Published 2012-05-21 · Federal Register document 2012-11869
Airworthiness Directives; The Boeing Company Airplanes
Publication summary
We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 747 series airplanes. That AD currently requires repetitive inspections for cracks of the fuselage skin lap splice between body station (BS) 400 and BS 520 at stringers S-6L and S-6R, and repair if necessary. This new AD shortens the interval for the repetitive inspections, requires modification for certain airplanes, and requires certain post-modification inspections for other airplanes. This AD was prompted by reports of multiple adjacent cracks on an airplane, and a recent fleet-wide evaluation of widespread fatigue damage of skin lap joints, which indicated the need for revised procedures and reduced compliance times. We are issuing this AD to detect and correct cracking of the fuselage skin lap splice between BS 400 and BS 520 at stringers S-6L and S-6R, which could result in sudden loss of cabin pressurization and the inability of the fuselage to withstand fail-safe loads.
Why this record is shown
Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:23:39.502075+00:00. The title, summary and date are source facts.
- Source revision
- federal_register_ad_metadata_2012-08bffa249ae9a205
- Source row
- results[158]
- Raw source SHA-256
- 08bffa249ae9a2053bbfc0d74663d089914e83fb91f9bc4c8409ea28239f6875
Final-rule publication
Recorded publication clauses
- AD identifier printed in this edition
- 2012-10-03
- Effective date printed in this edition
- 2012-06-25
Read 19 complete recorded clauses
Effective Date
(a) Effective Date
This airworthiness directive (AD) is effective June 25, 2012.
Exact source excerpt. Text positions 14791–14878, end exclusive, in the original decoded publication. SHA-256: 6467eeb717b6497d66482d7a37bd54946f734980d6323a2518854eef8ecec0d6
Affected ADs
(b) Affected ADs
This AD supersedes AD 90-21-17, Amendment 39-6768 (55 FR 41510,
October 12, 1990).
Exact source excerpt. Text positions 14878–14985, end exclusive, in the original decoded publication. SHA-256: 0ae97c21ab1c965d32ce8b50c6392be6a2c0a6626116448b6e0056c38b93f368
Applicability wording · Applicability
(c) Applicability
This AD applies to The Boeing Company Model 747-100, 747-100B,
747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series
airplanes, certificated in any category, as identified in Boeing
Service Bulletin 747-53A2303, Revision 2, dated October 1, 2009.
Exact source excerpt. Text positions 14985–15268, end exclusive, in the original decoded publication. SHA-256: 509b0ad06578160c3d5b3ad7cfcd3bf9e140e48c7f9d7d7a236989a196a4b2a4
Subject
(d) Subject
Joint Aircraft System Component (JASC)/Air Transport Association
(ATA) of America Code 53, Fuselage.
Exact source excerpt. Text positions 15268–15388, end exclusive, in the original decoded publication. SHA-256: 081af3d9c83e50199ea3d915af95e40eb49f717c012a8c46185298558678d959
Unsafe Condition
(e) Unsafe Condition
This AD was prompted by from reports of multiple adjacent cracks
on an airplane, and a recent fleet-wide evaluation of widespread
fatigue damage of skin lap joints, which indicated the need for
revised procedures and reduced compliance times. The Federal
Aviation Administration is issuing this AD to detect and correct
cracking of the fuselage skin lap splice between body station (BS)
400 and BS 520, at stringers S-6L and S-6R. Such cracking could
result in sudden loss of cabin pressurization and the inability of
the fuselage to withstand fail-safe loads.
Exact source excerpt. Text positions 15388–15984, end exclusive, in the original decoded publication. SHA-256: 395e6712388023c2fad15bd44a402d23da3ab1bac00c6a94b5e745fbcff3111a
Compliance
(f) Compliance
You are responsible for having the actions required by this AD
performed within the compliance times specified, unless the actions
have already been done.
Exact source excerpt. Text positions 15984–16162, end exclusive, in the original decoded publication. SHA-256: af3956da952ca797ed39bc4b318e4356f7014ac5b4c12bda0147d37f1ffa6cb8
Retained Inspections
(g) Retained Inspections
This paragraph restates the requirements of paragraph A. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information, reduced inspection interval, and added
subparagraph. Conduct a close visual or detailed inspection, and a
high frequency eddy current (HFEC) inspection, of the fuselage skin
lap splice between BS 400 and BS 520, at stringers S-6L and S-6R,
for cracking, in accordance with Boeing Alert Service Bulletin 747-
53A2303, dated June 2, 1988, or Revision 1, dated March 29, 1990; or
Boeing Service Bulletin 747-53A2303, Revision 2, dated October 1,
2009; at the times specified in paragraph (g)(1), (g)(2), or (g)(3)
of this AD. After the effective date of this AD, only Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009, may be
used. Adequate lighting must be used for this inspection. The eddy
current inspections may be conducted without removal of the paint,
provided the paint does not interfere with the inspections. Paint
must be removed, using an approved chemical stripper, in any
situation where the inspector determines that the paint is
interfering with the proper functioning of the inspection
instrument.
