[Federal Register Volume 73, Number 40 (Thursday, February 28, 2008)]
[Proposed Rules]
[Pages 10698-10701]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-3765]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28389; Directorate Identifier 2006-NM-171-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200, -200LR, -300, and 
-300ER Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: We are revising an earlier proposed airworthiness directive 
(AD) for certain Boeing Model 777-200, -200LR, -300, and -300ER series 
airplanes. The original NPRM would have required revising the 
Airworthiness Limitations (AWLs) section of the Instructions for 
Continued Airworthiness by incorporating new limitations for fuel tank 
systems to satisfy Special Federal Aviation Regulation No. 88 
requirements. The original NPRM would also have required the initial 
performance of certain repetitive inspections specified in the AWLs to 
phase in those inspections, and repair if necessary. The original NPRM 
resulted from a design review of the fuel tank systems. This action 
revises the original NPRM by reducing the initial compliance time of 
certain repetitive inspections, adding more airplanes, and referring to 
new service information. We are proposing this supplemental NPRM to 
prevent the potential for ignition sources inside fuel tanks caused by 
latent failures, alterations, repairs, or maintenance actions, which, 
in combination with flammable fuel vapors, could result in fuel tank 
explosions and consequent loss of the airplane.

DATES: We must receive comments on this supplemental NPRM by March 19, 
2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Kathrine Rask, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6505; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-
28389; Directorate Identifier 2006-NM-171-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We issued a notice of proposed rulemaking (NPRM) (the ``original 
NPRM'') to amend 14 CFR part 39 to

[[Page 10699]]

include an airworthiness directive (AD) that would apply to certain 
Boeing Model 777-200, -200LR, -300, and -300ER series airplanes. That 
original NPRM was published in the Federal Register on July 3, 2007 (72 
FR 36373). That original NPRM proposed to require revising the 
Airworthiness Limitations (AWLs) section of the Instructions for 
Continued Airworthiness by incorporating new limitations for fuel tank 
systems to satisfy Special Federal Aviation Regulation No. 88 
requirements. That original NPRM also proposed to require the initial 
performance of certain repetitive inspections specified in the AWLs to 
phase in those inspections, and repair if necessary.

Actions Since Original NPRM Was Issued

    Since we issued the original NPRM, Boeing has issued Revision 
October 2007 of section 9 of the 777 Maintenance Planning Data (MPD) 
Document, D622W001-9 (hereafter referred to as ``Revision October 2007 
of the MPD''). The original NPRM referred to Revision March 2006 of the 
MPD as the appropriate source of service information for accomplishing 
the proposed actions. Among other actions, Revision October 2007 of the 
MPD revises the task description for AWL No. 28-AWL-01 and increases 
the repetitive interval for AWL No. 28-AWL-18. (AWL No. 28-AWL-18 was 
introduced in Revision September 2007 of the MPD). We have revised 
paragraphs (f), (g), and (h) of this supplemental NPRM to refer to 
Revision October 2007 of the MPD.
    We have also determined that more airplanes would be affected by 
this supplemental NPRM. All Model 777 airplanes with an original 
standard airworthiness certificate or original export certificate of 
airworthiness issued before December 5, 2007, are affected by this 
supplemental NPRM. Accordingly, we have revised paragraph (c) of this 
supplemental NPRM. We have also updated the ``Costs of Compliance'' 
section of this supplemental NPRM to account for the additional 
airplanes.
    In paragraphs (h)(1)(i) and (h)(2)(i) of the original NPRM, we 
inadvertently specified the compliance time as ``* * * before the 
accumulation of 36,000 total flight cycles or within 120 months. * * 
*'' The correct compliance time is 16,000 total flight cycles or within 
3,000 days, as specified in Revision October 2007 of the MPD. We have 
revised this supplemental NPRM accordingly.

