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[Federal Register Volume 78, Number 159 (Friday, August 16, 2013)]
[Proposed Rules]
[Pages 49978-49982]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-19925]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0694; Directorate Identifier 2013-NM-097-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 airworthiness directive (AD) 2002-10-
11, which applies to certain the Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes. AD 2002-10-11 currently 
requires repetitive inspections for cracking and corrosion of the aft 
pressure bulkhead, and corrective actions if necessary; and, for 
certain airplanes, enlargement of frame chord drain holes, and 
repetitive inspections of the frame chord drain path for debris, and 
corrective actions if necessary. Since we issued AD 2002-10-11, we have 
received three reports of severe corrosion in the area affected by that 
AD. This proposed AD would, for certain airplanes, reduce the 
repetitive inspection interval, and add repetitive inspections of the 
frame chord drain path for obstructions and debris, and corrective 
actions if necessary. This proposed AD would also limit corrosion and 
cracking repairs of the aft pressure bulkhead accomplished after the 
effective date of this AD to those approved by the FAA in a manner 
described therein. In reviewing AD 2002-10-11, we noted that the drain 
path inspection was not required for certain airplanes, and could be 
eliminated for all airplanes if operators accomplished certain actions 
required by AD 2002-10-11. This proposed AD would add a drain path 
inspection for all airplanes. We are proposing this AD to detect and 
correct corrosion or cracking of the aft pressure bulkhead, which could 
result in loss of the aft pressure bulkhead web and stiffeners, and 
consequent rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by September 30, 
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: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 
425-917-6590; email: alan.pohl@faa.gov.

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-2013-0694; 
Directorate Identifier 2013-NM-097-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 May 14, 2002, we issued AD 2002-10-11, Amendment 39-12757 (67 FR 
36085, May 23, 2002), for certain Model 737-100, -200, -200C, -300, -
400, and -500 series airplanes. AD 2002-10-11 superseded AD 84-20-03 
R1, Amendment 39-5183 (50 FR 51235, December 16, 1985). AD 2002-10-11 
requires repetitive inspections for cracking and corrosion of the aft 
pressure bulkhead, and corrective actions if necessary; and, for 
certain airplanes, enlargement of frame chord drain holes, repetitive 
inspections of the frame chord drain path for obstructions and debris, 
and corrective actions if necessary. We issued AD 2002-10-11 to detect 
and correct corrosion or cracking of the aft pressure bulkhead at body 
station (BS) 1016, which could result in loss of the aft pressure 
bulkhead web and stiffeners, and consequent rapid decompression of the 
fuselage.

Actions Since AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 
2002), Was Issued

    Since 2010, we have received three reports of severe corrosion in 
the aft pressure bulkhead. Two of these airplanes were corroded 
completely through the thickness of the pressure web. The age of the 
airplanes when corrosion was found ranged from 12 to 17 years. The 
total flight hours ranged from 40,892 to 68,389 hours, and the total 
flight cycles ranged from 22,701 to 58,156 flight cycles.
    AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002),

[[Page 49979]]

requires repetitive inspections for corrosion at 2-year intervals for 
airplanes having line numbers 1 through 1042, and at 4-year intervals 
for airplanes having line numbers 1043 through 3132. All reports of 
severe corrosion have been from the latter group of airplanes with the 
longer repetitive inspection interval.
    In addition, repair procedures in Boeing Alert Service Bulletin 
737-53A1075, Revision 3, dated June 8, 2000, which is specified in 
paragraph (g) of AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 
23, 2002), as the appropriate source of service information, include 
instructions for blending out corrosion on the bulkhead web. The 
reworked web is more susceptible to subsequent corrosion.
    After consultation with the manufacturer, we have determined that 
reduction of the interval for the repetitive inspections from 4 years 
to 2 years, together with removal of repair instructions for blending 
out corrosion on the bulkhead web, will reduce the frequency and 
severity of corrosion findings and provide an acceptable level of 
safety.

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 2002-10-11, 
Amendment 39-12757 (67 FR 36085, May 23, 2002). This proposed AD would 
reduce the interval for the repetitive inspections for airplanes having 
line numbers (L/N) 1043 through 3132 inclusive from 4 years to 2 years; 
and would provide an option to inspect only the aft side of the aft 
pressure bulkhead every 3 months for a maximum of 2 years, at which 
time both the forward and aft sides of the aft pressure bulkhead would 
require repetitive inspections at 2-year intervals. This proposed AD 
would, for certain airplanes, add repetitive inspections of the frame 
chord drain path for debris, and corrective actions if necessary.

