impossible to access the inside of a conduit. U.S. 
Airways noted that the rule needs to be revised because there are areas 
where access to cables and wire runs is not possible.
    EASA suggested we change the rule to ATSRAC's original wording and 
stated that it will use this wording in its equivalent requirement, CS 
25.1719.
    We have decided to retain the wording of this requirement as 
proposed. However, it should be noted that it is not the intent of the 
rule to require human physical access in all cases. If such access is 
not possible because of physical design, then other inspection 
techniques could be allowed, such as use of a remote optical device. 
However, in response to U.S. Airways' statement, Sec.  25.1719 does 
require that access be provided to allow for inspection and replacement 
for any EWIS component if it is necessary for continued airworthiness. 
Therefore there will not be areas where EWIS components are 
inaccessible for airplanes with Sec.  25.1719 in their type 
certification basis.
    We have revised AC 25-1701-1 to reflect the fact that other types 
of inspection techniques could be approved when human physical access 
is not possible. Other types of emerging inspection techniques may not 
require physical access.
11. Protection of EWIS (Sec.  25.1721)
    Section 25.1721 requires that cargo or baggage compartments not 
contain any EWIS whose failure would adversely affect safe operation. 
It also requires that all EWIS be protected from damage by movement of 
people and from damage from items carried on the airplane by passengers 
or cabin crew.
    Section 25.1721 was proposed as Sec.  25.1727. Its rule number was 
changed to harmonize with regulations of foreign airworthiness 
authorities. No other changes have been made.
    Boeing suggested that this rule be revised to state that EWIS 
should be protected so it ``* * * cannot be damaged by normal movement 
of cargo or baggage in the compartment.'' It said this change will 
clarify requirements. Boeing, GE, and AIA/GAMA stated that maintenance 
personnel need to be trained in proper EWIS handling.
    We have decided against revising Sec.  25.1721 in the manner Boeing 
suggests. This requirement is not limited to ``normal movement.'' EWIS 
in cargo or baggage compartments must be designed and installed so it 
is protected in both normal and non-normal situations, such as when 
cargo

[[Page 63383]]

containers come loose and strike compartment walls during flight 
because of cargo system malfunctions.
    We agree that training personnel in proper handling of EWIS is also 
necessary. Although we have not mandated this training, except for 
technicians and inspectors working directly with EWIS, we have outlined 
a training program for a wide variety of personnel who work on 
airplanes. This training program is outlined in Advisory Circular 120-
YY, Aircraft Electrical Wiring Interconnection Systems Training 
Program. We made no changes due to these comments.
    GE requested that the phrase ``risk of damage'' be deleted from 
proposed Sec.  25.1727 (now Sec.  25.1721). It stated that risk of 
damage implies control of the failure effect of damage that is assumed 
to occur, as in Sec.  25.901(c). It said that because 14 CFR 25.1309 
already adequately controls the relationship between probability of a 
failure condition and its effect, risk of damage should be deleted from 
proposed Sec.  25.1727.
    We believe it is necessary to address both damage and risk of 
damage. Design and installation must be such that they preclude damage 
to EWIS to the extent possible when all design and installation factors 
are considered. We recognize, however, that it is not always possible 
to prevent possible damage because of design or installation 
considerations. EWIS components should be robust enough to minimize the 
damage that could occur if they come into contact with cargo, baggage, 
or personnel. We made no changes due to this comment.
12. Flammable Fluid Shutoff Means: EWIS (Sec.  25.1727)
    Section 25.1727 requires that EWIS associated with each flammable 
fluid shutoff means and control be ``fireproof'' (as defined in Sec.  
1.1) or located and protected so that any fire in a fire zone will not 
affect operation of the flammable fluid shutoff means, in accordance 
with Sec.  25.1189.
    Section 25.1727 was originally proposed as Sec.  25.1733. We have 
changed its number to facilitate harmonization with foreign 
airworthiness authorities. No other changes have been made.
    Boeing recommended that the word ``fireproof'' in Sec.  25.1733 
(now Sec.  25.1727) be replaced with ``fire resistant'' to be 
consistent with terminology used in Sec.  25.869(a) and proposed Sec.  
25.1735 (now Sec.  25.1733). AIA/GAMA stated that fire resistant and 
fireproof are not synonymous.
    AIA/GAMA is correct. ``Fireproof'' is a more stringent standard 
than ``fire retardant.'' The basis for proposed Sec.  25.1727 is the 
requirement of Sec.  25.1189(d) that ``each flammable fluid shutoff 
means and control must be fireproof or must be located and protected so 
that any fire in a fire zone will not affect its operation.''
    To ensure the effectiveness of flammable fluid shutoff means and 
controls, the requirement for EWIS associated with those systems must 
be as stringent as the requirement for other components of those 
systems.
13. Powerplant and APU Fire Detection System: EWIS (Sec.  25.1731)
    This rule requires that EWIS that are part of a fire or overheat 
detector system located in a fire zone be fire resistant, as defined in 
Sec.  1.1. It also requires that EWIS components of any fire or 
overheat detector system for any fire zone may not pass through another 
fire zone unless:
     They are protected against the possibility of false 
warning caused by fire in the zone through which they pass, or
     Each zone involved is simultaneously protected by the same 
detector or extinguishing system.
    This rule also requires that EWIS that are part of a fire or 
overheat detector system in a fire zone meet requirements of Sec.  
25.1203. Section 25.1203 requires approved, quick acting, fire or 
overheat detectors in each designated fire zone, and in the combustion, 
turbine, and tailpipe sections of turbine engine installations, to 
provide prompt indication of fire in those zones.
    Section 25.1731 was originally proposed as Sec.  25.1737. Its 
number was changed for purposes of harmonization. No other changes have 
been made.
    EASA requested that the reference to Sec.  25.1203 be moved to 
Sec.  25.1719 (now Sec.  25.1705 Systems and Functions: EWIS).
    The intent of Sec.  25.1731 is to ensure that any EWIS components 
associated with powerplant and auxiliary power units' fire detector 
systems be as robust and fire resistant as the other components making 
up these systems. The requirements of Sec.  25.1731 are based on those 
contained in Sec.  25.1203. It could create confusion if the 
requirements in Sec.  25.1731 were split between two separate subpart H 
regulations as requested by EASA. Therefore we have retained the 
originally proposed Sec.  25.1731 in this final rule.
14. Fire Detector Systems, General: EWIS (Sec.  25.1733)
    Section 25.1733 requires that EWIS associated with any installed 
fire protection system be considered in showing compliance with the 
applicable requirements for that particular system. This is a new 
requirement that has not previously existed in part 25. Current part 25 
regulations contain fire detection system requirements for powerplants, 
lavatories, and cargo compartments. Each of these fire detection 
systems requires electrical wire, and failure of this wire could lead 
to inability of the detection system to function properly. This rule 
applies to all required fire protection systems with the exception of 
those for powerplants and APUs. Requirements for EWIS associated those 
systems are contained in Sec.  25.1731.
    Section 25.1733 was originally proposed as Sec.  25.1735. Its 
number was changed to better harmonize with foreign airworthiness 
authorities. As stated previously in the discussion under the heading 
of Systems and Functions: EWIS (Sec.  25.1705), we have revised this 
rule to include references to Sec. Sec.  25.854 and 25.858, in response 
to comments from EASA.
    Boeing and GE requested that proposed Sec.  25.1735 (now Sec.  
25.1733) be removed from subpart H, because it is not directly related 
to EWIS certification. The commenters noted that any system, not just 
fire detection systems, which uses wiring in its design will be 
required to meet requirements of subpart H.
    We have decided to adopt this requirement as proposed. Fire 
detection systems need wire and other EWIS components to operate. 
Failure of an associated EWIS component could lead to inability of the 
detection system to function properly. Therefore EWIS components must 
be considered an integral part of the fire detection system and meet 
requirements of the applicable regulation.
15. Engine, Nacelle, and APU Wiring
    GE, Honeywell, and AIA/GAMA commented that engine, nacelle, and APU 
wiring should be exempt from the proposed EWIS certification and 
maintenance requirements. They said wiring in these areas is extremely 
rugged, has excellent reliability in service, and is easily accessible 
for inspection. They further stated that it is physically impossible 
for a wiring failure or deterioration in the propulsion system to cause 
a hazardous or catastrophic effect. They expressed the view that 
existing regulations are

[[Page 63384]]

adequate, as demonstrated by service experience, and application of 
these rules to engine, nacelle and APU wiring confers no safety benefit 
and would result in significant cost to industry.
    We agree that EWIS components installed on the engine are very 
robust. This is because the harsh environment in which they are 
installed and the critical function engines play in the safe operation 
of the airplane dictate such robust design and installation. However, 
we do not agree that it is impossible for an engine wiring failure to 
cause a hazardous or catastrophic condition. The following quote is 
from the ``Lauda Air B767 Accident Report,'' dated July 21, 1993, 
issued by the Aircraft Accident Investigation Committee Ministry of 
Transport and Communications, Thailand--

    Investigation of the accident disclosed that certain ``hot-
short'' conditions involving the electrical system occurring during 
an auto-restow command, could potentially cause the DCV to 
momentarily move to the deploy position.

    This illustrates that, in the past, there have been designs where 
an engine wiring failure could cause a catastrophic accident. 
Application of these requirements to all wiring on part 25 airplanes 
will help ensure that in the future we will minimize EWIS designs and 
installations that could lead to serious safety issues. Our position is 
consistent with ATSRAC's recommendation that engine wires not be 
excluded from compliance with these new requirements. Additionally, our 
regulatory analysis indicates that these rules are cost effective. We 
made no rule change due to these comments.
16. Designated Fire Zones
    General Electric (GE) commented that the entire rulemaking package 
was written from the perspective of wiring contained in the pressurized 
fuselage, and then extrapolated to other areas. It stated as an example 
the assumption made throughout the NPRM that an electrical fire is 
catastrophic. GE stated that this is not the case in a designated fire 
zone, because such zones contain specific design measures to safely 
detect, contain, and put out a fire. The commenter stated that 
unpressurized portions of the airplane spend much of the flight at 
ambient pressures which will not easily support combustion. GE 
suggested that itemizing fuel sources that are isolated from the 
pressurized portion of the airplane--engine oil, engine fuel--as if 
they coexisted with the heated and air-conditioned section of the 
aircraft is very misleading.
    We believe that a fire in a fire zone is a safety issue. Fire zones 
are designated as such because they are areas that have a higher 
potential for a fire to occur. These zones do have fire detection and 
suppression systems or other design features to mitigate effects of 
fire. But these features are designed to meet a limited set of test 
conditions for a limited duration of time and are not designed to meet 
all anticipated sets of conditions that may exist in a fire zone. Any 
fire on board an airplane, no matter where it occurs, has the potential 
for serious safety consequences.
    The rule package was written with the objective of ensuring the 
safety of wiring in the entire airplane, consistent with the intent of 
ATSRAC.
17. Goal of the New Wiring Subpart
    GE and AIA/GAMA commented that many of the proposed subpart H EWIS 
certification requirements are duplicative of existing part 25 rules. 
They asserted that repeating a requirement in multiple locations 
promotes differences in interpretation and confusion over acceptable 
means of compliance. They recommended that the proposed subpart contain 
new applicable requirements and act as a collector with references or 
points to the existing applicable rules. They said this packaging 
technique would provide the benefit of the common location sought by 
the FAA to bring focus to the importance of EWIS design and 
certification while minimizing the confusion, interpretation, and 
divergence that challenges use of duplicate rule sets.
    We do not agree with the opinion that the proposed certification 
requirements of subpart H are duplicates of existing part 25 
requirements. To be a duplicate implies that the requirement exists in 
both the new subpart H and in other places within part 25. This is not 
the case. As described in the proposal's preamble, some of the subpart 
H requirements previously resided in other part 25 subparts. But they 
have been relocated to the new subpart H, and in some cases enhanced, 
and no longer exist elsewhere in part 25. Also, many requirements of 
subpart H are new requirements. In some cases (for instance in Sec.  
25.1705 in this final rule), we reference existing part 25 requirements 
that are applicable to EWIS but have not been moved into subpart H 
because they do not lend themselves to division into wire and non-wire 
portions. The goal of collecting existing part 25 wire-related 
requirements and developing new requirements is to make them easy to 
locate, ensure their application to EWIS, and highlight the importance 
of considering wiring and its associated components as an airplane 
system. Eliminating the majority of the proposed subpart H requirements 
and simply referencing other wire-related requirements in a new Sec.  
25.1700 series paragraph would not support this goal.
18. Harmonization
    British Airways, Royal Dutch Airlines (KLM), Airbus, and the 
Association of Asia Pacific Airlines requested that the proposed FAA 
and European Aviation Safety Agency's (EASA) EWIS requirements and 
advisory material be fully harmonized and made identical where 
possible.
    Harmonization of these requirements with EASA has been our goal 
from the beginning. We have coordinated extensively with EASA and other 
national civil aviation authorities to achieve this common objective. 
While there may be some differences in wording because of our differing 
regulatory procedures, our intent is to harmonize the substantive 
requirements to the extent possible.

D. Instructions for Continued Airworthiness: EWIS (Sec.  25.1729 and 
Appendix H)

1. Requirements for EWIS ICA
    Section 25.1729 requires that applicants prepare EWIS ICA in 
accordance with requirements of Appendix H to part 25. Section 25.1729 
was originally proposed as Sec.  25.1739. Its number has been changed 
to facilitate harmonization with the regulations of foreign 
airworthiness authorities. Otherwise, this rule remains unchanged from 
the form in which it was proposed.
    This final rule also revises paragraph H25.4 and adds a new 
paragraph H25.5 to Appendix H--Instructions for Continued 
Airworthiness. Section H25.5 is a new requirement. It requires TC 
applicants and applicants for design change to develop maintenance 
information for EWIS as part of the ICA that are required for design 
approval. The EWIS ICA must be developed through the use of an enhanced 
zonal analysis procedure (EZAP). The ICA must include tasks, and 
intervals for performing those tasks, to reduce the likelihood of 
ignition sources and accumulation of combustible material and tasks to 
clean the EWIS of combustible material if there is not an effective 
task to reduce the likelihood of its accumulation. The ICA must also 
include--
     Instructions for protections and cautions to prevent 
accidental damage or contamination to EWIS during maintenance, 
alteration, or repairs.
     Acceptable maintenance practices in a standard format.

[[Page 63385]]

     Wire separation requirements as determined under Sec.  
25.1707.
     Information explaining the EWIS identification method and 
requirements for identifying any changes to EWIS under Sec.  25.1711.
     Electrical load data and instructions for updating that 
data.
    The ICA developed through the use of an EZAP must be in the form of 
a document appropriate for the information to be provided, easily 
recognizable as EWIS ICA, and either contain required EWIS ICA or 
specifically reference other portions of the ICA that contain this 
information.
    The amendment to section H25.4 requires that the Airworthiness 
Limitations section of the ICA include any mandatory replacement times 
for EWIS components.
    The final wording for the requirement for ICA as a single document 
was revised from its proposed form, to clarify intent, as discussed 
below. No other changes have been made to these rules.
2. ICA as a Single Document
    Boeing and AIA/GAMA requested we delete paragraph H25.5(b) of 
Appendix H. This paragraph requires that EWIS ICA be contained in a 
single document, easily recognizable as EWIS ICA. They said their 
current approach is to produce several documents, including the 
maintenance planning data document, airplane maintenance manual, and 
standard wiring practices manual, with appropriate cross-references. 
These documents may not be EWIS specific. Boeing and AIA/GAMA believe 
separating EZAP-generated maintenance activities from those required by 
Special Federal Aviation Regulation (SFAR) 88 defeats the intent of the 
rule and is impractical.
    Additionally, Airbus, and GE suggested we revise H25.5(b) to say 
``the ICA must be provided in a manner acceptable to the Administrator, 
where instructions specific to EWIS are easily recognizable.'' They 
believe there is no safety benefit in uniquely identifying ICA related 
to, but not specific to, EWIS. They also requested that proposed Sec.  
25.1739 (now Sec.  25.1729) be revised with a reference back to Sec.  
25.1529 or deleted in its entirety. They stated that Sec.  25.1529 
already requires Instructions for Continued Airworthiness to be 
developed in accordance with Appendix H.
    We do not agree that paragraph H25.5 (b) should be deleted or 
revised as requested. The requirements of paragraph (b) do not preclude 
incorporation by reference of detailed information. However, we expect 
the DAH to provide a document appropriate for the information provided, 
in other words, a single or source document that either includes the 
EZAP-generated EWIS ICA or specifies where those EWIS ICA can be 
located. This also means that, if incorporation by reference is the 
approach taken by the DAH, all referenced documents are available at 
the same time as the EWIS ICA source document. We have revised the text 
of final H25.5(b) to clarify that the requirement only applies to EWIS 
ICA developed in accordance with requirements of H25.5(a)(1) and that 
the ``document must either contain the required EWIS ICA or 
specifically reference other portions of the ICA that contain this 
information.'' This does not change the meaning of the requirement, but 
clarifies it.
    We also do not agree with the request to delete or revise Sec.  
25.1729. Having a separate requirement for EWIS ICA located within 
subpart H is consistent with the purpose of creating the new subpart. 
The goal was to collect existing part 25 wire-related requirements and 
develop new requirements, make them easy to locate, ensure their 
application to EWIS, and highlight the importance of considering wiring 
and its associated component as an airplane system. We made no changes 
due to this comment.
3. Standard Wiring Practices Manuals
    Airbus commented about the requirement to include acceptable 
maintenance practices in a standard format. Airbus made the point that 
electronic standard wiring practices manuals (SWPM), in which such 
maintenance practices can be found, are easily searchable. It requested 
that manufacturers who publish their SWPMs electronically be either 
exempt from the requirement for a standard format for SWPMs, and/or an 
interim master breakdown index (which was outlined in the AC as an 
approach to standardizing SWPM formats without rewriting them), or able 
to adopt a similar approach.
    We are rejecting Airbus's request to exempt electronic versions of 
the SWPM from requirements of part 25, Appendix H, H25.5. The objective 
of this requirement is to ensure that maintenance personnel can readily 
access necessary information. They may work on many different models, 
so having a standard format will facilitate this. An applicant may 
propose an alternative ``standard'' format to that described in the AC, 
as long as it achieves the same objective (again, taking into account 
that maintenance personnel will be working on a range of models). The 
master breakdown index described in AC 25-26 was developed so that 
existing non-electronic SWPMs would not have to be reformatted. An 
electronic SWPM, by definition, can be easily indexed to align with the 
master breakdown index format as depicted in the AC. We made no changes 
due to this comment.
4. Mandatory Replacement Times
    Airbus requested that the requirement in section H25.4 to include 
mandatory replacement times for EWIS in Airworthiness Limitations of 
ICA be deleted because it is not related to any requirements to define 
mandatory EWIS replacement times.
    We are retaining H25.4. The intent of this requirement is not to 
mandate life limits for EWIS components, but to ensure that the 
designer consider whether EWIS life limitations are applicable to a 
particular design and identify those limits in the Airworthiness 
Limitations section of the ICA. Such limitations, if any, would be 
identified when demonstrating compliance with Sec.  25.1703. That rule 
requires that EWIS be installed according to limitations specified for 
that EWIS component, and this might include life limits under certain 
circumstances. For example, a given EWIS component may be well suited 
for a particular environment, but because of technological limitations, 
the material it is made of may degrade over time when exposed to 
certain environmental stresses. The component manufacturer may 
recommend that certain tests be performed at given intervals to ensure 
that its material properties are still within its qualification limits, 
and if they are not, recommend that the component be replaced. Life 
limits might also be identified when demonstrating compliance with the 
EWIS safety assessment requirements of Sec.  25.1705, as part of 
identifying acceptable mitigation strategies to prevent hazardous or 
catastrophic failures. We made no changes due to this comment.
5. Wire Identification Method Information
    Airbus, AIA/GAMA, and GE suggested we delete the requirement in 
proposed H25.5 for information explaining wire identification methods 
and requirements for identifying changes to EWIS. They stated that 
changes to EWIS, including future identification, are the modifier's 
responsibility, and a DAH cannot anticipate all possible future changes 
and give instructions for identification methods for changed 
components.

[[Page 63386]]

    This requirement is intended to ensure that EWIS components added 
or changed due to post-TC modifications retain the same identification 
scheme used by the design approval holder. It is not necessary for the 
original DAH to anticipate future changes to EWIS. The original DAH is 
only required to describe the original identification scheme used. An 
example could be a particular color used to identify EWIS components 
associated with a fly-by-wire system. It is the responsibility of the 
future modifier to follow that EWIS identification scheme as required 
by Sec.  25.1711.
6. Electrical Load Data
    GE requested confirmation that H25.5(a)(2), (3), (4), and (5) do 
not apply to the existing fleet. Also, AIA/GAMA and GE contended that 
electrical load data is a certification issue, not a continued 
airworthiness issue, and future changes or updates to that information 
is the modifier's responsibility. They requested that paragraph 
H25.5(a)(5) be deleted.
    The requirements of H25.5(a)(2), (3), (4), and (5) do not apply to 
the existing fleet unless a modification is introduced that would 
require that these requirements be part of the type certification basis 
of the modification, in accordance with 14 CFR 21.101.
    We agree that it is the responsibility of modifiers (e.g., STC 
applicants) to ensure that they update the actual load data of the 
airplane they are modifying and document the electrical load data as 
required by H25.5(a)(5). However, we have decided against deleting 
paragraph H25.5(a)(5). We are using this requirement as a means to 
ensure that accurate electrical load data is available to those who 
need it. Accurate electrical load data is necessary to help ensure 
continued airworthiness. It is important that the load demand of an 
airplane's systems not exceed the generation and distribution capacity 
of its electrical power system. By ensuring this, the necessary levels 
of electrical power will always be available for those airplane systems 
needed for safe operation. We made no changes due to this comment.

