[Federal Register Volume 78, Number 45 (Thursday, March 7, 2013)]
[Proposed Rules]
[Pages 14719-14722]
From the Federal Register Online via the Government Publishing 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: [email protected].
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
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Action Labor cost Parts cost Cost per product Cost on U.S. operators
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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.
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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: [email protected].
(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:
[email protected].
(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]
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