Document ID: FAA-2007-28386-0013
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes
Posted Date: 2008-05-08T04:00Z

[Federal Register: May 8, 2008 (Volume 73, Number 90)]
[Rules and Regulations]               
[Page 25990-25997]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08my08-9]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28386; Directorate Identifier 2006-NM-162-AD; 
Amendment 39-15512; AD 2008-10-06]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-400, -400D, and -400F 
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 certain 
Boeing Model 747-400, -400D, and -400F 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 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

[[Page 25991]]

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 
certain Boeing Model 747-400, -400D, and -400F series airplanes. That 
NPRM was published in the Federal Register on July 3, 2007 (72 FR 
36385). 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 Temporary Revision (TR) 
09-010, dated March 2008. Boeing TR 09-010 is published as Section 9 of 
the Boeing 747-400 Maintenance Planning Data (MPD) Document, D621U400-
9, Revision March 2008 (hereafter referred to as ``Revision March 2008 
of the MPD''). The NPRM referred to Revision March 2006 of the MPD as 
the appropriate source of service information for accomplishing the 
proposed actions. Revision March 2008 of the MPD, among other actions, 
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-10.
     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.
     Adds new AWLs No. 28-AWL-30, No. 28-AWL-31, and No. 28-
AWL-32 to incorporate new critical design configuration control 
limitations (CDCCLs) for the electronic fuel level indication system 
(EFLI) for Model 747-400 series airplanes equipped with an auxiliary 
fuel tank.
    Accordingly, we have revised paragraphs (f), (g), and (h) of this 
AD to refer to Revision March 2008 of the MPD. 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-10 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 (k) to this AD specifying that 
actions done before the effective date of this AD in accordance with 
Revisions March 2006 through November 2007 of the MPD 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)(3) of this 
AD to require incorporating only AWLs No. 28-AWL-01 through No. 28-AWL-
23 inclusive. AWLs No. 28-AWL-24, No. 28-AWL-25, No. 28-AWL-26, No. 28-
AWL-27, No. 28-AWL-28, and No. 28-AWL-29 were added in other revisions 
of the MPD after March 2006 and before March 2008. We have issued a 
separate NPRM that proposes to incorporate AWL No. 28-AWL-25 into the 
FAA-approved maintenance program. We have also issued a separate NPRM 
that proposes to incorporate AWL No. 28-AWL-27 into the FAA-approved 
maintenance program. Those NPRMs were published in the Federal Register 
on January 31, 2008 (73 FR 5770 and 5773, respectively). We might issue 
additional rulemaking to require the incorporation of AWLs No. 28-AWL-
24, No. 28-AWL-26, No. 28-AWL-28, and No. 28-AWL-29. However, as an 
optional action, operators may incorporate those AWLs as specified in 
paragraph (g)(3) of this AD.
    Further, we have added a new paragraph (i) to this AD, which 
requires the incorporation of AWLs No. 28-AWL-30, No. 28-AWL-31, and 
No. 28-AWL-32 on Model 747-400 series airplanes equipped with an 
auxiliary fuel tank. Since none of these airplanes are on the U.S. 
Register, this change does not impose an additional burden on any U.S. 
operators.

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 (j) to this AD to specify 
that no alternative inspections, inspection intervals, or CDCCLs may be 
used unless they are part of a later approved revision of Revision 
March 2008 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 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-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 the MPD. 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

[[Page 25992]]

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 
747-400, -400D, and -400F 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-10. 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 to 6,000 
flight hours per year. Based on this number, the commenter states that 
the AWL tasks would be required at 6 years instead of 12 years.
    Qantas Airways and Lufthansa both note an inconsistency between the 
inspection interval specified in Revision March 2006 of the MPD 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. 
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 the MPD.
    We have reviewed the commenter's requests, and we agree to revise 
the compliance threshold for certain AWLs identified by the commenters. 
As stated previously, Revision March 2008 of the MPD 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 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.
    We agree that the task descriptions for AWL Nos. 28-AWL-01 and 28-
AWL-02 should be harmonized. Revision March 2008 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 AD to refer to 
Revision March 2008 of the MPD.