E. Continued Airworthiness and Safety Improvements Subparts for 
Operating Rules (Parts 91, 121, 125, 129)

1. Establishment of New Subparts
    This rule establishes new subparts in parts 91, 121, 125, and 129. 
These new subparts will contain operator requirements for continued 
airworthiness and safety improvements, just as the new part 26 will 
contain requirements for continued airworthiness and safety 
improvements applicable to DAHs. As we stated in the NPRM:

    The FAA believes that inclusion of certain rules under the new 
subparts will improve the reader's ability to readily identify rules 
pertinent to continued airworthiness. * * * The proposed new 
subparts consist of relocated, revised, and new regulations 
pertaining to continued airworthiness of the airplane. Unless we say 
otherwise, our purpose in moving requirements to these new subparts 
is to ensure easy visibility of those requirements applicable to the 
continued airworthiness of the airplane. We do not intend to change 
their legal effect in any other way. (70 FR 58537)

    Our creating these new subparts does not, by itself, impose any new 
requirements; it simply establishes the locations in which these 
requirements will be placed. In some cases, as with the fuel tank 
safety provisions of today's final rule, we may adopt parallel sections 
in all four new subparts. In other cases, as with the EWIS provisions 
of today's final rule, we may adopt requirements in only certain 
subparts. But in each case, the new requirements will only be adopted 
after public notice and opportunity to comment where we will explain 
the proposed scope and effect of the new requirements.
    Other new regulations and new subparts have been added to the CFR 
since publication of the NPRM. As a result, some of the rule numbers 
and some of the letter names for the new subparts that were proposed 
for this rule have already been used. In this final rule we have 
revised those rule numbers and subpart letter names where necessary.
    Provisions enabling each of the new Continued Airworthiness and 
Safety Improvements subparts, which were inadvertently left out of the 
proposal, have been added here. The placement of certain provisions 
within the rules has also been revised. The table below indicates the 
changes. Commenters' original references are retained here, however, 
for ease of reference to the proposal, including references to draft 
ACs.

       Table 3.--Operations Rules Changes From NPRM to Final Rule
------------------------------------------------------------------------
       Part                 Final rule                    NPRM
------------------------------------------------------------------------
91................  Sec.   91.1(d) (new).....  N/A.
91................  Subpart L--Continued       Subpart L--Continued
                     Airworthiness and Safety   Airworthiness and Safety
                     Improvements.              Improvements.
91................  Sec.   91.1501 Purpose     Sec.  Sec.   91.1501
                     and definition.            Purpose and definition.
91................  Sec.   91.1507 Fuel tank   Sec.   91.1507 Fuel tank
                     system inspection          system maintenance
                     program.                   program.
121...............  Sec.   121.1(g) (new)....  N/A.
121...............  Subpart AA--Continued      Subpart Y--Continued
                     Airworthiness and Safety   Airworthiness and Safety
                     Improvements.              Improvements.
121...............  Sec.   121.1101 Purpose    Sec.   121.901 Purpose
                     and definition.            and definition.
121...............  Sec.   121.1111            Sec.   121.911 Electrical
                     Electrical wiring          wiring interconnection
                     interconnection systems    systems (EWIS)
                     (EWIS) maintenance         maintenance program.
                     program..
121...............  Sec.   121.1113 Fuel tank  Sec.   121.913 Fuel tank
                     system maintenance         system maintenance
                     program.                   program.
125...............  Sec.   125.1(e) (new)....  N/A
125...............  Subpart M--Continued       Subpart M--Continued
                     Airworthiness and Safety   Airworthiness and Safety
                     Improvements.              Improvements.
125...............  Sec.   125.501 Purpose     Sec.   125.501 Purpose
                     and definition..           and definition.
125...............  Sec.   125.507 Fuel tank   Sec.   125.507 Fuel tank
                     system inspection          system inspection
                     program.                   program.
129...............  Subpart A--General.......  Subpart A--General.
129...............  Sec.   129.1(b)..........  Sec.   129.1(b).
129...............  Subpart B--Continued       Subpart B--Continued
                     Airworthiness and Safety   Airworthiness and Safety
                     Improvements.              Improvements.
129...............  Sec.   129.101 Purpose     Sec.   129.101 Purpose
                     and definition.            and definition.
129...............  Sec.   129.111 Electrical  Sec.   129.111 Electrical
                     wiring interconnection     wiring interconnection
                     systems (EWIS)             systems (EWIS)
                     maintenance program.       maintenance program.
129...............  Sec.   129.113 Fuel tank   Sec.   129.113 Fuel tank
                     system maintenance         system maintenance
                     program.                   program.
------------------------------------------------------------------------

[[Page 63387]]

2. Continued Airworthiness Subparts and Airworthiness Directives
    The Regional Airline Association (RAA) commented that proposed 
Sec.  121.901(a) (now Sec.  121.1101(a)), as a stand-alone provision, 
is unlimited in scope. It contended that the requirement can be 
interpreted to mean that operators must incorporate any future design 
and maintenance changes that a type certificate holder incorporates 
into its ICA, regardless of their airworthiness status. The RAA said 
that this would effectively eliminate the need for any future 
airworthiness directives. The RAA said it therefore has the potential 
to eliminate operator participation in the rulemaking process for 
future original equipment manufacturers' recommendations affecting 
maintenance and design of their fleet.
    In a similar vein, United Parcel Service (UPS) recommended we not 
adopt the new subpart for part 121 and instead use the part 39 AD 
process to implement required actions once the necessary data and 
documents have been developed by manufacturers. It stated the new 
subpart, as proposed, will allow the FAA to impose regulations prior to 
development of a technically feasible solution available for comment. 
UPS stated that operators would be unable to accurately comment on the 
cost and feasibility of the actions required for compliance. The 
current AD process allows operators the ability to comment on a 
specific solution with a known cost impact.
    We do not believe that Sec.  121.1101(a) as a stand-alone provision 
can be reasonably construed as unlimited in scope. Section 121.1101(a) 
describes the purpose of the new Subpart AA and who it is applicable 
to, and defines the ``FAA Oversight Office.'' It does not impose 
technical requirements. Any specific requirements for continued 
airworthiness and safety improvements will be proposed for comment in 
the same way as the EWIS and fuel tank safety requirements included in 
this final rule were proposed for comment. The FAA will continue to 
issue airworthiness directives in accordance with requirements of 14 
CFR part 39 when we find that an unsafe condition exists in a product 
and the condition is likely to exist or develop in other products of 
the same type design.
    We also disagree that subpart AA should not be created. The new 
requirements contained in subpart AA are necessary to raise the level 
of safety by correcting fleet-wide continued airworthiness issues. 
Airworthiness directives only address specific unsafe conditions that 
exist in a product and are likely to exist or develop on products of 
the same type design. Continued airworthiness issues, such as EWIS 
maintenance, affect all transport category airplanes. In addition, 
using ADs to implement these requirements would mean that ADs would 
need to be continually issued as new models, model variants, or 
modifications are introduced by a DAH. The use of the AD process to 
impose the requirements contained in subpart AA would not be the most 
effective method to address these issues.
    We do not believe that adopting the new subpart instead of issuing 
ADs will prevent operators from being able to accurately comment on the 
cost and feasibility of the manufacturers' proposed requirements. It 
would be impractical to set up a comment period for each specific set 
of maintenance changes developed by the manufacturers, as the commenter 
appears to want. However, a substantial cost/benefit analysis is always 
prepared to support any proposed 14 CFR regulation and public comments 
are solicited. This is a more comprehensive analysis than those 
prepared for an AD. We made no changes due to this comment.
3. Type and Scope of Requirements
    The Air Transport Association (ATA) commented that in proposed 
Sec.  121.1101(a), the words ``* * * may include, but are not limited 
to * * *'' can be interpreted to mean that at a minimum the operator's 
maintenance program must incorporate 100% of all design changes and 
100% of all ICA, not just the EWIS/FTS design changes and ICAs to be 
developed. ATA stated there is no justification presented in the NPRM 
for such an open-ended regulatory requirement. It said this requirement 
cannot be interpreted consistently by all operators impacted or by all 
the FAA Aviation Safety Inspectors with oversight responsibility. ATA 
recommended that the second sentence of Sec.  121.1101(a) be rewritten 
as follows:

    These requirements may include revising the maintenance program 
by incorporating the intent of applicable revisions to the 
Instructions for Continued Airworthiness, as identified in this 
subpart.

    As explained in the NPRM (at 58538-9), this rulemaking is one of 
several to adopt new requirements relating to continued airworthiness, 
and the purpose of creating these new subparts is to have a common 
location for all of these requirements, both existing and proposed. The 
purpose of Sec.  121.1101(a) (and its counterparts, Sec. Sec.  
91.1501(a), 125.501(a), and 129.101(a)), is to identify the type and 
scope of requirements that may be included within this subpart. It is 
purposely broad to encompass possible future rulemaking but does not 
itself impose requirements. Any future requirements will be proposed 
through the normal rulemaking process and all interested parties will 
be afforded the opportunity to comment on them.
    As under current requirements for ICA, a TC holder is required to 
update ICA to address any new design change for which they get 
approval. An operator altering an airplane to incorporate the new 
design change would have to update its maintenance program ``based on'' 
the approved ICA. TC holders may also update their ICA in the absence 
of design changes, but, as under existing regulations, these updates 
would not be mandatory unless we issue an AD mandating them, which we 
would do only if necessary to address an unsafe condition. Operators 
may also independently revise their EWIS and fuel tank ICA. Under 
today's final rule, these changes would have to be approved by their 
Principal Inspector.

F. Operating Requirements for EWIS (Parts 121 and 129)

1. Requirements for Maintenance and Inspection Program Revisions
    For those operating under parts 121 and 129, we are establishing, 
within the new Continued Airworthiness and Safety Improvements 
subparts, requirements to revise maintenance and inspection programs to 
include maintenance and inspection tasks for EWIS. The tasks must be 
based on ICA developed in accordance with Appendix H.
    We have extended the compliance dates for Sec. Sec.  121.1111 and 
129.111. They were originally proposed with a compliance date of 
December 16, 2008. But as a result of comments discussed earlier we 
have decided to fix the time for compliance as a number of months after 
the effective date, rather than as a hard date, and to also allow some 
additional time beyond that which was originally contemplated. The 
compliance date for these rules is now 39 months after the effective 
date of the rule. We have also revised these rules to clarify meaning, 
as discussed below.
2. ICA Developed by Design Approval Holders
    Boeing noted that the proposed operational regulations would 
require that the maintenance program revisions be based on ICA 
developed by the DAH.

[[Page 63388]]

Boeing would like clarification of the interpretation of the term 
``based on.'' It asked whether certificate holders are expected to 
adopt, without change, the ICA provided by the DAHs.
    As discussed previously, it was not our intent to require operators 
to use ICA developed by TC holders. While we think it is very likely 
that operators will use those ICA, we intend that they be able either 
to develop their own or to contract with third parties for ICA, as long 
as they meet the applicable requirements. We have revised the 
operational rules to clarify this flexibility. Deviations from the EWIS 
or fuel tank system maintenance programs that have been developed in 
accordance with the requirements of SFAR 88 or Appendix H must be 
approved by the operator's Principal Inspector, who will coordinate the 
changes with the FAA Oversight Office as appropriate. Similarly, later 
changes to either the EWIS maintenance program or the fuel tank system 
maintenance program must be approved by the operator's Principal 
Inspector, who will coordinate the changes with the FAA Oversight 
Office, as appropriate. In some cases, coordination with the Oversight 
Office will be necessary to ensure that the program's original 
objectives are still met. Details of these coordination procedures are 
defined in an FAA order and described in an advisory circular.
3. Different Requirements for Existing and Future Designs
    RAA requested that proposed Sec.  121.911 (now Sec.  121.1111) be 
revised so the performance objective of the ``retrofit'' requirements 
may be distinguished from the design changes that may be considered for 
newly manufactured fleet types. The commenter assumed that each OEM 
will be required to re-certify to the new standards provided in the 
part 25 proposal, and that carriers would be subjected to a massive 
retrofit program. NACA requested that we clarify requirements by being 
more specific about differences between new production aircraft and 
retrofitting aircraft. They ask if all the part 25 enhancements will 
become ICA and fall under these requirements.
    At the outset, Sec.  121.1111 requires neither ``retrofit'' nor 
``design changes.'' It simply imposes requirements for operators' 
maintenance programs. We agree that some clarification is appropriate. 
As explained in the NPRM, the purpose of Sec.  26.11 is to require type 
certificate holders to develop ICA for existing airplanes that would 
enable operators to comply with this section. For those airplanes, only 
certain provisions of new paragraph H25.5 (H25.5(a)(1) and (b)) are 
required. But for all future airplane designs subject to new Sec.  
25.1729, type certificate applicants must show compliance with all 
provisions of paragraphs H25.4(a)(3) and H25.5. Our intent in the 
operational rules is to require operators to incorporate into their 
maintenance programs all of the EWIS ICA developed for each of their 
airplanes. For existing airplanes, this would be limited to ICA meeting 
paragraphs H25.5(a)(1) and (b). For future airplanes, this would also 
include ICA meeting the remaining requirements of paragraphs 
H25.4(a)(3) and H25.5. We have revised Sec.  121.1111 (and Sec.  
129.111) to clarify these differences.
    KLM disagreed with the requirement for operators of all airplanes, 
regardless of the airplane's age, to implement maintenance program 
inspections and procedures for EWIS. The commenter contended that the 
amount of exposure to deteriorating factors on new aircraft is limited, 
so there is negligible benefit to performing additional maintenance 
tasks on wiring. The commenter also pointed out that checking wiring on 
a new aircraft may even cause more wiring failures due to maintenance 
near the wiring. KLM suggested we consider a threshold for starting the 
first inspections.
    Although older airplanes have been exposed to more stressors that 
can accelerate the degradation of wire and other EWIS components, age 
is not the sole factor in degradation. We do not want to specify a 
threshold for starting the first EWIS inspections. The intervals for 
performing the inspections, including the first ones, are determined by 
performing the EZAP analysis. Factors to be considered in establishing 
intervals are the hostility of the environment in which the EWIS is 
located and the likelihood of accidental damage. Neither of these 
factors is necessarily dependent on age, and EWIS failures can occur on 
newer airplanes. So the ``threshold'' for the first EWIS inspection 
would normally be the same as the interval, measured from the issuance 
of the first certificate of airworthiness. The results of the analysis 
are reviewed by industry working groups (as part of the MSG-3 process) 
and approved by the FAA Oversight Office. It is during the industry 
working group review that the final inspection intervals are set and 
subsequently approved by the FAA. We made no changes due to this 
comment.
4. ICA for Alterations
    British Airways requested that proposed Sec.  121.911 (now Sec.  
121.1111) be revised to state that if changes to the ICA are required 
after alterations, incorporation of these changes into the maintenance 
program may be delayed until after the airplane has resumed service, 
but before it reaches the ``relevant age or flight hours.'' The 
commenter expressed concern that the current wording would result in 
extended operational delays and grounded aircraft after minor 
alterations or repairs. British Airways also expressed concerns about 
SFAR 88-related alterations/component changes conducted while the 
airplane is in a normal operating environment (e.g., at the ramp). It 
asked whether inspections or incorporation of ICA changes to the 
maintenance program must be completed before resuming operations and, 
if so, requests a rule change allowing ICA incorporation into 
maintenance programs after the airplane returns to service but before 
it reaches the ``relevant age or flight hours.''
    The only alterations for which EWIS ICA will be developed are those 
for which compliance with either Sec. Sec.  26.11 or 25.1729 must be 
shown--in other words, major alterations approved under STCs or amended 
TCs. The only alterations for which fuel tank system ICA will be 
developed are those for which compliance with either SFAR 88 or Sec.  
25.1529 must be shown--again, major alterations approved under STCs or 
amended TCs. We believe that any of these alterations would be 
scheduled to occur during a period of allocated downtime such as a 
scheduled maintenance ``C Check.'' The maintenance planning for such 
modifications should include the actions necessary to incorporate 
additional EWIS or fuel tank ICA into the approved maintenance or 
inspection program. No additional time would be needed for these 
actions. Accordingly, no changes were made due to these comments.
5. Alaska Operations
    Senator Stevens of Alaska stated that this rule will have severe 
consequences to residents and cargo carriers operating in his state. 
Referencing Section 1205 of the Federal Aviation Reauthorization Act of 
1996 (49 U.S.C. 40113(f)), and the uniqueness of aviation in Alaska, 
Senator Stevens, Everts Air Cargo, and Alaska Senator Murkowski 
requested that ``intrastate'' operations in Alaska be exempted from 
this rule.
    Consistent with 49 U.S.C. 40113(f), the FAA has carefully 
considered the potential impact of this rulemaking on Alaska intrastate 
operators to determine whether intrastate service in Alaska would be 
adversely affected. We have

[[Page 63389]]

determined that there would not be an adverse effect and that 
regulatory distinctions are inappropriate.
    Under both EAPAS and the Fuel Tank Safety Rule, manufacturers are 
required to develop maintenance program revisions and make them 
available to operators to support their compliance with the operational 
rules. We have concluded that in the case of both the EAPAS and FTS 
operations rules, any burden on affected operators in implementing 
these changes would not have a significant impact. Under EAPAS, the 
changes would be integrated into existing inspections that are 
currently performed during heavy maintenance checks. The fuel tank 
tasks, which would be aligned with the EAPAS inspections, would also be 
performed during these checks. Because these additional inspections 
would be only a small additional piece of a much more extensive 
maintenance visit, we concluded that they would have no adverse effect 
on intrastate service in Alaska.
    Lynden Air Cargo requested that the L-382G aircraft be excluded 
from requirements of proposed Sec. Sec.  121.911 and 121.913 (now 
Sec. Sec.  121.1111 and 121.1113). Senator Stevens asked that Lynden 
Air Cargo's six L-382G airplanes in interstate operation be exempted. 
Lynden Air Cargo said that it does not carry passengers and operates a 
small fleet largely outside the U.S. It stated that it is in the public 
interest to maintain its unique capabilities in Alaska where it 
supports remote communities and projects with no roads or waterways, as 
well as regularly supporting the U.S. military during critical 
campaigns and the ongoing war on terrorism. Lynden Air Cargo also asked 
to be excluded from Sec.  121.909 (now Sec.  121.1109).
    We do not believe it is appropriate to exclude the L-382G from 
requirements of Sec. Sec.  121.1111 and 121.1113 for those airplanes in 
interstate operation. The safety rationale for these rules applies 
equally to that airplane. Lynden Air Cargo may apply for an exemption 
to these rules in accordance with 14 CFR part 11. However, under Sec.  
11.81, Lynden Air Cargo must provide information stating why granting 
such an exemption would be in the public interest and why it would not 
adversely affect safety, or how it would provide a level of safety 
equivalent to the final rule. Also, we are not granting Lynden Air 
Cargo's request for an exclusion from Sec.  121.1109. That requirement, 
which is not a new rule but simply a renumbering of the requirement 
formerly designated as Sec.  121.370a, has been in effect since 
November 1, 2002 (reference 67 FR 72761, December 6, 2002), and we did 
not make any changes to that rule other than changing its section 
number.
6. EWIS Inspections
    Lynden Air Cargo stated that it does not have the engineering staff 
to effectively analyze and comment on the myriad complexities 
associated with the proposed certification rule changes. However, it 
said that with an aircraft type certificated under CAR 4b (Lockheed L-
382G Hercules), the cost to ``retroactively'' apply these new 
certification rules would require extraordinary expenditures. Lynden 
had the following concerns about the practical application and 
implementation of specific inspection criteria for EWIS under EZAP-
developed methods:
     How does an inspector accomplishing a general visual 
inspection (GVI) or a detailed inspection (DET) of EWIS make a specific 
determination of airworthiness? The FAA has failed to state an 
objective criteria in its proposed rule (i.e., what will be the accept/
reject criteria?).
     If there are no actual circuit defects, what corrective 
action will be required? An immediate action? Or can it be scheduled 
and effectively planned for a future inspection action?
     Disturbing wire bundles for inspections can induce more 
problems than are corrected.
    The proposed operating rules do not require ``retroactive'' 
application of design requirements. They do require that operators 
include EWIS maintenance tasks in their maintenance programs. Any post-
inspection actions are based on results of the GVI or DET. If 
inspections determine that EWIS components need cleaning or repairing, 
procedures for accomplishing these tasks are contained in the airplane 
manufacturer's standard wiring practices manual or equivalent 
procedures developed by the operator. If inspection shows that no 
circuit defects exist (to use the words of the commenter) then no 
corrective action would be required. We agree that moving, or 
disturbing, wire bundles does have the potential to cause damage if not 
done with care. Precautions for preventing such damage should be part 
of the operator's overall EWIS maintenance program.
7. Non-U.S. Registered Airplanes
    Boeing requested that the FAA clarify whether the proposed part 129 
rule would affect foreign operators operating non-U.S. registered 
airplanes into the United States. They noted that part 129 usually 
applies to these operations and it seems unusual that they have been 
omitted in the proposed rule.
    Under International Civil Aviation Organization (ICAO) Annex \7\ 8, 
the state of registry of an airplane is the state responsible for its 
airworthiness. For this reason, the airworthiness regulations of part 
129, including those contained in new subpart B, apply only to U.S.-
registered airplanes.
---------------------------------------------------------------------------

    \7\ ICAO's 98 articles, created and accepted at its Chicago 
Convention, established the privileges and obligations of member 
states. Standards and recommended practices of ICAO are designated 
as ``Annexes'' to the Convention.
---------------------------------------------------------------------------

8. Taking Airplanes Out of Service
    US Airways requested clarification of Sec.  91.911 to stipulate 
that aircraft need not be taken out of service specifically to 
accomplish the revised inspections.
    We believe that U.S. Airways meant to ask for clarification of 
Sec.  121.911 (now Sec.  121.1111) instead of Sec.  91.911, which is 
not contained in the proposal. Operators will have considerable 
flexibility in determining when inspections will be performed. For 
example, in the appendix of the DAH EZAP AC, which describes an 
acceptable procedure for establishing EWIS inspection intervals, even 
inspections of EWIS located in the most severe environment with the 
highest risk of accidental damage may be performed at intervals ranging 
from an ``A'' check to a ``1-C'' check, which are normally scheduled 
maintenance intervals. Although we cannot guarantee that an airplane 
will not have to be taken out of service specifically to accomplish the 
new EWIS maintenance program requirements, we believe these tasks can 
be scheduled to be performed during other scheduled maintenance times. 
Section 121.1111 does not require tasks to be accomplished at any 
particular intervals. It only requires that the maintenance program for 
a particular airplane include inspections and procedures for EWIS.
9. Training
    The NTSB referred to its recommendation A-00-108 of Sept. 19, 2000, 
in which it asked the FAA to address the need for improved training of 
maintenance personnel to ensure adequate recognition and repair of 
potentially unsafe wiring conditions. The NTSB commented that, since 
non-EWIS maintenance actions often compromise EWIS safety, training of 
all maintenance personnel on EWIS maintenance and inspection is 
critical. The board would like us to amend the NPRM to specifically 
state that all maintenance personnel must receive EWIS training.