Changes to AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 
2002)

    This proposed AD would retain all the requirements of AD 2002-10-
11, Amendment 39-12757 (67 FR 36085, May 23, 2002). Since AD 2002-10-11 
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 2002-10-11,
 Amendment 39-12757 (67 FR 36085,     Corresponding requirement in this
           May 23, 2002)                         proposed AD
------------------------------------------------------------------------
 paragraph (a)                       paragraph (g)
 paragraph (b)                       paragraph (h)
 paragraph (c)                       paragraph (i)
 paragraph (d)                       paragraph (j)
 paragraph (e)                       paragraph (k)
 paragraph (f)                       paragraph (l)
 paragraph (g)                       paragraph (m)
------------------------------------------------------------------------

    Note 2 (detailed inspection definition) in AD 2002-10-11, Amendment 
39-12757 (67 FR 36085, May 23, 2002), has been removed from this 
proposed AD because it is described in Figure 1 of Boeing Alert Service 
Bulletin 737-53A1075, Revision 3, dated June 8, 2000.
    Paragraph (e) of AD 2002-10-11, Amendment 39-12757 (67 FR 36085, 
May 23, 2002), which is paragraph (k) in this proposed AD, has been 
revised to clarify that the required actions include inspecting the 
drain path in the chord frame for debris.
    The terminating action statement in paragraph (e)(1) of AD 2002-10-
11, Amendment 39-12757 (67 FR 36085, May 23, 2002), has been revised to 
terminate only the aft bulkhead inspection for cracking and corrosion 
in paragraph (g) of this proposed AD.
    Since we issued AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 
23, 2002), Boeing Commercial Airplanes received an Organization 
Designation Authorization (ODA). We have revised this proposed AD to 
delegate the authority to approve an alternative method of compliance 
for any repair required by this AD to the Boeing Commercial Airplanes 
ODA rather than a Designated Engineering Representative.

Differences Between the Proposed AD and the Service Information

    Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 
8, 2000, describes 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 ODA whom we have authorized to make those findings.
    This proposed AD would also reduce the repeat inspection interval 
for corrosion and cracking on airplanes having line numbers 1043 
through 3132.

Costs of Compliance

    We estimate that this proposed AD affects 419 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
----------------------------------------------------------------------------------------------------------------
Inspection......................  4 work-hours x $85 per           $0   $340 per inspection  $142,460 per
                                   hour = $340 per                       cycle.               inspection cycle.
                                   inspection cycle.
----------------------------------------------------------------------------------------------------------------

    The new requirements of this proposed AD add no additional economic 
burden.
    We estimate the following costs to do any necessary repairs that 
would be required based on the results of the proposed inspection. We 
have no way of determining the number of aircraft that might need these 
repairs:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                 Action                             Labor cost            Parts cost       Cost per product
----------------------------------------------------------------------------------------------------------------
Repair.................................  Up to 136 work-hours x $85 per      $5,217   Up to $16,777.
                                          hour = Up to $11,560.
----------------------------------------------------------------------------------------------------------------

[[Page 49980]]

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 proposed 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) 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), and adding 
the following new AD:

The Boeing Company: Docket No. FAA-2013-0694; Directorate Identifier 
2013-NM-097-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by September 30, 
2013.

(b) Affected ADs

    This AD supersedes AD 2002-10-11, Amendment 39-12757 (67 FR 
36085, May 23, 2002).

(c) Applicability

    This AD applies to The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category, line numbers 1 through 3132 inclusive.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by three reports of severe corrosion in the 
area affected by AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 
23, 2002). We are issuing this AD to detect and correct corrosion or 
cracking of the aft pressure bulkhead, which could result in loss of 
the aft pressure bulkhead web and stiffeners, and consequent rapid 
decompression of the airplane.

(f) Compliance

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

(g) Retained Initial Aft Pressure Bulkhead Inspection

    This paragraph restates the requirements of paragraph (a) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
clarification of the drain path inspection. For Model 737 series 
airplanes having line numbers (L/N) 1 through 929 inclusive, with 
more than 20,000 hours time-in-service or 7 years since date of 
manufacture, whichever occurs first: Within 120 days after January 
20, 1986 (the effective date of AD 84-20-03 R1, Amendment 39-5183 
(50 FR 51235, December 16, 1985)), unless already accomplished 
within the 21 months before January 20, 1986, visually inspect the 
body station (BS) 1016 pressure bulkhead, including inspecting for 
cracking and corrosion of the pressure bulkhead, and for debris in 
the drain path in the chord frame, according to Boeing Alert Service 
Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 
2, dated July 13, 1984; or Revision 3, dated June 8, 2000. Remove 
any obstruction to the drain hole in the frame chord and replace any 
deteriorated leveling compound as noted in Boeing Alert Service 
Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 
2, dated July 13, 1984; or Revision 3, dated June 8, 2000. Treat the 
area of inspection with corrosion inhibitor BMS 3-23, or equivalent. 
After the effective date of this AD, use only Boeing Alert Service 
Bulletin 737-53A1075, Revision 3, dated June 8, 2000, to do the 
actions required by this paragraph.

