AD 2011-08-51
Recurring
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 737-300 | Airworthiness Directives; The Boeing Company Model 737-300, -400, and -500 Series Airplanes |
Unsafe Condition
Cracking in the lower skin at the lower row of fasteners of the lap joints at stringers S-4R and S-4L, along the entire length from body station (BS) 360 to BS 908, could open up and result in an uncontrolled decompression of the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Repetitive external eddy current inspections of the lap joints at stringers S-4R and S-4L, along the entire length from BS 360 to BS 908. If a crack indication is found, either confirm the crack by doing internal eddy current inspections or repair the crack. As an alternative, 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 are also acceptable.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
The Boeing Company Model 737-300, -400, and -500 Series Airplanes
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
We are adopting a new airworthiness directive (AD) for the products listed above. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires repetitive external eddy current inspections of the lap joints at stringers S-4R and S-4L, along the entire length from body station (BS) 360 to BS 908. If a crack indication is found, the AD requires either confirming the crack by doing internal eddy current inspections, or repairing the crack. As an alternative to the external eddy current inspections, the AD 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. This AD was prompted by 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 are issuing this AD to detect and correct such cracking, which could result in an uncontrolled decompression of the airplane.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 76, Number 96 (Wednesday, May 18, 2011)]
[Rules and Regulations]
[Pages 28632-28635]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2011-11928]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2011-0348; Directorate Identifier 2011-NM-069-AD;
Amendment 39-16701; AD 2011-08-51]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model 737-300, -400,
and -500 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: We are adopting a new airworthiness directive (AD) for the
products listed above. This emergency AD was sent previously to all
known U.S. owners and operators of these airplanes. This AD requires
repetitive external eddy current inspections of the lap joints at
stringers S-4R and S-4L, along the entire length from body station (BS)
360 to BS 908. If a crack indication is found, the AD requires either
confirming the crack by doing internal eddy current inspections, or
repairing the crack. As an alternative to the external eddy current
inspections, the AD 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. This AD was prompted by 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 are issuing this AD to detect and correct such cracking,
which could result in an uncontrolled decompression of the airplane.
DATES: This AD is effective June 2, 2011 to all persons except those
persons to whom it was made immediately effective by Emergency AD 2011-
08-51, issued on April 5, 2011, which contained the requirements of
this amendment.
The Director of the Federal Register approved the incorporation by
reference of certain publications identified in the AD as of June 2,
2011.
We must receive comments on this AD by July 5, 2011.
ADDRESSES: You may send comments by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> 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 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; e-mail <a href="/cdn-cgi/l/email-protection#711c145f131e14121e1c31131e14181f165f121e1c"><span class="__cf_email__" data-cfemail="b9d4dc97dbd6dcdad6d4f9dbd6dcd0d7de97dad6d4">[email protected]</span></a>; Internet
<a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a>; or in person at the Docket Operations Office
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 street address for
the Docket Operations 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: Wayne Lockett, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone:
425-917-6447; fax: 425-917-6590; e-mail: <a href="/cdn-cgi/l/email-protection#e295839b8c87cc8e8d8189879696a2848383cc858d94"><span class="__cf_email__" data-cfemail="80f7e1f9eee5aeecefe3ebe5f4f4c0e6e1e1aee7eff6">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Discussion
On April 5, 2011, we issued Emergency AD 2011-08-51, which requires
repetitive external eddy current inspections of the lap joints at
stringers S-4R and S-4L, along the entire length from body station (BS)
360 to BS 908. If a crack indication is found, the AD requires either
confirming the crack by doing internal eddy current inspections, or
repairing the crack. As an alternative to the external eddy current
inspections, the AD 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. This action was prompted by 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. The airplane had accumulated 39,781 total
flight cycles
[[Page 28633]]
and 48,740 total flight hours. Such cracking, if not corrected, could
result in an uncontrolled decompression of the airplane.
Relevant Service Information
We reviewed Boeing Alert Service Bulletin 737-53A1319, dated April
4, 2011. That service bulletin describes procedures for external eddy
current inspections of the lap joints at stringers S-4R and S-4L, along
the entire length from BS 360 to BS 908. If a crack indication is
found, that service bulletin specifies either confirming the crack by
doing internal eddy current inspections, or repairing the crack. As an
alternative to the external eddy current inspections, that service
bulletin provides procedures 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. That service bulletin specifies contacting
Boeing for crack repair instructions.