(1) Within the next 100 landings after March 31, 1989 (the
effective date of AD 89-05-03, Amendment 39-6146 (54 FR 7397,
February 21, 1989), which was superseded by AD 90-21-17, Amendment
39-6768 (55 FR 41510, October 12, 1990)), for airplanes that have
accumulated 16,000 or more landings as of March 31, 1989, unless
previously accomplished within the last 4,900 landings.
(2) Within the next 1,000 landings after March 31, 1989, or
prior to the accumulation of 16,000 landings, whichever occurs
first, for airplanes that have accumulated between 12,000 and 16,000
landings, as of March 31, 1989 (the effective date of AD 89-05-03,
Amendment 39-6146 (54 FR 7397, February 21, 1989), which was
superseded by AD 90-21-17, Amendment 39-6768 (55 FR 41510, October
12, 1990)), unless previously accomplished within the last 4,000
landings.
(3) Prior to the accumulation of 13,000 landings for airplanes
that have accumulated 12,000 or fewer landings as of March 31, 1989
(the effective date of AD 89-05-03,
[[Page 29860]]
Amendment 39-6146 (54 FR 7397, February 21, 1989), which was
superseded by AD 90-21-17, Amendment 39-6768 (55 FR 41510, October
12, 1990)), unless previously accomplished within the last 5,000
landings.
(4) For the purposes of this AD, a detailed inspection is: ``An
intensive examination of a specific item, installation, or assembly
to detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at an
intensity deemed appropriate. Inspection aids such as mirror,
magnifying lenses, etc., may be necessary. Surface cleaning and
elaborate procedures may be required.''
Exact source excerpt. Text positions 16162–19095, end exclusive, in the original decoded publication. SHA-256: 52561f907b9216268ce0acedc931e3c7acd3c2fdb7e2e8378e533f8c619fbe17
Retained Inspection Compliance Time for SUD-Modified Airplanes
(h) Retained Inspection Compliance Time for SUD-Modified Airplanes
This paragraph restates the requirements of paragraph B. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. On airplanes which have been modified
to the stretched-upper-deck configuration, as identified in Boeing
Alert Service Bulletin 747-53A2303, dated June 2, 1988, or Revision
1, dated March 29, 1990; or Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009; the accumulated landing threshold
for compliance with paragraph (g) of this AD is measured from the
time of the stretched-upper-deck modification.
Exact source excerpt. Text positions 19095–19754, end exclusive, in the original decoded publication. SHA-256: e486284e7833ab6d30c9c3d25852b2af6a2d31473ff7b98643d51e745d360dae
Retained Repetitive Inspections
(i) Retained Repetitive Inspections
This paragraph restates the requirements of paragraph C. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. If no cracking is detected during the
inspections required by paragraph (g) of this AD, repeat the
inspections required by paragraph (g) of this AD one time at the
earlier of the times specified in paragraphs (i)(1) and (i)(2) of
this AD. Thereafter repeat the inspections at intervals not to
exceed 3,000 landings.
(1) Within 5,000 landings after the last inspection.
(2) Within 3,000 landings after the last inspection, or within
1,000 landings after the effective date of this AD, whichever occurs
later.
Exact source excerpt. Text positions 19754–20479, end exclusive, in the original decoded publication. SHA-256: 80d05a536cd1f4d468daec10a35c93688880a9acc07e8bea6f65139e1f874964
Retained Repair
(j) Retained Repair
This paragraph restates the requirements of paragraph D. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. If cracks are detected during the
inspections required by paragraph (g) of this AD, accomplish the
repair or preventive modification of the affected lap splice, in
accordance with Boeing Alert Service Bulletin 747-53A2303, dated
June 2, 1988, or Revision 1, dated March 29, 1990; or Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009; prior to
further pressurized flight. After the effective date of this AD,
only Boeing Service Bulletin747-53A2303, Revision 2, dated October
1, 2009, may be used. If cracks are repaired in local areas without
accomplishing preventive modification of the entire affected lap
area, continue inspections of the unmodified and unrepaired areas of
the affected lap splice in accordance with paragraph (i) of this AD.
Exact source excerpt. Text positions 20479–21443, end exclusive, in the original decoded publication. SHA-256: e7e0377bdb9ac5f7aa121d43f3d76df360d76637e7275b58cdf2978795569d46
Retained Inspection Compliance Time for Airplanes With Preventive Modification
(k) Retained Inspection Compliance Time for Airplanes With Preventive
Modification
This paragraph restates the requirements of paragraph E. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. For airplanes incorporating the
preventive modification, as described in Boeing Alert Service
Bulletin 747-53A2303, dated June 2, 1988, or Revision 1, dated March
29, 1990; or Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009; accomplish the inspections required by paragraph
(g) of this AD prior to the accumulation of 10,000 landings after
the modification and thereafter at intervals not to exceed 5,000
landings. If cracks are found, repair using a method approved in
accordance with the procedures specified in paragraph (q) of this
AD, prior to further pressurized flight.
