[Federal Register Volume 78, Number 102 (Tuesday, May 28, 2013)]
[Proposed Rules]
[Pages 31867-31871]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-12618]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0425; Directorate Identifier 2012-NM-224-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 adopt a new airworthiness directive (AD) for 
certain The Boeing Company Model 747 airplanes. This proposed AD was 
prompted by reports of cracking in the forward and aft inner chord of 
the body station (BS) 2598 bulkhead near the upper corners of the 
cutout for the horizontal stabilizer rear spar, and cracking in the 
bulkhead upper and lower web panels near the inner chord to shear deck 
connection. This proposed AD would require doing repetitive inspections 
for cracking in the bulkhead splice fitting, frame supports, forward 
and aft inner chords, and floor support; doing an inspection for 
cracking in the bulkhead upper web, doubler, and bulkhead lower web; 
and corrective actions if necessary; for certain airplanes, inspections 
for cracking in the repaired area of the bulkhead, and corrective 
actions if necessary; for certain airplanes, support frame modification 
and support frame inspections, and related investigative and corrective 
actions, if necessary; for certain airplanes, repetitive support frame 
post-modification inspections and inspections for cracking in the hinge 
support, and related investigative and corrective actions if necessary; 
for certain airplanes, a one-time inspection of the frame web and upper 
shear deck (floor support) chord aft side for fasteners; and a one-time 
inspection of the upper forward inner chord, frame support fitting and 
splice fitting, for the installation of certain fasteners; and related 
investigative and corrective actions if necessary; for certain 
airplanes, a one-time inspection of the upper forward inner chord, 
frame

[[Page 31868]]

support fitting and splice fitting for the installation of certain 
fasteners; a one-time inspection for any repair installed on the left 
and right side of the aft inner chord, and related investigative and 
corrective actions, if necessary; for certain airplanes, a one-time 
inspection of the support frame outer chord for cracking, and repair if 
necessary; and repetitive support frame post-repair inspections, and 
corrective actions, if necessary. We are proposing this AD to detect 
and correct fatigue cracking of the BS 2598 bulkhead structure, which 
could adversely affect the structural integrity of the bulkhead and the 
horizontal stabilizer support structure and result in loss of 
controllability of the airplane.

DATES: We must receive comments on this proposed AD by July 12, 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; 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 proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2013-0425; 
Directorate Identifier 2012-NM-224-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

    We received reports of cracking in the forward and aft inner chord 
of the BS 2598 bulkhead near the upper corners of the cutout for the 
horizontal stabilizer rear spar, and cracking in the bulkhead upper and 
lower web panels near the inner chord to shear deck connection. This 
condition, if not corrected, could result in fatigue cracking of the BS 
2598 bulkhead structure, which could result in inability of the 
structure to carry horizontal stabilizer flight loads, and loss of 
controllability of the airplane.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011; and Boeing Alert Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011. For information on the procedures 
and compliance times, see this service information at http://www.regulations.gov by searching for Docket No. FAA-2013-0425.

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 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) 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.

Differences Between the Proposed AD and the Service Information

    Where Part 1 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, 
specifies accomplishing inspections for cracks in forward and aft inner 
chords, splice fittings, floor supports, and upper and lower web 
panels, this AD also requires doing an open-hole high frequency eddy 
current (HFEC) inspection of the doubler. Figure 2 of Boeing Alert 
Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, includes 
the inspections.
    Where paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 747-53A2427, Revision 6, dated July 14, 2011; or 747-53A2473, 
Revision 4, dated December 1, 2011; specify to contact Boeing for 
repair data and do the repair, this AD requires doing those repairs in 
accordance with a method approved by the FAA.
    If cracking is found in any doubler during any inspection specified 
by paragraph (g) of this proposed AD, this proposed AD would require 
repairing using a method approved in accordance with the procedures 
specified in paragraph (o) of this AD.

Costs of Compliance

    We estimate that this proposed AD affects 165 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

[[Page 31869]]



                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Action                        Labor cost            Parts cost       Cost per product                 Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection.........................  24 work-hours x $85 per                 $0  $2,040 per inspection  $336,600 per inspection cycle.
                                      hour = $2,040 per                           cycle.
                                      inspection cycle.
Support frame modification.........  315 work-hours x $85 per                 0  $26,775..............  Up to $4,417,875.
                                      hour = $26,775.
Support frame upper corner fastener  16 work-hours x $85 per                  0  $1,360...............  Up to $224,400.
 inspection.                          hour = $1,360.
Support frame post-modification      200 work hours x $85 per                 0  $17,000..............  $2,805,000.
 inspection.                          hour = $17,000.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

Authority for This Rulemaking

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

Regulatory Findings

    We 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 this 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 adding the following new airworthiness 
directive (AD):

The Boeing Company: Docket No. FAA-2013-0425; Directorate Identifier 
2012-NM-224-AD.

