
[Federal Register: May 8, 2008 (Volume 73, Number 90)]
[Rules and Regulations]               
[Page 25974-25977]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08my08-5]                         

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26710; Directorate Identifier 2006-NM-147-AD; 
Amendment 39-15517; AD 2008-10-11]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 757 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 757 airplanes. This AD requires revising the Airworthiness 
Limitations (AWLs) section of the Instructions for Continued 
Airworthiness by incorporating new limitations for fuel tank systems to 
satisfy Special Federal Aviation Regulation No. 88 requirements. 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 becomes effective June 12, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the 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: Judy Coyle, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6497; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a supplemental notice of proposed rulemaking (NPRM) 
to amend 14 CFR part 39 to include an AD that would apply to all Boeing 
Model 757 airplanes. That supplemental NPRM was published in the 
Federal Register on August 1, 2007 (72 FR 41963). That supplemental 
NPRM proposed to require revising the Airworthiness Limitations (AWLs) 
section of the Instructions for Continued Airworthiness (ICA) by 
incorporating new limitations for fuel tank systems to satisfy Special 
Federal Aviation Regulation No. 88 requirements. That supplemental NPRM 
also proposed to require the initial inspection of certain repetitive 
inspections specified in the AWLs to phase-in those inspections, and 
repair if necessary. That supplemental NPRM also proposed to revise the 
original NPRM by aligning the compliance time for revising the AWLs 
section with the compliance date of the special maintenance program 
requirements, updating the listing of applicable airplane maintenance 
manuals in Appendix 1, and clarifying certain actions.

Actions Since Supplemental NPRM Was Issued

    Since we issued the supplemental NPRM, Boeing has issued Temporary 
Revision (TR) 09-008, dated March 2008. Boeing TR 09-008 is published 
as Section 9 of the Boeing 757 Maintenance Planning Document (MPD) 
Document, D622N001-9, Revision March 2008 (hereafter referred to as 
``Revision March 2008 of the MPD''). The supplemental 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 
cycles from AWLs No. 28-AWL-01, No. 28-AWL-03, and No. 28-AWL-14.
     Revises the task description for AWL No. 28-AWL-01 to 
harmonize it with AWL No. 28-AWL-02 by removing references to certain 
station numbers.
     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.
    Accordingly, we have revised paragraphs (f), (g), and (h) of this 
AD to refer to Revision March 2008 of the MPD. 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 November 2007 of the MPD are acceptable for compliance with the 
corresponding requirements of paragraphs (g) and (h) of this AD.
    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-14 to within 120 
months since the date of issuance of the original standard 
airworthiness certificate or the date of issuance of the original 
export certificate of airworthiness.

[[Page 25975]]

    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-24 
inclusive. AWL No. 28-AWL-25 was added in Revision October 2006 of the 
MPD, and AWL No. 28-AWL-26 was added in Revision January 2007 of the 
MPD. However, as an optional action, operators may incorporate those 
AWLs as specified in paragraph (g) of this AD.
    We have issued a separate NPRM (Docket No. FAA-2007-28598) that, in 
part, proposes to incorporate AWLs No. 28-AWL-20 and No. 28-AWL-26 into 
the AWLs section of the ICA. That NPRM was published in the Federal 
Register on July 9, 2007 (72 FR 37132). We have also issued AD 2008-06-
03, amendment 39-15415 (73 FR 13081, March 12, 2008) that, in part, 
requires revising the AWLs section of the ICA to incorporate AWLs No. 
28-AWL-23, No. 28-AWL-24, and No. 28-AWL-25. Therefore, we have added a 
new paragraph (k) to this AD specifying that incorporating AWLs No. 28-
AWL-23, No. 28-AWL-24, and No. 28-AWL-25 in accordance with paragraph 
(g) of this AD terminates the action required by paragraph (h)(2) of AD 
2008-06-03.

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 
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 1 of this AD to clarify that an 
operator must request approval for an AMOC if the operator cannot 
accomplish the proposed inspections because an airplane has been 
previously modified, altered, or repaired in the areas addressed by the 
proposed inspections.
     We have revised paragraph (h) of this AD to specify that 
accomplishing the applicable AWLs in Table 1 of this AD as part of an 
FAA-approved maintenance program before the applicable compliance time 
constitutes compliance with the applicable requirements of that 
paragraph.
     We have deleted Appendix 1 from this AD, since Revision 
March 2008 of the MPD already contains most of the updated information 
that is listed in Appendix 1 of the NPRM.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Extend the Task Intervals for Certain AWL Inspections

    KLM Royal Dutch Airlines, 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 extending certain AWL inspection intervals from 
10 years/36,000 flight cycles to 12 years for Model 757 airplanes.
    We disagree with KLM's request to extend certain AWL inspection 
intervals to 12 years. However, as stated previously, we have deleted 
the 36,000-total-flight-cycle parameter from Table 1 of this AD to 
correspond with the task intervals specified in Revision March 2008 of 
the MPD. In developing an appropriate compliance time for this action, 
we considered the urgency associated with the subject unsafe condition 
and the practical aspect of accomplishing the required actions within a 
period of time that corresponds to the normal scheduled maintenance for 
most affected operators. However, according to the provisions of 
paragraph (l) of this AD, we might approve requests to adjust the 
compliance time if the request includes data that prove that the new 
compliance time would provide an acceptable level of safety.

