[Federal Register Volume 78, Number 86 (Friday, May 3, 2013)]
[Proposed Rules]
[Pages 25898-25902]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-10481]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0364; Directorate Identifier 2011-NM-114-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 an existing airworthiness directive 
(AD) that applies to certain The Boeing Company Model 747 series 
airplanes. The existing AD currently requires inspection of the 
fuselage skin lap splice between body station (BS) 340 and BS 400 at 
stringers (S)-6L and S-6R, and repair, if necessary. Since we issued 
that AD, analysis results indicated that the protruding head fastener 
modification and related post-modification inspections currently 
required are not adequate to prevent cracking at the upper row of 
fasteners in the stringer 6 lap joint before the cracks reach a 
critical length. This proposed AD would add new repetitive inspections 
for cracking in the stringer 6 skin lap splice, which would terminate 
the existing inspections; and eventual modification of the lap splice, 
which would terminate the repetitive inspections; post-modification 
inspections; and corrective actions if necessary. This proposed AD 
would also add airplanes to the applicability. We are proposing this AD 
to detect and correct cracking at the upper row of fasteners in the 
stringer(s) 6 lap joint, which could result in a sudden loss of cabin 
pressurization and the inability of the fuselage to withstand failsafe 
loads.

DATES: We must receive comments on this proposed AD by June 17, 2013.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the 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 gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Bill Ashforth, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6432; 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-2013-0364; 
Directorate Identifier 2011-NM-114-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

[[Page 25899]]

will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On October 25, 1990, we issued AD 90-23-14, Amendment 39-6801 
(Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 1990), for certain 
The Boeing Company Model 747 series airplanes. AD 90-23-14 superseded 
AD 85-17-05, Amendment 39-5123 (Docket No. 85-NM-36-AD; 50 FR 33334, 
August 19, 1985). AD 90-23-14 requires inspection of the fuselage skin 
lap splice between BS 340 and BS 400 at S-6L and S-6R, and repair if 
necessary. AD 90-23-14 resulted from the FAA's determination to remove 
the crack repair deferral option permitted in AD 85-17-05. We issued AD 
90-23-14 to prevent a sudden loss of cabin pressurization and the 
inability of the fuselage to withstand failsafe loads.

Actions Since Existing AD (AD 90-23-14, Amendment 39-6801 (Docket No. 
90-NM-110-AD; 55 FR 46652, November 6, 1990)) Was Issued

    Since we issued AD 90-23-14, Amendment 39-6801 (Docket No. 90-NM-
110-AD; 55 FR 46652, November 6, 1990), analysis results have indicated 
that the post-modification inspections required by that AD for 
airplanes with an (optional) protruding head fastener modification are 
not adequate to prevent cracking at the upper row of fasteners in the 
stringer 6 lap joint before they reach a critical length.
    We have also determined that the stretched upper deck (SUD) 
modified airplanes that were added in Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010, have a 
unique configuration at the S-6 lap splice in Section 41. This 
configuration was determined not to be equivalent to the improved 
configuration used after line number 603 in terms of fatigue life. This 
determination was made after the S-6 splice was re-evaluated to remove 
the protruding head fastener modification option, which was 
incorporated in Boeing Special Attention Service Bulletin 747-53-2253, 
Revision 4, dated September 9, 2010. For the SUD modified airplanes, 
inspections specified in Boeing Alert Service Bulletin 747-53A2809, 
dated June 18, 2009, are currently required by other ADs. In addition, 
the external doubler modification specified in Boeing Service Bulletin 
747-53-2272, is currently required by other ADs. Boeing Special 
Attention Service Bulletin 747-53-2253, Revision 4, dated September 9, 
2010, therefore added the post-mod inspections for the SUD modified 
airplanes in lieu of revising the existing service information that is 
required by other ADs.

