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[Federal Register Volume 78, Number 45 (Thursday, March 7, 2013)]
[Proposed Rules]
[Pages 14719-14722]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-05191]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0205; Directorate Identifier 2012-NM-226-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

[[Page 14720]]

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
The Boeing Company Model 747SP series airplanes, and certain The Boeing 
Company Model 747-100B SUD and 747-300 series airplanes. This proposed 
AD was prompted by an evaluation by the design approval holder (DAH) 
indicating that the fuselage skin just above certain lap splice 
locations is subject to widespread fatigue damage (WFD). This proposed 
AD would require repetitive inspections for cracking of the fuselage 
skin above certain lap splice locations, and repair if necessary. We 
are proposing this AD to detect and correct fatigue cracking of the 
fuselage skin, which could result in reduced structural integrity of 
the airplane and sudden loss of cabin pressure.

DATES: We must receive comments on this proposed AD by April 22, 2013.

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, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. 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: Nathan Weigand, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6428; fax: 425-917-6590; email: Nathan.P.Weigand@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-2013-0205; 
Directorate Identifier 2012-NM-226-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

    Structural fatigue damage is progressive. It begins as minute 
cracks, and those cracks grow under the action of repeated stresses. 
This can happen because of normal operational conditions and design 
attributes, or because of isolated situations or incidents such as 
material defects, poor fabrication quality, or corrosion pits, dings, 
or scratches. Fatigue damage can occur locally, in small areas or 
structural design details, or globally. Global fatigue damage is 
general degradation of large areas of structure with similar structural 
details and stress levels. Multiple-site damage is global damage that 
occurs in a large structural element such as a single rivet line of a 
lap splice joining two large skin panels. Global damage can also occur 
in multiple elements such as adjacent frames or stringers. Multiple-
site-damage and multiple-element-damage cracks are typically too small 
initially to be reliably detected with normal inspection methods. 
Without intervention, these cracks will grow, and eventually compromise 
the structural integrity of the airplane, in a condition known as 
widespread fatigue damage (WFD). As an airplane ages, WFD will likely 
occur, and will certainly occur if the airplane is operated long enough 
without any intervention.
    The FAA's WFD final rule (75 FR 69746, November 15, 2010) became 
effective on January 14, 2011. The WFD rule requires certain actions to 
prevent catastrophic failure due to WFD throughout the operational life 
of certain existing transport category airplanes and all of these 
airplanes that will be certificated in the future. For existing and 
future airplanes subject to the WFD rule, the rule requires that DAHs 
establish a limit of validity (LOV) of the engineering data that 
support the structural maintenance program. Operators affected by the 
WFD rule may not fly an airplane beyond its LOV, unless an extended LOV 
is approved.
    The WFD rule (75 FR 69746, November 15, 2010) does not require 
identifying and developing maintenance actions if the DAHs can show 
that such actions are not necessary to prevent WFD before the airplane 
reaches the LOV. Many LOVs, however, do depend on accomplishment of 
future maintenance actions. As stated in the WFD rule, any maintenance 
actions necessary to reach the LOV will be mandated by airworthiness 
directives through separate rulemaking actions.
    We recognize that the WFD rule (75 FR 69746, November 15, 2010) is 
unusual in that it might depend on future rulemaking to fully achieve 
its safety objectives. In the context of WFD, this approach is 
necessary to enable DAHs to propose LOVs that allow operators the 
longest operational lives for their airplanes, and still ensure that 
WFD will not occur. This approach allows for an implementation strategy 
that provides flexibility to DAHs in determining the timing of service 
information development (with FAA approval), while providing operators 
with certainty regarding the LOV applicable to their airplanes.
    Two operators of Model 757 airplanes have reported cracking on two 
airplanes that initiated at multiple locations on the inboard surface 
of the skin, along the edge of the chem-milled step just above the skin 
lap splice (which was addressed by AD 2011-01-15, Amendment 39-16572 
(76 FR 1351, January 10, 2011)). No cracking of this kind has been 
reported on Model 747 airplanes, but analysis has determined that the 
Model 747 fuselage skin in certain areas might be susceptible to 
similar cracking. Such fatigue cracking of the fuselage skin could 
result in