Changes Made to This Supplemental NPRM

    For standardization purposes, we have revised this supplemental 
NPRM in the following ways:
     We have added a new paragraph (i) to this supplemental 
NPRM to specify that no alternative inspections, inspection intervals, 
or CDCCLs may be used unless they are part of a later approved revision 
of Revision October 2007 of the MPD, or unless they are approved as an 
alternative method of compliance (AMOC). Inclusion of this paragraph in 
the AD is intended to ensure that the AD-mandated airworthiness 
limitations changes are treated the same as the airworthiness 
limitations issued with the original type certificate.
     We have revised Note 2 of this AD to clarify that an 
operator must request approval for an AMOC if the operator cannot 
accomplish the proposed inspections because an airplane has been 
previously modified, altered, or repaired in the areas addressed by the 
proposed inspections.

Comments

    We gave the public the opportunity to participate in developing the 
original NPRM. We addressed certain comments received in this 
supplemental NPRM. The remaining comments are being evaluated and will 
be addressed in the final rule.

Request To Allow Inspections Done According to a Maintenance Program

    Japan Airlines (JAL) requests that we revise paragraph (h) of the 
original NPRM to allow an operator to update its FAA-approved 
maintenance program to include the initial inspections and repair for 
certain AWLs. JAL states that the original NPRM would require 
accomplishing the initial inspection and repair of certain AWLs, which 
would require JAL to establish a special inspection and special 
recordkeeping for the proposed requirement.
    We agree and have revised paragraphs (h)(1) and (h)(2) of this 
supplemental NPRM to specify that accomplishing the applicable AWL as 
part of an FAA-approved maintenance program before the applicable 
compliance time constitutes compliance with the applicable requirements 
of those paragraphs.

Request To Harmonize Task Descriptions

    JAL states that, in Revision March 2006 of the MPD, the task 
descriptions defining the applicable area are different for AWLs Nos. 
28-AWL-01 and 28-AWL-02. (AWL No. 28-AWL-01 is a repetitive inspection 
of the external wires over the center fuel tank, and AWL No. 28-AWL-02 
is a CDCCL to maintain the original design features for the external 
wires over the center fuel tank). JAL believes that the task 
descriptions for these AWLs should match. JAL presumes that, if one 
purpose for the inspection is to prevent a spark in the fuel vapor over 
the center fuel tank, then the applicable area should have a certain 
tolerance instead of defining the area by exact station number. JAL 
also requests that ``Sta. 1045'' be revised to ``Sta. 1245'' for AWL 
No. 28-AWL-01.
    We agree that the task descriptions for AWL Nos. 28-AWL-01 and 28-
AWL-02 should be harmonized, and that there is an error in the station 
number in the task description for AWL No. 28-AWL-01. Revision October 
2007 of the MPD includes a revised task description of AWL No. 28-AWL-
01, which addresses JAL's comments. As stated previously, we have 
revised this supplemental NPRM to refer to Revision October 2007 of the 
MPD.

Request To Add Additional References to Appendix 1

    Boeing requests that we revise Appendix 1 of the original NPRM to 
reflect the correct airplane maintenance manual (AMM) task titles and 
numbers for AWLs No. 28-AWL-02, No. 28-AWL-05, No. 28-AWL-06, No. 28-
AWL-08, No. 28-AWL-10, No. 28-AWL-12, No. 28-AWL-15, No. 28-AWL-16, No. 
28-AWL-17, and No. 28-AWL-19.
    JAL requests that we update Appendix 1 of the original NPRM to 
include all AWLs specified in the MPD, and that we indicate how to 
maintain the latest version of Appendix 1. JAL also requests that we 
correct the following errors in Appendix 1 of the original NPRM: (1) 
For AWL No. 28-AWL-04, change ``SWPM 20-10-15'' to ``SWPM 20-10-13,'' 
and (2) for AWL No. 28-AWL-15, change ``28-41-05-404-801'' to ``28-41-
05-400-801.''
    We disagree with revising the AMM references, since we have deleted 
Appendix 1 from this supplemental NPRM. The purpose of Appendix 1 was 
to assist operators in identifying the AMM tasks that could affect 
compliance with a CDCCL. However, we have also received several similar 
comments regarding the appendixes in other NPRMs that address the same 
unsafe condition on other Boeing airplanes. Those comments indicate 
that including non-required information in those NPRMs has caused 
confusion. Further, Revision October 2007 of the MPD contains most of 
the updated

[[Page 10700]]

information that is listed in Appendix 1 of the original NPRM. 
Therefore, we have removed Appendix 1 from this supplemental NPRM.

