
[Federal Register: May 8, 2008 (Volume 73, Number 90)]
[Rules and Regulations]               
[Page 25977-25984]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08my08-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28385; Directorate Identifier 2006-NM-181-AD; 
Amendment 39-15513; AD 2008-10-07]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP 
Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-
200F, 747-300, 747SR, and 747SP series airplanes. This AD requires 
revising the FAA-approved maintenance program by incorporating new 
airworthiness limitations (AWLs) for fuel tank systems to satisfy 
Special Federal Aviation Regulation No. 88 requirements. This AD also 
requires the initial inspection of

[[Page 25978]]

certain repetitive AWL inspections to phase in those inspections, and 
repair if necessary. 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 a fuel tank explosion and 
consequent loss of the airplane.

DATES: This AD is effective June 12, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 12, 
2008.

ADDRESSES: 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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Sulmo Mariano, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6501; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
all Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 
747-200F, 747-300, 747SR, and 747SP series airplanes. That NPRM was 
published in the Federal Register on July 3, 2007 (72 FR 36380). That 
NPRM proposed to require revising the FAA-approved maintenance program 
by incorporating new airworthiness limitations (AWLs) for fuel tank 
systems to satisfy Special Federal Aviation Regulation No. 88 
requirements. That NPRM also proposed to require the initial inspection 
of certain repetitive AWL inspections to phase in those inspections, 
and repair if necessary.

Actions Since NPRM Was Issued

    Since we issued the NPRM, Boeing has issued the Boeing 747-100/200/
300/SP Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D6-13747-CMR, Revision March 2008 (hereafter 
referred to as ``Revision March 2008 of Document D6-13747-CMR''). (For 
the purposes of Revision March 2008 of Document D6-13747-CMR, the Model 
747SR series airplane is basically a Model 747-100 series airplane with 
certain modifications to improve fatigue life.) The NPRM referred to 
Revision March 2006 of Document D6-13747-CMR as the appropriate source 
of service information for accomplishing the proposed actions. Revision 
March 2008 of Document D6-13747-CMR includes the following changes:
     Removes the repetitive task interval of 36,000 flight 
hours from AWLs No. 28-AWL-01, No. 28-AWL-03, and No. 28-AWL-13.
     Revises AWL No. 28-AWL-03 to reflect the new maximum loop 
resistance values associated with the lightning protection of the 
unpressurized fuel quantity indicating system (FQIS) wire bundle 
installations, and removes the joint resistance values.
     Revises AWL No. 28-AWL-06 to correct the numerical value 
given in milliohms for the bonding measurement.
    We have revised paragraphs (f), (g), and (h) of this AD to refer to 
Revision March 2008 of Document D6-13747-CMR. We also have removed 
reference to 36,000 total flight cycles from Table 1 of this AD and 
revised the initial threshold for accomplishing AWLs No. 28-AWL-01, No. 
28-AWL-03, and No. 28-AWL-13 to within 144 months since the date of 
issuance of the original standard airworthiness certificate or the date 
of issuance of the original export certificate of airworthiness. (The 
NPRM incorrectly specified 36,000 total ``flight cycles'' instead of 
``flight hours.'')
    We also have added a new paragraph (j) to this AD specifying that 
actions done before the effective date of this AD in accordance with 
Revisions March 2006 through January 2008 of Document D6-13747-CMR are 
acceptable for compliance with the corresponding requirements of 
paragraphs (g) and (h) of this AD.
    Operators should note that we have revised paragraph (g) of this AD 
to require incorporating only AWLs No. 28-AWL-01 through No. 28-AWL-19 
inclusive. AWLs No. 28-AWL-20, No. 28-AWL-21, and No. 28-AWL-22 were 
added in Revision January 2007 of Document D6-13747-CMR, and AWL No. 
28-AWL-23 was added in Revision September 2007 of Document D6-13747-
CMR. We issued a separate NPRM that proposes to incorporate AWL No. 28-
AWL-20 into the FAA-approved maintenance program. That NPRM (Docket No. 
FAA-2008-0091) was published in the Federal Register on January 31, 
2008 (73 FR 5770). We also issued a separate NPRM (Docket No. FAA-2008-
0090) that proposes to incorporate AWL No. 28-AWL-21 into the FAA-
approved maintenance program. That NPRM was published in the Federal 
Register on January 31, 2008 (73 FR 5773). We might issue additional 
rulemaking to require the incorporation of AWLs No. 28-AWL-22 and No. 
28-AWL-23. However, as an optional action, operators may incorporate 
those AWLs as specified in paragraph (g) of this AD.