[[Page 63390]]

    We agree with the NTSB on the importance of training personnel not 
directly involved with EWIS maintenance and inspection. But the cost of 
training all groups identified by ATSRAC as people working directly 
with, indirectly with, or in the vicinity of, EWIS was not commensurate 
with the benefits. While not required as a result of this final rule, 
AC 120-94 provides a sample curriculum for a more comprehensive 
training program. We strongly encourage organizations to voluntarily 
offer this training.
10. Reporting Requirements
    The NTSB commented that in its recommendation A-00-108 it asked the 
FAA to address improved reporting of potentially unsafe electrical 
wiring conditions. It noted that the NPRM holds manufacturers and 
operators responsible for proper maintenance and inspection of EWIS. 
The board contends there can be no quantitative measurement of how well 
the maintenance and inspection system is performing without an 
effective mechanism to collect basic data, examine the findings, and 
provide reporting about performance.
    The NTSB noted that, even though it has supported the FAA's 
previous NPRMs to revise and improve the service difficulty reporting 
(SDR) system, the FAA has withdrawn both. It noted that restricted 
access to existing data and inability to effectively search available 
data inhibits research into recurring or potential problems that may 
exist across operators, and such research is important in the 
prevention of accidents. The board strongly encouraged the FAA to amend 
the NPRM to address this issue and revise the SDR system, regardless of 
any potential industry opposition.
    We have developed an Enhanced Airworthiness Datamart (EADM), 
covering the years 1995 to the present, which provides analysts with a 
more detailed view of SDRs. We have deployed the EADM on the Aviation 
Safety Information Analysis and Sharing (ASIAS) system secured portal. 
It integrates those reports with information on aircraft age, hours, 
and cycles from the Airclaims database. The resulting data set allows 
the user to identify trends in service difficulties as a fleet of 
aircraft ages.
    Also, with the 1995 creation of the Air Transport Association (ATA) 
code 97 for electrical wiring, precise reporting of electrical problems 
is possible. In 1995 the FAA updated its Joint Aircraft Systems/
Component Codes (JASC) to include electrical wiring. We added ATA code 
97 to each airplane system category for the wiring within those 
systems. Because of these new analysis tools, we made no changes due to 
this comment. While the value of the contents of service difficulty 
reporting systems is contingent upon the accuracy of reporting by the 
operators, the data is publicly available and useful in analysis 
(http://av-info.faa.gov/isdr/SDRQueryControl.ASP?vB=IE&cD=32).

G. Operating Requirements for Fuel Tank Systems (Parts 91, 121, 125, 
and 129)

1. Requirements for Maintenance and Inspection Program Revisions
    This rule includes provisions for operators to revise their 
maintenance programs by adding maintenance tasks for fuel tanks. These 
maintenance tasks must be based on ICA that have been developed in 
accordance with SFAR 88 or Sec.  25.1529 and Appendix H and approved by 
the FAA Oversight Office. Parts 91, 121, 125, and 129 each contain 
these requirements in the new subparts for Continued Airworthiness and 
Safety Improvements. These fuel tank requirements are not new 
requirements. Rather, they clarify requirements of previously existing 
rules.
    When this rule was proposed in October 2005, our intent was to set 
the same operator compliance date for the fuel tank and EWIS 
maintenance program revisions. This would have allowed both sets of 
tasks to be added at the same time and required that the maintenance 
program be revised only once. As discussed earlier, the rulemaking 
process took longer than expected. At this time, we do not want to 
delay inclusion of the fuel tank tasks into maintenance. Thus, while 
the compliance date for the EWIS maintenance revision requirements of 
Sec. Sec.  121.1111 and 129.111 has been changed, the compliance date 
for this fuel tank maintenance revision requirement remains December 
16, 2008, the date that was originally proposed. We have, however, 
changed the date by which the certificate holder must submit 
maintenance instructions for auxiliary fuel tanks to the FAA Oversight 
Office. That date is now June 16, 2008. The list of airplanes excluded 
from the requirements of these rules has also been changed. The 
requirement in Sec.  26.11 that the EWIS ICA prepared by the DAH must 
be compared with fuel tank ICA to ensure compatibility and minimize 
redundancy remains unchanged.
2. Airplanes Excluded From Fuel Tank System Operating Requirements
    We have revised the list of airplanes excluded from the operating 
requirements for fuel tank systems. For these rules, which affect 
airplanes operating under parts 91, 121, 125, and 129, the list of 
excluded airplanes includes those models of airplanes that are neither 
U.S.-registered nor operated under these parts. Because of this, the 
type certificate holders have not complied with SFAR 88 and, in several 
cases, the type certificates have been surrendered. Subjecting these 
models to the operational requirements for fuel tank safety would, 
therefore, have no effect.
    Additionally, since the Vickers Viscount airplane was originally 
type certificated before January 1, 1958, this airplane is not subject 
to the EAPAS or Fuel Tank Safety rules because of the general exclusion 
of airplanes type certificated before that date. This airplane model 
has been removed from the exclusion list originally proposed. 
Similarly, the Convair and DC-3 models that have been modified to 
incorporate turbine-powered engines are also covered by this general 
exclusion. The Lockheed L-300 has been added to the exclusion list. 
That exception was granted because there is only one qualified 
aircraft, which was modified, used, and later retired by NASA in 1995. 
It would not be cost effective to bring it into 121 operations.
    The proposal excluded the Lockheed L-188, the Mitsubishi YS-11, and 
the BAC 1-11. There are still more than 20 airplanes of each model 
listed on the U.S. registry. For these models, the FAA has granted 
partial exemptions to the respective DAHs for SFAR 88 requirements. In 
each case, these exemptions, while relieving design approval holders of 
some requirements, also have required them to develop service 
information to be provided to affected operators and have explicitly 
declined to exempt the operators from these operational rules. 
Therefore, we have reconsidered the proposed exclusion of these models 
and concluded that they should not be excluded.
    The following airplane models are excluded from the Fuel Tank 
Safety Operational Rules:

(1) Bombardier CL-44
(2) Concorde
(3) deHavilland D.H. 106 Comet 4C
(4) VFW-Vereinigte Flugtechnische Werk VFW-614
(5) Illyushin Aviation IL 96T
(6) Bristol Aircraft Britannia 305
(7) Handley Page Herald Type 300

[[Page 63391]]

(8) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(9) Airbus Caravelle
(10) Lockheed L-300
3. Change in Operator Compliance Date for Auxiliary Fuel Tank ICA
    As stated in the NPRM preamble, the current FTS requirements 
mandate that ICA must be developed for the ``actual configuration of 
the fuel tank systems of each affected airplane.'' The fuel tank ICA 
must address the fuel tank system as defined by the airplane's type 
certificate (TC), any supplemental TCs, and any field-approved 
incorporated auxiliary fuel tank systems.
    In the NPRM preamble, we acknowledged that the original wording of 
the Fuel Tank Safety Rule proved to be unclear to many in the industry. 
We proposed revised regulatory language in the NPRM to clarify the 
original intent. The revision clarifies that holders of STCs, as well 
as TC holders for the affected airplane models, must develop ICA as 
required by SFAR 88, and that the operator is required to develop 
maintenance instructions for field-approved auxiliary fuel tanks. The 
clarified language regarding field-approved auxiliary fuel tanks was 
included in paragraphs 91.1507(b), 121.913(b) (the number of proposed 
Sec.  121.913 has been changed in this final rule to Sec.  121.1113), 
125.507(b), and 129.113(b) of the NPRM. Those paragraphs require 
operators to develop and submit to the FAA Oversight Office proposed 
ICA by December 16, 2007 to address their field-approved auxiliary fuel 
tanks.
    While the referenced paragraphs were clarifications and not newly 
proposed requirements, industry has expressed uncertainty regarding the 
scope of effort required by operators. As that uncertainty will not be 
completely addressed until issuance of this rule, which will provide 
the necessary clarification, we think it is appropriate to provide 
additional time for operators to develop and submit auxiliary fuel tank 
ICA proposals to the FAA Oversight Office. We have decided to extend 
the compliance date for these operator submittals to June 16, 2008. 
This will allow additional time for operators to conduct the necessary 
analyses and develop appropriate ICA, or contract with other experts to 
perform this work if needed. The June 16, 2008 date will also allow 
adequate time for the FAA's Oversight Office to review and approve the 
operator-developed ICA and for the operators to revise their 
maintenance programs accordingly by December 16, 2008.
4. Original Configuration and Auxiliary Fuel Tanks
    United Airlines referred to the statement in the NPRM that new 
maintenance programs must be developed based on the actual 
configuration of the aircraft. It asked if this is intended to include 
only major alterations (STCs), or minor alterations affecting wiring 
systems as well.
    The commenter refers to a portion of the NPRM discussing 
operational requirements of the Fuel Tank Safety Rule. As explained in 
the NPRM, we are revising these requirements to eliminate reference to 
the ``actual configuration'' of the fuel tank system. Instead, these 
requirements clarify that operators' maintenance programs must address 
the fuel tank system of the airplane as originally configured and 
auxiliary fuel tanks later installed. All auxiliary fuel tank 
installations are considered major alterations.
    On a related issue, under the operational rules adopted as part of 
the Fuel Tank Safety Rule (Sec.  121.370(b)), operators were required 
to revise their maintenance programs to include fuel tank safety 
instructions, regardless of whether TC and STC holders provided such 
revisions, as required by SFAR 88. In this final rule, we revise these 
operational requirements to require that operators revise their 
maintenance programs to incorporate fuel tank ICA developed by TC 
holders, ICA developed by the operator for field-approved auxiliary 
fuel tanks, and ICA developed by STC holders, if any. The effect of 
this change is that, except for auxiliary fuel tanks installed under 
field approvals, operators are not required to develop ICA to comply 
with this rule; they are only required to revise their programs to 
incorporate ICA developed by others. Therefore if an STC holder does 
not develop ICA, then the operator has no further action to comply with 
the operational rule for that STC design configuration. However, if it 
appears STC holders will not provide timely support for the operators, 
we will consider enforcement action.
5. Inspection and Maintenance Program Terminology
    Boeing commented that Sec.  125.507 refers to a fuel tank system 
inspection program; whereas the companion sections in parts 91, 121, 
and 129 refer to a fuel tank system maintenance program. It asked 
whether this difference was intentional, and, if so, what is the 
purpose of the difference.
    Boeing identifies a longstanding difference in terminology between 
the regulations applicable to air carrier operations (parts 121 and 
129) and other operations (parts 91 and 125). For air carriers, we 
commonly use the term ``maintenance program'' to refer to the required 
program for inspection and maintenance of aircraft (see Sec. Sec.  
121.367 and 129.14). For other operations, we use the term ``inspection 
program,'' which is typically narrower in scope than the programs 
required of air carriers (see Sec. Sec.  91.409 and 125.247). For 
purposes of this rulemaking, the requirements for the two types of 
programs are the same. As Boeing notes, we have not always been 
consistent in our use of this terminology.

H. Regulatory Evaluation

    The final regulatory evaluation that accompanies this final rule 
can be found in the docket. In response to comments, we have revised 
our cost and benefit estimates in several instances from those included 
in the initial regulatory evaluation.
1. Engine Costs
    GE commented that new rules invariably involve additional 
engineering work on the first certification program to comply. There is 
often redesign required partway through the program, especially when 
airplane rules are being applied to engine components, which are 
designed in advance of the airplane. GE estimated additional costs of 
understanding proposed subpart H and redesigning engine wiring 
accordingly at $3,000,000 to $7,000,000 for the first certification 
program only, and this figure doesn't include additional costs 
identified by regulation.
    We accept this estimate and incorporate this general engineering 
cost into the costs estimated in our final regulatory evaluation. To 
estimate total general engine design costs to the industry, we use a 
median of $5 million and multiply it by the number of engine 
manufacturers (5) to arrive at total costs of $25 million ($23.4 
million present value using a discount rate of 7%).
2. Wiring System Safety Analysis for Engines
    GE commented that the proposed Sec.  25.1705 (now Sec.  25.1709) 
requirement for an independent safety analysis of wiring systems would 
add to the certification cost of each new program. The incremental cost 
would be similar to the existing cost of a safety analysis.
    Since the original comment, the engine manufacturer has provided 
additional supporting data. The FAA agrees and incorporates this data 
into this regulatory evaluation. The total estimated cost to this 
engine

[[Page 63392]]

manufacturer as a result of this requirement is $6.6 million ($3.2 
million present value).
    We have revised our cost evaluation based upon this estimate. Using 
this annual estimate for one manufacturer, we have developed an 
industry estimate. The corresponding total cost for five engine 
manufacturers is $31.5 million ($14.7 million present value) and is 
contained in the final regulatory evaluation.
3. Labor Rates
    GE commented that the estimated fully burdened hourly labor cost of 
$55.18 for engineers is too low because it doesn't include employee 
benefits. GE contended that including benefits would bring labor costs 
to $73 per hour. Boeing commented that in this proposal and the 
proposed rule on ``Reduction of Fuel Tank Flammability in Transport 
Category Airplanes'' there were differences in the fully burdened rates 
used for aviation engineers and mechanics. Boeing requested that costs 
associated with this proposal be reevaluated using the more realistic 
rates contained in Docket No. FAA-2005-22997.
    We have updated the wage rates in our final regulatory analysis. In 
the final regulatory evaluation we use $75 as the burdened hourly cost 
for an engineer and $50 as the burdened hourly cost for a mechanic. A 
detailed discussion can be found in the ``key assumptions & labor 
rates'' section of the final regulatory evaluation.
4. The Regional Airplane Fleet
    The Regional Airline Association (RAA) requested we revise the 
cost-benefit analysis because it cites no regional transport category 
airplane accidents or incidents to indicate that concern over wiring 
systems is comparable for all airplanes affected by the proposed rule. 
The commenter said that wiring system malfunctions are generally unique 
to a specific fleet type, and the review of the NTSB database, most of 
the EAPAS NPRM Supplemental Material, and ATSRAC's review were limited 
to wiring discrepancies in airplanes with passenger seating of 100 
persons or more. The RAA stated that differences in the regional 
airline fleet would justify a less stringent design review. For 
example, no airplanes with 50 seats or less have in-flight 
entertainment systems. Regional airplane galleys generally have no more 
than a single coffee maker, and almost none have ovens, so the 
electrical loads and wiring required to support this type of service is 
minimal. Regional operators are less likely to revise seating or make 
other modifications to the cabin from their original configuration. The 
commenter said that inspection of regional airplanes affords fewer 
opportunities to disturb existing wiring, since accessibility into 
locations where wire bundles may be inadvertently damaged is limited. 
It noted that the turboprop fleet, in particular, operates at altitudes 
and locations where emergency landings can be readily accomplished.
    The RAA said its members will incur greater costs than the larger 
fleet because regional operators must amortize compliance costs over a 
significantly smaller seat revenue base.
    Smaller transport airplanes do, and will continue to, exhibit the 
same EWIS degradation issues found in larger transports in absence of 
this final rule. Since the NPRM, the NTSB has issued Safety 
Recommendations A-06-29 through -35 pertaining to fires on one 
particular model of regional jet. In the six months between October 
2005 and March 2006, there were a total of six fires on regional jets. 
A seventh fire occurred prior to that six month period. In addition to 
the danger posed by the resulting fires, the NTSB stated that two of 
the incident airplanes temporarily lost all flight displays. The 
investigation by the NTSB revealed that all of the fires originated 
from the same electrical component \8\ and that the fires were caused 
by moisture-induced short circuits between the electrical terminals of 
the contactors. If the requirements contained in this final rule had 
been in effect, the type of failure that was the cause of these seven 
fires would not have occurred. This is because several of the new 
requirements directly address the design issues that lead to the fires. 
The following bullets address the specific requirements and the reason 
the failures would have been prevented.
---------------------------------------------------------------------------

    \8\ An electrical contactor located in the avionics compartment 
beneath the floor and slightly aft of the captain's seat.
---------------------------------------------------------------------------

     Sec.  25.1701 provides a regulatory definition of an EWIS. 
The portion of the electrical contactor that was the cause of the 
failure would have been considered an EWIS component.
     Sec.  25.1703 requires the proper selection of EWIS 
components. Although the electrical contactor was qualified to perform 
its intended function by the current Sec.  25.1301, the new 
requirements of Sec.  25.1703 would have gone further by requiring a 
specific assessment of the component to ensure that it is installed 
correctly and operated within its limitations (Sec.  25.1703(a)(2)) and 
that if located in a known area of moisture accumulation (which it is) 
that it be protected to minimize any hazardous effects due to moisture 
(Sec.  25.1703(d)).
     Sec. Sec.  25.1707 and 25.1709 would have prevented 
redundant power sources for essential airplane systems from receiving 
power from the same electrical contactor, as was the case with this 
aircraft design. Section 25.1707 requires that adequate separation 
between power sources be provided and that they not interfere with each 
other. Section 25.1709 requires an EWIS safety assessment to 
demonstrate that failures cannot occur unless they can be shown to be 
either extremely remote or extremely improbable, depending on the 
severity of the failure.
    The regional jet (RJ) fleet uses the same EWIS components, design 
and installation methods, and maintenance techniques as the larger 
transports. Although RJs typically do not have in-flight entertainment 
systems and the same type of galleys as the larger transports, they 
share many systems that have historically exhibited EWIS-related 
problems. Examples are the power distribution systems, cargo areas, 
hydraulic systems, wheel wells, and high density areas such as the 
cockpit and avionics racks. On average, RJs fly more cycles per day 
than larger transports. So while their life cycle might be shorter in 
years than the larger transports, because their systems are cycled on a 
more frequent basis, their EWIS are subjected to more exacerbating 
factors causing degradation in a shorter period of time. We have 
reviewed SDR data spanning a five year period to specifically identify 
EWIS failures on RJs. Although the NTSB findings alone might 
demonstrate the underlying necessity of this final rule, in response to 
comment, the FAA has evaluated the annual number of wiring SDRs 
specifically by aircraft category. The final regulatory evaluation 
demonstrates that the number of EWIS failures for regional jets and 
large transports should not be examined separately.
5. Measure of Effectiveness
    The RAA requested that we validate use of a 68% effectiveness 
measure in the cost-benefit analysis. It noted that the benefit 
analysis suggests that by adopting the proposed regulations, ``industry 
will be able to detect 68 percent of EWIS problems before a failure 
occurs.'' This was based on an FAA review of service difficulty reports 
(SDR) for EWIS failures for the period 1995-2002 and expert judgment. 
The commenter said that it could not determine the validity of the SDR 
analysis, but that NTSB data over the last 10 years does not show the 
wiring

[[Page 63393]]

malfunctions projected by this benefit analysis. The RAA contended that 
the SDR review and expert judgment of SDR data does not reflect the 
types of malfunctions that would cause unscheduled landings or non-
fatal and fatal events, and that the effectiveness measure for this 
proposal is no better than 23%.
    Our evaluation was based on a review of thousands of SDR entries 
and on the ATSRAC-produced Intrusive Inspection Report. In the NPRM, we 
did not assume that the rule would be 100 percent effective. Instead we 
measured expected effectiveness at 68%. The judgment used to evaluate 
EWIS failures in the regulatory evaluation refers to conclusions 
reached by experienced FAA and industry engineering and operational 
personnel reviewing operator-reported data and applying their 
considerable expertise to determine operational impacts of the EWIS 
conditions identified. In response to comment, we have re-evaluated the 
expected effectiveness and lowered it to 60%. Total potential benefits 
are multiplied by the 60% effectiveness measure to arrive at the 
expected total benefits. The initial and final regulatory evaluations 
provide a detailed description of how we arrived at 68% and 60% 
effectiveness rates. Despite the effectiveness measure decreasing from 
68% (in the NPRM) to 60% (in the final rule), the total benefits 
increase. This is because the wiring problems were much greater than we 
originally estimated. Because of our comprehensive examination since 
the NPRM, we learned that there are more unscheduled landings and 
operational problems occurring from electrical wiring failures than 
originally included in our calculations. Since the NPRM we have 
analyzed all of the most recent data available.
    Existing rules require operators to submit reports notifying the 
FAA of the occurrence or detection of failures, malfunctions, or 
defects in systems and components of aircraft. These service difficulty 
reports (SDR) are filed when a system, component, or part of an 
aircraft, power plant, propeller, or appliance fails to operate in the 
normal or usual manner.
    The FAA reviewed all of the most recent reports from operators. The 
most recent reports from operators demonstrate that failures of the 
electrical wiring interconnection systems (EWIS) are much greater than 
previously anticipated and estimated in the NPRM.
    In our analysis, we quantify and estimate the economic impact that 
will occur when these electrical failures and malfunctions are averted. 
Although we categorize and quantify averting such failures as 
``operational benefits,'' the occurrence of these failures has a direct 
effect on passenger safety and such failures are often precursors to 
more serious events.
    In the NPRM we forecasted 1,118 unscheduled landings caused by 
wiring problems; of which 760 (68%) would be averted. In addition to 
the averted unscheduled landings, we estimated 968 events would cause 
delays; of which 658 (68%) would be averted.
    Based on the most recent data and our comprehensive review, in the 
final rule, we estimate roughly 2,202 unscheduled landings; of which 
1,321 (60%) will be averted. In addition, there will be 13,649 
electrical wiring failures that will have an operational impact; of 
which 8,189 (60%) will be averted.
    Accordingly, operational benefits increased in the final rule from 
$192 million (NPRM estimate) to $506 million.
    The revised safety benefits as reflected in the final rule are 
based on a revised effectiveness estimate of 60% and an updated 
forecast showing the trend of operators to use smaller aircraft with 
higher load factors. This caused an overall decrease in the estimated 
safety benefits as reflected in the final rule. A detailed discussion 
of the effectiveness determination can be found in the regulatory 
evaluation.
6. Operational Impacts
    UPS requested that we remove the operational improvements portion 
of the benefits calculation and restrict cost calculations to tangible 
safety benefits versus direct compliance costs. The commenter stated 
that this change would reduce the overall benefit calculation by $192.3 
million.
    The commenter contrasted the following to justify this request:
     The proposal calculates that averting a 3.5 hour delay 
will save airlines $35,739.
     The calculation in the proposed rule for Fuel Tank 
Flammability Reduction (FTFR), dated November 2005, uses a delay cost 
of $24.43 per minute, so a delay of 3.5 hours yields an estimated cost 
of $5,130 per event.
    UPS stated it is notable that the FAA cites the benefit of an 
averted delay in one proposed rule, and the cost of a similar delay in 
another. Both were open for comment at the same time. The commenter 
contended that the value of operational improvements is highly 
subjective, inconsistent, doesn't yield accurate results, and is 
specific to each operator.
    Boeing commented that it is unusual that the FAA has included 
averted delays, unscheduled landings, and failures of in-flight 
entertainment systems, which are essentially airline economic concerns, 
as part of the benefits accruing from the proposed rule. Boeing noted 
that the FAA included these benefits because, to quote the NPRM, 
``delays and unscheduled landings contain safety risks for passengers 
and crew and increase the likelihood of a more serious event.'' This 
commenter questioned the relationship between these non-normal but safe 
events. It disagreed with their inclusion in this analysis as a method 
of justifying rulemaking. Boeing stated that in past endeavors, the FAA 
has not permitted Boeing use of these events as benefits.
    We have decided to retain the operational impacts estimated in the 
benefit calculations. As prescribed by the Office of Management and 
Budget (OMB), the regulatory evaluation should attempt to quantify all 
potential real incremental benefits to society in monetary terms, and 
this includes operational improvements that would result from adoption 
of these requirements. We have clarified our terminology since the 
NPRM. This final rule evaluates operational impacts.
    The operational impacts (``delays'' in the NPRM) that are 
quantified in the final regulatory evaluation of EAPAS/FTS cannot be 
compared with delays estimated in the Fuel Tank Flammability Reduction 
NPRM (FTFR). The estimates contained in FTFR include crew costs, ground 
handling costs, and fuel costs. The operational impact benefits for 
EAPAS/FTS evaluate impacts from operator equipment malfunctions and 
failures in wiring as reported by operators in SDRs.
    Operational impacts caused by EWIS failures are more serious and 
have a higher cost impact than the delays characterized in the FTFR 
NPRM. Wiring failures have an immediate impact on operations and the 
model estimates them accordingly. Fuel tank inerting problems, 
addressed in FTFR, are not necessarily fixed immediately. The 
operational impact estimated in the regulatory evaluation for this rule 
uses operator reports of failures, malfunctions, or defects of systems 
and components of the aircraft. The five years of data and accompanying 
analysis is included in the final regulatory evaluation and in appendix 
C. These types of failures are more serious (in terms of cost and time) 
than the delay of $24.43 per minute as reported by ATA and used in that 
evaluation. The operational impacts (as

