
[Federal Register Volume 77, Number 185 (Monday, September 24, 2012)]
[Proposed Rules]
[Pages 58791-58794]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-23434]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0998; Directorate Identifier 2011-NM-249-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 737-600, -700, -700C, -800, -900, and 
-900ER series airplanes. This proposed AD was prompted by a new 
revision to the airworthiness limitations of the maintenance planning 
data document. This proposed AD would require revising the maintenance 
program to update inspection requirements to

[[Page 58792]]

detect fatigue cracking of principal structural elements (PSEs). We are 
proposing this AD to detect and correct fatigue cracking of various 
PSEs, which could adversely affect the structural integrity of these 
airplanes.

DATES: We must receive comments on this proposed AD by November 8, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

Examining the AD Docket

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

FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6440; fax: 
425-917-6590; email: nancy.marsh@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2012-0998; 
Directorate Identifier 2011-NM-249-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    In accordance with airworthiness standards requiring ``damage-
tolerance assessments'' (Part 25 of the Federal Aviation Regulations, 
Section 1529), all products certificated to comply with that section 
must have Instructions for Continued Airworthiness that include an 
Airworthiness Limitations Section (AWLs). The AWLs set forth:
     Mandatory replacement times for structural components,
     Structural inspection intervals, and
     Related approved structural inspection procedures 
necessary to show compliance with the damage-tolerance requirements.
    Compliance with the terms specified in the AWLs is required by 14 
CFR 43.16 (for persons maintaining products) and 14 CFR 91.403 (for 
operators).
    As airplanes gain service experience, or as the result of post-
certification testing and evaluation, it might become necessary to add 
additional life limits or structural inspections in order to ensure the 
continued structural integrity of the airplane. The manufacturer might 
revise the AWLs to include new or more restrictive life limits and 
inspections. However, in order to require compliance with those revised 
life limits and/or inspection intervals, the FAA must engage in 
rulemaking. Because loss of structural integrity would result in an 
unsafe condition, it is appropriate to impose these requirements 
through the airworthiness directive (AD) process.
    Boeing has completed additional analyses of fatigue cracking of 
PSEs on certain Model 737 airplanes, which included:
     Crack growth analysis,
     Service experience analysis,
     Crack growth testing,
     Fatigue testing, and
     Analysis of the effectiveness of applicable non-
destructive inspection techniques to detect cracking and other 
anomalies.
    The results of the analyses demonstrated the need to incorporate 
updated inspection requirements to detect fatigue cracking of PSEs. We 
are proposing this AD to detect and correct fatigue cracking of various 
PSEs, which could adversely affect the structural integrity of these 
airplanes.

Relevant Service Information

    We reviewed Subsection B, AWLs--Structural Inspections, of Section 
9, ``Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs),'' of Boeing 737-600, -700, -700C, -800, -900, and 
-900ER Maintenance Planning Data (MPD) Document, D626A001-CMR, Revision 
July 2011. The service information describes procedures for revising 
the airworthiness limitations of the maintenance planning document. 
Subsection B of this document contains updated inspection requirements 
to detect fatigue cracking of PSEs.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD affects 1,200 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

[[Page 58793]]



                                                 Estimated Costs
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                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
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Document Revision...................  1 work-hour x $85 per                $0              $85         $102,000
                                       hour = $85.
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Authority for This Rulemaking

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

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2012-0998; Directorate Identifier 
2011-NM-249-AD.

(a) Comments Due Date

    We must receive comments by November 8, 2012.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any 
category, with an original airworthiness certificate or original 
export certificate of airworthiness issued before April 3, 2012.
    (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 according 
to paragraph (j) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued damage tolerance of the affected structure. The FAA 
has provided guidance for this determination in FAA Advisory 
Circular (AC) 25.1529-1A, dated November 20, 2007 (http://
rgl.faa.gov/Regulatory--and--Guidance--Library/
rgAdvisoryCircular.nsf/list/AC%2025.1529-1A/$FILE/AC%2025.1529-
1A.pdf).

 (d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 52, Doors; 53, Fuselage; 54, Nacelles/Pylons; 
55, Stabilizers; and 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a new revision to the airworthiness 
limitations of the maintenance planning data document. We are 
issuing this AD to detect and correct fatigue cracking of various 
principal structural elements (PSEs), which could adversely affect 
the structural integrity of these airplanes.

(f) Compliance

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

(g) Maintenance Program Revision

    (1) Within 12 months after the effective date of this AD, revise 
the maintenance program by incorporating the information in 
Subsection B, AWLs--Structural Inspections, of Section 9, 
``Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs),'' of Boeing 737-600, -700, -700C, -800, -900, 
and -900ER Maintenance Planning Data (MPD) Document, D626A001-CMR, 
Revision July 2011, except as provided by paragraph (h) of this AD.
    (2) The initial compliance time for the inspections is within 
the applicable times specified in Subsection B, AWLs--Structural 
Inspections, of Section 9, ``Airworthiness Limitations (AWLs) and 
Certification Maintenance Requirements (CMRs),'' of Boeing 737-600, 
-700, -700C, -800, -900, and -900ER Maintenance Planning Data (MPD) 
Document, D626A001-CMR, Revision July 2011, or within 18 months 
after the effective date of this AD, whichever occurs later; or 
within the applicable time specified in Subsection B, AWLs--
Structural Inspections, of Section 9, ``Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs),'' of 
Boeing 737-600, -700, -700C, -800, -900, and -900ER Maintenance 
Planning Data (MPD) Document, D626A001-CMR, Revision July 2011, from 
the time of installation for new parts.
    (3) Reports specified in Section 9, ``Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs),'' of 
Boeing 737-600, -700, -700C, -800, -900, and -900ER Maintenance 
Planning Data (MPD) Document, D626A001-CMR, Revision July 2011, may 
be submitted within 10 days after the airplane is returned to 
service, instead of 10 days after each individual finding as 
specified in Section 9.

(h) No Alternative Inspections and Inspection Intervals

    After accomplishing the actions required by paragraph (g) of 
this AD, no alternative actions (i.e. alternative inspections) or 
inspection intervals may be used or incorporated unless the 
alternative action or interval is approved as an alternative method 
of compliance (AMOC) in accordance with the procedures specified in 
paragraph (j) of this AD.

[[Page 58794]]

(i) Paperwork Reduction Act Burden Statement

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty 
for failure to comply with a collection of information subject to 
the requirements of the Paperwork Reduction Act unless that 
collection of information displays a current valid OMB Control 
Number. The OMB Control Number for this information collection is 
2120-0056. Public reporting for this collection of information is 
estimated to be approximately 5 minutes per response, including the 
time for reviewing instructions, completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Comments concerning the accuracy of this 
burden and suggestions for reducing the burden should be directed to 
the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: 
Information Collection Clearance Officer, AES-200.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
ANM-120S, FAA, has the authority to approve AMOCs for this AD, if 
requested using the procedures found in 14 CFR 39.19. In accordance 
with 14 CFR 39.19, send your request to your principal inspector or 
local Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required in the area affected by this AD if it 
is approved by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle ACO, to make those findings. For a repair method to 
be approved, the repair must meet the certification basis of the 
airplane, and the approval must specifically refer to this AD.

(k) Related Information

    (1) For more information about this AD, contact Nancy Marsh, 
Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft 
Certification Office, FAA, 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6440; fax: 425-917-6590; email: 
nancy.marsh@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 
206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, Washington. For information on the 
availability of this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on September 12, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-23434 Filed 9-21-12; 8:45 am]
BILLING CODE 4910-13-P