Other Changes Made to This AD

    We have revised paragraph (h) of this AD to clarify that the 
actions identified in Table 1 of this AD must be done at the compliance 
time specified in that table. Also, for standardization purposes, we 
have revised this AD in the following ways:
     We have added a new paragraph (i) to this AD to specify 
that no alternative inspections, inspection intervals, or critical 
design configuration control limitations (CDCCLs) may be used unless 
they are part of a later approved revision of Revision March 2008 of 
Document D6-13747-CMR, 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 1 of this AD to clarify that an 
operator must request approval for an AMOC if the operator cannot 
accomplish the required inspections because an airplane has been 
previously modified, altered, or repaired in the areas addressed by the 
required inspections.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the six commenters.

Request To Allow Inspections Done According to a Maintenance Program

    Japan Airlines (JAL) requests that we revise paragraph (h) of the 
NPRM to allow an operator to update its FAA-

[[Page 25979]]

approved maintenance program to include the initial inspections and 
repair for certain AWLs. JAL states that the 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.
    The compliance times specified in paragraph (h) of this AD are 
intended to provide a grace period for those airplanes that have 
already exceeded the specified threshold in Document D6-13747-CMR. To 
be in compliance with the recording requirements of this AD, operators 
must record their compliance with the initial inspection for those 
airplanes over the specified threshold. We have revised paragraph (h) 
of this AD to specify that accomplishing the applicable AWLs as part of 
an FAA-approved maintenance program before the applicable compliance 
time constitutes compliance with the applicable requirements of that 
paragraph.

Request To Revise Intervals for Certain AWL Inspections

    KLM Royal Dutch Airlines (KLM), on behalf of several operators, 
requests that we review a 45-page proposal to align certain 
airworthiness limitation item (ALI) intervals with the applicable 
maintenance significant item (MSI) and enhanced zonal analysis 
procedure (EZAP) intervals for Model 737, 747, 757, 767, and 777 
airplanes. The recommendations in that proposal ensure that the ALI 
intervals align with the maintenance schedules of the operators. Among 
other changes, the proposal recommends revising certain AWL inspection 
intervals from 12 years/36,000 flight hours to only 12 years for Model 
747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 
747SR, and 747SP series airplanes.
    Qantas Airways also requests that the 36,000-flight-hour parameter 
be removed from the inspection interval for AWL No. 28-AWL-01, No. 28-
AWL-03, and No. 28-AWL-13. The commenter states that the flight-hour 
parameter does not adequately take into account actual airplane usage, 
and that the long haul utilization of the airplane is 5,000 flight 
hours per year. Based on this number, the commenter states that the AWL 
tasks would be required at 7.2 years instead of 12 years.
    Qantas Airways and TradeWinds Airlines both note an inconsistency 
between the inspection interval specified in Revision March 2006 of 
Document D6-13747-CMR and the compliance threshold specified in Table 1 
of the NPRM. Table 1 of the NPRM specifies accomplishing the initial 
inspection within 36,000 total flight cycles or 144 months 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. TradeWinds Airlines requests 
that we revise the compliance threshold to 36,000 ``total flight 
hours.'' However, Qantas Airways would welcome the change from ``flight 
hours'' to ``flight cycles,'' if the flight-hour parameter is not 
deleted from the inspection intervals specified in Revision March 2006 
of Document D6-13747-CMR.
    We have reviewed the commenter's requests, and we agree to revise 
the compliance threshold for certain AWLs identified by KLM and Qantas 
Airways. As stated previously, Revision March 2008 of Document D6-
13747-CMR specifies a repetitive interval of 144 months. We have 
revised the threshold specified in Table 1 of this AD accordingly.