Exact source excerpt. Text positions 21443–22302, end exclusive, in the original decoded publication. SHA-256: 139d459f9552fa25a99d72c7e1471fedee3b5ba36bb9101cdad56562bd2ccfb8
New Requirement of This AD: Post-Modification Inspections
(l) New Requirement of This AD: Post-Modification Inspections
For airplanes on which a protruding head fastener modification
has been done in accordance with Boeing Alert Service Bulletin 747-
53A2303, dated June 2, 1988, or Revision 1, dated March 29, 1990:
Within 10,000 flight cycles after modification, or within 500 flight
cycles after the effective date of this AD, whichever occurs later,
do an external HFEC inspection for cracking in the skin around the
fasteners in the upper row of the lap joint, in accordance with Part
5 of the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2303, Revision 2, dated October 1, 2009. If any crack is found,
before further flight repair in accordance with Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009 (except as
required by paragraph (p) of this AD), or do the modification
specified in paragraph (n) of this AD. Repeat the inspection in
affected uncracked areas at intervals not to exceed 500 flight
cycles, until the modification specified in paragraph (n) of this AD
is done. Accomplishment of the initial inspection and all applicable
corrective actions specified in this paragraph terminates the
requirements of paragraph (k) of this AD.
Exact source excerpt. Text positions 22302–23552, end exclusive, in the original decoded publication. SHA-256: 7c56c92de0943d3c6c7d800830fbffd2ec3977b289b040c50b776a975b5b85b7
New Requirement of This AD: Internal HFEC Inspection
(m) New Requirement of This AD: Internal HFEC Inspection
For airplanes on which an external doubler repair has been
installed as a modification that was done using a method other than
that specified in Boeing 747 structural repair manual (SRM) 53-30-
03, Figure 19, 25, 28 or 34: Within 10,000 flight cycles after
modification, or within 500 flight cycles after the effective date
of this AD, whichever occurs later, do an internal HFEC inspection
for cracking in the skin around the fasteners in the upper row of
the lap joint, in accordance with Part 5 of the Accomplishment
Instructions of Boeing Service Bulletin 747-53A2303, Revision 2,
dated October 1, 2009. If any crack is found, before further flight
repair in accordance with Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009 (except as required by paragraph
(p) of this AD), or do the modification specified in paragraph (n)
of this AD. Repeat the inspection in affected uncracked areas at
intervals not to exceed 500 flight cycles, until the modification
specified in paragraph (n) of this AD is done. Accomplishment of the
initial inspection and all applicable corrective actions specified
in this paragraph terminates the requirements of paragraph (k) of
this AD.
Exact source excerpt. Text positions 23552–24824, end exclusive, in the original decoded publication. SHA-256: e80148f09aad3b549e2d3d560be0d19ed4ca24625bc8e89e27953ce40dc62390
New Requirement of This AD: External Doubler Modification
(n) New Requirement of This AD: External Doubler Modification
For airplanes on which a protruding head fastener modification
or a Boeing 747 SRM 53-30-03 repair or modification has been
installed that was not done using Boeing 747 SRM 53-30-03, Figure
19, 25, 28, or 34, for the full length of the lap splice: Within
14,000 flight cycles after the first repair or modification was
done, or within 3,000 flight cycles after the effective date of this
AD, whichever occurs later, modify the skin and do all post-
modification inspections and repairs, in accordance with Part 3 of
the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2303, Revision 2, dated October 1, 2009, except as required by
paragraph (o) of this AD. Do the post-modification inspection within
10,000 flight cycles after installation of the modification. Repeat
the inspection thereafter at intervals not to exceed 3,000 flight
cycles. All applicable repairs must be done before further flight.
Exact source excerpt. Text positions 24824–25819, end exclusive, in the original decoded publication. SHA-256: 36b89ccd470270d9cc0fb62538974f4189c136fea28b3bee2571a121ed3a8849
Structural Modification
(o) Structural Modification
The provisions of paragraphs (o)(1) and (o)(2) of this AD apply
to airplanes on which no previous modification or repair has been
installed in the affected area.
(1) Accomplishment of the structural modification specified in
Part 3 of the Accomplishment Instructions of Boeing Service Bulletin
747-53A2303, Revision 2, dated October 1, 2009, satisfies the
requirements of AD 90-06-06, Amendment 39-6490 (55 FR 8374, March 7,
1990), for only the corresponding modification specified in Boeing
Alert Service Bulletin 747-53A2303, dated June 2, 1988, and Revision
1, dated March 29, 1990; and Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009.