[[Page 63394]]

estimated in the final regulatory evaluation) of wiring failures have 
safety impacts and increase the likelihood of a more serious event.
7. Training Costs
    GE commented that training addressed in proposed AC 120-YY is 
commercially available, at $60 per employee trained, to be repeated 
biannually. It stated that costs of having employees occupied in 
training rather than production were not factored into our estimate. GE 
said the training it investigated involves 17 modules, at an average of 
30 minutes each, resulting in 8.5 hours per trained employee, 
biannually, in addition to the $60 /employee/year. GE said the cost to 
operators and service shops of providing training is therefore $308/
employee/year. U.S. Airways stated that the average annual cost of 
$131,108 for developing a training program seems to be significantly 
below actual costs. United Airlines asked if operators will be expected 
to follow proposed AC120-YY. It says ``target level one'' training 
alone takes 40 hours and the three hours quoted in the NPRM seems 
extremely low.
    The FAA agrees that the required training might be available 
commercially. We base our cost estimates on module C of AC 120-94, 
which requires less intensive training than the program identified by 
commenters. The training required by this final rule does not apply to 
production personnel, but to maintenance and inspection personnel only, 
as required by Sec.  121.375. Therefore we did not consider the cost of 
having production personnel in training. We believe that the training 
covered by Module C is the minimum additional training required to 
comply with the new EWIS inspection requirements. We estimated the time 
to conduct this training at 3 hours for target groups 1, 2, 4, and 6, 
as provided by ATSRAC and stated in the initial regulatory evaluation. 
Training for the remaining modules and target groups is voluntary and 
not required for compliance with this final rule. No changes were made 
as a result of these comments.
    RAA stated that using care when working around wiring, being 
knowledgeable about electrical systems, and teaching technicians that a 
maintenance/alteration task is not complete until the area is 
thoroughly cleaned are simply common sense and need not be mandated. 
The commenter expressed confidence these maintenance practices already 
exist among its members, and said that specific retrofit requirements 
can be more efficiently mandated by Airworthiness Directives.
    RAA said one member suggested it would enhance its training not on 
how to develop inspection programs, but as a preventative maintenance 
aide for technicians. The commenter suggested the FAA (with industry 
assistance) issue an ``Electrical Systems Installation & Repair 
Standard Practices Hand Book'' that supplements or replaces the 
sections in AC 43.13, along with video training modules. RAA suggested 
that training on concepts like proper routing of wire bundles with 
sufficient supports that are not so tight as to increase the 
possibility of chafing within the bundle would be more beneficial than 
inspecting after the fact. The commenter said that availability of 
quality training to many technicians will result in a cultural change 
in the industry that can roll over to other practices.
    The final regulatory evaluation clearly shows that the benefits 
exceed the costs of the proposed EWIS maintenance requirements. As 
stated in the NPRM preamble discussion, investigations of previous 
accidents and examinations of other airplanes shows that deteriorated 
wiring, corrosion, improper wire installation and repairs, and 
contamination of wire bundles with various contaminants are common 
conditions in today's transport category fleet. Current maintenance 
practices do not adequately address wiring components, wiring 
inspection criteria are too general, and unacceptable conditions, such 
as improper repairs and installations, are not described in enough 
detail in maintenance instructions. We commend the RAA member airline 
for volunteering to enhance its EWIS training program and we encourage 
other companies to do the same. A complete EWIS training course, 
developed by ATSRAC, is contained in AC 120-94. Also, we have produced 
a course on good wiring practices which is available to the public 
through our Oklahoma City training center.
8. Costs for EZAP Analysis and Inspection of Engines
    GE commented that reviewing an engine manual to identify tasks that 
touch or approach wiring is estimated at 160 hours. Checking a manual 
for the 41 items listed on pages 10-11 of proposed AC120-XX (this 
material is now in the DAH EZAP AC), for each of the 14 harnesses per 
engine, is estimated at 40 hours. It estimated compliance costs to GE 
at $438,000. GE stated that incorporating all 41 elements on pages 10-
11 of proposed AC120-XX into a C-check would increase C-check time by a 
minimum of 1 day, resulting in 15,000 extra days of maintenance a year 
for operators, at a cost of $150 million annually.
    Our final regulatory evaluation accounts for additional cost 
estimates in part due to the comments received from the engine 
manufacturer. Since we are not making any changes to part 33, engine 
manufacturers will not be required to perform an EZAP. The FAA 
disagrees with GE's estimate because airplane manufacturers have 
already completed EZAP analyses on existing airplanes without support 
from engine manufacturers.
    We do not concur with GE's statement that performing an EZAP on 
engine-mounted EWIS components will result in an additional day being 
added to the length of a C-check (assuming that the frequency of the 
maintenance tasks require them to be completed on a C-check cycle). 
Based on data provided by one airplane manufacturer, we estimate that 
an additional 1 to 3 inspection tasks per engine will be necessary 
based on the results of applying EZAP to the engine zone. Since we 
anticipate that these additional tasks will be incorporated into 
scheduled maintenance down-times, no additional time for gaining access 
to the engines will be required. We expect that these additional tasks 
will be performed during scheduled maintenance visits and the 
corresponding costs are contained in the cleaning, inspection, and 
downtime sections of the regulatory evaluation.
    GE contended that supporting manufacturer compliance with proposed 
subpart I (now part 26) will involve an estimated 240 work days, or 
$140,000, plus travel expenses of $100,000, per program. Even with cost 
savings for technically similar engines, GE said its costs for the DAH 
requirements would be $3,600,000.
    Airplane manufacturers have already completed EZAP analyses on 
several different models of aircraft, and engine manufacturers have not 
provided support for these activities. We are not making any changes to 
part 33. Engine manufacturers are not required to support airframe 
manufacturers in complying with this final rule for either existing or 
future certification programs.
9. Engine Costs for Sec.  25.1362
    GE commented that costs of Sec.  25.1362 were not addressed. As 
discussed previously, this rule requires that a suitable electrical 
supply be provided to those services required for emergency procedures 
after an emergency landing or ditching. GE stated that because very low 
levels of electrical energy can ignite

[[Page 63395]]

fuel under laboratory conditions, it is not clear that any electrical 
supply to the fuel shut-off valve could be predicted to meet this rule. 
GE suggested that one way to comply would be by substituting a 
mechanical cable for the electrical signal to the engine fuel shut-off 
valve. It stated that such a cable, extending from the engine to the 
wing/body join, would increase costs by approximately $20,000 per 
engine installation. It would also be less reliable, leading to an 
incremental unreliability of 0.4 cable seizures per million attempted 
engine shutdowns, and incremental maintenance costs. GE estimated an 
average annual cost to operators of $1,000,000.
    We do not concur with GE's cost estimate for Sec.  25.1362 
compliance. GE interpreted the requirement to mean that electrical 
faults must be minimized to prevent them from causing a fire. The FAA's 
intent here is to ensure that there is necessary electrical power 
available to allow the emergency service equipment, such as a fuel 
shut-off valve, to operate after an emergency landing or ditching. Also 
as discussed previously, we have revised final Sec.  25.1362 to clarify 
this point. We made no changes due to this comment.
10. Wire Labeling Costs
    GE commented that the cost estimate for the labeling requirements 
of Sec.  25.1711 appears based on mechanics adding labels during final 
assembly. GE stated that identifying wires at 15-inch intervals 
requires many more than the estimated 3,500 labels per airplane. Since 
fly-by-wire aircraft typically contain 100 miles of wiring, a label at 
15-inch intervals equals over 422,000 labels per aircraft. GE stated 
that manufacturing wire with labels is more practical but would require 
that manufacturers invest in more tooling, plus drawing changes to 
harnesses and cables. GE estimated its cost at $9,300,000 over 25 years 
or $370,000 per year. Spectrum Technologies contended that the burden 
for wire identification labeling was significantly underestimated, 
particularly in relation to heat shrink labels and probably other 
types. The NPRM estimates a wire identification time of 30 seconds per 
label. Spectrum said that, based on industry practice, the time for 
heat shrink labeling is more like 240 seconds per sleeve.
    In response to the estimated cost of $0.05 per label, Spectrum 
contended that the typical figure for industry brand name heat shrink 
labels is more like $1.50, depending on size. It said that the total 
cost of adding just one heat shrink sleeve can be calculated as $2.88.
    The new rule does not require that additional labels be manually 
added to wiring. It only requires additional information to be included 
in the wire labeling that already exists. It appears that the commenter 
assumes that there are no labeling requirements in effect today. 
Section 25.1301 already requires that components be identified. The 
requirement contained in this final rule expands on those requirements 
by imposing additional labeling requirements. Complying with Sec.  
25.1711 will be a matter of providing additions to, or changing the 
type of, information already on the EWIS labels that exist today. Based 
upon existing practices, our analysis estimates this additional cost.
    Spectrum Technologies commented on the technical and economic 
advantages of a specific prescriptive means of compliance. Based on 
comments since the NPRM, we have verified our estimates. While we 
disagree with the specific estimates in the illustrative comment, we 
believe that manufacturers will demonstrate compliance using the most 
efficient and cost effective technology available.
11. Additional Certification and Operator Costs
    Boeing and AIA/GAMA commented that we failed to account for 
additional certification costs in complying with the new requirements 
in subpart H and supporting all subpart H requirements for amendments 
to existing type certificates. Boeing maintained that the FAA should 
account for these costs, as well as:
     Additional ``ongoing coordination necessary to ensure 
ongoing communication and cooperation between the applicants and the 
FAA'' described in draft Advisory Circular 25-XX.
     Costs borne by DAHs to perform the EZAP process detailed 
in draft Advisory Circular 120-XX (now in the DAH EZAP AC).
     Most importantly, increased costs associated with enhanced 
maintenance of wiring on all in-service airplanes.
    Boeing asked that we include these costs in the analysis to get a 
true understanding of the burden associated with the projected benefits 
of the proposed rule. AIA/GAMA requested we include costs to operators 
for enhanced EWIS maintenance and updated labor rates for engineers as 
well as these additional items:
     Additional DAH manufacturing costs for future part 25 TC 
and STC products that include new subpart H (regardless of seating 
capacity).
     Training for maintenance personnel. This should include 
existing airplanes subject to new Sec.  121.911 (now Sec.  121.1111), 
Sec.  125.507, and Sec.  129.111 EWIS ICA requirements as well as 
future airplanes that include new subpart H and associated EWIS ICA 
requirements.
     Additional general aviation operator (part 91/135) costs 
associated with enhanced maintenance of EWIS on all future airplanes 
that include new part 25 subpart H and associated EWIS ICA 
requirements. This should consider additional airplane downtime and 
necessary training for maintenance personnel.
     Additional repair station costs to update FAA-approved 
maintenance training manuals and provide training to their maintenance 
personnel.
    In response to these comments, the FAA estimates the costs for 
ongoing coordination necessary to ensure ongoing communication and 
cooperation between the applicants and the FAA. Neither the preliminary 
nor final regulatory evaluation includes cleaning and inspection costs 
for deliveries of future aircraft operated in parts 91 and 135 because 
there is no operational requirement to do so. Other than the increased 
cost of EWIS component identification addressed in the regulatory 
evaluation, we believe that there will be minimal additional 
manufacturing costs associated with complying with the new EWIS 
certification requirements.
    As in the preliminary regulatory evaluation, we continue to 
estimate the following costs:
     Subpart H TC certification costs.
     Subpart H STC certification costs.
     EZAP costs for existing TCs, future TCs, and future STCs.
     SWPM update costs.
     EWIS identification costs for TCs and STCs.
     Training costs for maintenance personnel.
     Planning costs to part 121 operators.
     Cleaning/inspection costs to part 121 operators.
     Downtime costs to part 121 operators.
12. Previous Rulemaking
    The RAA requested that the cost-benefit analysis be revised to 
account for previous rulemaking actions that mitigate likelihood that 
an accident/incident similar to those that prompted this rulemaking 
action will occur in the future. The RAA requested that if benefits of 
a revised cost-benefits analysis are less than the cost of adopting the 
operating rule, proposed

[[Page 63396]]

part 121 & 129 affecting the current fleet be withdrawn.
    The commenter considered the benefits analysis a ``double count,'' 
or a count of the same fatalities as a benefit in future accident 
avoidance as were counted to justify previous rulemaking. It stated 
that industry has spent millions of dollars in fleet retrofit and 
inspection improvements, mostly mandated by rulemaking, and there has 
been a dramatic decrease in the accident rate despite increased fleet 
growth. RAA said the estimated 5.3% ratio of accidents to incidents has 
changed dramatically in the last 10 years, but the benefits analysis 
does not acknowledge this.
    GE stated that the benefit claimed for this rule does not account 
for previous rules introduced to address the MD11 in-flight fire and 
accident, specifically the rule on cabin insulation materials. GE said 
that the effect of that rule was to prevent wire arcing from 
propagating into a fire within the pressurized fuselage, by removing 
flammable materials. The commenter argues that since significant 
measures have already been taken to prevent a recurrence of this kind 
of accident, the benefit claimed for the EAPAS rule package should be 
reduced accordingly, but says is not clear whether this has been done.
    The cost-benefit analysis evaluates the risk of passenger deaths 
associated with wiring failures. We analyze the historical number of 
wire failures and evaluate them in the context of this rulemaking. The 
accidents and incidents listed in appendix B of the preliminary 
regulatory evaluation included neither TWA 800 nor Swissair 111, so we 
have not ``double counted'' benefits as the RAA contends.
    Although we have issued various ADs and other rules dealing with 
flammability of insulation blankets, those rules do not address the 
issue of wire contamination that can also be a source of fuel for on-
board fires. Adoption of EAPAS will help minimize likelihood of an on-
board fire due to wire contamination and wire failures.
    We continue to observe an overall increase in wire-related failures 
as demonstrated in EWIS SDRs, accidents, and incidents. Although wire 
type and insulation materials have evolved over the years, the means to 
design, install, and maintain EWIS remain much the same. To reduce 
occurrences of wire-related incidents and accidents, it is necessary to 
adopt the requirements contained in this final rule.
13. Relevance to the Current Fleet
    The RAA requested that we revise the cost-benefit analysis to 
determine relevance of the ASTRAC analysis to the current fleet. It 
stated that the analysis and recommendations were largely based on 
inspections of wiring on decommissioned airplanes that at the time 
(1998) were older than 20 years (DC-8, DC-9, DC-10, 727, etc.). The RAA 
estimated that those airplane wiring systems were certified at least 50 
years ago, and since then aircraft wiring systems have improved. It 
further stated that the analysis estimates such airplanes represent 
less than 1% of the current fleet. The commenter asked how we can imply 
that ASTRAC's analysis has any relevance to today's fleet.
    The RAA also questioned the validity of using a 25-year period for 
determining benefits. It questioned projecting 25 years into the future 
to justify benefits for a retrofit rule and stated that all other 
retrofit rules have projected 10 to 20 years. The RAA called it 
unrealistic to use an accident/incident review for older aircraft 
projected to be retired from service before the end of the 25-year 
amortization period.
    We believe that ATSRAC's analysis is relevant to today's fleet. The 
regulatory evaluation cites ATSRAC's non-intrusive inspection report 
finding 3,372 total discrepancies during the non-intrusive wiring 
inspections of 81 airplanes. The ``effectiveness measure'' looks at 
continuing failures, malfunctions, or defects in the current fleet as 
reported by operators, and evaluates them with respect to the Intrusive 
Inspection Report. This final rule will change the certification, 
design, installation, and maintenance practices for EWIS, which, up to 
this time, have changed very little since the jet age began. In 
addition, the physical environments in which wires are installed and 
the types of hazards they are exposed to are very similar regardless of 
airplane age. At the same time, airplane designs have become more 
vulnerable to EWIS safety problems because they are more dependent on 
electrical systems and less dependent on mechanical systems, as in the 
case of electronic flight control systems.
    We chose the 25-year benefit period because we expect, on average, 
that a newly manufactured airplane would be in service for that period 
of time. There will also be airplanes delivered in the next 25 years 
that are impacted by these requirements. As stated in the preliminary 
regulatory evaluation the 25-year analysis parallels the expected 
useful life of an aircraft impacted by this proposal.
14. Accidents Indirectly Initiated by EWIS
    The NTSB was concerned that the cost-benefit analysis does not 
account for indirect EWIS-initiated accident causes, such as those that 
occurred during the June 6, 1992, accident involving COPA flight 201 
that crashed near Tucuti, Panama. For that accident, an instrument's 
gyroscope wire was believed to have frayed and shorted, leading to 
erroneous instrument indications and the pilots' loss of control of the 
airplane. The Board believes that the number of EWIS-related accidents 
and incidents that can be prevented will exceed that predicted by the 
FAA.
    We acknowledge that functional effects of wiring failures may have 
contributed to additional incidents and accidents. Although additional 
benefits could be estimated for indirect causes, we have focused our 
analysis on direct causes only.

I. Harmonization Changes to Transport Category Certification Rules 
(Part 25)

1. FAA/JAA (Joint Aviation Authority) Harmonization
    At the time the EWIS certification requirements in this final rule 
were being developed, several existing part 25 certification 
requirements were also undergoing revision as part of a separate joint 
harmonization effort with the European JAA.\9\ These rules were the 
result of an effort to develop a common, or ``harmonized'' set of 
standards between 14 CFR part 25 and JAR-25, which was then the 
European counterpart to part 25. Because this harmonization effort was 
essentially complete when drafting of this final rule began, the 
harmonized rules were used as the baseline for the new EWIS 
certification rules. The harmonized rules are finalized here. This 
final rule also further revises several of the harmonized rules to 
accommodate the new EWIS requirements.
---------------------------------------------------------------------------

    \9\ The JAA is the Joint Aviation Authority of Europe and the 
JAR is its Joint Aviation Requirements, the equivalent of our 
Federal Aviation Regulations. In the time since these rules were 
developed, in 2003, the European Aviation Safety Agency (EASA) was 
formed. EASA is now the principal aviation regulatory agency in 
Europe, and we intend to continue to work with EASA to ensure that 
this rule is also harmonized with its Certification Specifications 
(CS). But since the harmonization efforts involved in developing 
these rules occurred before EASA was formed, it was the JAA that was 
involved with them. So while the JAR and CS are essentially 
equivalent, and in the future we will be focusing on the CS, it is 
the JAR that will be referred to in the historical background 
discussions in this final rule.
---------------------------------------------------------------------------

    We received no comments about sections 25.899, 25.1309, and 
25.1310.

[[Page 63397]]

They are finalized here in the same form in which they were proposed.
2. Circuit Protective Devices (Sec.  25.1357)
    Section 25.1357 specifies standards for use, functional 
requirements, and installation requirements for electrical circuit 
protective devices. These standards protect the airplane's wiring from 
electrical faults or malfunctions. JAR paragraph 25.1357(d) contains a 
requirement to provide sufficient spare fuses, formerly located in 
paragraph (f). The reason the JAA moved this text from paragraph (f) to 
(d) was to make it clear that the spare fuse requirement does not apply 
to fuses that are inaccessible in flight. We are moving the spare fuse 
requirement of paragraph (f) to paragraph (d) to harmonize with the JAR 
requirement. This rule continues to address the underlying safety issue 
by providing protection for the airplane's electrical system from 
wiring faults or malfunctions, and by ensuring that there is no 
confusion about use of spare fuses in flight.
    In addition to the harmonization changes we made to Sec.  25.1757, 
we also added a requirement that airplane systems normally requiring 
power removal have a power switch to accomplish this, instead of 
relying on using the circuit breaker.
    Continental Airlines asked if the prohibition against circuit 
breaker use as the primary means of power removal or reset during 
normal operations applies to existing STC installations or to future 
amendments to existing STCs.
    Section 25.1357(f) will not require an existing installed STC 
system to be changed. As with any other change to the airworthiness 
standards of part 25, whether future amendments to those STCs would be 
required to comply with the requirements of Sec.  25.1357(f) would be 
determined in accordance with Sec.  21.101.
    AIA/GAMA and GE requested that we clarify what is meant in Sec.  
25.1357(f) by ``normal operation.'' They asked whether consideration 
for the need of a switch extends to non-normal or emergency situations.
    It is not the intent of the requirement that every electrically 
powered system in the airplane have a means to remove power other than 
a circuit breaker. We distinguish between airplane systems normally 
turned on and off during normal operations, such as passenger 
convenience systems, and those systems normally powered at all times, 
such as flight deck multi-function displays or the flight-management 
computer. But if, for example, the flight-management computer requires 
power cycling regularly as a part of normal operations, this system 
would also be required to have a means to do this other than using 
circuit breakers that are not specifically designed for use as a 
switch. Non-normal or emergency situations do not need to be considered 
when determining the need for a switch.
3. Precautions Against Injury (Sec.  25.1360)
    Section 25.1360 is a new rule requiring that the electrical system 
and equipment be designed to minimize risk of electrical shock and 
burns to the crew, passengers, and maintenance and servicing personnel 
during normal operations. This rule adopts the current JAR standard and 
is in line with current industry practice. It is unchanged from the 
form in which it was proposed.
    AIA/GAMA and GE requested that the term ``maintenance'' in Sec.  
25.1360 be limited to line maintenance.
    We infer from GE's comment that it wants Sec.  25.1360 amended to 
revise the phrase ``maintenance personnel'' to read ``line maintenance 
personnel.'' We are not adopting GE's request. We believe the intent of 
the requirement is clear because of the phrase ``using normal 
precautions.'' Maintenance personnel, whether working line or shop 
maintenance, are trained to use caution when working on, or around, 
live electrical circuits. Section 25.1360 requires, in part, that the 
airplane's electrical system be designed so that shock hazards to 
maintenance personnel are minimized when they are taking normal 
precautionary measures to avoid shock hazards. We made no changes due 
to this comment.
4. Electrical Supplies for Emergency Conditions (Sec.  25.1362)
    Section 25.1362 is a new rule that duplicates current JAR 
standards. It requires that a suitable electrical supply be provided to 
those services required for emergency procedures after an emergency 
landing or ditching. The circuits for these services must be designed, 
protected, and installed so that risk of the services being rendered 
ineffective under these emergency conditions is minimized. Section 
25.1362 has been changed from the form in which it was originally 
proposed in order to clarify meaning, as discussed below.
    Boeing Wichita requested that we clarify what is meant by the words 
``protected'' and ``minimized.'' Honeywell and GE asked that the second 
sentence of the section be deleted. They said there is no clear 
approach to providing electrical power to the fuel shut-off valve on an 
engine or APU without potential for it being an ignition source after 
an emergency landing. They suggested wording could be added to AC 
25.1362-1X as follows:

    Use of the normal aircraft supply voltage has been found to 
acceptably minimize the risk of fire.