Request To Harmonize Task Descriptions

    JAL states that, in Revision March 2006 of Document D6-13747-CMR, 
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.
    We agree that the task descriptions for AWL Nos. 28-AWL-01 and 28-
AWL-02 should be harmonized. Revision March 2008 of Document D6-13747-
CMR includes a revised task description of AWL No. 28-AWL-01, which 
addresses JAL's comments. As stated previously, we have revised this AD 
to refer to Revision March 2008 of Document D6-13747-CMR.

Request To Revise the Loop Resistance Values for AWL No. 28-AWL-03

    Boeing, KLM, and Qantas Airways state that the loop resistance 
values for AWL No. 28-AWL-03 specified in Revision March 2006 of 
Document D6-13747-CMR are going to be revised, since those values are 
relevant for production airplanes. The commenters also state that the 
revised values will be more representative of the expected values for 
in-service airplanes. Boeing points out that, according to paragraph 
(h) of the NPRM, the revised values should be able to be used in 
accordance with a later revision of Revision March 2006 of Document D6-
13747-CMR if the revision is approved by the Seattle Aircraft 
Certification Office (ACO), FAA.
    We agree that operators may use the revised loop resistance values 
for AWL No. 28-AWL-03 in accordance with Revision March 2008 of 
Document D6-13747-CMR. As stated previously, we have revised this AD 
accordingly.

Request To Clarify Use of Equivalent Tools and Chemicals

    JAL requests that we provide guidelines for using equivalent tools 
and chemical materials according to the component maintenance manuals 
(CMMs). JAL states that normally operators can use equivalents without 
FAA approval when the CMM specifies that equivalents may be used. JAL 
also states that it has received further clarification from Boeing 
specifying that unless a CDCCL refers to a certain tool by part number 
or certain chemicals by name, an operator can continue to use 
equivalent tools or materials according to the CMMs.
    We acknowledge the commenter's request and are working with Boeing 
to provide appropriate flexibility while still ensuring that items 
critical for maintaining safety continue to be specifically identified 
in the CMMs. However, to delay issuance of this AD would be 
inappropriate.
    We agree that when the CMMs allow use of equivalent tools or 
chemical materials, operators and repair stations may use equivalents. 
We have already approved the use of the CMMs at the revision levels 
specified in Revision March 2008 of Document D6-13747-CMR, including 
the use of equivalent tools or chemicals where the CMMs state 
equivalents are allowed. If the CMM does not allow use of an 
equivalent, none may be used. No change to this AD is necessary in this 
regard.

Request To Revise Appendix 1

    Boeing requests that we revise Appendix 1 of the NPRM as follows: 
(1) Correct the ATA section for AWL No. 28-AWL-03, (2) add an airplane 
maintenance manual (AMM) task title for AWL No. 28-AWL-08, and (3) add 
an ATA section for AWL No. 28-AWL-18.

[[Page 25980]]

    JAL requests that we update Appendix 1 of the NPRM to include all 
AWLs specified in the CMR, and that we indicate how to maintain the 
latest version of Appendix 1. JAL also requests that we correct the 
following error in Appendix 1 of the NPRM: For AWL No. 28-AWL-04, 
change ``SWPM 20-10-15'' to ``SWPM 20-10-13.''
    We disagree with revising the AMM references, since we have deleted 
Appendix 1 from this AD. 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 appendices 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 March 2008 of Document D6-13747-CMR contains most of 
the updated information that is listed in Appendix 1 of the NPRM. 
Therefore, we have removed Appendix 1 from this AD.