(2) After accomplishment of the modification specified in
paragraph (o)(1) of this AD, the applicable requirements and
compliance times of paragraphs (l) and (m) of this AD apply.
Exact source excerpt. Text positions 25819–26714, end exclusive, in the original decoded publication. SHA-256: f8201606dbdebc0dab08370ce4ffc5e0b54ac64577c27b3769d03e72f55f0e67
Exception to Service Bulletin Specification
(p) Exception to Service Bulletin Specification
Where Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009, specifies to contact Boeing for appropriate action:
Before further flight, repair using a method approved in accordance
with the procedures specified in paragraph (q) of this AD.
Exact source excerpt. Text positions 26714–27028, end exclusive, in the original decoded publication. SHA-256: 9c64127a3b319792dfb4cfef98889497b84a537cf5ec46519fd0f8efd7830dcb
Alternative Methods of Compliance (AMOCs)
(q) 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
[[Page 29861]]
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) or other person who 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 previously in accordance with AD 90-21-17,
Amendment 39-6768 (55 FR 41510, October 12, 1990), are approved as
AMOCs for the corresponding provisions of paragraphs (g) and (i) of
this AD. AMOCs approved previously in accordance with AD 90-21-17,
Amendment 39-6768 (55 FR 41510, October 12, 1990), are approved as
AMOCs for the corresponding provisions of paragraphs (j) and (n) of
this AD only if the repair or preventive modification of the
affected lap splice was done in accordance with Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009, including
Boeing Designated Engineering Representative (DER) or Airworthiness
Representative (AR) approvals of deviations to Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009.
Exact source excerpt. Text positions 27028–29084, end exclusive, in the original decoded publication. SHA-256: 0e0cdbecb0429ca238bccdbdc6f91977be84e6833919565283a94c997b39a09c
Related Information
(r) Related Information
For more information about this AD, contact Bill Ashforth,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington
98057-3356; telephone 425-917-6432; fax 425-917-6590; email:
[email protected].
Exact source excerpt. Text positions 29084–29395, end exclusive, in the original decoded publication. SHA-256: 3a56893f7018d65024d068153ec5760c65d0a20394df245234d5fac57e071494
Material Incorporated by Reference
(s) Material Incorporated by Reference
(1) You must use the following service information to do the
actions required by this AD, unless the AD specifies otherwise. The
Director of the Federal Register approved the incorporation by
reference (IBR) of the following service information under 5 U.S.C.
552(a) and 1 CFR part 51:
(i) Boeing Alert Service Bulletin 747-53A2303, dated June 2,
1988.
(ii) Boeing Alert Service Bulletin 747-53A2303, Revision 1,
dated March 29, 1990.
(iii) Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009.
(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; email
[email protected]; Internet https://www.myboeingfleet.com.
(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 Records
Administration (NARA). For information on the availability of this
material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Exact source excerpt. Text positions 29395–30864, end exclusive, in the original decoded publication. SHA-256: d91b491956f6625498f39e6518579d3f3d6d7d34011fffca2156d822d1d82e72
Explicit historical replacement wording
Find all recorded historical references to AD 2012-10-03 · 0 printed reference observations in this pinned collection.
These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.
Why these observations are shown
They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.
Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: eb2b7d000acb3625f5c68aa264e075299024828f3330ccf10ef56cbd748eb2d9. Source manifest: d80f7cd84522105b132bd728f2bf964b213fc14745e3a2aafb846b1aa15dfd28.
Official source · 2012-05-21
Publication text
This is the complete recorded text of this dated publication.
Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.
Read the complete official publication text
[Federal Register Volume 77, Number 98 (Monday, May 21, 2012)]
[Rules and Regulations]
[Pages 29857-29861]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-11869]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2011-0645; Directorate Identifier 2010-NM-009-AD;
Amendment 39-17052; AD 2012-10-03]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We are superseding an existing airworthiness directive (AD)
for certain The Boeing Company Model 747 series airplanes. That AD
currently requires repetitive inspections for cracks of the fuselage
skin lap splice between body station (BS) 400 and BS 520 at stringers
S-6L and S-6R, and repair if necessary. This new AD shortens the
interval for the repetitive inspections, requires modification for
certain airplanes, and requires certain post-modification inspections
for other airplanes. This AD was prompted by reports of multiple
adjacent cracks on an airplane, and a recent fleet-wide evaluation of
widespread fatigue damage of skin lap joints, which indicated the need
for revised procedures and reduced compliance times. We are issuing
this AD to detect and correct cracking of the fuselage skin lap splice
between BS 400 and BS 520 at stringers S-6L and S-6R, which could
result in sudden loss of cabin pressurization and the inability of the
fuselage to withstand fail-safe loads.
DATES: This AD is effective June 25, 2012.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of June 25, 2012.
ADDRESSES: 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; email [email protected];
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 AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (phone: 800-647-5527) is Document Management Facility,
U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Bill Ashforth, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office
(ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: 425-
917-6432; fax: 425-917-6590; email: [email protected].