Relevant Service Information

    We reviewed Boeing Special Attention Service Bulletin 747-53-2253, 
Revision 4, dated September 9, 2010. For information on the procedures 
and compliance times, see this service information at http://www.regulations.gov gov by searching for Docket No. FAA-2013-0364.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would retain the requirements of AD 90-23-14, 
Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 
1990). This proposed AD would add new repetitive inspections for 
cracking in the stringer 6 skin lap splice, which would terminate the 
existing inspections; eventual modification of the lap splice, which 
would terminate the repetitive inspections; post-modification 
inspections; and corrective actions if necessary. This proposed AD 
would also add airplanes to the applicability. This proposed AD would 
require accomplishing the actions specified in the service information 
described previously, except as discussed under ``Differences Between 
the Proposed AD and the Service Information.''
    The phrase ``related investigative actions'' might be used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that (1) are related to the primary actions, and (2) further 
investigate the nature of any condition found. Related investigative 
actions in an AD could include, for example, inspections.
    In addition, the phrase ``corrective actions'' might be used in 
this proposed AD. ``Corrective actions'' are actions that correct or 
address any condition found. Corrective actions in an AD could include, 
for example, repairs.

Differences Between the Proposed AD and the Service Information

    Boeing Special Attention Service Bulletin 747-53-2253, Revision 4, 
dated September 9, 2010, specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.

Change to Existing AD

    This proposed AD would retain certain requirements of AD 90-23-14, 
Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 
1990). Since AD 90-23-14 was issued, the AD format has been revised, 
and certain paragraphs have been rearranged. As a result, the 
corresponding paragraph identifiers have changed in this proposed AD, 
as listed in the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
 Requirement in AD 90-23-14, Amendment 39-
6801 (Docket No. 90-NM-110-AD;55 FR 46652,  Corresponding requirement in
             November 6, 1990)                    this proposed AD
------------------------------------------------------------------------
paragraph (A).............................  paragraph (g)
paragraph (B).............................  paragraph (h)
paragraph (C).............................  paragraph (i)
paragraph (D).............................  paragraph (j)
------------------------------------------------------------------------

    We have also added new paragraph (o)(3) to this proposed AD to 
clarify that if any cracking is found during any inspection required by 
this proposed AD, and Boeing Special Attention Service Bulletin 747-53-
2253, Revision 2, dated March 29, 1990, specifies to contact Boeing for 
appropriate action, this proposed AD would require repairing the crack 
using a method approved in accordance with the procedures specified in 
paragraph (q) of this proposed AD.

Costs of Compliance

    We estimate that this proposed AD affects 76 airplanes of U.S. 
registry. We estimate the following costs to comply with this proposed 
AD:

[[Page 25900]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Retained inspections from AD 90-   8 work-hours x $85               $0  $680 per inspection  $51,680 per
 23-14, Amendment 39-6801 (Docket   per hour = $680                      cycle.               inspection cycle
 No. 90-NM-110-AD; 55 FR 46652,     per inspection
 November 6, 1990).                 cycle.
New proposed pre-modification      8 work-hours x $85               $0  $680 per inspection  $51,680 per
 inspections.                       per hour = $680                      cycle.               inspection cycle
                                    per inspection
                                    cycle.
New proposed modification........  204 work-hours x                 $0  $17,340............  $1,317,840
                                    $85 per hour =
                                    $17,340.
New proposed post-modification     12 work-hours x $85              $0  $1,020 per           $77,520
 inspections.                       per hour = $1,020                    inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this 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. The FAA amends Sec.  39.13 by removing airworthiness directive (AD) 
90-23-14, Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, 
November 6, 1990), and adding the following new AD:

The Boeing Company: Docket No. FAA-2013-0364; Directorate Identifier 
2011-NM-114-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by June 17, 
2013.

(b) Affected ADs

    This AD supersedes AD 90-23-14, Amendment 39-6801 (55 FR 46652, 
November 6, 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 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by analysis results indicating that the 
protruding head fastener modification and related post-modification 
inspections currently required are not adequate to prevent cracking 
at the upper row of fasteners in the stringer (S)-6 lap joint before 
the cracks reach a critical length. We are issuing this AD to detect 
and correct cracking at the upper row of fasteners in the S-6 lap 
joint, which could result in a sudden loss of cabin pressurization 
and the inability of the fuselage to withstand failsafe loads.

