[Federal Register Volume 79, Number 221 (Monday, November 17, 2014)]
[Proposed Rules]
[Pages 68381-68384]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-27070]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2014-0772; Directorate Identifier 2014-NM-090-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 supersede Airworthiness Directive (AD) 2011-08-
51, which applies to certain The Boeing Company Model 737-300, -400,
and -500 series airplanes. AD 2011-08-51 currently requires repetitive
inspections of the lap joint at certain stringers along the entire
length from certain body stations. Since we issued AD 2011-08-51, an
evaluation by the design approval holder (DAH) has determined that the
lower fastener holes in the lower skin of the fuselage lap splice are
subject to widespread fatigue damage (WFD), and as a result the DAH
specified revised compliance times, an expanded inspection area, and
additional inspections for cracks and open pockets, and corrective
actions if necessary. Additionally, this evaluation has also determined
that the repetitive inspection interval can be increased for lap
splices with certain new fay scratches. This proposed AD would expand
the inspection area, require additional inspections for cracks and open
pockets, and corrective actions if necessary, and revise the compliance
times. We are proposing this AD to detect and correct fatigue cracking
of the lower fastener holes in the lower skin of the fuselage lap
splice, which could result in reduced structural integrity of the
airplane.
DATES: We must receive comments on this proposed AD by January 2, 2015.
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 view this referenced 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 by searching for and locating Docket No. FAA-2014-
0772; 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
[[Page 68382]]
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6447; 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 proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2014-0772;
Directorate Identifier 2014-NM-090-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 structural 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.
In the context of WFD, this action 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.
On May 6, 2011, we issued AD 2011-08-51, Amendment 39-16701 (76 FR
28632, May 18, 2011), for certain The Boeing Company Model 737-300, -
400, and -500 series airplanes. AD 2011-08-51 requires repetitive
external eddy current inspections of the lap joints at stringers S-4R
and S-4L, from body station (BS) 360 to BS 908. If a crack indication
is found, AD 2011-08-51 requires either confirming the crack by doing
internal eddy current inspections, or repairing the crack. As an
alternative to the external eddy current inspections, AD 2011-08-51
provides for internal eddy current and detailed inspections for cracks
in the lower skin at the lower row of fasteners at stringers S-4L and
S-4R. AD 2011-08-51 resulted from a report indicating that a Model 737-
300 series airplane experienced a rapid decompression when the lap
joint at stringer S-4L between BS 664 and BS 727 cracked and opened up
due to cracking in the lower skin at the lower row of fasteners. We
issued AD 2011-08-51 to detect and correct such cracking, which could
result in an uncontrolled decompression of the airplane.
Actions Since AD 2011-08-51, Amendment 39-16701 (76 FR 28632, May 18,
2011), Was Issued
Since we issued AD 2011-08-51, Amendment 39-16701 (76 FR 28632, May
18, 2011), an evaluation by the DAH has determined that the lower
fastener holes in the lower skin of the fuselage lap splice are subject
to WFD, and as a result the DAH specified revised compliance times, an
expanded inspection area, and additional inspections for cracks and
open pockets, and corrective actions if necessary. Additionally, this
evaluation has also determined that the repetitive inspection interval
can be increased for lap splices with certain new fay scratches.
Relevant Service Information
We reviewed Boeing Alert Service Bulletin 737-53A1319, Revision 2,
dated April 4, 2014. For information on the procedures and compliance
times, see this service information at http://www.regulations.gov by
searching for and locating Docket No. FAA-2014-0772.
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 these same type
designs.
Proposed AD Requirements
Although this proposed AD does not explicitly restate the
requirements of AD 2011-08-51, Amendment 39-16701 (76 FR 28632, May 18,
2011), this proposed AD would retain certain requirements of AD 2011-
08-51. Those requirements are referenced in the service information
identified previously, which, in turn, are referenced in paragraphs (g)
and (l) of this proposed AD. 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.''
[[Page 68383]]
Differences Between This Proposed AD and the Service Information
Boeing Alert Service Bulletin 737-53A1319, Revision 2, dated April
4, 2014, specifies to contact the manufacturer for instructions on how
to inspect and 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.
Interim Action
We consider this proposed AD interim action. An investigation is
ongoing and no terminating action has been developed. Once terminating
action is developed, approved, and available, we might consider
additional rulemaking.
Costs of Compliance
We estimate that this proposed AD affects 130 airplanes of U.S.
registry.
We estimate the following costs to comply with this proposed AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Repetitive inspections [actions 6 or 4,270 work-hours None............. $510 or $362,950 $66,300 or
retained from AD 2011-08-51, (depending on per inspection $47,183,500 per
Amendment 39-16701 (76 FR inspection method) x cycle. inspection
28632, May 18, 2011)]. $85 per work-hour = cycle.
$510 or $362,950 per
inspection cycle.
Repetitive inspections [new 4 or 550 work-hours None............. $340 or 46,750 $44,200 or
proposed action]. (depending on per inspection $6,077,500 per
inspection method) x cycle. inspection
$85 per hour = $340 cycle.
or 46,750 per
inspection cycle.
One-time inspections [new 5,370 work-hours x $85 None............. $456,450......... $59,338,500.
proposed action]. per hour = $456,450.
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We have received no definitive data that would enable us to provide
a 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 have 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 that the 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. Amend Sec. 39.13 by removing Airworthiness Directive (AD) 2011-08-
51, Amendment 39-16701 (76 FR 28632, May 18, 2011), and adding the
following new AD:
The Boeing Company: Docket No. FAA-2014-0772; Directorate Identifier
2014-NM-090-AD.
(a) Comments Due Date
The FAA must receive comments on this AD action by January 2,
2015.