(a) Comments Due Date

    We must receive comments by July 12, 2013.

(b) Affected ADs

    This AD affects AD 2010-14-07, Amendment 39-16352 (75 FR 38001, 
July 1, 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, 747SR, and 747SP series airplanes, certificated in 
any category, as identified in Boeing Alert Service Bulletin 747-
53A2427, Revision 6, dated July 14, 2011.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of cracking in the forward and 
aft inner chord of the body station (BS) 2598 bulkhead near the 
upper corners of the cutout for the horizontal stabilizer rear spar, 
and cracking in the bulkhead upper and lower web panels near the 
inner chord to shear deck connection. We are issuing this AD to 
detect and correct fatigue cracking of the BS 2598 bulkhead 
structure, which could adversely affect the structural integrity of 
the bulkhead and the horizontal stabilizer support structure and 
result in loss of controllability of the airplane.

(f) Compliance

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

(g) Inspections of the Bulkhead (Support Frame)

    For airplanes on which the bulkhead (support frame) modification 
specified in Boeing Service Bulletin 747-53A2473 has not been 
accomplished: At the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2427, 
Revision 6, dated July 14, 2011, except as provided by paragraph 
(m)(1), (m)(2), or (m)(3), as applicable, of this AD, do an open-
hole and surface high frequency eddy current (HFEC) inspection for 
cracking in the bulkhead (support frame) which includes the bulkhead 
splice fitting, frame supports, forward and aft inner chords, and 
floor support; do a surface HFEC inspection for cracking in the 
bulkhead upper web and doubler; do an open-hole and surface HFEC 
inspection for cracking in the bulkhead lower web; and do all 
applicable corrective actions; in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2427, Revision 
6, dated July 14, 2011, except as required by paragraphs (m)(4), 
(m)(5) and (m)(6) of this AD, and except as provided by paragraph 
(h) of this AD. Do all applicable corrective actions before further 
flight. Repeat the applicable inspections, thereafter, at the 
applicable times in paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011. Doing 
the modification required by paragraph (j) of this AD terminates the 
repetitive inspections required by this paragraph.

(h) Interim Modification

    For airplanes in groups 1 and 2 as identified in Boeing Alert 
Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, on 
which no cracking was found during any inspection required by 
paragraph (g) of this AD: At the applicable times specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-53A2427, Revision 6, dated July 14, 2011, except as provided by 
paragraph (m)(2) of this AD, do the interim modification, in 
accordance with

[[Page 31870]]

the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-53A2427, Revision 6, dated July 14, 2011. Doing the interim 
modification terminates the repetitive inspection requirement of 
paragraph (g) of this AD in the area of the modification only. The 
repetitive inspections of the bulkhead lower web, as specified in 
paragraph (g) of this AD, must be done. If the aft inner chord 
repair or upper web repair specified in Boeing Alert Service 
Bulletin 747-53A2427, Revision 6, dated July 14, 2011, has been 
accomplished, an interim modification on the side of the airplane 
that has the repair is not required by this paragraph.

(i) Post-Repair Inspection or Post-Interim Modification Inspection

    For airplanes on which an interim modification, or aft inner 
chord repair, or upper web repair has been done as specified in 
paragraph (g) or (h) of this AD: At the applicable times specified 
in paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
747-53A2427, Revision 6, dated July 14, 2011, except as specified in 
paragraph (m)(1), (m)(2), or (m)(3), as applicable, of this AD, do 
the actions specified in paragraph (i)(1) and (i)(2) of this AD, and 
all applicable corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2427, Revision 6, dated July 14, 2011, except as required by 
paragraph (m)(4) of this AD. Do all applicable corrective actions 
before further flight. Repeat the inspections thereafter at the 
applicable intervals specified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 747-53A2427, Revision 6, dated July 
14, 2011. Doing the modification required by paragraph (j) of this 
AD terminates the repetitive inspections required by this paragraph.
    (1) Do forward side surface HFEC inspections for cracking of the 
bulkhead forward inner chord, splice fitting, and frame support.
    (2) Do surface and open-hole HFEC inspections for cracking in 
the repaired area of the bulkhead.