(h) Retained Drain Hole Enlargement

    This paragraph restates the requirements of paragraph (b) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised service bulletin requirements. For airplanes identified in 
paragraph (g) of this AD: Within 1 year after January 20, 1986 (the 
effective date of AD 84-20-03 R1, Amendment 39-5183 (50 FR 51235, 
December 16, 1985)), accomplish the drain hole enlargement as shown 
in Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated 
September 2, 1983; Revision 2, dated July 13, 1984; or Revision 3, 
dated June 8, 2000. After the effective date of this AD, use only 
Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 
2000, to do the actions required by this paragraph.

(i) Retained Corrective Action With Revised Compliance Methods

    This paragraph restates the requirements of paragraph (c) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised compliance methods. If cracking or corrosion is found during 
any inspection required by paragraph (g) or (j) of this AD: Before 
further flight, repair according to paragraph (i)(1) or (i)(2) of 
this AD, as applicable.
    (1) If the inspection was done before the effective date of this 
AD: Repair according to Boeing Alert Service Bulletin 737-53A1075, 
Revision 1, dated September 2, 1983; Revision 2, dated July 13, 
1984; or Revision 3, dated June 8, 2000.
    (2) If the inspection was done on or after the effective date of 
this AD: Repair using a method approved in accordance with the 
procedures specified in paragraph (p) of this AD.

(j) Retained Repetitive Inspections Required by Paragraph (g) of This 
AD

    This paragraph restates the requirements of paragraph (d) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised actions. For airplanes identified in paragraph (g) of this 
AD: Repeat the visual inspections and corrosion inhibitor treatment 
specified in paragraph (g) of this AD at intervals not to exceed 2 
years. Accomplishment of the initial aft pressure bulkhead 
inspection required by paragraph (k) of this AD terminates the 
inspection required by this paragraph.

(k) Retained Aft Bulkhead Detailed Inspection

    This paragraph restates the requirements of paragraph (e) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised terminating action. Do a detailed inspection for cracking or 
corrosion of the aft pressure bulkhead at BS 1016 (including the 
forward and aft sides of the pressure web, forward and aft sides of 
the pressure chord, pressure chord radius,

[[Page 49981]]

forward and aft sides of the angle stiffener, forward and aft chord, 
stringer end fitting, system penetration doublers, channel 
stiffeners and fasteners, ``Z'' stiffeners and fasteners, and 
fasteners common to the pressure chord and pressure web), according 
to Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 
8, 2000. Do this inspection at the applicable time shown in 
paragraph (k)(1), (k)(2), or (k)(3) of this AD.
    (1) For airplanes on which an inspection has previously been 
done according to the requirements of paragraph (g) of this AD: Do 
the inspection within 2 years since the most recent inspection 
according to paragraph (g) or (j) of this AD, as applicable. For the 
airplanes identified in paragraph (g) of this AD, accomplishment of 
the inspection required by paragraph (k) of this AD terminates the 
inspections for cracking and corrosion required by paragraph (j) of 
this AD.
    (2) For airplanes having L/Ns 930 through 1042 inclusive, on 
which an inspection has not previously been done according to 
paragraph (g) of this AD: Do the inspection within 2 years after 
June 27, 2002 (the effective date AD 2002-10-11, Amendment 39-12757 
(67 FR 36085, May 23, 2002)).
    (3) For airplanes having L/Ns 1043 through 3132 inclusive, on 
which an inspection has not previously been done according to 
paragraph (g) of this AD: Do the inspection within 6 years since the 
airplane's date of manufacture, or within 2 years after June 27, 
2002 (the effective date AD 2002-10-11, Amendment 39-12757 (67 FR 
36085, May 23, 2002)), whichever occurs later.

(l) Retained Repetitive Inspections

    This paragraph restates the requirements of paragraph (f) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised compliance times. Repeat the inspection in paragraph (k) of 
this AD at the applicable time shown in paragraph (l)(1) or (l)(2) 
of this AD.
    (1) For airplanes having L/Ns 1 through 1042 inclusive: Repeat 
the inspection thereafter at intervals not to exceed 2 years.
    (2) For airplanes having L/Ns 1043 through 3132 inclusive: 
Repeat the inspection thereafter within 2 years since the last 
inspection or within 120 days after the effective date of this AD, 
whichever occurs later.