(f) Compliance

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

(g) Retained Inspection for Unmodified Airplanes With Revised Service 
Information

    This paragraph restates the requirements of paragraph (A) of AD 
90-23-14, Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, 
November 6, 1990), with revised service information. For airplanes 
identified in Boeing Service Bulletin 747-53-2253, Revision 2, dated 
March 29, 1990, and that have not been modified as specified in 
Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 
1990; In accordance with the schedule indicated below, perform a 
high frequency eddy current (HFEC) inspection of the fuselage lap 
joint for cracks between body station (BS) 340 and BS 400, or aft as 
far as the crew door, at stringer S-6L and S-6R, in accordance with 
Boeing Service Bulletin 747-53-2253, Revision 2, dated March 29, 
1990; or Boeing Special Attention Service Bulletin 747-53-2253, 
Revision 4, dated September 9, 2010. As of the effective date of 
this AD, only Boeing Special Attention Service Bulletin 747-53-2253, 
Revision 4, dated September 9, 2010, may be used to accomplish the 
actions required by this paragraph.
    (1) Inspection Schedule:
    (i) Unless previously accomplished within the last 2,750 
landings, perform the initial inspection within the next 250 
landings after December 11, 1990 (the effective date of AD 90-23-14, 
Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 
1990)), or prior to the accumulation of 10,000 landings after the 
modification, whichever occurs later.
    (ii) Repeat the inspection thereafter at intervals not to exceed 
3,000 landings.

[[Page 25901]]

    (2) If cracks are found, repair prior to further flight, in 
accordance with Boeing Service Bulletin 747-53-2253, Revision 2, 
dated March 29, 1990; or Boeing Special Attention Service Bulletin 
747-53-2253, Revision 4, dated September 9, 2010. As of the 
effective date of this AD, only Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010, may be 
used to accomplish the actions required by this paragraph.

(h) Retained Inspection for Modified Airplanes With Revised Service 
Information

    This paragraph restates the requirements of paragraph (B) of AD 
90-23-14, Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, 
November 6, 1990), with revised service information. For airplanes 
identified in Boeing Service Bulletin 747-53-2253, Revision 2, dated 
March 29, 1990, and that have been modified as specified in Boeing 
Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990; In 
accordance with the schedule below, perform an HFEC inspection of 
the fuselage lap joint for cracks between BS 340 and BS 400, or aft 
as far as the crew door, at S-6L and S-6R, in accordance with Boeing 
Service Bulletin 747-53-2253, Revision 2, dated March 29, 1990, or 
Boeing Special Attention Service Bulletin 747-53-2253, Revision 4, 
dated September 9, 2010. As of the effective date of this AD, use 
only Boeing Special Attention Service Bulletin 747-53-2253, Revision 
4, dated September 9, 2010, to accomplish the action required by 
this paragraph. Accomplishment of the actions required by paragraph 
(k) of this AD terminates the requirements of this paragraph.
    (1) Inspection Schedule:
    (i) Unless previously accomplished within the last 2,750 
landings, perform the initial inspection within the next 250 
landings after December 11, 1990 (the effective date of AD 90-23-14, 
Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 
1990)), or prior to the accumulation of 10,000 landings after the 
modification, whichever occurs later.
    (ii) Repeat the inspection thereafter at intervals not to exceed 
3,000 landings.
    (2) If cracks are found, repair prior to further flight, in 
accordance with Boeing Service Bulletin 747-53-2253, Revision 2, 
dated March 29, 1990; or Boeing Special Attention Service Bulletin 
747-53-2253, Revision 4, dated September 9, 2010. As of the 
effective date of this AD, only Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010, may be 
used to accomplish the actions required by this paragraph.