Request To Revise Note 1

    Boeing requests that we revise Note 1 of the 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 AWLs might be required if an operator has previously 
modified, altered, or repaired the areas addressed by the limitations. 
Boeing requests that we revise Note 1 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 clarified the language in Note 1 of 
this AD 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 AD is necessary in this regard.

Request To Extend the Grace Period for AWL No. 28-AWL-03

    KLM expects to have problems accomplishing the initial inspection 
of AWL No. 28-AWL-03 within the 24-month grace period. KLM states that 
if it does the check and does not reach the specified values, then tank 
entry outside of heavy maintenance would be necessary. KLM also states 
that it would be helpful to plan to do this inspection during an 
overhaul.
    We infer that KLM requests that we extend the grace period for AWL 
No. 28-AWL-03 in Table 1 of this AD to allow accomplishing the initial 
inspection during a regularly scheduled ``D'' check (about 6 years). We 
disagree with extending the grace period to 6 years. In developing an 
appropriate compliance time for this action, we considered the safety 
implications, the rate of lightning strikes in the fleet, and the 
average age of the fleet. In consideration of these items, we have 
determined that an initial compliance time of 144 months (as discussed 
previously) with a grace period of 24 months will ensure an acceptable 
level of safety. We have not changed the grace period for AWL No. 28-
AWL-03 in this regard.

Request To Extend the Exceptional Short-Term Extension

    Qantas Airways requests that we allow exceptional short-term 
extensions of 10 percent of the task interval or 6 months, whichever is 
less, for AWL tasks. The commenter believes that the exceptional short-
term extension of 30 days, which is specified in Revision March 2006 of 
Document D6-13747-CMR, is too small for AWL tasks having 12-year 
intervals. The commenter states that, as part of the Boeing 747 
Corrosion Prevention and Control Program mandated by AD 90-25-05, 
amendment 39-6790 (55 FR 49268, November 27, 1990), operators were 
given a provision to invoke exceptional short-term extensions of 10 
percent of the task interval or 6 months, whichever is less. The 
commenter states that this is a more appropriate magnitude because 
operators are often permitted one-time exceptional extensions to 
maintenance checks and tasks of this proportion. The commenter also 
states that limiting the extension period to 30 days means that a ``D'' 
check can never be extended by more than 30 days, which would force 
operators to do certain AWL inspections outside of a ``D'' check.
    We disagree with the commenter's request because exceptional short-
term extensions are, in essence, pre-approved extensions without 
Seattle ACO review of the specifics of the situation. We consider that 
the ability to extend the interval without further approval for 30 days 
should be sufficient for most circumstances. However, if an operator 
finds that it needs an extension longer than 30 days, with appropriate 
justification one may be requested from the Seattle ACO, or governing 
regulatory authority. Longer extensions may be granted on a case-by-
case basis because, as Qantas Airways points out, the task interval is 
long, and the FAA is interested in limiting out-of-sequence work. We 
have not changed this AD in this regard.

Request To Require Latest Revision of the AMM

    JAL requests that we revise the NPRM to require incorporation of 
the latest revision of the manufacturer's AMM. JAL asserts that we have 
allowed Boeing to include statements in the Boeing AMM allowing 
operators to use certain CMM revision levels or later revisions. JAL 
states that, with the exception of the CMM, operators cannot find what 
revision level of the AMM needs to be incorporated into the operator's 
AMM in order to comply with the proposed requirements of the NPRM. JAL 
also states that it could take several weeks to incorporate the 
manufacturer's AMM.
    JAL further requests that we clarify whether it is acceptable to 
change the procedures in the AMM with Boeing's acceptance. JAL states 
that the CMR notes that any use of parts, methods, techniques, or 
practices not contained in the applicable CDCCL and AWL inspection must 
be approved by the FAA office that is responsible for the airplane 
model type certificate, or applicable regulatory agency. JAL also 
states that the Boeing AMM or CMM notes to obey the manufacturer's 
procedures when doing maintenance that affects a CDCCL or AWL 
inspection. However, JAL believes that according to the NPRM it is 
acceptable to change the AMM procedures with Boeing's acceptance.
    We disagree with the changes proposed by the commenter. This AD 
does not require revising the AMM. This AD does require revising your 
maintenance program to incorporate the AWLs identified in Revision 
March 2008 of Document D6-13747-CMR. However, complying with the AWL 
inspections or CDCCLs will require other actions by operators including 
AMM revisions. In the U.S., operators are not required to use original 
equipment manufacturer (OEM) maintenance manuals. Operators may develop 
their own manuals, which are reviewed and accepted by the FAA Flight 
Standards Service. In order to maintain that flexibility for operators, 
most of the AWLs contain all of the critical information, such as 
maximum bonding resistances and minimum separation requirements. The 
FAA Flight Standards Service will only accept operator manuals that 
contain all of the information specified in the AWLs, so there is no 
need to require

