Document ID: FAA-2013-0097-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2013-03-06T05:00Z

[Federal Register Volume 78, Number 44 (Wednesday, March 6, 2013)]
[Proposed Rules]
[Pages 14469-14473]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-05178]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0097; Directorate Identifier 2011-NM-243-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to certain The Boeing Company Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 
747-400D, 747-400F, and 747SR series airplanes. The existing AD 
currently requires repetitive inspections to find cracking of the web, 
strap, inner chords, inner chord angle of the forward edge frame of the 
number 5 main entry door cutouts, the frame segment between stringers 
16 and 31, and repair if necessary; and repetitive inspections for 
cracking of repairs. Since we issued that AD, we have received multiple 
reports of cracking outside of the previous fuselage inspection areas 
and a report of a crack that initiated at the aft edge of the inner 
chord rather than initiating at a fastener location, which was the 
previous cracking location. This proposed AD would expand the previous 
fuselage areas that are inspected for cracking. We are proposing this 
AD to detect and correct such cracks, which could cause damage to the 
adjacent body structure and could result in depressurization of the 
airplane in flight.

DATES: We must receive comments on this proposed AD by April 22, 2013.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may review copies of the service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at the 
FAA, call 425-227-1221.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Nathan Weigand, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6428; fax: 425-917-6590; email: Nathan.P.Weigand@faa.gov.

[[Page 14470]]

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-2013-0097; 
Directorate Identifier 2011-NM-243-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    On September 15, 2010, we issued AD 2010-20-08, Amendment 39-16442 
(75 FR 61337, October 5, 2010), for certain Model 747-100, 747-100B, 
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, and 747SR series airplanes. That AD requires repetitive 
inspections to find cracking of the web, strap, inner chords, inner 
chord angle of the forward edge frame of the number 5 main entry door 
cutouts, the frame segment between stringers 16 and 31, and repair if 
necessary; and repetitive inspections for cracking of repairs. That AD 
resulted from additional reports of cracks that have been found in the 
strap and inner chord of the forward edge frame of the number 5 main 
entry door cutouts, between stringers 16 and 23. We issued that AD to 
detect and correct such cracks, which could cause damage to the 
adjacent body structure and could result in depressurization of the 
airplane in flight.

Actions Since Existing AD (75 FR 61337, October 5, 2010) Was Issued

    Since we issued AD 2010-20-08, Amendment 39-16442 (75 FR 61337, 
October 5, 2010), we have received multiple reports of cracking outside 
of the previous fuselage inspection areas and a report of a crack that 
initiated at the aft edge of the inner chord rather than initiating at 
a fastener location, which was the previous cracking location.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 747-53A2450, Revision 7, 
dated November 2, 2011. For information on the procedures and 
compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2013-0097.

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 all requirements of AD 2010-20-08, 
Amendment 39-16442 (75 FR 61337, October 5, 2010). This proposed AD 
would also expand the previous fuselage areas that are inspected for 
cracking.
    The phrase ``related investigative actions'' might be used in this 
proposed AD. ``Related investigative actions'' are follow-on actions 
that: (1) Are related to the primary actions, and (2) are actions that 
further investigate the nature of any condition found. Related 
investigative actions in an AD could include, for example, inspections.
    In addition, the phrase ``corrective actions'' might be used in 
this proposed AD. ``Corrective actions'' are actions that correct or 
address any condition found. Corrective actions in an AD could include, 
for example, repairs.

Difference Between the Proposed AD and Relevant Service Information

    Boeing Alert Service Bulletin 747-53A2450, Revision 7, dated 
November 2, 2011, 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:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Costs of Compliance

    We estimate that this proposed AD affects 151 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                     Labor cost          Parts cost     Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspections [retained actions    Up to 44 work-hours x                $0  Up to $3,740 per    Up to $564,740 per
 from AD 2010[dash]20-08,         $85 per hour = $3,740                    inspection cycle.   inspection cycle.
 Amendment 39-16442 (75 FR        per inspection cycle.
 61337, October 5, 2010)].
Inspections [new proposed        Up to 121 work-hours x                0  Up to $10,285 per   Up to $1,553,035
 action].                         $85 per hour = $10,285                   inspection cycle.   per inspection
                                  per inspection cycle.                                        cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this proposed 
AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

[[Page 14471]]

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) 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010), and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2013-0097; Directorate Identifier 
2011-NM-243-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by April 22, 
2013.

(b) Affected ADs

    This AD supersedes AD 2010-20-08, Amendment 39-16442 (75 FR 
61337, October 5, 2010).