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 90-21-17, Amendment 39-6768 (55 FR 41510,
October 12, 1990). That AD applies to the specified products. The NPRM
was published in the Federal Register on June 29, 2011 (76 FR 38074).
That NPRM proposed to continue to require repetitive inspections for
cracks of the fuselage skin lap splice between body station (BS) 400
and BS 520 at stringers S-6L and S-6R, and repair if necessary; and
added modification for certain airplanes and certain post-modification
inspections for other airplanes.
Comments
We gave the public the opportunity to participate in developing
this AD. The following presents the comments received on the proposal
(76 FR 38074, June 29, 2011) and the FAA's response to each comment.
[[Page 29858]]
Request To Remove Conflicting Requirement
Boeing stated that certain compliance times conflict in the
proposed AD (76 FR 38074, June 29, 2011). To resolve the conflict,
Boeing requested that we remove paragraph (k) from the proposed AD.
(Paragraph (k) was retained from AD 90-21-17, Amendment 39-6768 (55 FR
41510, October 12, 1990).) The initial compliance time for the
inspections specified in paragraphs (k), (l), and (m) of the proposed
AD is 10,000 flight cycles after certain modifications have been done.
Boeing noted that the repetitive interval is 5,000 flight cycles for
paragraph (k) of the proposed AD--but Boeing Service Bulletin 747-
53A2303, Revision 2, dated October 1, 2009, specifies 500 flight cycles
for paragraphs (l) and (m) of the proposed AD. Boeing stated that the
preventive modifications include the protruding head fastener
modification and the external reinforcement doubler installation (which
does not cut the lap).
We partially agree with the request. We agree that, as written, the
compliance times specified in paragraphs (l) and (m) of the proposed AD
(76 FR 38074, June 29, 2011) would have conflicted with the compliance
time specified in paragraph (k) in the proposed AD, as described by the
commenter. But, for airplanes nearing the 5,000-flight-cycle repetitive
interval specified in paragraph (k) of the AD on the new effective
date, removing paragraph (k) from the AD would allow an unwarranted
extension of time to comply, and could compromise the continued safe
operation of those airplanes. We have therefore retained paragraph (k)
in this AD. We have further determined that, once the applicable
inspections specified in paragraph (l) or (m) of the AD have been
initiated, the actions in paragraph (k) are no longer necessary. To
avoid the conflict described by the commenter, we have revised
paragraphs (l) and (m) of this AD to state that their accomplishment
terminates the requirements of paragraph (k) of this AD.
Request To Revise Modification Requirements
Boeing requested that we revise paragraph (n) of the proposed AD
(76 FR 38074, June 29, 2011) to specify separate requirements for the
two groups of affected airplanes, so that the proposed AD agrees with
the actions specified in Table 2 of paragraph 1.E., ``Compliance,'' of
Boeing Service Bulletin 747-53A2303, Revision 2, dated October 1, 2009.
One group affected by paragraph (n) of the proposed AD (76 FR
38074, June 29, 2011) is airplanes on which no previous modification or
repair has been installed in the affected area. For those airplanes,
Boeing requested that we require a structural modification in
accordance with Part 3 of Boeing Service Bulletin 747-53A2303, Revision
2, dated October 1, 2009, within the compliance time specified in
paragraph A. of AD 90-06-06, Amendment 39-6490 (55 FR 8374, March 7,
1990).
(AD 90-06-06, Amendment 39-6490 (55 FR 8374, March 7, 1990),
applies to certain Boeing Model 747 series airplanes and requires
structural modifications in accordance with Boeing Document D6-35999,
dated March 31, 1989. That document in turn refers to Boeing Alert
Service Bulletin 747-53A2303, dated June 2, 1988, as another source of
guidance for doing that modification.)
Boeing requested no change for the remaining airplanes identified
in paragraph (n) of the proposed AD (76 FR 38074, June 29, 2011).
We partially agree. For the referenced airplanes, this same
modification is one of the requirements of AD 90-06-06, Amendment 39-
6490 (55 FR 8374, March 7, 1990). The compliance time for this
modification is 23,000 total accumulated flight cycles, or within 4
years after the effective date (April 17, 1990), whichever occurs
later. To clarify the ADs' requirements, we have removed those
airplanes from paragraph (n) of the NPRM (76 FR 38074, June 29, 2011)
and added a new paragraph (o) in this AD, which explains that, for
those airplanes, accomplishment of the referenced modification
satisfies the corresponding requirement for AD 90-06-06, but post-
modification inspections are required. We have re-identified subsequent
paragraphs in this AD accordingly.
Request To Refer to Service Information for Compliance Data
Boeing requested that the FAA review the compliance data in the
proposed AD (76 FR 38074, June 29, 2011). Boeing noted that the
proposed AD repeated all the compliance data as stated in Boeing
Service Bulletin 747-53A2303, Revision 2, dated October 1, 2009. Boeing
requested that we refer to the compliance table in this service
bulletin as the source of all compliance data, except as noted.