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

    Boeing, KLM, Lufthansa, and Qantas Airways state that the loop 
resistance values for AWL No. 28-AWL-03 specified in Revision March 
2006 of the MPD 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 the MPD 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 the 
MPD. As stated previously, we have revised this AD accordingly.

Request To Revise Estimated Costs

    Qantas Airways states that the work-hour estimates provided in the 
NPRM seem too small. The commenter has submitted its estimates for AWLs 
No. 28-AWL-01, No. 28-AWL-03, No. 28-AWL-10, No. 28-AWL-17, and No. 28-
AWL-21.
    We infer the commenter requests that we revise the ``Costs of 
Compliance'' section of this AD to reflect its estimates. We agree to 
include the work-hour estimates for the initial accomplishment of AWLs 
No. 28-AWL-01, No. 28-AWL-03, and No. 28-AWL-10 in this AD. We have not 
included the estimate for AWL No. 28-AWL-17, since this AD does not 
need to require the initial inspection of that AWL to phase in the 
inspection. The initial inspection of AWL No. 28-AWL-17 should have 
been previously accomplished as part of the existing FAA-approved 
maintenance program. We also have not included the estimate for AWL No. 
28-AWL-21 because incorporation of that AWL has been postponed, as 
specified in Revision 24, dated June 2006, of the MPD.

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 the MPD, 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) Reference an additional ATA section for AWL No. 28-AWL-02, (2) 
correct the airplane maintenance manual (AMM) task titles and numbers 
for AWL No. 28-AWL-09, (3) correct the AMM task number for AWL No. 28-
AWL-10, (4) delete certain information from the ATA section for AWL No. 
28-AWL-21, and

[[Page 25993]]

(4) add AMM task titles and numbers for AWL No. 28-AWL-23.
    JAL requests that we update Appendix 1 of the 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 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 the MPD 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 Extend the Grace Period for AWL No. 28-AWL-03

    Lufthansa and KLM expect to have problems accomplishing the initial 
inspection of AWL No. 28-AWL-03 within the 24-month grace period. The 
commenters state that if they do the check and do not reach the 
specified values, then tank entry outside of heavy maintenance would be 
necessary. The commenters also state that it would be helpful to plan 
to do this inspection during an overhaul.
    We infer that the commenters request 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 
the MPD, 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 Add Applicability to Table 1

    Lufthansa states that the applicability of AWL inspections should 
be included in Table 1 of the AD.
    We disagree because the AWL inspections listed in Table 1 of this 
AD are applicable to all airplanes identified in paragraph (c) of this 
AD. 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 MPD 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 the MPD. 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 
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

[[Page 25994]]

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 MPD. 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 Revise Note 2

    Boeing requests that we revise Note 2 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 MPD 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 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 clarified the language in Note 2 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 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 Subsection 
D of the MPD 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 Subsection D of the MPD, 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 an 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 the MPD. 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

[[Page 25995]]

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 MPD and 
that additional equipment should also be designated. For example, AWL 
No. 28-AWL-03 would require using loop 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 53-21 and 53-01 of the Boeing 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 the MPD, 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 596 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
                                                                     Cost per          U.S.-
            Action               Work hours          Parts           airplane       registered      Fleet cost
                                                                                     airplanes
----------------------------------------------------------------------------------------------------------------
Maintenance program revision.               8  None.............            $640              57         $36,480
Initial accomplishment of AWL               6  None.............             480              57          27,360
 28-AWL-01.
Initial accomplishment of AWL              32  None.............           2,560              57         145,920
 28-AWL-03.
Initial accomplishment of AWL               2  None.............             180              57           9,120
 28-AWL-10.
----------------------------------------------------------------------------------------------------------------

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

[[Page 25996]]

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, 
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:

2008-10-06 Boeing: Amendment 39-15512. Docket No. FAA-2007-28386; 
Directorate Identifier 2006-NM-162-AD.

Effective Date

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

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-400, -400D, and -400F 
series airplanes, certificated in any category; with an original 
standard airworthiness certificate or original export certificate of 
airworthiness issued before April 12, 2006.