(c) Applicability

    This AD applies to The Boeing Company Model 747-100, 747-100B, 
747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-
400D, 747-400F, and 747SR series airplanes, certificated in any 
category, having line numbers 1 through 1419 inclusive; except for 
Model 747-400 series airplanes that have been modified into the 
Model 747-400 large cargo freighter configuration.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by multiple reports of cracking outside of 
the previous inspection areas and a report of a crack that initiated 
at the aft edge of the inner chord rather than initiating at a 
fastener location. We are issuing this AD to detect and correct such 
cracks, which could cause damage to the adjacent body structure and 
could result in a rapid depressurization of the airplane.

(f) Compliance

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

(g) Retained Repetitive Inspections for Frame Segment Between Stringers 
23 and 31 (No Terminating Action)

    This paragraph restates the requirements of paragraph (g) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For 
airplanes having line numbers 1 through 1304 inclusive: Inspect the 
airplane for cracks between stringers 23 and 31 per Boeing Alert 
Service Bulletin 747-53A2450, Revision 2, including Appendix A, 
dated January 4, 2001; or Boeing Alert Service Bulletin 747-53A2450, 
Revision 5, dated January 29, 2009; at the later of the applicable 
times specified in paragraph (h) or (i) of this AD, per table 1 to 
paragraphs (g) and (h) of this AD, as follows. Where there are 
differences between the AD and Boeing Alert Service Bulletin 747-
53A2450, Revision 2, including Appendix A, dated January 4, 2001; or 
Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated January 
29, 2009: the AD prevails.

                      Table 1 to Paragraphs (g) and (h) of This AD--Inspection Requirements
----------------------------------------------------------------------------------------------------------------
               Type of inspection                                        Area to inspect
----------------------------------------------------------------------------------------------------------------
(1) Detailed Visual............................  Strap inner chords forward and aft of the web, and exposed web
                                                  adjacent to the inner chords on station 2231 frame from
                                                  stringers 23 through 31 per Figure 5 or Figure 6 of the
                                                  service bulletins specified in paragraph (g) or (h) of this
                                                  AD, as applicable.
(2) Surface High Frequency Eddy Current (HFEC).  Station 2231 inner chord angles at lower main sill interface
                                                  per Figure 5 or Figure 6 of the service bulletins specified in
                                                  paragraph (g) or (h) of this AD, as applicable.
(3) Open Hole HFEC.............................  Station 2231 frame fastener locations per Figures 4 and 7, and
                                                  either Figure 5 or 6 of the service bulletins specified in
                                                  paragraph (g) or (h) of this AD, as applicable.
(4) Surface HFEC...............................  Around fastener locations on station 2231 inner chords from
                                                  stringers 23 through 31 per Figure 5 or Figure 6 of the
                                                  service bulletins specified in paragraph (g) or (h) of this
                                                  AD, as applicable.
(5) Low Frequency Eddy Current (LFEC)..........  Station 2231 frame strap in areas covered by the reveal per
                                                  Figure 5 or Figure 6 of the service bulletins specified in
                                                  paragraph (g) or (h) of this AD, as applicable.
----------------------------------------------------------------------------------------------------------------

    Note 1 to paragraph (g) of this AD: There is no terminating 
action currently available for the inspections required by paragraph 
(g) of this AD.

(h) Retained Compliance Times

    This paragraph restates the requirements of paragraph (h) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). Do 
the inspections specified in paragraph (g) of this AD at the 
applicable times specified in paragraph (h)(1) or (h)(2) of this AD. 
Repeat the inspections at intervals not to exceed 3,000 flight 
cycles until the inspections required by paragraph (m) or (o) of 
this AD are done. Where there are differences between the AD and 
Boeing Alert Service Bulletin 747-53A2450, Revision 2, including 
Appendix A, dated January 4, 2001; or Boeing Alert Service Bulletin 
747-53A2450, Revision 5, dated January 29, 2009: the AD prevails.
    (1) Do the inspections per table 1 to paragraphs (g) and (h) of 
this AD at the applicable time specified in the logic diagram in 
Figure 1 of Boeing Alert Service Bulletin 747-53A2450, Revision 2, 
including Appendix A, dated January 4, 2001. Where the compliance 
time in the logic diagram specifies a compliance time beginning 
``from receipt of this service bulletin,'' this AD requires that the 
compliance time begin ``after September 12, 2001 (the effective date 
of AD 2001-16-02, Amendment 39-12370 (66 FR 41440, August 8, 
2001)).''
    (2) After November 9, 2010 (the effective date of AD 2010-20-08, 
Amendment 39-16442 (75 FR 61337, October 5, 2010)), do the 
inspections per table 1 to paragraphs (g) and

[[Page 14472]]

(h) of this AD at the applicable compliance time specified in 
paragraph 1.E., ``Compliance'' of Boeing Alert Service Bulletin 747-
53A2450, Revision 5, dated January 29, 2009. Where the compliance 
time in Boeing Alert Service Bulletin 747-53A2450, Revision 2, 
including Appendix A, dated January 4, 2001, specifies a compliance 
time beginning ``after the date on Revision 2 of this service 
bulletin,'' this AD requires that the compliance time begin ``after 
September 12, 2001 (the effective date of AD 2001-16-02, Amendment 
39-12370 (66 FR 41440, August 8, 2001)).''