Request To Revise Note 2

    Boeing requests that we revise Note 2 of the original NPRM to 
clarify the need for an AMOC. Boeing states that the current wording is 
difficult to follow, and that the note is meant to inform operators 
that an AMOC to the required MPD AWLs may be required if an operator 
has previously modified, altered, or repaired in the areas addressed by 
limitations. Boeing requests that we revise Note 2 as follows:
     Add the words ``according to paragraph (g)'' at the end of 
the first sentence.
     Replace the words ``revision to'' with ``deviation from'' 
in the last sentence.
     Delete the words ``(g) or'' and ``as applicable'' from the 
last sentence.
    As stated previously, we have simplified the language in Note 2 of 
this supplemental NPRM for standardization with other similar ADs. The 
language the commenter requests that we change does not appear in the 
revised note. Therefore, no additional change to this supplemental NPRM 
is necessary in this regard.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    We are proposing this supplemental NPRM because we evaluated all 
pertinent information and determined an unsafe condition exists and is 
likely to exist or develop on other products of the same type design. 
Certain changes described above expand the scope of the original NPRM. 
As a result, we have determined that it is necessary to reopen the 
comment period to provide additional opportunity for the public to 
comment on this supplemental NPRM.

Costs of Compliance

    We estimate that this supplemental NPRM would affect 127 airplanes 
of U.S. registry. The following table provides the estimated costs, at 
an average labor rate of $80 per work hour, for U.S. operators to 
comply with this supplemental NPRM.

                                                 Estimated Costs
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                                                                                  Number of U.S.-
                Action                   Work         Parts          Cost per       registered      Fleet cost
                                        hours                        airplane        airplanes
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Maintenance program revision.........        8  None............            $640             127         $81,280
Inspection...........................        8  None............             640             127          81,280
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866,
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979), and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new AD:


Boeing: Docket No. FAA-2007-28389; Directorate Identifier 2006-NM-
171-AD.

Comments Due Date

    (a) We must receive comments by March 19, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200, -200LR, -300, and -
300ER series airplanes; certificated in any category; with an 
original standard airworthiness certificate or original export 
certificate of airworthiness issued before December 5, 2007.

    Note 1: Airplanes with an original standard airworthiness 
certificate or original export certificate of airworthiness issued 
on or after December 5, 2007, must be already in compliance with the 
airworthiness limitations (AWLs) specified in this AD because those 
limitations were applicable as part of the airworthiness 
certification of those airplanes.


    Note 2: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR 91.403(c). For airplanes 
that have been previously modified, altered, or repaired in the 
areas addressed by these inspections, the operator may not be able 
to accomplish the inspections described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance (AMOC) 
according to paragraph (j) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued operational safety of the airplane.


[[Page 10701]]



Unsafe Condition

    (d) This AD results from a design review of the fuel tank 
systems. We are issuing this AD to prevent the potential for 
ignition sources inside fuel tanks caused by latent failures, 
alterations, repairs, or maintenance actions, which, in combination 
with flammable fuel vapors, could result in fuel tank explosions and 
consequent loss of the airplane.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Service Information

    (f) The term ``Revision October 2007 of the MPD,'' as used in 
this AD, means Section 9 of the Boeing 777 Maintenance Planning 
Document (MPD) Document, D622W001-9, Revision October 2007.

Revision of Airworthiness Limitations (AWLs) Section

    (g) Before December 16, 2008, revise the AWLs section of the 
Instructions for Continued Airworthiness by incorporating the 
information in the sections specified in paragraphs (g)(1) and 
(g)(2) of this AD into the MPD; except that the initial inspections 
specified in paragraph (h) of this AD must be done at the compliance 
times specified in paragraph (h) of this AD.
    (1) Subsection D, ``AIRWORTHINESS LIMITATIONS--SYSTEMS, FUEL 
SYSTEMS AIRWORTHINESS LIMITATIONS,'' of Revision October 2007 of the 
MPD.
    (2) Subsection E, ``PAGE FORMAT: SYSTEMS AIRWORTHINESS 
LIMITATIONS,'' of Revision October 2007 of the MPD.