Referring to paragraph 1.E., ``Compliance,'' of a service bulletin
may be an efficient way to convey compliance time information in an AD,
if the compliance times are complex or numerous. But specifying simpler
compliance times within an AD--as in paragraphs (l), (m), and (n) in
this AD--is also acceptable and enforceable. For requirements retained
from a superseded AD--as in paragraphs (g) through (k) in this AD--we
routinely restate the existing language from the AD that is being
superseded, including the text describing the compliance times. We have
not changed this AD regarding this issue.
Explanation of Additional Changes to This AD
The information in Note 1 of the proposed AD (76 FR 38074, June 29,
2011) has been moved to a new paragraph (g)(4) in this AD.
As explained in the proposed AD (76 FR 38074, June 29, 2011),
paragraph (p) in the proposed AD (paragraph (q) in this final rule) was
revised to add delegation of authority to Boeing Commercial Airplanes
Organization Designation Authorization (ODA) to approve an alternative
method of compliance for any repair required by this AD. We have also
changed paragraph (k) of this AD to reflect this change.
Conclusion
We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
the AD with the changes described previously and minor editorial
changes. We have determined that these minor changes:
<bullet> Are consistent with the intent that was proposed in the
NPRM (76 FR 38074, June 29, 2011) for correcting the unsafe condition;
and
<bullet> Do not add any additional burden upon the public than was
already proposed in the NPRM (76 FR 38074, June 29, 2011).
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of the AD.
Costs of Compliance
There are about 165 airplanes of the affected design in the
worldwide fleet; of these, 64 are U.S.-registered airplanes. The
following table provides the estimated costs for U.S. operators to
comply with this AD.
[[Page 29859]]
Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average labor
Action Work hours rate per hour Parts Cost per airplane Fleet cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection (required by AD 90-21-17, 8....................... $85 $0..................... $680 per inspection $43,520 per inspection
Amendment 39-6768 (55 FR 41510, cycle. cycle.
October 12, 1990).
Modification (new action)........... Up to 370............... 85 Between $954 and $2,064 Up to $33,514.......... Up to $2,144,896.
--------------------------------------------------------------------------------------------------------------------------------------------------------
We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions 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
We have determined that 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 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 removing airworthiness directive (AD)
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), and adding
the following new AD:
2012-10-03 The Boeing Company: Amendment 39-17052; Docket No. FAA-
2011-0645; Directorate Identifier 2010-NM-009-AD.
(a) Effective Date
This airworthiness directive (AD) is effective June 25, 2012.
(b) Affected ADs
This AD supersedes AD 90-21-17, Amendment 39-6768 (55 FR 41510,
October 12, 1990).
(c) Applicability
This AD applies to The Boeing Company Model 747-100, 747-100B,
747-200B, 747-200C, 747-200F, 747-300, 747SR, and 747SP series
airplanes, certificated in any category, as identified in Boeing
Service Bulletin 747-53A2303, Revision 2, dated October 1, 2009.
(d) Subject
Joint Aircraft System Component (JASC)/Air Transport Association
(ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by from reports of multiple adjacent cracks
on an airplane, and a recent fleet-wide evaluation of widespread
fatigue damage of skin lap joints, which indicated the need for
revised procedures and reduced compliance times. The Federal
Aviation Administration is issuing this AD to detect and correct
cracking of the fuselage skin lap splice between body station (BS)
400 and BS 520, at stringers S-6L and S-6R. Such cracking could
result in sudden loss of cabin pressurization and the inability of
the fuselage to withstand fail-safe loads.
(f) Compliance
You are responsible for having the actions required by this AD
performed within the compliance times specified, unless the actions
have already been done.
(g) Retained Inspections
This paragraph restates the requirements of paragraph A. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information, reduced inspection interval, and added
subparagraph. Conduct a close visual or detailed inspection, and a
high frequency eddy current (HFEC) inspection, of the fuselage skin
lap splice between BS 400 and BS 520, at stringers S-6L and S-6R,
for cracking, in accordance with Boeing Alert Service Bulletin 747-
53A2303, dated June 2, 1988, or Revision 1, dated March 29, 1990; or
Boeing Service Bulletin 747-53A2303, Revision 2, dated October 1,
2009; at the times specified in paragraph (g)(1), (g)(2), or (g)(3)
of this AD. After the effective date of this AD, only Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009, may be
used. Adequate lighting must be used for this inspection. The eddy
current inspections may be conducted without removal of the paint,
provided the paint does not interfere with the inspections. Paint
must be removed, using an approved chemical stripper, in any
situation where the inspector determines that the paint is
interfering with the proper functioning of the inspection
instrument.
