Document ID: FAA-2012-1156-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2012-12-04T05:00Z

[Federal Register Volume 77, Number 233 (Tuesday, December 4, 2012)]
[Proposed Rules]
[Pages 71723-71729]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-29170]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 77, No. 233 / Tuesday, December 4, 2012 / 
Proposed Rules  

[[Page 71723]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1156; Directorate Identifier 2011-NM-205-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 737-200, -200C, -
300, and -400 series airplanes. The existing AD currently requires 
repetitive inspections to detect cracking of the corners of the door 
frame and the cross beams of the aft cargo door, and corrective actions 
if necessary. The existing AD also requires a modification to the aft 
cargo door, which terminates the repetitive inspections. Since we 
issued that AD, we have received reports of cracking on doors on 
airplanes that were not included in the existing AD. This proposed AD 
would add airplanes to the applicability, add inspections and related 
investigative and corrective actions, and revise certain inspection 
types. This proposed AD would also reduce the compliance time, for 
certain doors, to do a modification of the doors. We are proposing this 
AD to prevent fatigue cracking of the corners of the door frame and the 
cross beams of the aft cargo door, which could result in rapid 
depressurization of the airplane.

DATES: We must receive comments on this proposed AD by January 18, 
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, 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 98057-3356. 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, Washington 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-2012-1156; 
Directorate Identifier 2011-NM-205-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 July 2, 2001, we issued AD 2000-06-13 R1, Amendment 39-12317 (66 
FR 36146, July 11, 2001), for certain The Boeing Company Model 737-200, 
-200C, -300, and -400 series airplanes. That AD requires repetitive 
inspections to detect cracking of the corners of the door frame and the 
cross beams of the aft cargo door, and corrective actions, if 
necessary. That AD also requires a modification to the aft cargo door, 
which terminates the repetitive inspections. That AD resulted from 
reports of cracking in the forward and aft corner frame of the aft 
cargo door and in the lower cross beam. We issued that AD to prevent 
fatigue cracking of the corners of the door frame and the cross beams 
of the aft cargo door, which could result in rapid depressurization of 
the airplane.

Actions Since Existing AD 2000-06-13 R1, Amendment 39-12317 (66 FR 
36146, July 11, 2001) Was Issued

    Since we issued AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, 
July 11, 2001), we received reports of cracking on doors on airplanes 
that were not included in the existing AD. Therefore, we have 
determined that the applicability of AD 2000-06-13 R1 must be expanded 
to include all The Boeing Company Model 737-200, -200C, -300, -400, and 
-500 series airplanes in order to adequately address the identified 
unsafe condition. The existing AD also bases compliance times and 
repetitive intervals on airplane flight cycles. Since that AD was 
issued, we have determined that door interchangeability has a 
significant impact on addressing the unsafe condition. Doors may be 
rotated from airplane to airplane, and a door may have accumulated 
considerably more cycles than the

[[Page 71724]]

airplane on which it is installed. Therefore, this proposed AD bases 
compliance times and repetitive intervals on door flight cycles.
    In addition, more work is necessary on airplanes that have not 
accomplished the repair or preventive modification specified in Boeing 
Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 
1999, or previous issues of that service bulletin. We have also 
determined that the compliance time to do a modification of those doors 
should be reduced. We referred to Boeing Alert Service Bulletin 737-
52A1079, Revision 6, dated November 18, 1999, as the appropriate source 
of service information for accomplishing the required actions specified 
in AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). 
We have also determined that additional work is necessary on airplanes 
on which certain repairs and modifications specified in Boeing Alert 
Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999, or 
previous issues of that service bulletin, have been done.

Relevant Service Information

    We reviewed the following service information:
     Boeing Alert Service Bulletin 737-52A1153, dated July 13, 
2011.
     Boeing Alert Service Bulletin 737-52A1079, Revision 7, 
dated December 17, 2010.
     Boeing Special Attention Service Bulletin 737-52-1154, 
dated December 17, 2010.
    For information on the procedures and compliance times, see this 
service information at http://www.regulations.gov by searching for 
Docket No. FAA-2012-1156.

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 the requirements of AD 2000-06-13 
R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). This proposed AD 
would add airplanes to the applicability. This proposed AD would also 
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 action, 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.

Change to Existing Requirements

    Since AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 
2001), 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 existing AD 2000-
06-13 R1, Amendment 39[dash]12317    Corresponding requirement  in this
   (66 FR 36146, July 11, 2001)                 proposed AD
 
------------------------------------------------------------------------
paragraph (a)....................  paragraph (h)
paragraph (b)....................  paragraph (i)
paragraph (c)....................  paragraph (j)
paragraph (d)....................  paragraph (k)
paragraph (e)....................  paragraph (l)
------------------------------------------------------------------------

     We have revised the retained paragraph (d) of AD 2000-06-13 R1, 
Amendment 39-12317 (66 FR 36146, July 11, 2001) (which corresponds to 
paragraph (k) of this proposed AD), by removing reference to Boeing 737 
Nondestructive Test Manual, Part 6, Chapter 51-00-00 (Figure 4 or 
Figure 23) for the high frequency eddy current inspection. Instead, we 
have added Note 1 to paragraph (k) of this proposed AD to specify that 
guidance on the inspection can be found in Boeing 737 Nondestructive 
Test Manual, Part 6, Chapter 51-00-00 (Figure 4 or Figure 23).
    We have also moved the method of compliance specified in Note 3 of 
AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), into 
paragraph (m) of this proposed AD.
    We have also revised the language for the credit for previous 
service information specified in Note 4 of AD 2000-06-13 R1, Amendment 
39-12317 (66 FR 36146, July 11, 2001), and included it in paragraph (n) 
of this proposed AD.