(j) Bulkhead (Support Frame) Modification and Inspections

    For airplanes on which the bulkhead (support frame) modification 
specified in Boeing Alert Service Bulletin 747-53A2473, dated March 
24, 2005; Revision 1, dated February 20, 2007; Revision 2, dated 
August 28, 2009; Revision 3, dated July 14, 2011; or Revision 4, 
dated December 1, 2011, has not been done as of the effective date 
of this AD: At the applicable time in tables 2 and 3 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011, do the bulkhead (support frame) 
modification and inspections and all applicable related 
investigative and corrective actions; in accordance with steps 
3.B.3., 3.B.4., and 3.B.5. of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2473, Revision 4, dated 
December 1, 2011, except as required by paragraph (m)(4) of this AD. 
Do all applicable related investigative and corrective actions 
before further flight. Doing the modification in this paragraph 
terminates the inspections required by paragraphs (g) and (i) of 
this AD.

(k) Post Modification Inspections

    (1) For airplanes on which the bulkhead (support frame) 
modification has been done as specified in Boeing Service Bulletin 
747-53A2473, dated March 24, 2005; Revision 1, dated February 20, 
2007; Revision 2, dated August 28, 2009; Revision 3, dated July 14, 
2011; or Revision 4, dated December 1, 2011: Except as provided by 
paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in 
tables 6, 7, 8, and 9 of paragraph 1.E., ``Compliance'' of Boeing 
Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do 
support frame post-modification inspections, and open-hole HFEC 
inspection for cracking in the hinge support, and do all applicable 
related investigative and corrective actions, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011, except as required by paragraph 
(m)(4). Do all applicable related investigative and corrective 
actions before further flight. Repeat the inspections thereafter at 
the applicable times in tables 6, 7, 8, and 9 of paragraph 1.E., 
``Compliance,'' of Boeing Service Bulletin 747-53A2473, Revision 4, 
dated December 1, 2011.
    (2) For airplanes on which the support frame modification has 
been done as specified in Boeing Service Bulletin 747-53A2473, 
Revision 1, dated February 20, 2007: Except as specified in 
paragraphs (m)(7) and (m)(8) of this AD, at the applicable time in 
tables 4 and 5 of paragraph 1.E., ``Compliance'' of Boeing Service 
Bulletin 747-53A2473, Revision 4, dated December 1, 2011, do a one-
time general visual inspection of the frame web and upper shear deck 
(floor support) chord aft side for fasteners that were installed as 
part of an inner chord repair removal; and a one-time general visual 
inspection of the upper forward inner chord, frame support fitting 
and splice fitting, for the installation of certain fasteners; and 
do all applicable related investigative and corrective actions; in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2473, Revision 4, dated December 1, 2011, except as 
required by paragraph (m)(4) of this AD. Do all applicable related 
investigative and corrective actions at the applicable times 
specified in tables 4 and 5 of paragraph 1.E., ``Compliance'' of 
Boeing Service Bulletin 747-53A2473, Revision 4, dated December 1, 
2011.
    (3) For airplanes on which the support frame modification has 
been done as specified in Boeing Service Bulletin 747-53A2473, dated 
March 24, 2005: Except as specified in paragraphs (m)(7) and (m)(8) 
of this AD, at the applicable time in tables 5 and 10 of paragraph 
1.E., ``Compliance'' of Boeing Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011, do a one-time general visual 
inspection of the upper forward inner chord, frame support fitting, 
and splice fitting for the installation of certain fasteners; a one-
time general visual inspection for any repair installed on the left 
and right side of the aft inner chord; and do all applicable related 
investigative and corrective actions; in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011, except as required by paragraph 
(m)(4) of this AD. Do all applicable related investigative and 
corrective actions at the applicable times specified in tables 5 and 
10 of paragraph 1.E., ``Compliance'' of Boeing Service Bulletin 747-
53A2473, Revision 4, dated December 1, 2011.
    (4) For airplanes on which a post-modification inspection was 
done in accordance with paragraph 3.B.8. of Part 1 of the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, 
Revision 3, dated July 14, 2011: Except as required by paragraphs 
(m)(7) and (m)(8) of this AD, at the applicable time in table 11 of 
paragraph 1.E., ``Compliance'' of Boeing Service Bulletin 747-
53A2473, Revision 4, dated December 1, 2011, do a one-time surface 
HFEC inspection of the support frame outer chord for cracking, in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Service Bulletin 747-53A2473, Revision 4, dated December 1, 2011. If 
any cracking is found, repair before further flight, using a method 
approved in accordance with the procedures specified in paragraph 
(o) of this AD.