(b) Affected ADs
This AD replaces AD 2011-08-51, Amendment 39-16701 (76 FR 28632,
May 18, 2011).
(c) Applicability
This AD applies to The Boeing Company Model 737-300, -400, and -
500 series airplanes, certificated in any category, as identified in
Boeing Alert Service Bulletin 737-53A1319, Revision 2, dated April
4, 2014.
(d) Subject
Air Transport Association (ATA) of America Code 53: Fuselage.
(e) Unsafe Condition
This AD was prompted by an evaluation by the design approval
holder (DAH) that has determined that the lower fastener holes in
the lower skin of the fuselage lap splice are subject to widespread
fatigue damage (WFD). We are issuing this AD to detect and correct
fatigue cracking of the lower fastener holes in the lower skin of
the fuselage lap splice, which could result in reduced structural
integrity of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
[[Page 68384]]
(g) Repetitive Inspections for Crack Indications at Stringers S-4R and
S-4L, Body Station (BS) 360 to BS 908
At the applicable time specified in Table 1 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014: Do an external eddy current
inspection, or internal eddy current and detailed inspections, for
crack indications at stringers S-4R and S-4L, from body station (BS)
360 to BS 908, except as provided by paragraph (h) of this AD, in
accordance with Part 1 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014.
Repeat the inspection(s) thereafter at the applicable intervals
specified in Table 1 or Table 2, as applicable, of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014. Either inspection option may be
used at any repetitive inspection cycle.
(h) One-Time Inspections for Cracks at Stringers S-4L and S-4R, BS 360
to BS 908
At the applicable time specified in Table 3 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014, except as required by paragraph (m)
of this AD: Do one-time internal detailed and eddy current
inspections for cracks at stringers S-4R and S-4L, from BS 360 to BS
908, in accordance with Part 2 of the Accomplishment Instructions of
Boeing Alert Service Bulletin 737-53A1319, Revision 2, dated April
4, 2014. Accomplishment of the inspections required by this
paragraph does not terminate the repetitive inspections required by
paragraph (g) of this AD.
(i) One-Time Inspections for Cracks at Stringer S-4R, BS 908 to BS 1016
For airplanes identified as Group 2, 3, 5, and 7 in Boeing Alert
Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014: At
the applicable time specified in Table 4 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014, except as required by paragraph (m)
of this AD, do one-time internal detailed and eddy current
inspections for cracks at stringer S-4R, from BS 908 to BS 1016, in
accordance with Part 3 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014.
(j) Repetitive Inspections for Cracks at Stringer S-4R, BS 908 to BS
1016
For airplanes identified as Group 2, 3, 5, and 7 in Boeing Alert
Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014: At
the applicable time specified in Table 5 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014, except as required by paragraph (m)
of this AD, do external eddy current inspections, or internal eddy
current and detailed inspections, for cracks at stringer S-4R, from
BS 908 to BS 1016, in accordance with Part 4 of the Accomplishment
Instructions of Boeing Alert Service Bulletin 737-53A1319, Revision
2, dated April 4, 2014. Repeat the inspection(s) thereafter at the
applicable intervals specified in Table 5 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014. Either inspection option may be
used at any repetitive inspection cycle.
(k) General Visual Inspection for Open Pockets at Stringer S-4R, BS 908
to BS 1016
For airplanes identified as Group 1, 4, and 6 in Boeing Alert
Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014: At
the applicable time specified in Table 6 of paragraph 1.E.,
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1319,
Revision 2, dated April 4, 2014, except as required by paragraph (m)
of this AD, do a general visual inspection for open pockets of the
lower skin panel at stringer S-4R, from BS 908 to BS 1016, in
accordance with Part 5 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 737-53A1319, Revision 2, dated April 4, 2014.
If any open pocket is found, before further flight, inspect and
repair using a method approved in accordance with the procedures
specified in paragraph (o) of this AD.
(l) Corrective Action
If any crack is found during any inspection required by this AD:
Before further flight, repair using a method approved in accordance
with the procedures specified in paragraph (o) of this AD.
Accomplishment of repairs approved in accordance with the procedures
specified in paragraph (o) of this AD terminates the repetitive
inspections specified in paragraphs (g) and (j) of this AD in the
repaired areas only.
(m) Service Information Exception
Where Boeing Alert Service Bulletin 737-53A1319, Revision 2,
dated April 4, 2014, specifies a compliance time ``after the
Revision 2 date of this service bulletin,'' this AD requires
compliance within the specified compliance time after the effective
date of this AD.
(n) Credit for Previous Actions
This paragraph provides credit for actions required by paragraph
(g) of this AD, if those actions were performed before the effective
date of this AD using Boeing Alert Service Bulletin 737-53A1319,
dated April 4, 2011; or Boeing Alert Service Bulletin 737-53A1319,
Revision 1, dated April 8, 2011. Boeing Alert Service Bulletin 737-
53A1319, dated April 4, 2011, is incorporated by reference in AD
2011-08-51, Amendment 39-16701 (76 FR 28632, May 18, 2011). Boeing
Alert Service Bulletin 737-53A1319, Revision 1, dated April 8, is
not incorporated by reference in this AD.
(o) 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 paragraph (p)(1) 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.
(4) AMOCs approved for AD 2011-08-51, Amendment 39-16701 (76 FR
28632, May 18, 2011), are approved as AMOCs for the corresponding
provisions of paragraphs (g) and (l) of this AD.
(p) Related Information
(1) For more information about this AD, contact Wayne Lockett,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6447; 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 view this referenced 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 November 5, 2014.
Jeffrey E. Duven,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2014-27070 Filed 11-14-14; 8:45 am]
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