Since we issued the emergency AD, we have approved Revision 1 of
this service bulletin as an alternative method of compliance (AMOC)
with certain requirements of emergency AD 2011-08-51. We have added
paragraph (l)(4) to this AD to provide information on this approved
AMOC.
FAA's Determination
We are issuing 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.
AD Requirements
This AD requires accomplishing the actions specified in the service
information described previously, except as discussed under
``Differences Between the AD and the Service Information.''
Differences Between the AD and the Service Information
That service bulletin specifies to contact the manufacturer for
instructions on how to repair certain conditions, but this AD requires
repairing those conditions in one of the following ways:
<bullet> In accordance with a method that we approve; or
<bullet> 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.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of
this AD. The FAA has found that the risk to the flying public justifies
waiving notice and comment prior to adoption of this rule because
cracking in the lower skin at the lower row of fasteners of the lap
joints at stringers S-4R and S-4L, along the entire length from BS 360
to BS 908, could open up and result in an uncontrolled decompression of
the airplane. Therefore, we find that notice and opportunity for prior
public comment are impracticable and that good cause exists for making
this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight
safety and was not preceded by notice and an opportunity for public
comment. However, we invite you to send any written data, views, or
arguments about this AD. Send your comments to an address listed under
the ADDRESSES section. Include the docket number FAA-2011-0348 and
Directorate Identifier 2011-NM-069-AD at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this AD. We will
consider all comments received by the closing date and may amend this
AD because of those comments.
We will post all comments we receive, without change, to <a href="http://www.regulations.gov">http://www.regulations.gov</a>, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this AD.
Costs of Compliance
We estimate that this AD affects 195 airplanes of U.S. registry. We
estimate the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Inspections........... 6 or 15 work-hours None................. $510 or $1,275 per $99,450 or $248,625
(depending on inspection cycle. per inspection
inspection method) x cycle.
$85 per work-hour.
----------------------------------------------------------------------------------------------------------------
We have received no definitive data that would enable us to provide
a cost estimate for the on-condition actions (confirming crack
indications and repairing cracks) specified in this 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
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),
(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
[[Page 28634]]
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.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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):
2011-08-51 The Boeing Company: Amendment 39-16701; Docket No. FAA-
2011-0348; Directorate Identifier 2011-NM-069-AD.
Effective Date
(a) This AD is effective June 2, 2011 to all persons except
those persons to whom it was made immediately effective by Emergency
AD 2011-08-51, issued on April 5, 2011, which contained the
requirements of this amendment.
Affected ADs
(b) None.
Applicability
(c) 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, dated April
4, 2011.
Subject
(d) Joint Aircraft System Component (JASC)/Air Transport
Association (ATA) of America Code 53: Fuselage.
Unsafe Condition
(e) This AD was prompted by a report indicating that a Model
737-300 series airplane experienced a rapid decompression when the
lap joint at stringer S-4L between body station (BS) 664 and BS 727
cracked and opened up due to cracking in the lower skin at the lower
row of fasteners. We are issuing this AD to detect and correct such
cracking, which could result in an uncontrolled decompression of the
airplane.
Compliance
(f) Comply with this AD within the compliance times specified,
unless already done.
Inspections
(g) At the applicable time specified in paragraph (g)(1),
(g)(2), or (g)(3) of this AD: Except as provided by paragraphs (h)
and (i) of this AD, do external eddy current inspections of the lap
joint at stringers S-4R and S-4L, along the entire length from body
station (BS) 360 to BS 908, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin 737-53A1319, dated
April 4, 2011. If any crack indication is detected, before further
flight, either confirm the crack indication by doing eddy current
inspections from the interior of the fuselage in the lower skin at
the lower row of fasteners at stringer S-4L and S-4R, in accordance
with Boeing Alert Service Bulletin 737-53A1319, dated April 4, 2011,
or repair in accordance with paragraph (j) of this AD.
(1) For airplanes that have accumulated fewer than 30,000 total
flight cycles as of the effective date of this AD: Inspect before
the accumulation of 30,000 total flight cycles, or within 20 days
after the effective date of this AD, whichever occurs later.