(i) Retained Landing Determination

    This paragraph restates the provisions of paragraph (C) of AD 
90-23-14, Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, 
November 6, 1990), with compliance time limitation. For purposes of 
complying with paragraphs (g) and (h) of this AD, the number of 
landings may be determined to be equal to the number of 
pressurization cycles where the cabin pressure differential was 
greater than 1.5 pounds per square inch (psi); After the effective 
date of this AD, the 1.5 psi cabin pressure differential is not 
allowed.

(j) Retained Inspection Adjustment Factor

    This paragraph restates the requirements of paragraph (D) of AD 
90-23-14, Amendment 39-6801 (55 FR 46652, November 6, 1990) with 
compliance time limitation. For Model 747SR airplanes only: Based on 
a continued mixed operation of lower cabin differentials, the 
initial inspection thresholds and the repetitive inspection 
intervals specified in paragraphs (g) and (h) of this AD may be 
multiplied by a 1.2 adjustment factor; After the effective date of 
this AD, the 1.2 adjustment factor is not allowed.

(k) New Inspections: Groups 1 Through 5 Airplanes

    For airplanes in Groups 1 through 5, as identified in Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010: At the time specified in Table 1 of paragraph 
1.E., ``Compliance,'' of Boeing Special Attention Service Bulletin 
747-53-2253, Revision 4, dated September 9, 2010, except where Table 
1 of paragraph 1.E., ``Compliance,'' of Boeing Special Attention 
Service Bulletin 747-53-2253, Revision 4, dated September 9, 2010, 
refers to a compliance time of 250 flight cycles after December 11, 
1990 (the effective date of AD 90-23-14, Amendment 39-6801 (Docket 
No. 90-NM-110-AD; 55 FR 46652, November 6, 1990)), the compliance 
time in this AD is 250 flight cycles after the effective date of 
this AD; do external detailed and HFEC inspections for cracks in the 
stringer 6 skin lap splice, and do all applicable corrective 
actions, as applicable; in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 747-53-
2253, Revision 4, dated September 9, 2010, except as required by 
paragraph (o) of this AD. Do all applicable corrective actions at 
the applicable time specified in paragraph 1.E., ``Compliance,'' of 
Boeing Special Attention Service Bulletin 747-53-2253, Revision 4, 
dated September 9, 2010. Accomplishment of the actions required by 
this paragraph terminates the requirements of paragraphs (g) and (h) 
of this AD.

(l) New Repetitive Pre-modification Inspections: Groups 1 Through 5 
Airplanes

    For airplanes in Groups 1 through 5, as identified in Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010: Repeat the inspections required by paragraph (k) 
of this AD at the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 747-53-
2253, Revision 4, dated September 9, 2010, until accomplishment of 
the modification required by paragraph (m) of this AD.

(m) New Modification: Groups 1 Through 5 Airplanes

    (1) For airplanes in Groups 1 through 5, as identified in Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010, on which the structural repair manual (SRM) 
repair specified in Part 1 of the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 747-53-2253, Revision 4, 
dated September 9, 2010, has not been done: Before the accumulation 
of 20,000 total flight cycles, or within 1,000 flight cycles after 
the effective date of this AD, whichever occurs later, install the 
doubler modification, and do all applicable related investigative 
and corrective actions, in accordance with Part 3 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010. All 
applicable related investigative and corrective actions must be done 
before further flight. Compliance with the requirements of this 
paragraph terminates the requirements of paragraphs (k) and (l) of 
this AD.
    (2) For airplanes in Groups 1 through 5, as identified in Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010, on which the SRM repair specified in Part 1 of 
the Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010, has been 
done: Within 3,000 flight cycles after accomplishing the SRM repair 
or within 1,000 flight cycles after the effective date of this AD, 
whichever occurs later, install the doubler modification, and do all 
applicable related investigative and corrective actions, in 
accordance with Part 3 of the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010. All applicable related investigative and 
corrective actions must be done before further flight. Compliance 
with the requirements of this paragraph terminates the requirements 
of paragraphs (k) and (l) of this AD.