(i) Retained Repetitive Inspections for Frame Segment Between Stringers 
23 and 31

    This paragraph restates the requirements of paragraph (i) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). 
Within 3,000 flight cycles after accomplishment of the inspections 
specified in Figure 1 of Boeing Alert Service Bulletin 747-53A2450, 
dated May 4, 2000; or Boeing Alert Service Bulletin 747-53A2450, 
Revision 1, dated July 6, 2000; repeat the inspections specified in 
paragraph (g) of this AD at intervals not to exceed 3,000 flight 
cycles until the inspections required by paragraph (m) or (o) of 
this AD are done. Where there are differences between the AD and 
Boeing Alert Service Bulletin 747-53A2450, Revision 2, dated January 
4, 2001; or Boeing Alert Service Bulletin 747-53A2450, Revision 5, 
dated January 29, 2009: the AD prevails.

(j) Retained Additional Repetitive Inspections (for Frame Segment 
Between Stringers 16 and 23)

    This paragraph restates the requirements of paragraph (j) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010).
    (1) For all airplanes: Before the accumulation of 16,000 total 
flight cycles, or within 1,500 flight cycles after November 9, 2010 
(the effective date of AD 2010-20-08, Amendment 39-16442 (75 FR 
61337, October 5, 2010)), whichever occurs later, do a detailed 
inspection, an open hole HFEC inspection, a surface HFEC inspection, 
and a subsurface LFEC inspection for cracking of the forward edge 
frame of the number 5 main entry door cutouts, at station 2231, 
between stringers 16 and 23; in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2450, Revision 
5, dated January 29, 2009. Repeat the inspections thereafter at 
intervals not to exceed 3,000 flight cycles.
    (2) The part number of the nut for fastener code ``K'' in Figure 
7 of Boeing Alert Service Bulletin 747-53A2450, Revision 5, dated 
January 29, 2009, should be ``BACN10JC3CD,'' instead of 
``BACB30JC3CD.'' In addition, the part number of the optional nut 
for this fastener code should be ``BACN10YR3CD,'' instead of 
``BACN10YR4CD'' in Boeing Alert Service Bulletin 747-53A2450, 
Revision 5, dated January 29, 2009.

(k) Retained Repetitive Inspections for Line Numbers 1305 and On (for 
Frame Segment Between Stringers 23 and 31)

    This paragraph restates the requirements of paragraph (k) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For 
airplanes having line numbers 1305 and on: Before the accumulation 
of 16,000 total flight cycles, or within 1,500 flight cycles after 
November 9, 2010 (the effective date of AD 2010-20-08, Amendment 39-
16442 (75 FR 61337, October 5, 2010)), whichever occurs later, do a 
detailed inspection, an open hole HFEC inspection, a surface HFEC 
inspection, and a subsurface LFEC inspection for cracking of the 
forward edge frame of the number 5 main entry door cutouts, at 
station 2231, between stringers 23 and 31; in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2450, Revision 5, dated January 29, 2009. Repeat the inspections 
thereafter at intervals not to exceed 3,000 flight cycles.

(l) Retained Corrective Action for Paragraphs (g), (j), and (k) of This 
AD

    This paragraph restates the requirements of paragraph (l) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). If 
any crack is found during any inspection required by paragraph (g), 
(j), or (k) of this AD, before further flight, repair the crack in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, in accordance with data meeting the 
type certification basis of the airplane approved by the Boeing 
Commercial Airplanes Organization Designation Authorization (ODA) 
that has been authorized by the Manager, Seattle ACO, to make those 
findings; or in accordance with Boeing Alert Service Bulletin 747-
53A2450, Revision 5, dated January 29, 2009; as applicable. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the approval letter must specifically 
reference this AD. As of November 9, 2010 (the effective date of AD 
2010-20-08), repair the crack using a method approved in accordance 
with the procedures specified in paragraph (s) of this AD.