[[Page 25981]]

operators to use the OEM maintenance manuals.
    Regarding JAL's request for clarification of approval of AWL 
changes, we infer JAL is referring to the following sentence located in 
the ``Changes to AMMs Referenced in Fuel Tank System AWLs'' section of 
the NPRM: ``A maintenance manual change to these tasks may be made 
without approval by the Manager, Seattle ACO, through an appropriate 
FAA principal maintenance inspector (PMI) or principal avionics 
inspector (PAI), by the governing regulatory authority, or by using the 
operator's standard process for revising maintenance manuals.'' If 
changes need to be made to tasks associated with an AWL, they may be 
made using an operator's normal process without approval of the Seattle 
ACO, as long as the change maintains the information specified in the 
AWL. For some CDCCLs, it was beneficial to not put all the critical 
information into the CMR. This avoids duplication of a large amount of 
information. In these cases, the CDCCL refers to a specific revision of 
the CMM. U.S. operators are required to use those CMMs. Any changes to 
the CMMs must be approved by the Seattle ACO.

Request To Delete Reference to Task Cards

    All Nippon Airways (ANA) requests that we delete the words ``and 
task cards,'' unless the task card references are listed in Section D 
of Document D6-13747-CMR or Appendix 1 of the AD. Those words are 
located in the following sentence in the ``Ensuring Compliance with 
Fuel Tank System AWLs'' section of the NPRM: ``Operators that do not 
use Boeing's revision service should revise their maintenance manuals 
and task cards to highlight actions tied to CDCCLs to ensure that 
maintenance personnel are complying with the CDCCLs.'' ANA believes 
that if a task card refers to the AMM, which includes the CDCCL note, 
then highlighting the CDCCL items is not necessary because they are 
already highlighted in the AMM and maintenance personnel always refer 
to the AMM. ANA further states that the applicable task card references 
are not listed in Section D of Document D6-13747-CMR, or in Appendix 1 
of the NPRM; they refer only to the AMM. ANA, therefore, states that it 
is difficult to find out or distinguish the affected task card.
    JAL believes that the proposed requirement regarding the CDCCLs is 
to incorporate the manufacturer's maintenance manuals into an 
operator's maintenance manual. If the description of a CDCCL is missing 
from the manufacturer's AMM, then JAL believes that operators are not 
responsible for the requirements of the AD.
    We agree that the task cards might not need to be revised because 
an operator might find that the AMM notes are sufficient. However, we 
disagree with deleting the reference to the task cards since some 
operators might need to add notes to their task cards. This AD does not 
require any changes to the maintenance manuals or task cards. The AD 
requires incorporating new AWLs into the operator's maintenance 
program. It is up to the operator to determine how best to ensure 
compliance with the new AWLs. In the ``Ensuring Compliance with Fuel 
Tank System AWLs'' section of the NPRM, we were only suggesting, not 
requiring, ways that an operator could implement CDCCLs into its 
maintenance program. We have not changed this AD in this regard.