    We do not agree to delete the second sentence of Sec.  25.1362. The 
intent of the requirement is to prevent disconnection of the electrical 
supply to the required services before the emergency procedures are 
completed. The concern of this rule is not that the circuits are the 
source of the fire but rather that they be capable of shutting off the 
services that could contribute to the fire. We concur with Boeing 
Wichita's request to clarify the intent of the requirements and we have 
revised the final Sec.  25.1362 to do this. We have also revised the 
associated advisory circular to clarify appropriate means of 
compliance.
5. Electrical Appliances, Motors, and Transformers (Sec.  25.1365)
    Section 25.1365 is a new rule within the ``Miscellaneous 
Equipment'' section of subpart F concerning design and installation of 
domestic appliances, electrical motors, and transformers. The term 
``domestic appliance'' is used to refer to those items placed on the 
airplane to provide service amenities to passengers. Examples of 
domestic appliances are cooktops, ovens, microwave ovens, coffee 
makers, water heaters, refrigerators, and toilet flush systems. Section 
25.1365 requires that domestic appliances be designed and installed so 
that in the event of failures, the requirements of Sec. Sec.  25.1309 
(b), (c), and (d) would be satisfied. It requires that galleys and 
cooking appliances be such as to minimize risk of overheating or fire 
and that they be installed to prevent damage or contamination of other 
equipment from fluids or vapors resulting from spillage during use of 
the appliances. It also requires that all electric motors and 
transformers be provided with a thermal protection device unless it can 
be shown that the circuit protective device required by Sec.  
25.1357(a) would be sufficient to show compliance with requirements of 
Sec.  25.1309(b). We made no changes to this rule.
    Honeywell and GE requested that we change the wording of Sec.  
25.1365(d) to limit it to motors and transformers for domestic systems.
    We have decided against limiting applicability of Sec.  25.1365(d) 
to domestic appliances. Our intent is that Sec.  25.1365(d) apply to 
all motors and transformers on the airplane. While the NPRM only 
discussed domestic appliances, the risk of smoke or fire hazard 
addressed by this paragraph is

[[Page 63398]]

not limited to domestic appliances. The exception to this would be if a 
circuit protective device is shown to negate the need for the thermal 
protective device (as allowed by the rule language). We would 
anticipate that engine- and APU-mounted motors and transformers would 
fall into this category because adding thermal protection devices in 
those cases could negatively impact the reliability of those devices. 
The intended scope of this paragraph is apparent both from the rule 
language and from the advisory material for that section:

    Section 25.1365(d) is broader in scope [than just domestic 
appliances] and requires that all electric motors and transformers, 
including those on domestic appliances, have a thermal protection 
device * * *.

J. Additional Certification Rule Changes

1. Rules Changed to Accommodate Subpart H
    To create the new subpart H as the single place for the majority of 
wiring certification requirements, some existing requirements applying 
to wire were moved out of the rules in which they currently exist and 
placed in the new subpart. The rules of which those EWIS requirements 
were previously a part or which were the basis of a new EWIS 
requirement have thus been revised to support the new EWIS subpart. 
They are:
     Sec.  25.611.
     Sec.  25.855.
     Sec.  25.869.
     Sec.  25.1203.
     Sec.  25.1301.
     Sec.  25.1309.
     Sec.  25.1353.
     Sec.  25.1357.
    We did not receive any comments about most of these rule revisions, 
and they are finalized here in the same form in which they were 
proposed. Some rules received minor editorial changes that did not 
change their meaning and do not require discussion here. We did receive 
comments about Sec.  25.1353 and made revisions to it, as discussed 
below.
2. Electrical Equipment and Installations (Sec.  25.1353)
    Section 25.1353 requires that electrical equipment and controls 
must be installed so that operation of any one unit or system of units 
will not adversely affect the simultaneous operation of any other 
electrical unit or system essential to safe operation. Any electrical 
interference likely to be present in the airplane must not result in 
hazardous effects upon the airplane or its systems. Section 25.1353 is 
revised to remove references to wiring and cables to accommodate the 
relocation of wiring requirements to the new subpart H. We've further 
revised this rule in response to comments and to avoid redundancy.
    AIA/GAMA and GE requested that we delete the reference to Sec.  
25.1357 from proposed Sec.  25.1353(b). We agree that the proposed 
Sec.  25.1353(b) references to Sec.  25.1357 and the subpart H 
requirements are unnecessary. Section 25.1301(b) requires that EWIS 
meet requirements of subpart H of part 25. So the reference to some of 
those requirements in proposed Sec.  25.1353(b) is redundant. The 
reference to Sec.  25.1357 in Sec.  25.1353(b) is not necessary because 
Sec.  25.1717 requires that electrical wires and cables be designed and 
installed so they are compatible with the circuit protection devices 
required by Sec.  25.1357. We've amended the final rule to reflect 
this.
    Boeing Wichita asked, in regard to Sec.  25.1353(a), that we 
clarify whether ``any electrical interference likely to be present on 
the airplane'' is limited to items approved for installation, or 
includes anything likely to be carried onto the airplane, like customer 
printers and fax machines.
    This rule applies to equipment that is installed and certified to 
part 25. It does not cover interference that may come from items 
carried on board by people. Operational rules cover such items (i.e., 
Sec. Sec.  121.306, 125.204, 135.144).
    U.S. Airways asked that we clarify the electrical bonding 
requirements in Sec.  25.1353. It contended that, by definition, the 
bonding point is part of the EWIS and as such could be the fault. In 
that instance it would not provide the required return path.
    The intent of the requirement is that electrical return paths be 
adequately sized and properly installed to handle the highest normal 
and fault current levels that would be expected to occur. The 
requirement is not addressing a fault of the bonding path itself.

IV. Regulatory Notices and Analyses

Paperwork Reduction Act

    As required by the Paperwork Reduction Act of 1995 (44 U.S.C. 
3507(d)), the FAA submitted a copy of the new information collection 
requirements in this final rule to the Office of Management and Budget 
for its review. OMB approved the collection of this information and 
assigned OMB Control Number 2120-0723.
    This final rule consists of regulatory changes applying to wiring 
systems and fuel tank systems in transport category airplanes. Some of 
those changes will require new information collection. Comments 
received about these requirements and the FAA's response are discussed 
earlier in this document, under the Disposition of Comments section. 
The new information requirements and the persons who would be required 
to provide that information are described below.

Required Information, Use, and Respondents

    (1) Section Sec.  25.1711 requires that electrical wiring 
interconnection systems (EWIS) components be labeled to identify the 
component, its function, and its design limitations, if any. If the 
EWIS is part of a system that requires redundancy, the labeling must 
also include component part number, function, and separation 
requirements for bundles. This specificity of labeling will be required 
to ensure that maintenance can be handled properly and with the 
appropriate caution for maintaining the safety features the wiring 
system was designed to provide. The information marked on the wires 
will be used by maintenance personnel for repair and cautionary tasks, 
and by modifiers so that original safety features are retained during 
modifications. The future airplane manufacturer and anyone who modifies 
the airplane will bear the burden of this labeling requirement.
    (2) Section Sec.  26.11 requires that existing TC holders develop 
Instructions for Continued Airworthiness (ICA) for EWIS, and that those 
ICA be approved by the FAA. Applicants for approval of design changes 
will be required to develop revisions to those EWIS ICA for any 
modifications to the airplane that might affect them. Section Sec.  
25.1729 and Appendix H will apply the requirement for EWIS ICA to 
future applicants for TCs. EWIS ICA will be used by operators to 
prepare their maintenance programs. This requirement is necessary to 
ensure that wiring is properly maintained and inspected to avoid 
problems that could affect safety.
    (3) Section 26.11 will also require that TC holders submit to the 
FAA a plan detailing how they intend to comply with its requirements. 
This information will be used by the FAA to assist the TC holder in 
complying with requirements. The compliance plan is necessary to ensure 
that TC holders fully understand the requirements and are able to 
provide information needed by the operators for the operators' timely 
compliance with the rule.
    (4) Anyone operating an airplane under part 121 will be required to 
revise their existing maintenance program to incorporate the 
maintenance and inspection tasks for EWIS contained in

[[Page 63399]]

the EWIS ICA. The information incorporated into the maintenance program 
will be used by maintenance personnel to maintain the integrity of 
airplane wiring systems. This requirement is necessary to ensure that 
wiring is properly maintained and inspected to avoid problems that 
could affect safety.
    (5) As a result of the revised maintenance programs that will be 
required for airplanes operating under part 121, maintenance personnel 
will be performing inspections and maintenance procedures to address 
safety issues specific to wiring systems. Although this final rule does 
not specifically require new training, existing Sec.  121.375 requires 
that certificate holders or persons performing maintenance have a 
training program to ensure that persons determining the adequacy of 
such work (including inspectors) are fully informed about the 
procedures and techniques involved and are competent to perform them. 
To comply with this requirement in relation to requirements for revised 
maintenance programs for EWIS included in this final rule, certificate 
holders will be required to develop any additional training program 
needed to ensure that the appropriate personnel are adequately prepared 
to carry out the revised maintenance programs.
    (6) The revision to part 25 Appendix H requires that future 
manufacturers include acceptable EWIS practices in their ICA, presented 
in a standard format. This information will be used by maintenance 
personnel for wiring maintenance and repairs. The requirement is 
necessary because information about cautionary tasks during maintenance 
that can prevent situations that could compromise safety need to be 
available to maintenance personnel. Standard wiring practices manuals, 
in which this information is presented, often differ from manufacturer 
to manufacturer and so are difficult for maintenance personnel to find 
specific information in. The requirement for a standard format is meant 
to correct this. Because of this rule, manufacturers will change their 
Standard Wiring Practices Manuals (SWPM).

Annual Burden Estimate

    To provide estimates of the burden to collect information, the FAA 
developed categories. The following summary table contains the impacted 
entities, average annual hours and the corresponding average annual 
cost. Details of the estimates are in the paragraphs below.

------------------------------------------------------------------------
                   Requirement/entities
                         affected          Annual hours     Annual cost
------------------------------------------------------------------------
1a..............  TC Labeling--Hardware.  ..............         $21,525
1b..............  TC Labeling--Labor....           1,788          89,400
1c..............  STC Labeling--Hardware  ..............          83,688
1d..............  STC Labeling--Labor...           6,953         347,634
2a..............  Existing TC Holders--           11,450         858,720
                   EZAP.
2b..............  Future TC Applicants--           7,156         536,700
                   EZAP.
2c..............  Future STC Applicants--          6,283         471,225
                   EZAP.
2d..............  ICA Approval..........              96           7,200
3...............  Compliance Plan                    128           9,600
                   Development.
4...............  Operators Revise                 2,550         191,268
                   Maintenance Program.
5...............  Training Development..           2,208         165,600
6...............  SWPM..................             734          55,040
                                         -------------------------------
                  Total.................          39,346       2,837,600
------------------------------------------------------------------------

    1a. The FAA estimates that an additional 3,500 labels might be 
installed in each newly certificated part 25 airplane. We calculate 
hardware costs by multiplying 3,500 labels per airplane by 5 cents per 
label, and then by the total annual estimated deliveries (123) of 
affected aircraft. Thus, the annual cost for TC identification hardware 
is $21,525.
    1b. With 3,500 labels installed in 123 affected aircraft annually, 
we estimate a total of 430,500 labels. The total estimated annual 
average hours are 1,788. Using the burdened hourly cost for a mechanic 
($50), the annual labor cost burden for TC identification is $89,400.
    1c. The requirements contained in this final rule will also affect 
airplane modifiers when electrical wiring supplemental type 
certificates (STC) are installed on airplanes. We estimate that 
approximately 103 STCs a year will require additional identification of 
roughly 250 additional labels (.05 per label) per STC installation. 
Since we estimate 250 labels at .05 per label, each STC installation 
will cost an additional $12.50. The annual hardware cost of $83,688 is 
estimated by multiplying the number of STCs (103) by the number of 
airplane installations per STC (65) and finally by the additional 
hardware cost of $12.50.
    1d. For the STC identification labor costs, we estimate roughly 
1,673,750 additional labels will be installed annually (103 STCs x 250 
labels x 65 aircraft). The identification requirements for STCs will 
require an annual burden of approximately 6,953 hours. Using the 
burdened hourly cost of a mechanic ($50), the annual labor cost for the 
identification requirement to airplane modifiers is $347,634.
    2a. Part 26 requires TC holders to perform an EZAP analysis to 
develop Instructions for Continued Airworthiness (ICA) for EWIS. Over 
the period of analysis, the FAA estimates the proposal would require 
11,450 average annual engineering hours resulting in the average annual 
cost of $858,720 (using the fully burdened hourly rate of $75 for an 
engineer).
    2b. Future TC applicants will also perform an EZAP analysis to 
develop ICA for EWIS. The FAA estimates one part 25 type certificate 
per year, with the estimated average annual labor hours to perform the 
analysis of 7,156. This would result in average annual costs of 
$536,700.
    2c. Future applicants for supplemental type certificates will also 
perform an EZAP analysis to develop ICA for EWIS. The total annual 
number of affected STCs is 103. The annual burden hours of 6,283 is 
calculated by multiplying the annual number of STCs (103) by the hourly 
estimate to perform EZAP on an STC (61). Using the estimate of 61 hours 
per STC and the burdened hourly cost of $75, the corresponding costs to 
perform EZAP on 103 STCs annually will be $471,225.
    2d. The FAA estimates 60 labor hours (per airplane model) to submit 
ICA to the FAA for approval. The FAA estimates 2,400 hours for roughly 
40 models. The average annual hours are 96, with corresponding average 
annual

[[Page 63400]]

costs of $7,200 (using the burdened hourly cost of $75).
    3. Manufacturers will present a compliance plan for approval 
describing how they intend to comply with the requirements in the final 
rule. Over the period of analysis, the average annual estimated cost to 
the manufacturer to develop the compliance plan is $9,600, with annual 
hours of 128.
    4. Operators will revise their existing maintenance program to 
incorporate the maintenance and inspection tasks for EWIS contained in 
the ICA. Over the period of analysis, the FAA estimates 63,756 total 
hours, or 2,550 average annual hours required to revise existing 
maintenance programs. Using the burdened labor cost for an engineer, 
the average annual planning cost is $191,268.
    5. The estimated cost to develop training considers the industry's 
standard training factor of 200 hours per one hour of prepared training 
material. 600 hours is the estimated training development time for the 
3-hour training course for each operator. When combined with 92 
operators, the total hours would be 55,200 or 2,208 annually. Combined 
with the burdened hourly cost of $75, the average annual cost for 
training development would be $165,600.
    6. Manufacturers will change the Standard Wiring Practices Manual 
(SWPM). The FAA calculates 734 as the average annual hours required to 
update manuals resulting in the average annual burden of roughly 
$55,040.
    An agency may not collect or sponsor the collection of information, 
nor may it impose an information collection requirement unless it 
displays a currently valid Office of Management and Budget (OMB) 
control number.

International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to comply with 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
determined that there are no ICAO Standards and Recommended Practices 
that correspond to these regulations.

Economic Assessment, Regulatory Flexibility Determination, Trade Impact 
Assessment, and Unfunded Mandates Assessment

    Changes to federal regulations must undergo several economic 
analyses. First, Executive Order 12866 directs that each federal agency 
shall propose or adopt a regulation only upon a reasoned determination 
that the benefits of the intended regulation justify its costs. Second, 
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires 
agencies to analyze the economic impact of regulatory changes on small 
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits 
agencies from setting standards that create unnecessary obstacles to 
the foreign commerce of the United States. In developing U.S. 
standards, this Trade Act requires agencies to consider international 
standards and, where appropriate, that they be the basis of U.S. 
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L. 
104-4) requires agencies to prepare a written assessment of the costs, 
benefits, and other effects of proposed or final rules that include a 
federal mandate likely to result in the expenditure by state, local, or 
tribal governments, in the aggregate, or by the private sector, of $100 
million or more annually (adjusted for inflation with base year of 
1995).
    In conducting these analyses, the FAA has determined that this 
final rule: (1) Has benefits that justify its costs; (2) will not have 
a significant economic impact on a substantial number of small 
entities; (3) will not create unnecessary obstacles to the foreign 
commerce of the United States; and (4) will not impose an unfunded 
mandate on state, local, or tribal governments, or on the private 
sector by exceeding the threshold identified above. While this rule is 
not economically significant as defined in section 3(f) of Executive 
Order 12866 or in DOT's Regulatory Policy and Procedures, it is 
otherwise significant under both documents. Accordingly, the rulemaking 
package has been reviewed by OMB. These analyses are summarized below.

Total Costs and Benefits of This Rulemaking

    The total estimated cost of this final rule is $416 million ($233 
million present value). The total estimated benefits are $801 million 
($388 million present value). In the NPRM, we examined certain specific 
(narrower) categories of operational benefits for the operators. Since 
the NPRM, and at the request of commenters, we have performed an all-
encompassing and exhaustive review of all wiring failures as required 
to be reported by the operators. This review demonstrated that airline 
operational impact from electrical wiring interconnection system (EWIS) 
failures alone was greater than previously anticipated and estimated in 
the NPRM. Appropriately, in this final rule, we estimate the higher 
benefits.

------------------------------------------------------------------------
                                      Nominal values   Present value (in
           Cost category              (in millions)        millions)
------------------------------------------------------------------------
           Harmonization                         $-                 $-
------------------------------------------------------------------------
Part 25 Subpart H--Certification..              $68.1              $35.6
Part 25 Subpart H--Engines........               31.6               26.6
Part 26 ICA.......................               22.9               22.1
Part 121 ICA Operater Cost........              292.2              147.6
Approval Cost.....................                1.7                1.4
                                   -------------------------------------
    Total Cost....................              416                233
------------------------------------------------------------------------
         Benefit category            Nominal values     Present values
------------------------------------------------------------------------
Total Operational Benefits........             $506.3             $237.5
Total Safety Benefits.............              294.6              150.6
                                   -------------------------------------
    Total--All Benefits...........              801               388
------------------------------------------------------------------------
* Minor differences in totals due to rounding.

    Who Will Be Affected by This Rulemaking?
     Manufacturers of Part 25 Airplanes
     Operators of large transport category airplanes
     Part 25 applicants
     Engine Manufacturers

[[Page 63401]]

Assumptions and Sources of Information
     Discount rate--7%
     Period of analysis--25 Years, 2006 through 2030
     Burdened labor rate (as shown in key assumptions and 
labor rates in regulatory evaluation)
--Aerospace engineers--$75/hour
--Maintenance personnel--$50/hour
     Value of fatality avoided--Value of fatality avoided--
$3.0 million (Source: ``Revised Departmental Guidance, Treatment of 
Value of Life and Injuries in Preparing Economic Evaluations,'' 
Office of the Secretary of Transportation Memorandum'', January 29, 
2002)''. Value of Life and Injuries in Preparing Economic 
Evaluations,'' Office of the Secretary of Transportation 
Memorandum'', January 29, 2002).
     Fleet-Safety Performance Analysis System (SPAS)
     Fleet Growth (2.8% per year) & Passenger Occupancy 
Rates--FAA Aerospace Forecasts Years 2006-2017
     Failures, Incidents and Accidents--The National 
Aviation Safety Data Analysis Center
     Aircraft Value--Economic Values for Evaluation of 
Federal Aviation Administration Investment and Regulatory Programs 
1998
Articles Referenced
     Irrgang, M.E. ``Airline Irregular Operations'' Handbook 
of Airline Economics, 1995.
     Wojcik, Leonard A. ``Models To Understand Airline and 
Air Traffic Management Authority Decision-Making Interactions in 
Schedule Disruptions: From Simple Games to Agent-Based Models,'' 
Handbook of Airline Strategy, 2001.
     Wright, T.P. ``American Methods of Aircraft 
Production'' 1939.

Alternatives We Considered

    Alternative 1--Require operators to clean & inspect each airplane 
every C-check or every three years. This would result in an estimated 
additional $179.3 million ($72.2 million present value) in cleaning and 
inspection costs, and an additional $88 million ($31.6 million present 
value) in downtime. This alternative would result in additional costs 
of $251.5 million ($120.3 million present value) with no commensurate 
increase in benefits.
    Alternative 2--Explicitly require EWIS training for other groups of 
people in addition to maintenance workers. The groups and additional 
costs are:
     Flight deck crew--$126 million ($76 million present 
value).
     Cabin crew--$63 million ($38 million present value).
    The total estimated additional cost of this alternative is roughly 
$189 million ($113 million present value) with no commensurate increase 
in benefits.
    Alternative 3--No new regulation (status quo)--
    There was a midair explosion in 1996 involving a 747 airplane. Two 
years later, another commercial airplane (an MD-11) crashed into the 
Atlantic Ocean, killing all 229 people aboard. The investigations and 
later examinations of other airplanes showed deteriorated wiring, 
corrosion, improper wire installation and repairs, and the 
contamination of wiring in commercial aircraft. We have observed and 
analyzed a continuing trend in electrical wiring events. The 
continuance of these events is demonstrated in accidents, incidents, 
and service difficulties that endanger passengers. The FAA believes 
that this trend of events is unacceptable, that this rulemaking is 
necessary to improve aviation safety, and that this final rule will 
decrease the frequency of these events. By introducing the new 
maintenance, inspection, and design criteria for airplane wiring 
contained in this final rule, we are ensuring that there will be a 
substantial decrease in the number of electrical-wiring-related 
accidents and incidents, and thereby an increase in aviation safety.