    Note 1: Airplanes with an original standard airworthiness 
certificate or original export certificate of airworthiness issued 
on or after April 12, 2006, must be already in compliance with the 
airworthiness limitations 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 (l) 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 the MPD,'' as used in this 
AD, means Boeing Temporary Revision (TR) 09-010, dated March 2008. 
Boeing TR 09-010 is published as Section 9 of the Boeing 747-400 
Maintenance Planning Data (MPD) Document, D621U400-9, Revision March 
2008.

Maintenance Program Revision

    (g) Before December 16, 2008, revise the FAA-approved 
maintenance program by incorporating the information in the 
subsections specified in paragraphs (g)(1), (g)(2), and (g)(3) of 
this AD; except that the initial inspections specified in Table 1 of 
this AD must be done at the compliance times specified in Table 1. 
Accomplishing the revision in accordance with a later revision of 
the MPD is an acceptable method of compliance if the revision is 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA.
    (1) Subsection B, ``AIRWORTHINESS LIMITATIONS (AWLs)--SYSTEMS,'' 
of Revision March 2008 of the MPD.
    (2) Subsection C, ``PAGE FORMAT: FUEL SYSTEMS AIRWORTHINESS 
LIMITATIONS,'' of Revision March 2008 of the MPD.
    (3) Subsection D, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS,'' 
AWLs No. 28-AWL-01 through No. 28-AWL-23 inclusive, of Revision 
March 2008 of the MPD. As an optional action, AWLs No. 28-AWL-24 
through No. 28-AWL-29 inclusive, as identified in Subsection D of 
Revision March 2008 of the MPD, also may be incorporated into the 
FAA-approved maintenance program.

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 Subsection D of Revision March 2008 
of the MPD. The repair must be done before further flight. 
Accomplishing the actions required by this paragraph in accordance 
with a later revision of the MPD 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 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.''

    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.''

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

[[Page 25997]]

28-AWL-10.....................  A special detailed          Within 144 months since    Within 60 months after
                                 inspection of the fault     the date of issuance of    the effective date of
                                 current bond of the         the original standard      this AD.
                                 fueling shutoff valve       airworthiness
                                 actuator of the center      certificate or the date
                                 wing tank to verify         of issuance of the
                                 electrical bond.            original export
                                                             certificate of
                                                             airworthiness.
----------------------------------------------------------------------------------------------------------------

Incorporation of Additional AWLs for Certain Airplanes

    (i) For Model 747-400 series airplanes equipped with an 
auxiliary fuel tank: Before December 16, 2008, revise the FAA-
approved maintenance program by incorporating AWLs No. 28-AWL-30, 
No. 28-AWL-31, and No. 28-AWL-32 of Subsection D of Revision March 
2008 of the MPD. Accomplishing the revision in accordance with a 
later revision of the MPD is an acceptable method of compliance if 
the revision is approved by the Manager, Seattle ACO.

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

    (j) After accomplishing the applicable actions specified in 
paragraphs (g), (h), and (i) 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 the MPD 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 (l) of this 
AD.

Credit for Actions Done According to Previous Revisions of the MPD

    (k) Actions done before the effective date of this AD in 
accordance with Section 9 of the Boeing 747-400 MPD Document, 
D621U400-9, Revision 23, dated March 2006; Revision 24, dated June 
2006; Revision November 2006; Revision December 2006; Revision 
December 2006 R1; Revision May 2007; Revision October 2007; or 
Revision November 2007; are acceptable for compliance with the 
corresponding requirements of paragraphs (g) and (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (l)(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

    (m) You must use Boeing Temporary Revision 09-010, dated March 
2008, to the Boeing 747-400 Maintenance Planning Data (MPD) 
Document, D621U400-9, to do the actions required by this AD, unless 
the AD specifies otherwise. Boeing Temporary Revision 09-010 is 
published as Section 9 of the Boeing 747-400 Maintenance Planning 
Data (MPD) Document, D621U400-9, Revision March 2008.
    (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. E8-9897 Filed 5-7-08; 8:45 am]

BILLING CODE 4910-13-P