Request To Clarify Meaning of Task Cards

    JAL requests that we clarify whether ``task cards,'' as found in 
the ``Recording Compliance with Fuel Tank System AWLs'' section of the 
NPRM, means Boeing task cards only or if they also include an 
operator's unique task cards.
    We intended that ``task cards'' mean both Boeing and an operator's 
unique task cards, as applicable. The intent is to address whatever 
type of task cards are used by mechanics for maintenance. This AD would 
not require any changes to the AMMs or task cards relative to the 
CDCCLs. We are only suggesting ways an operator might implement CDCCLs 
into its maintenance program. No change to this AD is necessary in this 
regard.

Request To Delete Reference to Parts Manufacturer Approval (PMA) Parts

    ANA requests that we delete the words ``Any use of parts (including 
the use of parts manufacturer approval (PMA) approved parts),'' unless 
a continuous supply of CMM specified parts is warranted or the FAA is 
open 24 hours to approve alternative parts for in-house repair by the 
operator. Those words are located in the following sentence in the 
``Changes to CMMs Cited in Fuel Tank System AWLs'' section of the NPRM: 
``Any use of parts (including the use of parts manufacturer approval 
(PMA) approved parts), methods, techniques, and practices not contained 
in the CMMs needs to be approved by the Manager, Seattle ACO, or 
governing regulatory authority.''
    ANA states that in some cases the parts specified in the CMMs 
cannot be obtained from the parts market or directly from the component 
vendor, so an operator is forced into using alternative parts to keep 
its schedule. ANA requests that we direct the component vendor to 
ensure a continuous supply of CMM parts and to direct the component 
vendor to remedy a lack of parts if parts are not promptly supplied. 
ANA further requests that we direct the component vendor to promptly 
review the standard parts and allow use of alternative fasteners and 
washers listed in Boeing D590. ANA asserts that, in some cases, a 
component vendor specifies the uncommon part to preserve its monopoly.
    We disagree with revising the ``Changes to CMMs Cited in Fuel Tank 
System AWLs'' section of the NPRM. We make every effort to identify 
potential problems with the parts supply, and we are not aware of any 
problems at this time. The impetus to declare overhaul and repair of 
certain fuel tank system components as CDCCLs arose from in-service 
pump failures that resulted from repairs not done according to OEM 
procedures. We have approved the use of the CMMs--including parts, 
methods, techniques, and practices--at the revision levels specified in 
Revision March 2008 of Document D6-13747-CMR. Third-party spare parts, 
such as parts approved by PMA, have not been reviewed.
    An operator may submit a request to the Seattle ACO, or governing 
regulatory authority, for approval of an AMOC if sufficient data are 
submitted to substantiate that use of an alternative part would provide 
an acceptable level of safety. The CDCCLs do not restrict where repairs 
can be performed, so an operator may do the work in-house as long as 
the approved CMMs are followed. If operators would like to change those 
procedures, they can request approval of the changes. The FAA makes 
every effort to respond to operators' requests in a timely manner. If 
there is a potential for disrupting the flight schedule, the operator 
should include that information in its request. Operators should 
request approval for the use of PMA parts and alternative procedures 
from the FAA or the governing regulatory authority in advance in order 
to limit schedule disruptions. We have not changed this AD in this 
regard.

Request To Identify Other Test Equipment

    JAL states that certain test equipment is designated in the CMR and 
that additional equipment should also be designated. For example, AWL 
No. 28-AWL-03 would require using loop

[[Page 25982]]

resistance tester, part number (P/N) 906-10246-2 or -3. Therefore, JAL 
requests that we also identify alternative test equipment, so that 
operators do not need to seek an AMOC to use other equipment.
    We disagree with identifying other test equipment. We cannot 
identify every possible piece of test equipment. We ensure that some 
are listed as recommended by the manufacturer. With substantiating 
data, operators can request approval of an alternative tester from the 
Seattle ACO, or the governing regulatory agency. We have not changed 
this AD in this regard.