Benefits of This Rulemaking

    The FAA estimates $801 million ($388 million present value) as the 
total benefits of this final rule. In the table below, the categories 
of benefits are shown. The middle column gives the nominal values of 
quantified benefits, and the right-hand column gives the total 
incremental present value benefits broken down by category type.

Costs of This Rulemaking

    The FAA estimates $416 million ($233 million present value) as the 
total cost of this final rule. The following table specifies the cost 
categories, incremental nominal costs and incremental present value 
costs.

------------------------------------------------------------------------
                                      Nominal values     Present values
             Benefits                 (in millions)      (in millions)
------------------------------------------------------------------------
                           Operational Impacts
------------------------------------------------------------------------
Averted unscheduled landings......             $274.3             $128.8
Other Operational Impacts.........              232.0              108.7
                                   -------------------------------------
    Total Operation Benefits......              506.3              237.5
------------------------------------------------------------------------
                             Safety Benefits
------------------------------------------------------------------------
Averted Non fatal events..........              $44.4              $22.7
Averted Fatal events..............              250.2              127.9
                                   -------------------------------------
    Total Safety Benefits.........              294.6              150.6
                                   -------------------------------------
        Total--All Benefits.......              801                388
------------------------------------------------------------------------

                              Cost Summary
------------------------------------------------------------------------
                                 Nominal values (in   Present values (in
             Cost                    millions)            millions)
------------------------------------------------------------------------
         Harmonization                   $-                   $-
------------------------------------------------------------------------
                    Part 25 Subpart H--Certification
------------------------------------------------------------------------
TC Certification Cost.........              $31.0                $15.8
TC-EZAP Future................               12.9                  6.6
STC Certification Cost........               11.3                  5.8
STC Labeling Hardware.........                2.0                  1.0

[[Page 63402]]

STC Labeling Labor............                8.3                  4.8
TC Labeling Hardware..........                0.5                  0.3
TC Labeling Labor.............                2.1                  1.2
                               -----------------------------------------
    Total Certification Costs.               68.1                 35.5
------------------------------------------------------------------------
                       Part 25 Subpart H--Engines
------------------------------------------------------------------------
Engine Certification..........              $25.0                $23.4
Safety Analysis...............                6.6                  3.2
                               -----------------------------------------
    Total Engine Costs........               31.6                 26.6
------------------------------------------------------------------------
                               Part 26 ICA
------------------------------------------------------------------------
EZAP..........................              $21.5                $20.8
SWPM..........................                1.4                  1.3
                               -----------------------------------------
    Total Part 26 ICA Costs...               22.9                 22.1
------------------------------------------------------------------------
                       Part 121 ICA Operater Costs
------------------------------------------------------------------------
Planning......................               $4.8                 $4.2
Training......................               20.7                 14.2
Training Development..........                4.1                  3.6
Cleaning & Inspections........              189.5                 94.0
Downtime......................               72.1                 31.6
                               -----------------------------------------
    Total Operator Costs......              291.2                147.6
------------------------------------------------------------------------
                             Approval Costs
------------------------------------------------------------------------
Approve EWIS ICA For Future                  $0.126               $0.064
 TCs..........................
Approve ICA For Existing TCs..                0.156                0.151
Approve ICA for Future STCs...                0.556                0.284
Approve Inspection &                          0.828                0.801
 Maintenance Program..........
Compliance Plan...............                0.240                0.232
                               -----------------------------------------
    Total Approval Costs......                1.9                  1.5
                               -----------------------------------------
        Total Costs...........              416                  233
------------------------------------------------------------------------

Final Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes ``as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objectives of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation. To achieve this principle, agencies are required 
to solicit and consider flexible regulatory proposals and to explain 
the rationale for their actions to assure that such proposals are given 
serious consideration.'' The RFA covers a wide range of small entities, 
including small businesses, not-for-profit organizations, and small 
governmental jurisdictions.
    Agencies must perform a review to determine whether a rule will 
have a significant economic impact on a substantial number of small 
entities. If the agency determines that it will, the agency must 
prepare a regulatory flexibility analysis as described in the RFA.
    We have conducted a complete regulatory flexibility analysis to 
assess the impact on small entities. The FAA uses the size standards 
from the Small Business Administration for Air Transportation and 
Aircraft Manufacturing specifying companies with less than 1,500 
employees as small entities.
    The FAA believes that this final rule will not result in a 
significant economic impact on a substantial number of small entities. 
The purpose of this analysis is to provide the reasoning underlying the 
FAA determination. The FAA has determined that:

     No part 25 manufacturers are small entities.
     There will not be a significant impact on a substantial 
number of amended TC or supplemental TC (STC) applicants.
     There will not be a significant impact on a substantial 
number of small carriers as a result of this final rule.

    The current United States part 25 airplane manufacturers include: 
Boeing, Cessna Aircraft, Gulfstream Aerospace, Learjet (owned by 
Bombardier), Lockheed Martin, McDonnell Douglas (a wholly-owned 
subsidiary of The Boeing Company), Raytheon Aircraft, and Sabreliner 
Corporation. These manufacturers will incur type certificate (TC) and 
amended TC costs. Because all U.S. transport-aircraft category 
manufacturers have more than 1,500 employees, none are considered small 
entities.
    Future STC applicants will incur additional compliance costs. These 
applicants will incur the cost only if the applicant believes the 
expected revenue from additional sales will exceed the expected cost. 
While future STC costs will be passed on to airplane operators, it is 
not possible to determine operator

[[Page 63403]]

would buy and install such STCs. Because expected revenue would be 
greater than the expected cost, the FAA believes there will not be a 
significant impact on a substantial number of STC applicants.
    Furthermore, the FAA also calculates economic impact on small-
business part 121 operators. We measured the economic impact on small 
part 121 operators by dividing the compliance cost by the firm's annual 
revenue. The impact of this final rule is below \1/2\ of one percent 
for eighteen small entities where data was available. For the remaining 
3, where data was available, the cost impact is 0.83%, 1.08% and 1.68% 
of revenues. Therefore, the FAA believes that this final rule will not 
have a significant economic impact on a substantial number of small-
business part 121 operators.
    The full regulatory flexibility analysis can be found in the final 
regulatory evaluation. No part 25 manufacturers are small entities, 
there will not be a significant impact on a substantial number of 
amended TC or STC applicants, and there will not be a significant 
impact on a substantial number of small operators. Therefore, as the 
Acting FAA Administrator, I certify that this rule will not have a 
significant economic impact on a substantial number of small entities.

Final International Trade Impact Assessment

    The Trade Agreements Act of 1979 (Pub. L. 96-39) prohibits Federal 
agencies from establishing any standards or engaging in related 
activities that create unnecessary obstacles to the foreign commerce of 
the United States. Legitimate domestic objectives, such as safety, are 
not considered unnecessary obstacles. The statute also requires 
consideration of international standards and, where appropriate, that 
they be the basis for U.S. standards. The FAA has assessed the 
potential effect of this final rule and determined that it will impose 
the same costs on domestic and international entities and thus has a 
neutral trade impact.

Final Unfunded Mandates Assessment

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement 
assessing the effects of any Federal mandate in a proposed or final 
agency rule that may result in an expenditure of $100 million or more 
(adjusted annually for inflation with the base year 1995) in any one 
year by State, local, and tribal governments, in the aggregate, or by 
the private sector; such a mandate is deemed to be a ``significant 
regulatory action.'' The FAA currently uses an inflation-adjusted value 
of $128.1 million in lieu of $100 million.
    This final rule does not contain such a mandate. The requirements 
of Title II do not apply.

Executive Order 13132, Federalism

    The FAA has analyzed this final rule under the principles and 
criteria of Executive Order 13132, Federalism. We determined that this 
action will not have a substantial direct effect on the States, or the 
relationship between the national Government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, and therefore does not have federalism implications.
    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat. 
3213) requires the FAA, when modifying its regulations in a manner 
affecting intrastate aviation in Alaska, to consider the extent to 
which Alaska is not served by transportation modes other than aviation, 
and to establish appropriate regulatory distinctions. In the NPRM, we 
requested comments on whether the proposed rule should apply 
differently to intrastate operations in Alaska. We did receive comments 
from Senators Stevens and Murkowski and Everts Air Cargo on this 
subject, as discussed earlier. Also as discussed earlier, however, we 
have determined that there would not be an adverse effect on Alaska 
intrastate operators, the burden of this rule on affected intrastate 
operators in Alaska would be minimal, and based on the administrative 
record of this rulemaking, that there is no need to make any regulatory 
distinctions applicable to intrastate aviation in Alaska.

Environmental Analysis

    FAA Order 1050.1E identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act in the absence of extraordinary circumstances. The FAA has 
determined this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 312f and involves no extraordinary 
circumstances.

Regulations That Significantly Affect Energy Supply, Distribution, or 
Use

    The FAA has analyzed this final rule under Executive Order 13211, 
Actions Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use (May 18, 2001). We have determined that it is not 
a ``significant energy action'' under Executive Order 12866, and it is 
not likely to have a significant adverse effect on the supply, 
distribution, or use of energy.

Availability of Rulemaking Documents

    You can get an electronic copy using the Internet by--
    (1) Searching the Federal eRulemaking Portal http://www.regulations.gov
    (2) Visiting the FAA's Regulations and Policies Web page at http://

http://www.faa.gov/regulations_policies/; or

    (3) Accessing the Government Printing Office's Web page at http://www.gpoaccess.gov/fr/index.html
.

    You can also get a copy by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW., Washington, DC 20591, or by calling (202) 267-9680. Make 
sure to identify the amendment number or docket number of this 
rulemaking.
    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, if submitted on behalf 
of an association, business, labor union, etc.). You may review DOT's 
complete Privacy Act statement in the Federal Register published on 
April 11, 2000 (Volume 65, Number 70; Pages 19477-78) or you may visit 
http://www.regulations.gov.

Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires FAA to comply with small entity requests for information 
or advice about compliance with statutes and regulations within its 
jurisdiction. If you are a small entity and you have a question 
regarding this document, you may contact its local FAA official, or the 
person listed under the FOR FURTHER INFORMATION CONTACT heading at the 
beginning of the preamble. You can find out more about SBREFA on the 
Internet at http://www.faa.gov/regulations_policies/rulemaking/sbre_act/
.

List of Subjects

14 CFR Part 1

    Air Transportation.

14 CFR Part 21

    Aircraft, Aviation safety, Exports, Imports, Reporting and 
recordkeeping.

[[Page 63404]]

14 CFR Parts 25, 91, 125

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements, Continued airworthiness.

14 CFT Part 26

    Aircraft, Aviation safety, Continued airworthiness.

14 CFR Parts 121, 129

    Air carriers, Aircraft, Aviation safety, Reporting and 
recordkeeping requirements, Continued airworthiness.

V. The Amendments

0
In consideration of the foregoing, the Federal Aviation Administration 
amends Chapter I of Title 14, Code of Federal Regulations parts 1, 21, 
25, 26, 91, 121, 125, and 129 as follows:

PART 1--DEFINITIONS AND ABBREVIATIONS

0
1. The authority citation for part 1 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

0
2. Amend Sec.  1.2 to add the abbreviation ``EWIS'' in alphabetical 
order to read as follows:

Sec.  1.2  Abbreviations and symbols.

* * * * *
    EWIS, as defined by Sec.  25.1701 of this chapter, means electrical 
wiring interconnection system.
* * * * *

PART 21--CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS

0
3. The authority citation for part 21 continues to read as follows:

    Authority: 42 U.S.C. 7572; 49 U.S.C. 106(g), 40105, 40113, 
44701-44702, 44704, 44707, 44709, 44711, 44713, 44715, 45303.

Subpart A--General

0
4. Amend part 21 by adding a new Sec.  21.7 to read as follows:

Sec.  21.7  Continued airworthiness and safety improvements for 
transport category airplanes.

    (a) On or after December 10, 2007, the holder of a design approval 
and an applicant for a design approval must comply with the applicable 
continued airworthiness and safety improvement requirements of part 26 
of this subchapter.
    (b) For new transport category airplanes manufactured under the 
authority of the FAA, the holder or licensee of a type certificate must 
meet the applicable continued airworthiness and safety improvement 
requirements specified in part 26 of this subchapter for new production 
airplanes. Those requirements only apply if the FAA has jurisdiction 
over the organization responsible for final assembly of the airplane.

Subpart B--Type Certification

0
5. Amend Sec.  21.17 by revising paragraph (a) introductory text to 
read as follows:

Sec.  21.17  Designation of applicable regulations.

    (a) Except as provided in Sec.  23.2, Sec.  25.2, Sec.  27.2, Sec.  
29.2, and in parts 26, 34 and 36 of this subchapter, an applicant for a 
type certificate must show that the aircraft, aircraft engine, or 
propeller concerned meets--
* * * * *

0
6. Amend Sec.  21.31 by revising paragraph (c) to read as follows:

Sec.  21.31  Type design.

* * * * *
    (c) The Airworthiness Limitations section of the Instructions for 
Continued Airworthiness as required by parts 23, 25, 26, 27, 29, 31, 33 
and 35 of this subchapter, or as otherwise required by the 
Administrator; and as specified in the applicable airworthiness 
criteria for special classes of aircraft defined in Sec.  21.17(b); and
* * * * *

0
7. Amend Sec.  21.50 by revising paragraph (b) to read as follows:

Sec.  21.50  Instructions for continued airworthiness and 
manufacturer's maintenance manuals having airworthiness limitations 
sections.

* * * * *
    (b) The holder of a design approval, including either the type 
certificate or supplemental type certificate for an aircraft, aircraft 
engine, or propeller for which application was made after January 28, 
1981, shall furnish at least one set of complete Instructions for 
Continued Airworthiness, to the owner of each type aircraft, aircraft 
engine, or propeller upon its delivery, or upon issuance of the first 
standard airworthiness certificate for the affected aircraft, whichever 
occurs later. The Instructions must be prepared in accordance with 
Sec. Sec.  23.1529, 25.1529, 25.1729, 27.1529, 29.1529, 31.82, 33.4, 
35.4, or part 26 of this subchapter, or as specified in the applicable 
airworthiness criteria for special classes of aircraft defined in Sec.  
21.17(b), as applicable. Thereafter, the holder of a design approval 
must make those instructions available to any other person required by 
this chapter to comply with any of the terms of those instructions. In 
addition, changes to the Instructions for Continued Airworthiness shall 
be made available to any person required by this chapter to comply with 
any of those instructions.

Subpart D--Changes to Type Certificates

0
8. Amend Sec.  21.101 by revising paragraph (b) introductory text and 
adding a new paragraph (g) to read as follows:

Sec.  21.101  Designation of applicable regulations.

* * * * *
    (b) Except as provided in paragraph (g) of this section, if 
paragraphs (b)(1), (2), or (3) of this section apply, an applicant may 
show that the changed product complies with an earlier amendment of a 
regulation required by paragraph (a) of this section, and of any other 
regulation the Administrator finds is directly related. However, the 
earlier amended regulation may not precede either the corresponding 
regulation incorporated by reference in the type certificate, or any 
regulation in Sec. Sec.  23.2, 25.2, 27.2, or 29.2 of this subchapter 
that is related to the change. The applicant may show compliance with 
an earlier amendment of a regulation for any of the following:
* * * * *
    (g) Notwithstanding paragraph (b) of this section, for transport 
category airplanes, the applicant must show compliance with each 
applicable provision of part 26 of this chapter, unless the applicant 
has elected or was required to comply with a corresponding amendment to 
part 25 of this chapter that was issued on or after the date of the 
applicable part 26 provision.

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

0
9. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702 and 44704.

0
10. Amend Sec.  25.611 by re-designating the existing paragraph as 
paragraph (a) and adding new paragraph (b) to read as follows:

Sec.  25.611  Accessibility provisions.

    (a) * * *
    (b) EWIS must meet the accessibility requirements of Sec.  25.1719.

[[Page 63405]]

0
11. Amend Sec.  25.855 by revising paragraph (e) introductory text and 
adding new paragraph (j) as follows:

Sec.  25.855  Cargo or baggage compartments.

* * * * *
    (e) No compartment may contain any controls, lines, equipment, or 
accessories whose damage or failure would affect safe operation, unless 
those items are protected so that--
* * * * *
    (j) Cargo or baggage compartment electrical wiring interconnection 
system components must meet the requirements of Sec.  25.1721.

0
12. Amend Sec.  25.869 by removing paragraph (a)(4) and revising 
paragraphs (a)(2) and (a)(3) as follows:

Sec.  25.869  Fire protection: systems.

    (a) * * *
    (2) Equipment that is located in designated fire zones and is used 
during emergency procedures must be at least fire resistant.
    (3) EWIS components must meet the requirements of Sec.  25.1713.
* * * * *

0
13. Amend part 25 by adding a new Sec.  25.899 to subpart D to read as 
follows:

Sec.  25.899  Electrical bonding and protection against static 
electricity.

    (a) Electrical bonding and protection against static electricity 
must be designed to minimize accumulation of electrostatic charge that 
would cause--
    (1) Human injury from electrical shock,
    (2) Ignition of flammable vapors, or
    (3) Interference with installed electrical/electronic equipment.
    (b) Compliance with paragraph (a) of this section may be shown by--
    (1) Bonding the components properly to the airframe; or
    (2) Incorporating other acceptable means to dissipate the static 
charge so as not to endanger the airplane, personnel, or operation of 
the installed electrical/electronic systems.

0
14. Amend Sec.  25.1203 by revising paragraph (e) and adding a new 
paragraph (h) as follows:

Sec.  25.1203  Fire detector system.

* * * * *
    (e) Components of each fire or overheat detector system in a fire 
zone must be fire-resistant.
* * * * *
    (h) EWIS for each fire or overheat detector system in a fire zone 
must meet the requirements of Sec.  25.1731.

0
15. Amend Sec.  25.1301 by designating the introductory text as 
paragraph (a), re-designating paragraphs (a) through (d) as (a)(1) 
through (4), and adding a new paragraph (b) as follows:

Sec.  25.1301  Function and installation.

* * * * *
    (b) EWIS must meet the requirements of subpart H of this part.

0
16. Amend Sec.  25.1309 by removing paragraph (e) and re-designating 
paragraph (g) as paragraph (e), and revising paragraph (f) as follows:

Sec.  25.1309  Equipment, systems, and installations.

* * * * *
    (f) EWIS must be assessed in accordance with the requirements of 
Sec.  25.1709.

0
17. Amend part 25 by adding a new Sec.  25.1310, to read as follows:

Sec.  25.1310  Power source capacity and distribution.

    (a) Each installation whose functioning is required for type 
certification or under operating rules and that requires a power supply 
is an ``essential load'' on the power supply. The power sources and the 
system must be able to supply the following power loads in probable 
operating combinations and for probable durations:
    (1) Loads connected to the system with the system functioning 
normally.
    (2) Essential loads, after failure of any one prime mover, power 
converter, or energy storage device.
    (3) Essential loads after failure of--
    (i) Any one engine on two-engine airplanes; and
    (ii) Any two engines on airplanes with three or more engines.
    (4) Essential loads for which an alternate source of power is 
required, after any failure or malfunction in any one power supply 
system, distribution system, or other utilization system.
    (b) In determining compliance with paragraphs (a)(2) and (3) of 
this section, the power loads may be assumed to be reduced under a 
monitoring procedure consistent with safety in the kinds of operation 
authorized. Loads not required in controlled flight need not be 
considered for the two-engine-inoperative condition on airplanes with 
three or more engines.

0
18. Revise Sec.  25.1353 to read as follows:

Sec.  25.1353  Electrical equipment and installations.

    (a) Electrical equipment and controls must be installed so that 
operation of any one unit or system of units will not adversely affect 
the simultaneous operation of any other electrical unit or system 
essential to safe operation. Any electrical interference likely to be 
present in the airplane must not result in hazardous effects on the 
airplane or its systems.
    (b) Storage batteries must be designed and installed as follows:
    (1) Safe cell temperatures and pressures must be maintained during 
any probable charging or discharging condition. No uncontrolled 
increase in cell temperature may result when the battery is recharged 
(after previous complete discharge)--
    (i) At maximum regulated voltage or power;
    (ii) During a flight of maximum duration; and
    (iii) Under the most adverse cooling condition likely to occur in 
service.
    (2) Compliance with paragraph (b)(1) of this section must be shown 
by test unless experience with similar batteries and installations has 
shown that maintaining safe cell temperatures and pressures presents no 
problem.
    (3) No explosive or toxic gases emitted by any battery in normal 
operation, or as the result of any probable malfunction in the charging 
system or battery installation, may accumulate in hazardous quantities 
within the airplane.
    (4) No corrosive fluids or gases that may escape from the battery 
may damage surrounding airplane structures or adjacent essential 
equipment.
    (5) Each nickel cadmium battery installation must have provisions 
to prevent any hazardous effect on structure or essential systems that 
may be caused by the maximum amount of heat the battery can generate 
during a short circuit of the battery or of individual cells.
    (6) Nickel cadmium battery installations must have--
    (i) A system to control the charging rate of the battery 
automatically so as to prevent battery overheating;
    (ii) A battery temperature sensing and over-temperature warning 
system with a means for disconnecting the battery from its charging 
source in the event of an over-temperature condition; or
    (iii) A battery failure sensing and warning system with a means for 
disconnecting the battery from its charging source in the event of 
battery failure.
    (c) Electrical bonding must provide an adequate electrical return 
path under both normal and fault conditions, on airplanes having 
grounded electrical systems.

0
19. Amend Sec.  25.1357 by revising paragraphs (d) and (f) to read as 
follows:

Sec.  25.1357  Circuit protective devices.

* * * * *

[[Page 63406]]

    (d) If the ability to reset a circuit breaker or replace a fuse is 
essential to safety in flight, that circuit breaker or fuse must be 
located and identified so that it can be readily reset or replaced in 
flight. Where fuses are used, there must be spare fuses for use in 
flight equal to at least 50% of the number of fuses of each rating 
required for complete circuit protection.
* * * * *
    (f) For airplane systems for which the ability to remove or reset 
power during normal operations is necessary, the system must be 
designed so that circuit breakers are not the primary means to remove 
or reset system power unless specifically designed for use as a switch.
* * * * *

0
20. Amend part 25 by adding a new Sec.  25.1360 to read as follows:

Sec.  25.1360  Precautions against injury.