(2) For airplanes that have accumulated 30,000 or more total
flight cycles and fewer than 35,000 total flight cycles as of the
effective date of this AD: Inspect within 20 days after the
effective date of this AD.
(3) For airplanes that have accumulated 35,000 total flight
cycles or more as of the effective date of this AD: Inspect within 5
days after the effective date of this AD.
(h) For areas repaired with external doublers, paragraphs (h)(1)
and (h)(2) of this AD apply.
(1) If the repair meets the criteria specified in paragraphs
3.B.1.c.(1) and 3.B.1.c.(2) of Boeing Alert Service Bulletin 737-
53A1319, dated April 4, 2011, no inspection of the lower skin at the
lap joint lower fastener row is required under the doubler.
(2) If the repair does not meet the criteria specified in
paragraphs 3.B.1.c.(1) and 3.B.1.c.(2) of Boeing Alert Service
Bulletin 737-53A1319, dated April 4, 2011, inspect the lower skin
lap joint lower row internally in the area covered by the doubler,
in accordance with Boeing Alert Service Bulletin 737-53A1319, dated
April 4, 2011.
(i) The inspections required by paragraph (g) of this AD may
alternatively be done by internal eddy current and detailed
inspections for cracks in the lower skin at the lower row of
fasteners at stringer S-4L and S-4R, along the entire length from BS
360 to BS 908, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin 737-53A1319, dated April 4, 2011.
(j) If any crack is found during any inspection required by this
AD: Before further flight, repair the crack using a method approved
in accordance with the procedures specified in paragraph (l) of this
AD.
(k) Repeat the inspections specified in either paragraph (g) or
(i) of this AD thereafter at intervals not to exceed 500 flight
cycles. Either inspection method may be used at any repetitive
inspection cycle.
Alternative Methods of Compliance (AMOCs)
(l)(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 e-mailed to <a href="/cdn-cgi/l/email-protection#fcc5d1bdb2b1d1af999d88889099d1bdbfb3d1bdb1b3bfd1ae998d89998f888fbc9a9d9dd29b938a"><span class="__cf_email__" data-cfemail="291004686764047a4c485d5d454c04686a66046864666a047b4c585c4c5a5d5a694f4848074e465f">[email protected]</span></a>.
(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 emergency AD 2011-08-51 are approved as
AMOCs for the corresponding requirements of this AD.
Related Information
(m)(1) For further information about this AD, contact Wayne
Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle
Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton,
Washington 98057-3356; phone: 425-917-6447; fax: 425-917-6590; e-
mail: <a href="/cdn-cgi/l/email-protection#186f7961767d3674777b737d6c6c587e7979367f776e"><span class="__cf_email__" data-cfemail="d8afb9a1b6bdf6b4b7bbb3bdacac98beb9b9f6bfb7ae">[email protected]</span></a>.
(2) For copies of the service information referenced 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; e-mail
<a href="/cdn-cgi/l/email-protection#3c5159125e53595f53517c5e535955525b125f5351"><span class="__cf_email__" data-cfemail="472a226925282224282a072528222e29206924282a">[email protected]</span></a>; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. You
may review copies of the referenced service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
Material Incorporated by Reference
(n) You must use Boeing Alert Service Bulletin 737-53A1319,
dated April 4, 2011, to do the actions required by this AD, unless
the AD specifies otherwise.
(1) The Director of the Federal Register approved the
incorporation by reference of this service information under 5
U.S.C. 552(a) and 1 CFR part 51.
(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; e-mail
<a href="/cdn-cgi/l/email-protection#026f672c606d67616d6f42606d676b6c652c616d6f"><span class="__cf_email__" data-cfemail="4d2028632f22282e22200d2f222824232a632e2220">[email protected]</span></a>; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(3) You may review copies of the 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.
(4) You may also review copies of the service information that
is incorporated by reference at the National Archives and
[[Page 28635]]
Records Administration (NARA). For information on the availability
of this material at an NARA facility, call 202-741-6030, or go to
<a href="http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html">http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html</a>.
Issued in Renton, Washington, on May 6, 2011.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2011-11928 Filed 5-17-11; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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