Request to Clarify AWL No. 28-AWL-02

    JAL requests that we clarify the intent of AWL No. 28-AWL-02. JAL 
states that Chapters 53-01 and 53-21 of the Boeing 747 AMM specify 
doing an inspection of the external wires over the center fuel tank 
according to AMM 28-11-00 before installing the floor panel over the 
center wing tank based on AWL No. 28-AWL-02. JAL also states that, 
according to Revision March 2006 of Document D6-13747-CMR, AWL No. 28-
AWL-02 contains two limitations: maintaining the existing wire bundle 
routing and clamping, and installing any new wire bundle per the Boeing 
standard wiring practices manual (SWPM). Therefore, JAL believes it is 
not necessary to inspect the external wires over the center fuel tank 
according to AMM 28-11-00 before installing the floor panel over the 
center wing tank, unless that wire bundle routing and clamping are 
changed.
    We point out that AWL No. 28-AWL-02 also contains a third 
limitation: Verifying that all wire bundles over the center fuel tank 
are inspected according to AWL No. 28-AWL-01, which refers to AMM 28-
11-00 for accomplishing the inspection. We do not agree that the 
inspection should be required only if the wire bundle routing and 
clamping are changed while maintenance is accomplished in the area. If 
any of the other bundles have a clamp or routing failure, it must be 
detected and corrected. After accomplishing the inspection required by 
AWL No. 28-AWL-01, an operator would not need to repeat the inspection 
for another 12 years. No change to this AD is necessary in this regard.

Request for Clarification for Recording Compliance With CDCCLs

    JAL requests that we clarify the following sentence: ``An entry 
into an operator's existing maintenance record system for corrective 
action is sufficient for recording compliance with CDCCLs, as long as 
the applicable maintenance manual and task cards identify actions that 
are CDCCLs.'' That sentence is located in the ``Recording Compliance 
with Fuel Tank System AWLs'' section of the NPRM. Specifically, JAL 
asks whether an operator must indicate the CDCCL in their recording 
documents or whether it is sufficient for the recording document to 
call out the applicable AMMs that are tied to the CDCCLs.
    We have coordinated with the FAA Flight Standards Service and it 
agrees that, for U.S.-registered airplanes, if the applicable AMMs and 
task cards identify the CDCCL, then the entry into the recording 
documents does not need to identify the CDCCL. However, if the 
applicable AMMs and tasks cards do not identify the CDCCL, then they 
must be identified. Other methods may be accepted by the appropriate 
FAA PMI or PAI, or governing regulatory authority. No change to this AD 
is necessary in this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We also determined that 
these changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    There are about 308 airplanes of the affected design in the 
worldwide fleet. 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 AD.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                  Number of U.S.-
              Action                 Work           Parts            Cost per       registered      Fleet cost
                                    hours                            airplane        airplanes
----------------------------------------------------------------------------------------------------------------
Maintenance program revision.....        8  None................            $640              93         $59,520
Inspections......................        8  None................             640              93          59,520
----------------------------------------------------------------------------------------------------------------

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator,

[[Page 25983]]

the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-10-07 Boeing: Amendment 39-15513. Docket No. FAA-2007-28385; 
Directorate Identifier 2006-NM-181-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective June 12, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP 
series airplanes, certificated in any category.

    Note 1: 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 (k) 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.

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 a fuel tank explosion 
and consequent loss of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Service Information Reference

    (f) The term ``Revision March 2008 of Document D6-13747-CMR,'' 
as used in this AD, means Boeing 747-100/200/300/SP Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D6-13747-CMR, Revision March 2008. (For the purposes of 
Revision March 2008 of Document D6-13747-CMR, the Model 747SR series 
airplane is basically a Model 747-100 series airplane with certain 
modifications to improve fatigue life.)