    (a) Shock. The electrical system must be designed to minimize risk 
of electric shock to crew, passengers, and servicing personnel and to 
maintenance personnel using normal precautions.
    (b) Burns. The temperature of any part that may be handled by a 
crewmember during normal operations must not cause dangerous 
inadvertent movement by the crewmember or injury to the crewmember.

0
21. Amend part 25 by adding a new Sec.  25.1362 to read as follows:

Sec.  25.1362  Electrical supplies for emergency conditions.

    A suitable electrical supply must be provided to those services 
required for emergency procedures after an emergency landing or 
ditching. The circuits for these services must be designed, protected, 
and installed so that the risk of the services being rendered 
ineffective under these emergency conditions is minimized.

0
22. Amend part 25 by adding a new Sec.  25.1365 to read as follows:

Sec.  25.1365  Electrical appliances, motors, and transformers.

    (a) Domestic appliances must be designed and installed so that in 
the event of failures of the electrical supply or control system, the 
requirements of Sec.  25.1309(b), (c), and (d) will be satisfied. 
Domestic appliances are items such as cooktops, ovens, coffee makers, 
water heaters, refrigerators, and toilet flush systems that are placed 
on the airplane to provide service amenities to passengers.
    (b) Galleys and cooking appliances must be installed in a way that 
minimizes risk of overheat or fire.
    (c) Domestic appliances, particularly those in galley areas, must 
be installed or protected so as to prevent damage or contamination of 
other equipment or systems from fluids or vapors which may be present 
during normal operation or as a result of spillage, if such damage or 
contamination could create a hazardous condition.
    (d) Unless compliance with Sec.  25.1309(b) is provided by the 
circuit protective device required by Sec.  25.1357(a), electric motors 
and transformers, including those installed in domestic systems, must 
have a suitable thermal protection device to prevent overheating under 
normal operation and failure conditions, if overheating could create a 
smoke or fire hazard.

0
23. Amend part 25 by adding new subpart H to read as follows:
Subpart H--Electrical Wiring Interconnection Systems (EWIS)
Sec.
25.1701 Definition.
25.1703 Function and installation: EWIS.
25.1705 Systems and functions: EWIS.
25.1707 System separation: EWIS.
25.1709 System safety: EWIS.
25.1711 Component identification: EWIS.
25.1713 Fire protection: EWIS.
25.1715 Electrical bonding and protection against static 
electricity: EWIS.
25.1717 Circuit protective devices: EWIS.
25.1719 Accessibility provisions: EWIS.
25.1721 Protection of EWIS.
25.1723 Flammable fluid fire protection: EWIS.
25.1725 Powerplants: EWIS.
25.1727 Flammable fluid shutoff means: EWIS.
25.1729 Instructions for Continued Airworthiness: EWIS.
25.1731 Powerplant and APU fire detector system: EWIS.
25.1733 Fire detector systems, general: EWIS.

Subpart H--Electrical Wiring Interconnection Systems (EWIS)

Sec.  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.
    (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.

Sec.  25.1703  Function and installation: EWIS.

    (a) Each EWIS component installed in any area of the aircraft must:
    (1) Be of a kind and design appropriate to its intended function.
    (2) Be installed according to limitations specified for the EWIS 
components.
    (3) Perform the function for which it was intended without 
degrading the airworthiness of the airplane.
    (4) Be designed and installed in a way that will minimize 
mechanical strain.
    (b) Selection of wires must take into account known characteristics 
of the wire in relation to each installation and application to 
minimize the risk of wire damage, including any arc tracking phenomena.
    (c) The design and installation of the main power cables (including 
generator cables) in the fuselage must allow for a reasonable degree of 
deformation and stretching without failure.

[[Page 63407]]

    (d) EWIS components located in areas of known moisture accumulation 
must be protected to minimize any hazardous effects due to moisture.

Sec.  25.1705  Systems and functions: EWIS.

    (a) EWIS associated with any system required for type certification 
or by operating rules must be considered an integral part of that 
system and must be considered in showing compliance with the applicable 
requirements for that system.
    (b) For systems to which the following rules apply, the components 
of EWIS associated with those systems must be considered an integral 
part of that system or systems and must be considered in showing 
compliance with the applicable requirements for that system.
    (1) Sec.  25.773(b)(2) Pilot compartment view.
    (2) Sec.  25.981 Fuel tank ignition prevention.
    (3) Sec.  25.1165 Engine ignition systems.
    (4) Sec.  25.1310 Power source capacity and distribution.
    (5) Sec.  25.1316 System lightning protection.
    (6) Sec.  25.1331(a)(2) Instruments using a power supply.
    (7) Sec.  25.1351 General.
    (8) Sec.  25.1355 Distribution system.
    (9) Sec.  25.1360 Precautions against injury.
    (10) Sec.  25.1362 Electrical supplies for emergency conditions.
    (11) Sec.  25.1365 Electrical appliances, motors, and transformers.
    (12) Sec.  25.1431(c) and (d) Electronic equipment.

Sec.  25.1707  System separation: EWIS.

    (a) Each EWIS must be designed and installed with adequate physical 
separation from other EWIS and airplane systems so that an EWIS 
component failure will not create a hazardous condition. Unless 
otherwise stated, for the purposes of this section, adequate physical 
separation must be achieved by separation distance or by a barrier that 
provides protection equivalent to that separation distance.
    (b) Each EWIS must be designed and installed so that any electrical 
interference likely to be present in the airplane will not result in 
hazardous effects upon the airplane or its systems.
    (c) Wires and cables carrying heavy current, and their associated 
EWIS components, must be designed and installed to ensure adequate 
physical separation and electrical isolation so that damage to circuits 
associated with essential functions will be minimized under fault 
conditions.
    (d) Each EWIS associated with independent airplane power sources or 
power sources connected in combination must be designed and installed 
to ensure adequate physical separation and electrical isolation so that 
a fault in any one airplane power source EWIS will not adversely affect 
any other independent power sources. In addition:
    (1) Airplane independent electrical power sources must not share a 
common ground terminating location.
    (2) Airplane system static grounds must not share a common ground 
terminating location with any of the airplane's independent electrical 
power sources.
    (e) Except to the extent necessary to provide electrical connection 
to the fuel systems components, the EWIS must be designed and installed 
with adequate physical separation from fuel lines and other fuel system 
components, so that:
    (1) An EWIS component failure will not create a hazardous 
condition.
    (2) Any fuel leakage onto EWIS components will not create a 
hazardous condition.
    (f) Except to the extent necessary to provide electrical connection 
to the hydraulic systems components, EWIS must be designed and 
installed with adequate physical separation from hydraulic lines and 
other hydraulic system components, so that:
    (1) An EWIS component failure will not create a hazardous 
condition.
    (2) Any hydraulic fluid leakage onto EWIS components will not 
create a hazardous condition.
    (g) Except to the extent necessary to provide electrical connection 
to the oxygen systems components, EWIS must be designed and installed 
with adequate physical separation from oxygen lines and other oxygen 
system components, so that an EWIS component failure will not create a 
hazardous condition.
    (h) Except to the extent necessary to provide electrical connection 
to the water/waste systems components, EWIS must be designed and 
installed with adequate physical separation from water/waste lines and 
other water/waste system components, so that:
    (1) An EWIS component failure will not create a hazardous 
condition.
    (2) Any water/waste leakage onto EWIS components will not create a 
hazardous condition.
    (i) EWIS must be designed and installed with adequate physical 
separation between the EWIS and flight or other mechanical control 
systems cables and associated system components, so that:
    (1) Chafing, jamming, or other interference are prevented.
    (2) An EWIS component failure will not create a hazardous 
condition.
    (3) Failure of any flight or other mechanical control systems 
cables or systems components will not damage the EWIS and create a 
hazardous condition.
    (j) EWIS must be designed and installed with adequate physical 
separation between the EWIS components and heated equipment, hot air 
ducts, and lines, so that:
    (1) An EWIS component failure will not create a hazardous 
condition.
    (2) Any hot air leakage or heat generated onto EWIS components will 
not create a hazardous condition.
    (k) For systems for which redundancy is required, by certification 
rules, by operating rules, or as a result of the assessment required by 
Sec.  25.1709, EWIS components associated with those systems must be 
designed and installed with adequate physical separation.
    (l) Each EWIS must be designed and installed so there is adequate 
physical separation between it and other aircraft components and 
aircraft structure, and so that the EWIS is protected from sharp edges 
and corners, to minimize potential for abrasion/chafing, vibration 
damage, and other types of mechanical damage.

Sec.  25.1709  System safety: EWIS.

    Each EWIS must be designed and installed so that:
    (a) Each catastrophic failure condition--
    (1) Is extremely improbable; and
    (2) Does not result from a single failure.
    (b) Each hazardous failure condition is extremely remote.

Sec.  25.1711  Component identification: EWIS.

    (a) EWIS components must be labeled or otherwise identified using a 
consistent method that facilitates identification of the EWIS 
component, its function, and its design limitations, if any.
    (b) For systems for which redundancy is required, by certification 
rules, by operating rules, or as a result of the assessment required by 
Sec.  25.1709, EWIS components associated with those systems must be 
specifically identified with component part number, function, and 
separation requirement for bundles.
    (1) The identification must be placed along the wire, cable, or 
wire bundle at appropriate intervals and in areas of the airplane where 
it is readily visible to maintenance, repair, or alteration personnel.

[[Page 63408]]

    (2) If an EWIS component cannot be marked physically, then other 
means of identification must be provided.
    (c) The identifying markings required by paragraphs (a) and (b) of 
this section must remain legible throughout the expected service life 
of the EWIS component.
    (d) The means used for identifying each EWIS component as required 
by this section must not have an adverse effect on the performance of 
that component throughout its expected service life.
    (e) Identification for EWIS modifications to the type design must 
be consistent with the identification scheme of the original type 
design.

Sec.  25.1713  Fire protection: EWIS.

    (a) All EWIS components must meet the applicable fire and smoke 
protection requirements of Sec.  25.831(c) of this part.
    (b) EWIS components that are located in designated fire zones and 
are used during emergency procedures must be fire resistant.
    (c) Insulation on electrical wire and electrical cable, and 
materials used to provide additional protection for the wire and cable, 
installed in any area of the airplane, must be self-extinguishing when 
tested in accordance with the applicable portions of Appendix F, part 
I, of 14 CFR part 25.

Sec.  25.1715  Electrical bonding and protection against static 
electricity: EWIS.

    (a) EWIS components used for electrical bonding and protection 
against static electricity must meet the requirements of Sec.  25.899.
    (b) On airplanes having grounded electrical systems, electrical 
bonding provided by EWIS components must provide an electrical return 
path capable of carrying both normal and fault currents without 
creating a shock hazard or damage to the EWIS components, other 
airplane system components, or airplane structure.

Sec.  25.1717  Circuit protective devices: EWIS.

    Electrical wires and cables must be designed and installed so they 
are compatible with the circuit protection devices required by Sec.  
25.1357, so that a fire or smoke hazard cannot be created under 
temporary or continuous fault conditions.

Sec.  25.1719  Accessibility provisions: EWIS.

    Access must be provided to allow inspection and replacement of any 
EWIS component as necessary for continued airworthiness.

Sec.  25.1721  Protection of EWIS.

    (a) No cargo or baggage compartment may contain any EWIS whose 
damage or failure may affect safe operation, unless the EWIS is 
protected so that:
    (1) It cannot be damaged by movement of cargo or baggage in the 
compartment.
    (2) Its breakage or failure will not create a fire hazard.
    (b) EWIS must be designed and installed to minimize damage and risk 
of damage to EWIS by movement of people in the airplane during all 
phases of flight, maintenance, and servicing.
    (c) EWIS must be designed and installed to minimize damage and risk 
of damage to EWIS by items carried onto the aircraft by passengers or 
cabin crew.

Sec.  25.1723  Flammable fluid fire protection: EWIS.

    EWIS components located in each area where flammable fluid or 
vapors might escape by leakage of a fluid system must be considered a 
potential ignition source and must meet the requirements of Sec.  
25.863.

Sec.  25.1725  Powerplants: EWIS.

    (a) EWIS associated with any powerplant must be designed and 
installed so that the failure of an EWIS component will not prevent the 
continued safe operation of the remaining powerplants or require 
immediate action by any crewmember for continued safe operation, in 
accordance with the requirements of Sec.  25.903(b).
    (b) Design precautions must be taken to minimize hazards to the 
airplane due to EWIS damage in the event of a powerplant rotor failure 
or a fire originating within the powerplant that burns through the 
powerplant case, in accordance with the requirements of Sec.  
25.903(d)(1).

Sec.  25.1727  Flammable fluid shutoff means: EWIS.

    EWIS associated with each flammable fluid shutoff means and control 
must be fireproof or must be located and protected so that any fire in 
a fire zone will not affect operation of the flammable fluid shutoff 
means, in accordance with the requirements of Sec.  25.1189.

Sec.  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.

Sec.  25.1731  Powerplant and APU fire detector system: EWIS.

    (a) EWIS that are part of each fire or overheat detector system in 
a fire zone must be fire-resistant.
    (b) No EWIS component of any fire or overheat detector system for 
any fire zone may pass through another fire zone, unless:
    (1) It is protected against the possibility of false warnings 
resulting from fires in zones through which it passes; or
    (2) Each zone involved is simultaneously protected by the same 
detector and extinguishing system.
    (c) EWIS that are part of each fire or overheat detector system in 
a fire zone must meet the requirements of Sec.  25.1203.

Sec.  25.1733  Fire detector systems, general: EWIS.

    EWIS associated with any installed fire protection system, 
including those required by Sec. Sec.  25.854 and 25.858, must be 
considered an integral part of the system in showing compliance with 
the applicable requirements for that system.

0
24. Amend H25.1 of Appendix H to part 25 by revising paragraph (a) to 
read as follows:

Appendix H To Part 25--Instructions For Continued Airworthiness

    H25.1 General.
    (a) This appendix specifies requirements for preparation of 
Instructions for Continued Airworthiness as required by Sec. Sec.  
25.1529, 25.1729, and applicable provisions of parts 21 and 26 of 
this chapter.

* * * * *

0
25. Amend H25.4 of Appendix H to part 25 by revising paragraph (a)(1) 
and adding new paragraph (a)(3) to read as follows:

Appendix H To Part 25--Instructions for Continued Airworthiness

* * * * *
    H25.4 Airworthiness Limitations section.
    (a) * * *
    (1) Each mandatory replacement time, structural inspection 
interval, and related structural inspection procedures approved 
under Sec.  25.571.
* * * * *
    (3) Any mandatory replacement time of EWIS components as defined 
in section 25.1701.

* * * * *

0
26. Amend Appendix H to part 25 by adding new paragraph H25.5 to read 
as follows:

Appendix H To Part 25--Instructions for Continued Airworthiness

* * * * *
    H25.5 Electrical Wiring Interconnection System (EWIS) 
Instructions for Continued Airworthiness.
    (a) The applicant must prepare Instructions for Continued 
Airworthiness (ICA) applicable to EWIS as defined by Sec.  25.1701 
that are

[[Page 63409]]

approved by the FAA and include the following:
    (1) Maintenance and inspection requirements for the EWIS 
developed with the use of an enhanced zonal analysis procedure that 
includes:
    (i) Identification of each zone of the airplane.
    (ii) Identification of each zone that contains EWIS.
    (iii) Identification of each zone containing EWIS that also 
contains combustible materials.
    (iv) 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.
    (v) Identification of--
    (A) Tasks, and the intervals for performing those tasks, that 
will reduce the likelihood of ignition sources and accumulation of 
combustible material, and
    (B) Procedures, and the intervals for performing those 
procedures, that will effectively clean the EWIS components of 
combustible material if there is not an effective task to reduce the 
likelihood of combustible material accumulation.
    (vi) Instructions for protections and caution information that 
will minimize contamination and accidental damage to EWIS, as 
applicable, during performance of maintenance, alteration, or 
repairs.
    (2) Acceptable EWIS maintenance practices in a standard format.
    (3) Wire separation requirements as determined under Sec.  
25.1707.
    (4) Information explaining the EWIS identification method and 
requirements for identifying any changes to EWIS under Sec.  
25.1711.
    (5) Electrical load data and instructions for updating that 
data.
    (b) 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 to be provided, and they must be easily recognizable as 
EWIS ICA. This document must either contain the required EWIS ICA or 
specifically reference other portions of the ICA that contain this 
information.

0
27. Amend 14 CFR by adding new part 26 to read as follows:

PART 26--CONTINUED AIRWORTHINESS AND SAFETY IMPROVEMENTS FOR 
TRANSPORT CATEGORY AIRPLANES

Subpart A--General
Sec.
26.1 Purpose and scope.
26.3 Definitions.
26.5 Applicability table.
Subpart B--Enhanced Airworthiness Program for Aging Systems 26.11 
Electrical wiring interconnection systems (EWIS) maintenance program.

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702 and 44704.

Subpart A--General

Sec.  26.1  Purpose and scope.

    (a) This part establishes requirements for support of the continued 
airworthiness of and safety improvements for transport category 
airplanes. These requirements may include performing assessments, 
developing design changes, developing revisions to Instructions for 
Continued Airworthiness (ICA), and making necessary documentation 
available to affected persons. Requirements of this part that establish 
standards for design changes and revisions to the ICA are considered 
airworthiness requirements.
    (b) Except as provided in paragraph (c) of this section, this part 
applies to the following persons, as specified in each subpart of this 
part:
    (1) Holders of type certificates and supplemental type 
certificates.
    (2) Applicants for type certificates and supplemental type 
certificates and changes to those certificates (including service 
bulletins describing design changes).
    (3) Persons seeking design approval for airplane repairs, 
alterations, or modifications that may affect airworthiness.
    (4) Holders of type certificates and their licensees producing new 
airplanes.
    (c) An applicant for approval of a design change is not required to 
comply with any applicable airworthiness requirement of this part if 
the applicant elects or is required to comply with a corresponding 
amendment to part 25 of this chapter that is adopted concurrently or 
after that airworthiness requirement.
    (d) For the purposes of this part, the word ``type certificate'' 
does not include supplemental type certificates.

Sec.  26.3  Definitions.

    For the purposes of this part:
    FAA Oversight Office is 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.

Sec.  26.5  Applicability table.

    Table 1 of this section provides an overview of the applicability 
of this part. It provides guidance in identifying what sections apply 
to various types of entities. The specific applicability of each 
subpart and section is specified in the regulatory text.

                Table 1.--Applicability of Part 26 Rules
------------------------------------------------------------------------
                                                            Applicable
                                                             sections
                                                         ---------------
                                                             Subpart B
                                                            (EAPAS/FTS)
------------------------------------------------------------------------
Effective Date of Rule..................................             TBD
Existing \1\ TC Holders.................................           26.11
Pending \1\ TC Applicants...............................           26.11
Existing \1\ STC Holders................................             N/A
Pending \1\ STC/ATC Applicants..........................           26.11
Future \2\ STC/ATC Applicants...........................           26.11
Manufacturers...........................................             N/A
Persons Seeking Design Approval of Repairs..............            N/A
------------------------------------------------------------------------
\1\ As of the effective date of the identified rule.
\2\ Application made after the effective date of the identified rule.

Subpart B--Enhanced Airworthiness Program for Aging Systems

Sec.  26.11  Electrical wiring interconnection systems (EWIS) 
maintenance program.

    (a) Except as provided in paragraph (g) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of the 
original certification, or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more or
    (2) A maximum payload capacity of 7,500 pounds or more.
    (b) Holders of, and applicants for, type certificates, as 
identified in paragraph (d) of this section must develop Instructions 
for Continued Airworthiness (ICA) for the representative airplane's 
EWIS in accordance with part 25, Appendix H paragraphs H25.5(a)(1) and 
(b) of this subchapter in effect on December 10, 2007 for each affected 
type design, and submit those ICA for review and approval by the FAA 
Oversight Office. For purposes of this section, the ``representative 
airplane'' is the configuration of each model series airplane that 
incorporates all variations of EWIS used in production on that series 
airplane, and all TC-holder-designed modifications mandated by 
airworthiness directive as of the effective date of this rule. Each 
person specified in paragraph (d) of this section must also review any 
fuel tank system ICA developed by that person to comply with SFAR 88 to 
ensure compatibility with the EWIS ICA, including minimizing redundant 
requirements.
    (c) Applicants for amendments to type certificates and supplemental 
type certificates, as identified in paragraph (d) of this section, 
must:

[[Page 63410]]

    (1) Evaluate whether the design change for which approval is sought 
necessitates a revision to the ICA required by paragraph (b) of this 
section to comply with the requirements of Appendix H, paragraphs 
H25.5(a)(1) and (b). If so, the applicant must develop and submit the 
necessary revisions for review and approval by the FAA Oversight 
Office.
    (2) Ensure that any revised EWIS ICA remain compatible with any 
fuel tank system ICA previously developed to comply with SFAR 88 and 
any redundant requirements between them are minimized.
    (d) The following persons must comply with the requirements of 
paragraph (b) or (c) of this section, as applicable, before the dates 
specified.
    (1) Holders of type certificates (TC): December 10, 2009.
    (2) Applicants for TCs, and amendments to TCs (including service 
bulletins describing design changes), if the date of application was 
before December 10, 2007 and the certificate was issued on or after 
December 10, 2007: December 10, 2009 or the date the certificate is 
issued, whichever occurs later.
    (3) Unless compliance with Sec.  25.1729 of this subchapter is 
required or elected, applicants for amendments to TCs, if the 
application was filed on or after December 10, 2007: December 10, 2009, 
or the date of approval of the certificate, whichever occurs later.
    (4) Applicants for supplemental type certificates (STC), including 
changes to existing STCs, if the date of application was before 
December 10, 2007 and the certificate was issued on or after December 
10, 2007: June 7, 2010, or the date of approval of the certificate, 
whichever occurs later.
    (5) Unless compliance with Sec.  25.1729 of this subchapter is 
required or elected, applicants for STCs, including changes to existing 
STCs, if the application was filed on or after December 10, 2007, 
December 10, 2009, or the date of approval of the certificate, 
whichever occurs later.
    (e) Each person identified in paragraphs (d)(1), (d)(2), and (d)(4) 
of this section must submit to the FAA Oversight Office for approval a 
compliance plan by March 10, 2008. The compliance plan must include the 
following information:
    (1) A proposed project schedule, identifying all major milestones, 
for meeting the compliance dates specified in paragraph (d) of this 
section.
    (2) A proposed means of compliance with this section, identifying 
all required submissions, including all compliance items as mandated in 
part 25, Appendix H paragraphs H25.5(a)(1) and (b) of this subchapter 
in effect on December 10, 2007, and all data to be developed to 
substantiate compliance.
    (3) A proposal for submitting a draft of all compliance items 
required by paragraph (e)(2) of this section for review by the FAA 
Oversight Office not less than 60 days before the compliance time 
specified in paragraph (d) of this section.
    (4) A proposal for how the approved ICA will be made available to 
affected persons.
    (f) Each person specified in paragraph (e) must implement the 
compliance plan, or later approved revisions, as approved in compliance 
with paragraph (e) of this section.
    (g) This section does not apply to the following airplane models:

(1) Lockheed L-188
(2) Bombardier CL-44
(3) Mitsubishi YS-11
(4) British Aerospace BAC 1-11
(5) Concorde
(6) deHavilland D.H. 106 Comet 4C
(7) VFW--Vereinigte Flugtechnische Werk VFW-614
(8) Illyushin Aviation IL 96T
(9) Bristol Aircraft Britannia 305
(10) Handley Page Herald Type 300
(11) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(12) Airbus Caravelle
(13) Lockheed L-300

PART 91--GENERAL OPERATING AND FLIGHT RULES

0
28. The authority citation for part 91 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 1155, 40103, 40113, 40120, 44101, 
44111, 44701, 44709, 44711, 44712, 44715, 44716, 44717, 44722, 
46306, 46315, 46316, 46504, 46506-46507, 47122, 47508, 47528-47531, 
articles 12 and 29 of the Convention on International Civil Aviation 
(61 stat. 1180).