(m) Retained Post-Repair Inspections

    This paragraph restates the requirements of paragraph (m) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). 
Except as required by paragraph (n) of this AD, for airplanes on 
which the forward edge frame of the number 5 main entry door 
cutouts, at station 2231, between stringers 16 and 31, is repaired 
as specified in Boeing Alert Service Bulletin 747-53A2450: Within 
3,000 flight cycles after doing the repair or within 1,500 flight 
cycles after November 9, 2010 (the effective date of AD 2010-20-08), 
whichever occurs later, do the detailed, LFEC, and HFEC inspections 
of the repaired area for cracks, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2450, Revision 5, dated January 29, 2009. If no cracking is 
found, repeat the inspections thereafter at intervals not to exceed 
3,000 flight cycles. If any crack is found: Before further flight, 
repair using a method approved in accordance with the procedures 
specified in paragraph (s) of this AD. Doing the inspections 
specified in paragraph (m) of this AD terminates the repetitive 
inspections required by paragraphs (g), (h), (i), (j), and (k) of 
this AD for the repaired area.

(n) Retained Post-Repair Inspection Restriction

    This paragraph restates the requirements of paragraph (n) of AD 
2010-20-08, Amendment 39-16442 (75 FR 61337, October 5, 2010). For 
any frame that is repaired in accordance with a method other than 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-53A2450, Revision 5, dated January 29, 2009: Do the inspection 
in accordance with a method approved in accordance with the 
procedures specified in paragraph (s) of this AD.

(o) New Repetitive Inspections With Expanded Inspection Area

    Before the accumulation of 16,000 total flight cycles, or within 
3,000 flight cycles after the effective date of this AD, whichever 
occurs later, do the inspections required by paragraphs (o)(1) 
through (o)(5) of this AD, except as specified in paragraph (p) of 
this AD. Do all actions required by this paragraph in accordance 
with the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-53A2450, Revision 7, dated November 2, 2011. Repeat the 
inspections thereafter at the applicable times specified in 
Paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-53A2450, Revision 7, dated November 2, 2011. Accomplishment of 
the initial inspections required by this paragraph terminates the 
requirements of paragraphs (g) through (k) of this AD.
    (1) Do a detailed inspection for cracking on the frame strap, 
inner chords forward and aft of the web, and exposed web adjacent to 
the inner chords from stringer 15 to 31.
    (2) Do an HFEC inspection of the station 2231 frame fastener 
locations for cracking from stringer 16 to 31, including locations 
common to the upper main sill strap and stringer clip at stringer 
16.
    (3) Do an HFEC inspection for cracking of the frame inner chords 
around the fastener heads from stringer 15 to 31.
    (4) Do an HFEC inspection for cracking of the aft edge of the 
aft inner chord, of the forward edge of the forward inner chord, and 
of the forward and aft edges of the frame strap from stringer 15 to 
31.
    (5) Do an LFEC inspection for cracking of the station 2231 frame 
strap from stringer 16 to 31 in areas covered by the reveal.

(p) New Post-Repair Inspection for Repaired Areas

    For airplanes on which the post-repair inspections are being 
done as specified in paragraph (m) of this AD: For the repaired area 
only, continue the inspections as specified in paragraph (m) of this 
AD in lieu of the inspections specified in paragraph (o) of this AD.

(q) New Corrective Action

    If any cracking is found during any inspection required by 
paragraph (o), (p), or (r) of this AD: Before further flight, repair 
the cracking using a method approved in accordance with the 
procedures specified in paragraph (s) of this AD.

 (r) New Post-Repair Repetitive Inspections and Corrective Action

    For any airplane repaired as specified in paragraph (q) of this 
AD: Within 3,000 flight

[[Page 14473]]

cycles after doing the repair, do detailed, LFEC, and HFEC 
inspections of the repaired area for cracking, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-53A2450, Revision 7, dated November 2, 2011. If no cracking is 
found, repeat the inspections thereafter at intervals not to exceed 
3,000 flight cycles. If any cracking is found: Before further 
flight, do the actions specified in paragraph (q) of this AD.

(s) 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: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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 2010-20-08, 
Amendment 39-16442 (75 FR 61337, October 5, 2010), are approved as 
AMOCs for the corresponding provisions of paragraphs (g) through (m) 
of this AD.
    (5) AMOCs approved previously in accordance with AD 2010-20-08, 
Amendment 39-16442 (75 FR 61337, October 5, 2010), that have post-
repair inspections, are approved as AMOCs for the corresponding 
provisions of paragraph (o) of this AD for the repaired area only.

(t) Related Information

    (1) For more information about this AD, Nathan Weigand, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6428; fax: 425-917-6590; email: 
Nathan.P.Weigand@faa.gov.
    (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 February 25, 2013.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-05178 Filed 3-5-13; 8:45 am]
BILLING CODE 4910-13-P