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

    Boeing states 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. Boeing also 
states 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 supplemental 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 Note 1

    Boeing requests that we revise Note 1 of the supplemental 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 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 simplified 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.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 990 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.

[[Page 25976]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Number of
                                                                     Cost per          U.S.-
                     Action                         Work  hours      airplane       registered      Fleet cost
                                                                                     airplanes
----------------------------------------------------------------------------------------------------------------
AWLs revision...................................               8            $640             639        $408,960
Inspections.....................................               8             640             639         408,960
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

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

    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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2008-10-11 Boeing: Amendment 39-15517. Docket No. FAA-2006-26710; 
Directorate Identifier 2006-NM-147-AD.

Effective Date

    (a) This AD becomes effective June 12, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 757-200, -200PF, -200CB, 
and -300 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 (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

    (f) The term ``Revision March 2008 of the MPD'' as used in this 
AD, means Boeing Temporary Revision (TR) 09-008, dated March 2008. 
Boeing TR 09-008 is published as Section 9 of the Boeing 757 
Maintenance Planning Document (MPD) Document, D622N001-9, Revision 
March 2008.

Revision of Airworthiness Limitations (AWLs) Section

    (g) Before December 16, 2008, revise the AWLs section of the 
Instructions for Continued Airworthiness (ICA) by incorporating the 
information in the subsections specified in paragraphs (g)(1) 
through (g)(3) of this AD into the MPD; 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 E, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS,'' 
of Revision March 2008 of the MPD.
    (2) Subsection F, ``PAGE FORMAT: SYSTEMS AIRWORTHINESS 
LIMITATIONS,'' of Revision March 2008 of the MPD.
    (3) Subsection G, ``AIRWORTHINESS LIMITATIONS--FUEL SYSTEM 
AWLs,'' AWLs No. 28-AWL-01 through No. 28-AWL-24 inclusive, of 
Revision March 2008 of the MPD. As an optional action, AWLs No. 28-
AWL-25 and No. 28-AWL-26, as identified in Subsection G of Revision 
March 2008 of the MPD, also may be incorporated into the AWLs 
section of the ICA.

Initial Inspections and Repair

    (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 G of Revision March 2008 of 
the MPD. The repair must be done before further flight. 
Accomplishing the actions 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.

[[Page 25977]]



                                          Table 1.--Initial Inspections
----------------------------------------------------------------------------------------------------------------
                                                                    Compliance time  (whichever occurs later)
               AWL No.                       Description       -------------------------------------------------
                                                                       Threshold               Grace period
----------------------------------------------------------------------------------------------------------------
(1) 28-AWL-01........................  A detailed inspection    Within 120 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.
(2) 28-AWL-03........................  A special detailed       Within 120 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.
(3) 28-AWL-14........................  A special detailed       Within 120 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.
----------------------------------------------------------------------------------------------------------------


    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.''

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 
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

    (j) Actions done before the effective date of this AD in 
accordance with Section 9 of the Boeing 757 MPD Document, D622N001-
9, Revision March 2006; Revision October 2006; Revision January 
2007; or Revision November 2007; are acceptable for compliance with 
the corresponding requirements of paragraphs (g) and (h) of this AD.

Terminating Action for AD 2008-06-03, Amendment 39-15415

    (k) Incorporating AWLs No. 28-AWL-23, No. 28-AWL-24, and No. 28-
AWL-25 into the AWLs section of the ICA in accordance with paragraph 
(g) of this AD terminates the action required by paragraph (h)(2) of 
AD 2008-06-03.

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 (TR) 09-008, dated 
March 2008, to the Boeing 757 Maintenance Planning Document (MPD) 
Document, D622N001-9, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. Boeing TR 09-008 is 
published as Section 9 of the Boeing 757 Maintenance Planning 
Document (MPD) Document, D622N001-9, Revision March 2008.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this document in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information.
    (3) You may review copies 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/cfr/ibr-
locations.html.

    Issued in Renton, Washington, on April 29, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-9917 Filed 5-7-08; 8:45 am]

BILLING CODE 4910-13-P