0
29. Amend Sec.  91.1 by adding a new paragraph (d) to read as follows:

Sec.  91.1  Applicability.

* * * * *
    (d) This part also establishes requirements for operators to take 
actions to support the continued airworthiness of each airplane.

0
30. Amend part 91 by adding new Subpart L as follows:
Subpart L--Continued Airworthiness and Safety Improvements
Sec.
91.1501 Purpose and definition.
91.1503 [Reserved]
91.1505 [Reserved]
91.1507 Fuel tank system inspection program.

Subpart L--Continued Airworthiness and Safety Improvements

Sec.  91.1501  Purpose and definition.

    (a) This subpart requires operators to support the continued 
airworthiness of each airplane. These requirements may include, but are 
not limited to, revising the inspection program, incorporating design 
changes, and incorporating revisions to Instructions for Continued 
Airworthiness.
    (b) For purposes of this subpart, the ``FAA Oversight Office'' is 
the aircraft certification office or office of the Transport Airplane 
Directorate with oversight responsibility for the relevant type 
certificate or supplemental type certificate, as determined by the 
Administrator.

Sec.  91.1503  [Reserved]

Sec.  91.1505  [Reserved]

Sec.  91.1507  Fuel tank system inspection program.

    (a) Except as provided in paragraph (g) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7,500 pounds or more.
    (b) For each airplane on which an auxiliary fuel tank is installed 
under a field approval, before June 16, 2008, the operator must submit 
to the FAA Oversight Office proposed maintenance instructions for the 
tank that meet the requirements of Special Federal Aviation Regulation 
No. 88 (SFAR 88) of this chapter.
    (c) After December 16, 2008, no operator may operate an airplane 
identified in paragraph (a) of this section unless the inspection 
program for that airplane has been revised to include applicable 
inspections, procedures, and limitations for fuel tank systems.
    (d) The proposed fuel tank system inspection program revisions 
specified in paragraph (c) of this section must be based on fuel tank 
system Instructions for Continued Airworthiness (ICA) that have been 
developed in accordance with the applicable provisions of SFAR 88 of 
this chapter or Sec.  25.1529 and part 25, Appendix H, of this chapter, 
in effect on June 6, 2001 (including those developed for auxiliary fuel 
tanks, if any, installed under supplemental type certificates or other 
design approval) and that have been approved by the FAA Oversight 
Office.

[[Page 63411]]

    (e) After December 16, 2008, before returning an airplane to 
service after any alterations for which fuel tank ICA are developed 
under SFAR 88, or under Sec.  25.1529 in effect on June 6, 2001, the 
operator must include in the inspection program for the airplane 
inspections and procedures for the fuel tank system based on those ICA.
    (f) The fuel tank system inspection program changes identified in 
paragraphs (d) and (e) of this section and any later fuel tank system 
revisions must be submitted to the Flight Standards District Office 
(FSDO) responsible for review and approval.
    (g) This section does not apply to the following airplane models:

(1) Bombardier CL-44
(2) Concorde
(3) deHavilland D.H. 106 Comet 4C
(4) VFW-Vereinigte Flugtechnische Werk VFW-614
(5) Illyushin Aviation IL 96T
(6) Bristol Aircraft Britannia 305
(7) Handley Page Herald Type 300
(8) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(9) Airbus Caravelle
(10) Lockheed L-300

0
31. Re-designate the text of Sec.  91.410 as new Sec.  91.1505, remove 
and reserve paragraph (b), and revise the section heading of newly re-
designated Sec.  91.1505 to read as follows:

Sec.  91.1505  Repairs assessment for pressurized fuselages.

* * * * *

Sec.  91.410  [Reserved]

0
32. Add and reserve a new Sec.  91.410.

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL 
OPERATIONS

0
33. The authority citation for part 121 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 40119, 41706, 44101, 44701-
44702, 44705, 44709-44711, 44713, 44716-44717, 44722, 44901, 44903-
44904, 44912, 45101-45105, 46105, 46301.

0
34. Amend Sec.  121.1 by adding a new paragraph (g) to read as follows:

Sec.  121.1  Applicability

* * * * *
    (g) This part also establishes requirements for operators to take 
actions to support the continued airworthiness of each airplane.

0
35. Amend part 121 by adding new subpart AA to read as follows:
Subpart AA--Continued Airworthiness and Safety Improvements
Sec.
121.1101 Purpose and definition.
121.1103 [Reserved]
121.1105 [Reserved]
121.1107 [Reserved]
121.1109 [Reserved]
121.1111 Electrical wiring interconnection systems (EWIS) 
maintenance program.
121.1113 Fuel tank system maintenance program.

Subpart AA--Continued Airworthiness and Safety Improvements

Sec.  121.1101  Purpose and definition.

    (a) This subpart requires persons holding an air carrier or 
operating certificate under part 119 of this chapter to support the 
continued airworthiness of each airplane. These requirements may 
include, but are not limited to, revising the maintenance program, 
incorporating design changes, and incorporating revisions to 
Instructions for Continued Airworthiness.
    (b) For purposes of this subpart, the ``FAA Oversight Office'' is 
the aircraft certification office or office of the Transport Airplane 
Directorate with oversight responsibility for the relevant type 
certificate or supplemental type certificate, as determined by the 
Administrator.

Sec.  121.1103  [Reserved]

Sec.  121.1105  [Reserved]

Sec.  121.1107  [Reserved]

Sec.  121.1109  [Reserved]

Sec.  121.1111  Electrical wiring interconnection systems (EWIS) 
maintenance program.

    (a) Except as provided in paragraph (f) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7500 pounds or more.
    (b) After March 10, 2011, no certificate holder may operate an 
airplane identified in paragraph (a) of this section unless the 
maintenance program for that airplane includes inspections and 
procedures for electrical wiring interconnection systems (EWIS).
    (c) The proposed EWIS maintenance program changes must be based on 
EWIS Instructions for Continued Airworthiness (ICA) that have been 
developed in accordance with the provisions of Appendix H of part 25 of 
this chapter applicable to each affected airplane (including those ICA 
developed for supplemental type certificates installed on each 
airplane) and that have been approved by the FAA Oversight Office.
    (1) For airplanes subject to Sec.  26.11 of this chapter, the EWIS 
ICA must comply with paragraphs H25.5(a)(1) and (b).
    (2) For airplanes subject to Sec.  25.1729 of this chapter, the 
EWIS ICA must comply with paragraph H25.4 and all of paragraph H25.5.
    (d) After March 10, 2011, before returning an airplane to service 
after any alterations for which EWIS ICA are developed, the certificate 
holder must include in the airplane's maintenance program inspections 
and procedures for EWIS based on those ICA.
    (e) The EWIS maintenance program changes identified in paragraphs 
(c) and (d) of this section and any later EWIS revisions must be 
submitted to the Principal Inspector for review and approval.
    (f) This section does not apply to the following airplane models:

(1) Lockheed L-188
(2) Bombardier CL-44
(3) Mitsubishi YS-11
(4) British Aerospace BAC 1-11
(5) Concorde
(6) deHavilland D.H. 106 Comet 4C
(7) VFW-Vereinigte Flugtechnische Werk VFW-614
(8) Illyushin Aviation IL 96T
(9) Bristol Aircraft Britannia 305
(10) Handley Page Herald Type 300
(11) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(12) Airbus Caravelle
(13) Lockheed L-300

Sec.  121.1113  Fuel tank system maintenance program.

    (a) Except as provided in paragraph (g) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7500 pounds or more.
    (b) For each airplane on which an auxiliary fuel tank is installed 
under a field approval, before June 16, 2008, the certificate holder 
must submit to the FAA Oversight Office proposed maintenance 
instructions for the tank that meet the requirements of Special Federal 
Aviation Regulation No. 88 (SFAR 88) of this chapter.
    (c) After December 16, 2008, no certificate holder may operate an 
airplane identified in paragraph (a) of this section unless the 
maintenance program for that airplane has been revised to include 
applicable

[[Page 63412]]

inspections, procedures, and limitations for fuel tanks systems.
    (d) The proposed fuel tank system maintenance program revisions 
must be based on fuel tank system Instructions for Continued 
Airworthiness (ICA) that have been developed in accordance with the 
applicable provisions of SFAR 88 of this chapter or Sec.  25.1529 and 
part 25, Appendix H, of this chapter, in effect on June 6, 2001 
(including those developed for auxiliary fuel tanks, if any, installed 
under supplemental type certificates or other design approval) and that 
have been approved by the FAA Oversight Office.
    (e) After December 16, 2008, before returning an aircraft to 
service after any alteration for which fuel tank ICA are developed 
under SFAR 88 or under Sec.  25.1529 in effect on June 6, 2001, the 
certificate holder must include in the maintenance program for the 
airplane inspections and procedures for the fuel tank system based on 
those ICA.
    (f) The fuel tank system maintenance program changes identified in 
paragraphs (d) and (e) of this section and any later fuel tank system 
revisions must be submitted to the Principal Inspector for review and 
approval.
    (g) This section does not apply to the following airplane models:

(1) Bombardier CL-44
(2) Concorde
(3) deHavilland D.H. 106 Comet 4C
(4) VFW-Vereinigte Flugtechnische Werk VFW-614
(5) Illyushin Aviation IL 96T
(6) Bristol Aircraft Britannia 305
(7) Handley Page Herald Type 300
(8) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(9) Airbus Caravelle
(10) Lockheed L-300

Sec.  121.368  [Re-designated as Sec.  121.1105]

0
36. Re-designate Sec.  121.368 as new Sec.  121.1105.

Sec.  121.368  [Reserved]

0
37. Add and reserve a new Sec.  121.368.

0
38. Re-designate Sec.  121.370 as new Sec.  121.1107, remove and 
reserve paragraph (b), and revise the section heading to read as 
follows:

Sec.  121.1107  Repairs assessment for pressurized fuselages.

* * * * *

Sec.  121.370  [Reserved]

0
39. Add and reserve a new Sec.  121.370.

Sec.  121.370a  [Re-designated as Sec.  121.1109]

0
40. Re-designate Sec.  121.370a as new Sec.  121.1109.

Sec.  121.370a  [Reserved]

0
41. Add and reserve a new Sec.  121.370a.

PART 125--CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING 
CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 
6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH 
AIRCRAFT

0
42. The authority citation for part 125 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44705, 44710-
44711, 44713, 44716-44717, 44722.

0
43. Amend Sec.  125.1 by adding a new paragraph (e) to read as follows:

Sec.  125.1  Applicability.

* * * * *
    (e) This part also establishes requirements for operators to take 
actions to support the continued airworthiness of each airplane.

0
44. Amend part 125 by adding new subpart M to read as follows:
Subpart M--Continued Airworthiness and Safety Improvements
Sec.
125.501 Purpose and definition.
125.503 [Reserved]
125.505 [Reserved]
125.507 Fuel tank system inspection program.

Subpart M--Continued Airworthiness and Safety Improvements

Sec.  125.501  Purpose and definition.

    (a) This subpart requires operators to support the continued 
airworthiness of each airplane. These requirements may include, but are 
not limited to, revising the inspection program, incorporating design 
changes, and incorporating revisions to Instructions for Continued 
Airworthiness.
    (b) For purposes of this subpart, the ``FAA Oversight Office'' is 
the aircraft certification office or office of the Transport Airplane 
Directorate with oversight responsibility for the relevant type 
certificate or supplemental type certificate, as determined by the 
Administrator.

Sec.  125.503  [Reserved]

Sec.  125.505  [Reserved]

Sec.  125.507  Fuel tank system inspection program.

    (a) Except as provided in paragraph (g) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7500 pounds or more.
    (b) For each airplane on which an auxiliary fuel tank is installed 
under a field approval, before June 16, 2008, the certificate holder 
must submit to the FAA Oversight Office proposed maintenance 
instructions for the tank that meet the requirements of Special Federal 
Aviation Regulation No. 88 (SFAR 88) of this chapter.
    (c) After December 16, 2008, no certificate holder may operate an 
airplane identified in paragraph (a) of this section unless the 
inspection program for that airplane has been revised to include 
applicable inspections, procedures, and limitations for fuel tank 
systems.
    (d) The proposed fuel tank system inspection program revisions must 
be based on fuel tank system Instructions for Continued Airworthiness 
(ICA) that have been developed in accordance with the applicable 
provisions of SFAR 88 of this chapter or Sec.  25.1529 and part 25, 
Appendix H, of this chapter, in effect on June 6, 2001 (including those 
developed for auxiliary fuel tanks, if any, installed under 
supplemental type certificates or other design approval) and that have 
been approved by the FAA Oversight Office.
    (e) After December 16, 2008, before returning an aircraft to 
service after any alteration for which fuel tank ICA are developed 
under SFAR 88, or under Sec.  25.1529 in effect on June 6, 2001, the 
certificate holder must include in the inspection program for the 
airplane inspections and procedures for the fuel tank system based on 
those ICA.
    (f) The fuel tank system inspection program changes identified in 
paragraphs (d) and (e) of this section and any later fuel tank system 
revisions must be submitted to the Principal Inspector for review and 
approval.
    (g) This section does not apply to the following airplane models:

(1) Bombardier CL-44
(2) Concorde
(3) deHavilland D.H. 106 Comet 4C
(4) VFW-Vereinigte Flugtechnische Werk VFW-614
(5) Illyushin Aviation IL 96T
(6) Bristol Aircraft Britannia 305
(7) Handley Page Herald Type 300
(8) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(9) Airbus Caravelle
(10) Lockheed L-300
0
45. Re-designate Sec.  125.248 as new Sec.  125.505, remove and reserve 
paragraph (b), and revise the section heading of newly re-designated 
Sec.  125.505 to read as follows:

[[Page 63413]]

Sec.  125.505  Repairs assessment for pressurized fuselages.

* * * * *

Sec.  125.248  [Reserved]

0
46. Add and reserve a new Sec.  125.248.

PART 129--OPERATIONS: FOREIGN AIR CARRIERS AND FOREIGN OPERATORS OF 
U.S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE

0
47. The authority citation for part 129 continues to read as follows:

    Authority: 49 U.S.C. 1372, 40113, 40119, 44101, 44701-44702, 
44705, 44709-44711, 44713, 44716-44717, 44722, 44901-44904, 44906, 
44912, 46105, Pub. L. 107-71 sec. 104.

Sec.  129.16  [Re-designated as Sec.  129.109]

0
48. Re-designate Sec.  129.16 as Sec.  129.109.

Sec.  129.32  [Re-designated as Sec.  129.107]

0
49. Re-designate Sec.  129.32 as Sec.  129.107, revise the section 
heading of newly re-designated Sec.  129.107, and remove and reserve 
paragraph (b). The revised heading reads as follows:

Sec.  129.107  Repairs assessment for pressurized fuselages.

* * * * *

Sec.  129.33  [Re-designated as Sec.  129.105]

0
50. Re-designate Sec.  129.33 as Sec.  129.105.
0
51. Designate newly re-designated Sec. Sec.  129.105, 129.107, and 
129.109 as Subpart B and add a new subpart heading to read as follows:

Subpart B--Continued Airworthiness and Safety Improvements

* * * * *
0
52. Designate existing Sec. Sec.  129.1, 129.11, 129.13, 129.14, 
129.15, 129.17, 129.18, 129.19, 129.20, 129.21, 129.22, 129.23, 129.25, 
129.28, and 129.29, as Subpart A and add a new subpart heading to read 
as follows:

Subpart A--General

* * * * *
0
53. Revise paragraph (b) of Sec.  129.1 to read as follows:

Sec.  129.1  Applicability and definitions.

* * * * *
    (b) Operations of U.S.-registered aircraft solely outside the 
United States. In addition to the operations specified under paragraph 
(a) of this section, Sec. Sec.  129.14 and 129.20 and subpart B of this 
part also apply to U.S.-registered aircraft operated solely outside the 
United States in common carriage by a foreign person or foreign air 
carrier.
* * * * *

0
54. Add Sec.  129.101 to subpart B to read as follows:

Sec.  129.101  Purpose and definition.

    (a) This subpart requires a foreign person or foreign air carrier 
operating a U.S. registered airplane in common carriage to support the 
continued airworthiness of each airplane. These requirements may 
include, but are not limited to, revising the maintenance program, 
incorporating design changes, and incorporating revisions to 
Instructions for Continued Airworthiness.
    (b) For purposes of this subpart, the ``FAA Oversight Office'' is 
the aircraft certification office or office of the Transport Airplane 
Directorate with oversight responsibility for the relevant type 
certificate or supplemental type certificate, as determined by the 
Administrator.

Sec.  129.103  [Reserved]

0
55. Add and reserve Sec.  129.103 to subpart B.
0
56. Add Sec.  129.111 to subpart B to read as follows:

Sec.  129.111  Electrical wiring interconnection systems (EWIS) 
maintenance program.

    (a) Except as provided in paragraph (f) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7500 pounds or more.
    (b) After March 10, 2011, no foreign person or foreign air carrier 
may operate a U.S.-registered airplane identified in paragraph (a) of 
this section unless the maintenance program for that airplane includes 
inspections and procedures for EWIS.
    (c) The proposed EWIS maintenance program changes must be based on 
EWIS Instructions for Continued Airworthiness (ICA) that have been 
developed in accordance with the provisions of Appendix H of part 25 of 
this chapter applicable to each affected airplane (including those ICA 
developed for supplemental type certificates installed on each 
airplane) and that have been approved by the FAA Oversight Office.
    (1) For airplanes subject to Sec.  26.11 of this chapter, the EWIS 
ICA must comply with paragraphs H25.5(a)(1) and (b).
    (2) For airplanes subject to Sec.  25.1729 of this chapter, the 
EWIS ICA must comply with paragraph H25.4 and all of paragraph H25.5.
    (d) After March 10, 2011, before returning a U.S.-registered 
airplane to service after any alterations for which EWIS ICA are 
developed, the foreign person or foreign air carrier must include in 
the maintenance program for that airplane inspections and procedures 
for EWIS based on those ICA.
    (e) The EWIS maintenance program changes identified in paragraphs 
(c) and (d) of this section and any later EWIS revisions must be 
submitted to the Principal Inspector or Flight Standards International 
Field Office responsible for review and approval.
    (f) This section does not apply to the following airplane models:

(1) Lockheed L-188
(2) Bombardier CL-44
(3) Mitsubishi YS-11
(4) British Aerospace BAC 1-11
(5) Concorde
(6) deHavilland D.H. 106 Comet 4C
(7) VFW-Vereinigte Flugtechnische Werk VFW-614
(8) Illyushin Aviation IL 96T
(9) Bristol Aircraft Britannia 305
(10) Handley Page Herald Type 300
(11) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(12) Airbus Caravelle
(13) Lockheed L-300

0
57. Add Sec.  129.113 to subpart B to read as follows:

Sec.  129.113  Fuel tank system maintenance program.

    (a) Except as provided in paragraph (g) of this section, this 
section applies to transport category, turbine-powered airplanes with a 
type certificate issued after January 1, 1958, that, as a result of 
original type certification or later increase in capacity, have--
    (1) A maximum type-certificated passenger capacity of 30 or more, 
or
    (2) A maximum payload capacity of 7500 pounds or more.
    (b) For each U.S.-registered airplane on which an auxiliary fuel 
tank is installed under a field approval, before June 16, 2008, the 
foreign person or foreign air carrier operating the airplane must 
submit to the FAA Oversight Office proposed maintenance instructions 
for the tank that meet the requirements of Special Federal Aviation 
Regulation No. 88 (SFAR 88) of this chapter.
    (c) After December 16, 2008, no foreign person or foreign air 
carrier may operate a U.S.-registered airplane identified in paragraph 
(a) of this section unless the maintenance program for that airplane 
has been revised to include applicable inspections, procedures, and 
limitations for fuel tank systems.

[[Page 63414]]

    (d) The proposed fuel tank system maintenance program revisions 
must be based on fuel tank system Instructions for Continued 
Airworthiness (ICA) that have been developed in accordance with the 
applicable provisions of SFAR 88 of this chapter or Sec.  25.1529 and 
part 25, Appendix H, of this chapter, in effect on June 6, 2001 
(including those developed for auxiliary fuel tanks, if any, installed 
under supplemental type certificates or other design approval) and that 
have been approved by the FAA Oversight Office.
    (e) After December 16, 2008, before returning a U.S.-registered 
airplane to service after any alteration for which fuel tank ICA are 
developed under SFAR 88, or under Sec.  25.1529 in effect on June 6, 
2001, the foreign person or foreign air carrier must include in the 
maintenance program for the airplane inspections and procedures for the 
fuel tank system based on those ICA.
    (f) The fuel tank system maintenance program changes identified in 
paragraphs (d) and (e) of this section and any later fuel tank system 
revisions must be submitted to the Principal Inspector or Flight 
Standards International Field Office responsible for review and 
approval.
    (g) This section does not apply to the following airplane models:

(1) Bombardier CL-44
(2) Concorde
(3) deHavilland D.H. 106 Comet 4C
(4) VFW-Vereinigte Flugtechnische Werk VFW-614
(5) Illyushin Aviation IL 96T
(6) Bristol Aircraft Britannia 305
(7) Handley Page Herald Type 300
(8) Avions Marcel Dassault--Breguet Aviation Mercure 100C
(9) Airbus Caravelle
(10) Lockheed L-300

    Issued in Washington, DC, on October 22, 2007.
Robert A. Sturgell,
Acting Administrator.
[FR Doc. E7-21434 Filed 11-7-07; 8:45 am]

BILLING CODE 4910-13-P