(l) Post-Modification Post-Repair Inspections

    For airplanes on which post-modification inspection cracks were 
repaired by doing the installation of an upper or lower corner post-
modification web crack repair as specified in Boeing Service 
Bulletin 747-53A2473, Revision 4, dated December 1, 2011: At the 
applicable times specified in tables 6 and 8 of paragraph 1.E., 
``Compliance'' of Boeing Service Bulletin 747-53A2473, Revision 4, 
dated December 1, 2011, do a bulkhead (support frame) post-repair 
inspection, and do all applicable corrective actions, in accordance 
with paragraph a., b., or c. of Part 4 of paragraph 3.B.8 of the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011, as applicable, except as 
required by paragraph (m)(4) of this AD. Repeat the inspection, 
thereafter, at the applicable times specified in tables 6 and 8 of 
paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 747-
53A2473, Revision 4, dated December 1, 2011.

(m) Exceptions

    (1) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011, specifies a compliance time after the date on 
Revision 2 of this service bulletin, this AD requires compliance 
within the specified compliance time as of August 28, 2001 (the 
effective date of AD 2001-15-03, Amendment 39-12337 (66 FR 38365, 
July 24, 2001)).
    (2) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011, specifies a compliance time after the date on 
Revision 4 of this service bulletin, this AD requires compliance 
within the specified compliance time as of April 13, 2006 (the 
effective date of AD 2006-05-06, Amendment 39-14503 (71 FR 12125, 
March 9, 2006)).

[[Page 31871]]

    (3) Where Boeing Alert Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011, specifies a compliance time after the date on 
Revision 6 of this service bulletin, this AD requires compliance 
within the specified compliance time ``after the effective date of 
this AD.''
    (4) If any cracking is found during any inspection required by 
this AD, and Boeing Alert Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011; or Boeing Service Bulletin 747-53A2473, 
Revision 4, dated December 1, 2011; 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 (o) of this AD.
    (5) If, during any inspection required by paragraph (g) of this 
AD, any cracking is found in the doubler, before further flight, 
repair, using a method approved in accordance with the procedures 
specified in paragraph (o) of this AD.
    (6) Where Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2427, Revision 6, dated July 14, 2011, 
specifies accomplishing inspections for cracks for forward and aft 
inner chords, splice fittings, floor supports, and upper and lower 
web panels, this AD also requires doing an open-hole HFEC inspection 
of the doubler.
    (7) Where Boeing Service Bulletin 747-53A2473, Revision 4, dated 
December 1, 2011, specifies a compliance time after the date on 
Revision 2 of the service bulletin, this AD requires compliance 
within the specified compliance time as of August 5, 2010 (the 
effective date of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, 
July 1, 2010)).
    (8) Where Boeing Service Bulletin 747-53A2473, Revision 4, dated 
December 1, 2011, specifies a compliance time after the date on 
Revision 3 or 4 of the service bulletin, this AD requires compliance 
within the specified compliance time ``after the effective date of 
this AD.''

(n) Terminating Action for Certain Requirements of AD 2010-14-07, 
Amendment 39-16352 (75 FR 38001, July 1, 2010)

    (1) Accomplishing the inspections, repairs, and modification in 
accordance with Boeing Service Bulletin 747-53A2473, Revision 4, 
dated December 1, 2011, is a terminating action for the 
corresponding inspections, repairs, and modification at the STA 2598 
support frame required by paragraphs (i), (j), (k)(1), (m), (n), 
(o), (p), (q), (r), (s), (t), (u), and (v) of AD 2010-14-07, 
Amendment 39-16352 (75 FR 38001, July 1, 2010). When Boeing Service 
Bulletin 747-53A2473, Revision 4, dated December 1, 2011, specifies 
to contact Boeing for repair instructions, the repair instructions 
must be approved by the FAA in accordance with paragraph (o) of this 
AD. All provisions of AD 2010-14-07 that are not specifically 
referenced in this paragraph remain fully applicable and must be 
complied with.
    (2) Accomplishing the inspections, repairs and interim 
modification in accordance with Boeing Service Bulletin 747-53A2427, 
Revision 6, dated July 14, 2011, is a terminating action for the 
corresponding inspections, repairs and interim modification at the 
STA 2598 bulkhead required by paragraphs (i), (j), (o), (s), (t), 
(u), and (v) of AD 2010-14-07, Amendment 39-16352 (75 FR 38001, July 
1, 2010). When Boeing Service Bulletin 747-53A2427, Revision 6, 
dated July 14, 2011, specifies to contact Boeing for repair data, 
the repair data must be approved by the FAA in accordance with 
paragraph (o) of this AD. All provisions of AD 2010-14-07 that are 
not specifically reference in this paragraph remain fully applicable 
and must be complied with.

(o) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in 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.

(p) 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 May 17, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-12618 Filed 5-24-13; 8:45 am]
BILLING CODE 4910-13-P