(1) Within the next 100 landings after March 31, 1989 (the
effective date of AD 89-05-03, Amendment 39-6146 (54 FR 7397,
February 21, 1989), which was superseded by AD 90-21-17, Amendment
39-6768 (55 FR 41510, October 12, 1990)), for airplanes that have
accumulated 16,000 or more landings as of March 31, 1989, unless
previously accomplished within the last 4,900 landings.
(2) Within the next 1,000 landings after March 31, 1989, or
prior to the accumulation of 16,000 landings, whichever occurs
first, for airplanes that have accumulated between 12,000 and 16,000
landings, as of March 31, 1989 (the effective date of AD 89-05-03,
Amendment 39-6146 (54 FR 7397, February 21, 1989), which was
superseded by AD 90-21-17, Amendment 39-6768 (55 FR 41510, October
12, 1990)), unless previously accomplished within the last 4,000
landings.
(3) Prior to the accumulation of 13,000 landings for airplanes
that have accumulated 12,000 or fewer landings as of March 31, 1989
(the effective date of AD 89-05-03,
[[Page 29860]]
Amendment 39-6146 (54 FR 7397, February 21, 1989), which was
superseded by AD 90-21-17, Amendment 39-6768 (55 FR 41510, October
12, 1990)), unless previously accomplished within the last 5,000
landings.
(4) For the purposes of this AD, a detailed inspection is: ``An
intensive examination of a specific item, installation, or assembly
to detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at an
intensity deemed appropriate. Inspection aids such as mirror,
magnifying lenses, etc., may be necessary. Surface cleaning and
elaborate procedures may be required.''
(h) Retained Inspection Compliance Time for SUD-Modified Airplanes
This paragraph restates the requirements of paragraph B. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. On airplanes which have been modified
to the stretched-upper-deck configuration, as identified in Boeing
Alert Service Bulletin 747-53A2303, dated June 2, 1988, or Revision
1, dated March 29, 1990; or Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009; the accumulated landing threshold
for compliance with paragraph (g) of this AD is measured from the
time of the stretched-upper-deck modification.
(i) Retained Repetitive Inspections
This paragraph restates the requirements of paragraph C. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. If no cracking is detected during the
inspections required by paragraph (g) of this AD, repeat the
inspections required by paragraph (g) of this AD one time at the
earlier of the times specified in paragraphs (i)(1) and (i)(2) of
this AD. Thereafter repeat the inspections at intervals not to
exceed 3,000 landings.
(1) Within 5,000 landings after the last inspection.
(2) Within 3,000 landings after the last inspection, or within
1,000 landings after the effective date of this AD, whichever occurs
later.
(j) Retained Repair
This paragraph restates the requirements of paragraph D. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. If cracks are detected during the
inspections required by paragraph (g) of this AD, accomplish the
repair or preventive modification of the affected lap splice, in
accordance with Boeing Alert Service Bulletin 747-53A2303, dated
June 2, 1988, or Revision 1, dated March 29, 1990; or Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009; prior to
further pressurized flight. After the effective date of this AD,
only Boeing Service Bulletin747-53A2303, Revision 2, dated October
1, 2009, may be used. If cracks are repaired in local areas without
accomplishing preventive modification of the entire affected lap
area, continue inspections of the unmodified and unrepaired areas of
the affected lap splice in accordance with paragraph (i) of this AD.
(k) Retained Inspection Compliance Time for Airplanes With Preventive
Modification
This paragraph restates the requirements of paragraph E. of AD
90-21-17, Amendment 39-6768 (55 FR 41510, October 12, 1990), with
revised service information. For airplanes incorporating the
preventive modification, as described in Boeing Alert Service
Bulletin 747-53A2303, dated June 2, 1988, or Revision 1, dated March
29, 1990; or Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009; accomplish the inspections required by paragraph
(g) of this AD prior to the accumulation of 10,000 landings after
the modification and thereafter at intervals not to exceed 5,000
landings. If cracks are found, repair using a method approved in
accordance with the procedures specified in paragraph (q) of this
AD, prior to further pressurized flight.
(l) New Requirement of This AD: Post-Modification Inspections
For airplanes on which a protruding head fastener modification
has been done in accordance with Boeing Alert Service Bulletin 747-
53A2303, dated June 2, 1988, or Revision 1, dated March 29, 1990:
Within 10,000 flight cycles after modification, or within 500 flight
cycles after the effective date of this AD, whichever occurs later,
do an external HFEC inspection for cracking in the skin around the
fasteners in the upper row of the lap joint, in accordance with Part
5 of the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2303, Revision 2, dated October 1, 2009. If any crack is found,
before further flight repair in accordance with Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009 (except as
required by paragraph (p) of this AD), or do the modification
specified in paragraph (n) of this AD. Repeat the inspection in
affected uncracked areas at intervals not to exceed 500 flight
cycles, until the modification specified in paragraph (n) of this AD
is done. Accomplishment of the initial inspection and all applicable
corrective actions specified in this paragraph terminates the
requirements of paragraph (k) of this AD.