[[Page 14721]]

reduced structural integrity of the airplane and sudden loss of cabin 
pressure. The skin at the edge of chem-milled steps above certain skin 
lap splices has been determined to be structure that is susceptible to 
WFD.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 747-53A2854, dated 
September 17, 2012. For information on the procedures and compliance 
times, see this service information at http://www.regulations.gov by 
searching for Docket No. FAA-2013-0205.

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, except as discussed 
under ``Differences Between the Proposed AD and the Service 
Information.''
    The phrase ``related investigative actions'' might be used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that: (1) are related to the primary actions, and (2) are actions that 
further investigate the nature of any condition found. Related 
investigative actions in an AD could include, for example, inspections.
    In addition, the phrase ``corrective actions'' might be used in 
this proposed AD. ``Corrective actions'' are actions that correct or 
address any condition found. Corrective actions in an AD could include, 
for example, repairs.

Differences Between the Proposed AD and the Service Information

    Boeing Alert Service Bulletin 747-53A2854, dated September 17, 
2012, specifies to contact the manufacturer for instructions on how to 
repair certain conditions, but this proposed AD would require repairing 
those conditions in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 4 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
         Action                 Labor cost          Parts cost       Cost per product     Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Inspection..............  Up to 57                            $0  Up to $4,845, per       Up to $19,380, per
                           work[dash]hours x $85                   inspection cycle.       inspection cycle.
                           per hour = $4,845,
                           per inspection cycle.
----------------------------------------------------------------------------------------------------------------

     We have received no definitive data that would enable us to 
provide cost estimates for the on-condition actions specified in this 
proposed AD.

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

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 airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2013-0205; Directorate Identifier 
2012-NM-226-AD.

(a) Comments Due Date

    We must receive comments by April 22, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company airplanes, certificated in 
any category, identified in paragraphs (c)(1), (c)(2), and (c)(3) of 
this AD.
    (1) All Model 747SP airplanes.
    (2) Model 747-100B SUD airplanes, line numbers 636 and 655.
    (3) Model 747-300 airplanes, line numbers 692 through 695 
inclusive.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 53, Fuselage.

[[Page 14722]]

(e) Unsafe Condition

    This AD was prompted by an evaluation by the design approval 
holder (DAH) indicating that the fuselage skin just above certain 
lap splice locations is subject to widespread fatigue damage (WFD). 
We are issuing this AD to detect and correct fatigue cracking of the 
fuselage skin, which could result in reduced structural integrity of 
the airplane and sudden loss of cabin pressure.

(f) Compliance

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

(g) Repetitive Inspection

    Perform external sliding probe eddy current inspections of the 
fuselage skin for cracking, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2854, dated 
September 17, 2012, except where this service bulletin specifies to 
contact Boeing for inspection instructions, this AD requires doing 
the inspection using a method approved in accordance with the 
procedures specified in paragraph (h) of this AD. Do the inspection 
at the applicable initial compliance time specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 747-53A2854, 
dated September 17, 2012, except where this service bulletin 
specifies a compliance time after the ``original issue date of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.
    (1) If no cracking is found during any inspection required by 
paragraph (g) of this AD, repeat the inspection thereafter at the 
applicable compliance time intervals specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2854, dated 
September 17, 2012.
    (2) If any cracking is found during any inspection required by 
paragraph (g) of this AD: Before further flight, repair the cracking 
using a method approved in accordance with the procedures specified 
in paragraph (h) of this AD.

 (h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
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 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.

(i) Related Information

    (1) For more information about this AD, contact Nathan Weigand, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6428; fax: 425-917-6590; email: 
Nathan.P.Weigand@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, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, WA. For information on the availability of this 
material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on February 20, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-05191 Filed 3-6-13; 8:45 am]
BILLING CODE 4910-13-P
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