(m) Retained Repair

    This paragraph restates the requirements of paragraph (g) of AD 
2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002), with 
revised repair requirements. If any corrosion or cracking is found 
during any inspection according to paragraph (k) or (l) of this AD: 
Do the applicable action specified in paragraph (m)(1) or (m)(2) of 
this AD.
    (1) If the inspection was done prior to the effective date of 
this AD: Before further flight, repair according to Boeing Alert 
Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. 
Exception: If corrosion or cracking of the web and stiffeners is 
outside the limits specified in Boeing Alert Service Bulletin 737-
53A1075, Revision 3, dated June 8, 2000, or if corrosion or cracking 
is found in any structure not covered by the repair instructions in 
Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 
2000, before further flight, repair according to a method approved 
by the Manager, Seattle Aircraft Certification Office (ACO), or per 
data meeting the type certification basis of the airplane approved 
by the Boeing Commercial Airplanes Organization Designation 
Authorization (ODA) who has been authorized by the Manager, Seattle 
ACO, to make such findings. For a repair method to be approved by 
the Manager, Seattle ACO, as required by this paragraph, the 
Manager's approval letter must specifically reference this AD.
    (2) After the effective date of this AD, if any corrosion or 
cracking is found during any inspection required by this AD: Before 
further flight, repair the corrosion or cracking using a method 
approved in accordance with the procedures specified in paragraph 
(p) of this AD.

(n) New Drain Path Repetitive Inspection

    For airplanes having L/N 1 through 3132 inclusive: Within 2 
years since the last inspection in accordance with paragraph (k) of 
this AD or within 2 years after the effective date of this AD, 
whichever occurs later: Do a general visual inspection of the drain 
path in the chord frame for debris. Remove any obstruction to the 
drain hole in the frame chord and replace any deteriorated leveling 
compound. Treat the area of inspection with corrosion inhibitor BMS 
3-23, or equivalent. Repeat the actions required by this paragraph 
at intervals not to exceed 2 years. Do all actions required by this 
paragraph in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 
2000. For the purposes of this AD, a general visual inspection is a 
visual examination of an interior or exterior area, installation, or 
assembly to detect obvious damage, failure, or irregularity. This 
level of inspection is made from within touching distance unless 
otherwise specified. A mirror may be necessary to ensure visual 
access to all surfaces in the inspection area. This level of 
inspection is made under normally available lighting conditions such 
as daylight, hangar lighting, flashlight, or droplight and may 
require removal or opening of access panels or doors. Stands, 
ladders, or platforms may be required to gain proximity to the area 
being checked.

(o) New Optional Repetitive Aft Pressure Bulkhead Inspection for 
Certain Airplanes and Corrective Action

    For airplanes having L/Ns 1043 through 3132 inclusive: In lieu 
of performing the inspection required by paragraph (l) of this AD, 
operators may do the actions specified in this paragraph. Within 2 
years from the most recent aft pressure bulkhead inspection done as 
specified in Boeing Alert Service Bulletin 737-53A1075, Revision 1, 
dated September 2, 1983; Revision 2, dated July 13, 1984; or 
Revision 3, dated June 8, 2000; or within 120 days after the 
effective date of this AD, whichever occurs later, do a detailed 
inspection for cracking or corrosion of the aft side of the aft 
pressure bulkhead at BS 1016 (including the aft sides of the 
pressure web, aft sides of the pressure chord, pressure chord 
radius, aft chord, stringer end fitting, system penetration 
doublers, and fasteners common to the pressure chord and pressure 
web), in accordance with the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. 
If any corrosion or cracking is found: Before further flight, repair 
the corrosion or cracking using a method approved in accordance with 
the procedures specified in paragraph (p) of this AD. Repeat the 
inspection thereafter at intervals not to exceed 90 days. Within 2 
years after the initial inspection done in accordance with this 
paragraph: Do the actions specified in paragraph (k) of this AD, and 
repeat thereafter at intervals not to exceed 2 years.

(p) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle 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 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 2002-10-11, 
Amendment 39-12757 (67 FR 36085, May 23, 2002), are approved as 
AMOCs for the corresponding provisions of this AD.

 (q) Related Information

    (1) For more information about this AD, contact Alan Pohl, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98057-3356; phone: (425) 917-6450; fax: (425) 917-6590; email: 
alan.pohl@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, Washington 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, Washington. For information on the 
availability of this material at the FAA, call 425-227-1221.

[[Page 49982]]

    Issued in Renton, Washington, on August 9, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-19925 Filed 8-15-13; 8:45 am]
BILLING CODE 4910-13-P
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