(m) New Requirement of This AD: Internal HFEC Inspection
For airplanes on which an external doubler repair has been
installed as a modification that was done using a method other than
that specified in Boeing 747 structural repair manual (SRM) 53-30-
03, Figure 19, 25, 28 or 34: Within 10,000 flight cycles after
modification, or within 500 flight cycles after the effective date
of this AD, whichever occurs later, do an internal HFEC inspection
for cracking in the skin around the fasteners in the upper row of
the lap joint, in accordance with Part 5 of the Accomplishment
Instructions of Boeing Service Bulletin 747-53A2303, Revision 2,
dated October 1, 2009. If any crack is found, before further flight
repair in accordance with Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009 (except as required by paragraph
(p) of this AD), or do the modification specified in paragraph (n)
of this AD. Repeat the inspection in affected uncracked areas at
intervals not to exceed 500 flight cycles, until the modification
specified in paragraph (n) of this AD is done. Accomplishment of the
initial inspection and all applicable corrective actions specified
in this paragraph terminates the requirements of paragraph (k) of
this AD.
(n) New Requirement of This AD: External Doubler Modification
For airplanes on which a protruding head fastener modification
or a Boeing 747 SRM 53-30-03 repair or modification has been
installed that was not done using Boeing 747 SRM 53-30-03, Figure
19, 25, 28, or 34, for the full length of the lap splice: Within
14,000 flight cycles after the first repair or modification was
done, or within 3,000 flight cycles after the effective date of this
AD, whichever occurs later, modify the skin and do all post-
modification inspections and repairs, in accordance with Part 3 of
the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2303, Revision 2, dated October 1, 2009, except as required by
paragraph (o) of this AD. Do the post-modification inspection within
10,000 flight cycles after installation of the modification. Repeat
the inspection thereafter at intervals not to exceed 3,000 flight
cycles. All applicable repairs must be done before further flight.
(o) Structural Modification
The provisions of paragraphs (o)(1) and (o)(2) of this AD apply
to airplanes on which no previous modification or repair has been
installed in the affected area.
(1) Accomplishment of the structural modification specified in
Part 3 of the Accomplishment Instructions of Boeing Service Bulletin
747-53A2303, Revision 2, dated October 1, 2009, satisfies the
requirements of AD 90-06-06, Amendment 39-6490 (55 FR 8374, March 7,
1990), for only the corresponding modification specified in Boeing
Alert Service Bulletin 747-53A2303, dated June 2, 1988, and Revision
1, dated March 29, 1990; and Boeing Service Bulletin 747-53A2303,
Revision 2, dated October 1, 2009.
(2) After accomplishment of the modification specified in
paragraph (o)(1) of this AD, the applicable requirements and
compliance times of paragraphs (l) and (m) of this AD apply.
(p) Exception to Service Bulletin Specification
Where Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009, specifies to contact Boeing for appropriate action:
Before further flight, repair using a method approved in accordance
with the procedures specified in paragraph (q) of this AD.
(q) 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
[[Page 29861]]
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) or other person who 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 previously in accordance with AD 90-21-17,
Amendment 39-6768 (55 FR 41510, October 12, 1990), are approved as
AMOCs for the corresponding provisions of paragraphs (g) and (i) of
this AD. AMOCs approved previously in accordance with AD 90-21-17,
Amendment 39-6768 (55 FR 41510, October 12, 1990), are approved as
AMOCs for the corresponding provisions of paragraphs (j) and (n) of
this AD only if the repair or preventive modification of the
affected lap splice was done in accordance with Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009, including
Boeing Designated Engineering Representative (DER) or Airworthiness
Representative (AR) approvals of deviations to Boeing Service
Bulletin 747-53A2303, Revision 2, dated October 1, 2009.
(r) Related Information
For more information about this AD, contact Bill Ashforth,
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington
98057-3356; telephone 425-917-6432; fax 425-917-6590; email:
[email protected].
(s) Material Incorporated by Reference
(1) You must use the following service information to do the
actions required by this AD, unless the AD specifies otherwise. The
Director of the Federal Register approved the incorporation by
reference (IBR) of the following service information under 5 U.S.C.
552(a) and 1 CFR part 51:
(i) Boeing Alert Service Bulletin 747-53A2303, dated June 2,
1988.
(ii) Boeing Alert Service Bulletin 747-53A2303, Revision 1,
dated March 29, 1990.
(iii) Boeing Service Bulletin 747-53A2303, Revision 2, dated
October 1, 2009.
(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; email
[email protected]; Internet https://www.myboeingfleet.com.
(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 Records
Administration (NARA). For information on the availability of this
material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Issued in Renton, Washington, on May 8, 2012.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-11869 Filed 5-18-12; 8:45 am]
BILLING CODE 4910-13-P
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