(n) New Repetitive Post-modification Inspections: Modified Airplanes

    For airplanes modified as specified in Part 3 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010, at the 
applicable time specified in Table 3 or 4 of paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 747-53-
2253, Revision 4, dated September 9, 2010: Do detailed and eddy 
current inspections to detect cracking of the skin, frames, and tear 
straps, as applicable, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-53-2253, Revision 4, dated September 9, 2010. If any 
crack is found, repair before further flight using a method approved 
in accordance with the procedures specified in paragraph (q) of this 
AD. Repeat the applicable inspections thereafter at the applicable 
times specified in paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 747-53-2253, Revision 4, dated September 
9, 2010.

(o) Exceptions to Service Information Specifications

    (1) If any cracking is found during any inspection required by 
this AD, and Boeing Special Attention Service Bulletin 747-53-2253, 
Revision 4, dated September 9, 2010; specifies to contact Boeing for 
appropriate action: Before further flight, repair the crack using a 
method approved in accordance with

[[Page 25902]]

the procedures specified in paragraph (q) of this AD.
    (2) Although Boeing Special Attention Service Bulletin 747-53-
2253, Revision 4, dated September 9, 2010, specifies to submit 
certain information to the manufacturer, this AD does not include 
that requirement.
    (3) As of the effective date of this AD, if any cracking is 
found during any inspection required by this AD, and Boeing Special 
Attention Service Bulletin 747-53-2253, Revision 2, dated March 29, 
1990, specifies to contact Boeing for appropriate action: Before 
further flight, repair the crack using a method approved in 
accordance with the procedures specified in paragraph (q) of this 
AD.

(p) Credit for Previous Actions

    This paragraph provides credit for the repairs and doubler 
modifications required by paragraphs (k) and (m) of this AD, if 
those actions were performed before the effective date of this AD 
using the service information specified in paragraphs (p)(1) through 
(p)(4) of this AD. Post-modification inspections must continue, as 
required by paragraph (n) of this AD.
    (1) Boeing Service Bulletin 747-53-2253, dated December 14, 
1984, which is not incorporated by reference in this AD.
    (2) Boeing Service Bulletin 747-53-2253, Revision 1, dated 
January 25, 1990, which is not incorporated by reference in this AD.
    (3) Boeing Service Bulletin 747-53-2253, Revision 2, dated March 
29, 1990.
    (4) Boeing Service Bulletin 747-53-2253, Revision 3, dated March 
24, 1994, which is not incorporated by reference in 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 to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO, to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) AMOCs approved previously in accordance with AD 90-23-14, 
Amendment 39-6801 (Docket No. 90-NM-110-AD; 55 FR 46652, November 6, 
1990), are approved as AMOCs for the corresponding provisions of 
this AD:
    (5) AMOCs approved previously for the ADs specified in 
paragraphs (q)(5)(i) through (q)(5)(vi) of this AD, for repair and 
doubler modification installations in the area affected by Boeing 
Special Attention Service Bulletin 747-53-2253, Revision 4, dated 
September 9, 2010, are approved as AMOCs for the actions specified 
in paragraphs (g), (h), (k), (l), and (m) of this AD. The post-
modification inspections required by paragraph (n) of this AD must 
be accomplished.
    (i) AD 2010-10-05, Amendment 39-16284 (75 FR 27424, May 17, 
2010).
    (ii) AD 2010-09-03, Amendment 39-16268 (75 FR 22514, April 29, 
2010).
    (iii) AD 2009-04-16, Amendment 39-15822 (74 FR 8737, February 
26, 2009). (iv) AD 91-11-01, Amendment 39-6997 (56 FR 22306, May 15, 
1991).
    (v) AD 90-06-06 Amendment 39-6490 (55 FR 8374, March 7, 1990).
    (vi) AD 2006-24-02 Amendment 39-14831 (71 FR 67445, November 22, 
2006).

(r) Related Information

    (1) For more information about this AD, contact Bill Ashforth, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6432; fax: 425-917-6590; email: 
[email protected].
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the 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 April 24, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-10481 Filed 5-2-13; 8:45 am]
BILLING CODE 4910-13-P