Initial Inspections and Repair

    (h) Do the inspections required by paragraphs (h)(1) and (h)(2) 
of this AD at the compliance times specified in paragraphs (h)(1) 
and (h)(2), in accordance with the applicable AWLs described in 
Subsection E, ``PAGE FORMAT: SYSTEMS AIRWORTHINESS LIMITATIONS,'' of 
Revision October 2007 of the MPD. If any discrepancy is found during 
these inspections, repair the discrepancy before further flight in 
accordance with Revision October 2007 of the MPD.
    (1) At the later of the times specified in paragraphs (h)(1)(i) 
and (h)(1)(ii) of this AD, do a detailed inspection of external 
wires over the center fuel tank for damaged clamps, wire chafing, 
and wire bundles in contact with the surface of the center fuel 
tank, and repair any discrepancy, in accordance with AWL No. 28-AWL-
01. Accomplishing AWL No. 28-AWL-01 as part of an FAA-approved 
maintenance program before the applicable compliance time specified 
in paragraph (h)(1)(i) or (h)(1)(ii) of this AD constitutes 
compliance with the requirements of this paragraph.
    (i) Before the accumulation of 16,000 total flight cycles, or 
within 3,000 days since the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, whichever occurs 
first.
    (ii) Within 72 months after the effective date of this AD.

    Note 3: For the purposes of this AD, a detailed inspection is: 
``An intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirror, magnifying lenses, etc., may be necessary. Surface cleaning 
and elaborate procedures may be required.''

    (2) At the later of the times specified in paragraphs (h)(2)(i) 
and (h)(2)(ii) of this AD, do a special detailed inspection 
(resistance test) of the lightning shield-to-ground termination of 
the out tank wiring of the fuel quantity indicating system (FQIS) 
and, as applicable, repair (restore) the bond to ensure the shield-
to-ground termination meets specified resistance values, in 
accordance with AWL No. 28-AWL-03. Accomplishing AWL No. 28-AWL-03 
as part of an FAA-approved maintenance program before the applicable 
compliance time specified in paragraph (h)(2)(i) or (h)(2)(ii) of 
this AD constitutes compliance with the requirements of this 
paragraph.
    (i) Before the accumulation of 16,000 total flight cycles, or 
within 3,000 days since the date of issuance of the original 
standard airworthiness certificate or the date of issuance of the 
original export certificate of airworthiness, whichever occurs 
first.
    (ii) Within 24 months after the effective date of this AD.

    Note 4: For the purposes of this AD, a special detailed 
inspection is: ``An intensive examination of a specific item, 
installation, or assembly to detect damage, failure, or 
irregularity. The examination is likely to make extensive use of 
specialized inspection techniques and/or equipment. Intricate 
cleaning and substantial access or disassembly procedure may be 
required.''

No Alternative Inspections, Inspection Intervals, or Critical Design 
Configuration Control Limitation (CDCCLs)

    (i) After accomplishing the actions specified in paragraphs (g) 
and (h) of this AD, no alternative inspections, inspection 
intervals, or CDCCLs may be used unless the inspections, intervals, 
or CDCCLs are part of a later revision of Revision October 2007 of 
the MPD that is approved by the Manager, Seattle Aircraft 
Certification Office (ACO); or unless the inspections, intervals, or 
CDCCLs are approved as an AMOC in accordance with the procedures 
specified in paragraph (j) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle ACO, FAA, ATTN: Kathrine Rask, 
Aerospace Engineer, Propulsion Branch, ANM-140S, 1601 Lind Avenue, 
SW., Renton, Washington 98057-3356; telephone (425) 917-6505; fax 
(425) 917-6590; has the authority to approve AMOCs for this AD, if 
requested using the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on February 20, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-3765 Filed 2-27-08; 8:45 am]
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