Maintenance Program Revision

    (g) Before December 16, 2008, revise the FAA-approved 
maintenance program to incorporate the information in Section D, 
``AIRWORTHINESS LIMITATIONS--SYSTEMS,'' AWLs No. 28-AWL-01 through 
No. 28-AWL-19 inclusive, of Revision March 2008 of Document D6-
13747-CMR; except that the initial inspections required by paragraph 
(h) of this AD must be done at the applicable compliance time 
specified in that paragraph. As an optional action, AWLs No. 28-AWL-
20 through No. 28-AWL-23 inclusive, as identified in Section D of 
Revision March 2008 of Document D6-13747-CMR, also may be 
incorporated into the FAA-approved maintenance program. 
Accomplishing the revision in accordance with a later revision of 
Document D6-13747-CMR is an acceptable method of compliance if the 
revision is approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA.

Initial Inspections and Repair if Necessary

    (h) Do the inspections specified in Table 1 of this AD at the 
compliance time specified in Table 1 of this AD, and repair any 
discrepancy, in accordance with Section D of Revision March 2008 of 
Document D6-13747-CMR. The repair must be done before further 
flight. Accomplishing the actions required by this paragraph in 
accordance with a later revision of Document D6-13747-CMR is an 
acceptable method of compliance if the revision is approved by the 
Manager, Seattle ACO. Accomplishing the inspections identified in 
Table 1 of this AD as part of an FAA-approved maintenance program 
before the applicable compliance time specified in Table 1 of this 
AD constitutes compliance with the requirements of this paragraph.

    Note 2: 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.''


    Note 3: 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.''


                                          Table 1.--Initial Inspections
----------------------------------------------------------------------------------------------------------------
                                                                    Compliance Time  (whichever occurs later)
               AWL No.                       Description       -------------------------------------------------
                                                                       Threshold               Grace period
----------------------------------------------------------------------------------------------------------------
28-AWL-01............................  A detailed inspection    Within 144 months since  Within 72 months after
                                        of external wires over   the date of issuance     the effective date of
                                        the center fuel tank     of the original          this AD.
                                        for damaged clamps,      standard airworthiness
                                        wire chafing, and wire   certificate or the
                                        bundles in contact       date of issuance of
                                        with the surface of      the original export
                                        the center fuel tank.    certificate of
                                                                 airworthiness.
28-AWL-03............................  A special detailed       Within 144 months since  Within 24 months after
                                        inspection of the        the date of issuance     the effective date of
                                        lightning shield to      of the original          this AD.
                                        ground termination on    standard airworthiness
                                        the out-of-tank fuel     certificate or the
                                        quantity indicating      date of issuance of
                                        system to verify         the original export
                                        functional integrity.    certificate of
                                                                 airworthiness.
28-AWL-13............................  A special detailed       Within 144 months since  Within 60 months after
                                        inspection of the        the date of issuance     the effective date of
                                        fault current bond of    of the original          this AD.
                                        the fueling shutoff      standard airworthiness
                                        valve actuator of the    certificate or the
                                        center wing tank to      date of issuance of
                                        verify electrical bond.  the original export
                                                                 certificate of
                                                                 airworthiness.
----------------------------------------------------------------------------------------------------------------

No Alternative Inspections, Inspection Intervals, or Critical Design 
Configuration Control Limitations (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 March 2008 of 
Document D6-13747-CMR that is approved by the Manager, Seattle ACO; 
or unless the inspections, intervals, or CDCCLs are approved as an 
AMOC in accordance with the procedures specified in paragraph (k) of 
this AD.

[[Page 25984]]

Credit for Actions Done According to Previous Revisions of the Service 
Information

    (j) Actions done before the effective date of this AD in 
accordance with Boeing 747-100/200/300/SP Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-
CMR, Revision March 2006; Revision May 2006; Revision December 2006; 
Revision January 2007; Revision September 2007; or Revision January 
2008; are acceptable for compliance with the corresponding 
requirements of paragraphs (g) and (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with 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.

Material Incorporated by Reference

    (l) You must use Boeing 747-100/200/300/SP Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements 
(CMRs), D6-13747-CMR, Revision March 2008, to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on April 28, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-9896 Filed 5-7-08; 8:45 am]

BILLING CODE 4910-13-P