Differences Between the Proposed AD and the Service Information

    Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010; and Boeing Special Attention Service Bulletin 737 
52-1154, dated December 17, 2010; specify to contact the manufacturer 
for instructions on how to repair certain conditions, but this proposed 
AD would require repairing those conditions in one of the following 
ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.
    Table 2 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-52A1079, Revision 7, dated December 17, 2010, references 
an incorrect part number for reinforcement angles. Paragraph (q) of 
this proposed AD specifies the correct part number.
    Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and 
Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated December 
17, 2010; specify accomplishing supplemental structural inspections. 
Those inspections are not required by this proposed AD. The damage 
tolerance inspections specified in those service bulletins may be used 
in support of compliance with section 121.1109(c)(2) or 129.109(b)(2) 
of the Federal Aviation Regulations (14 CFR 121.1109(c)(2) or 14 CFR 
129.109(b)(2)).

Clarification of Line Numbers

    For certain actions, Boeing Alert Service Bulletin 737-52A1079, 
Revision

[[Page 71725]]

7, dated December 17, 2010, specifies line numbers 6 through 873 
inclusive, but the corresponding action in Boeing Alert Service 
Bulletin 737-52A1153, dated July 13, 2011, specifies line numbers prior 
to 874. Airplanes having line numbers 1 through 5 are out of service; 
therefore, those airplanes are not subject to the requirements of this 
proposed AD.

Costs of Compliance

    We estimate that this proposed AD affects 581 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                          Number of airplanes of
               Action                      Labor cost             Parts cost         Cost per product         U.S. Registry       Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Detailed inspection [retained        2 work-hours x $85 per  $0                   $170 per inspection    494                      $83,890 per inspection
 action from existing AD 2000-06-13   hour = $170 per                              cycle.                                          cycle.
 R1, Amendment 39[dash]12317 (66 FR   inspection cycle.
 36146, July 11, 2001)].
High frequency eddy current          4 work-hours x $85 per  $0                   $340 per inspection    494                      $167,960 per
 inspection [retained action from     hour = $340 per                              cycle.                                          inspection cycle.
 existing AD 2000-06-13 R1,           inspection cycle.
 Amendment 39[dash]12317 (66 FR
 36146, July 11, 2001)].
Modification [retained action from   144 work-hours x $85    $5,430               $17,670..............  494                      $8,728,980
 existing AD 2000-06-13 R1,           per hour = $12,240.
 Amendment 39[dash]12317 (66 FR
 36146, July 11, 2001)].
Determination of door configuration  1 work-hour x $85 per   $0                   $85..................  581                      $49,385
 [new proposed action].               hour = $85.
Inspections [new proposed action]..  6 work-hours x $85 per  $0                   $510 per inspection    581                      $296,310 per
                                      hour = $510 per                              cycle.                                          inspection cycle.
                                      inspection cycle.
Modification [new proposed action].  59 work-hours x $85     $30,536              $35,551..............  (1)                      Unknown.
                                      per hour = $5,015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The number of airplanes that would be required to have this modification accomplished is dependent on no cracking being found during a certain
  inspection.

    We estimate the following costs to do any necessary related 
investigative and corrective actions that would be required based on 
the results of the proposed inspections. We have no way of determining 
the number of aircraft that might need these actions:

                           On-Condition Costs
------------------------------------------------------------------------
                                                               Cost per
           Action                Labor cost      Parts cost     product
------------------------------------------------------------------------
Related investigative and     59 work-hours x  $30,536        $35,551
 corrective actions.           $85 per hour =
                               $5,015.
------------------------------------------------------------------------

Authority for This Rulemaking

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

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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]

    2. The FAA amends Sec.  39.13 by removing airworthiness directive 
(AD) 2000-06-13 R1, Amendment 39-12317

[[Page 71726]]

(66 FR 36146, July 11, 2001), and adding the following new AD:

The Boeing Company: Docket No. FAA-2012-1156; Directorate Identifier 
2011-NM-205-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by January 18, 
2013.

(b) Affected ADs

    This AD supersedes AD 2000-06-13 R1, Amendment 39-12317 (66 FR 
36146, July 11, 2001), which revised AD 2000-06-13, Amendment 39-
11654 (65 FR 17583, April 4, 2000). AD 2000-06-13 superseded AD 98-
25-06, Amendment 39-10931 (63 FR 67769, December 9, 1998).

(c) Applicability

    This AD applies to all The Boeing Company Model 737-200, -200C, 
-300, -400, and -500 series airplanes, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 52, Doors.

(e) Unsafe Condition

    This AD was prompted by reports of cracking in the forward and 
aft corner frame of the aft cargo door and in the lower cross beam. 
We are issuing this AD to prevent fatigue cracking of the corners of 
the door frame and the cross beams of the aft cargo door, which 
could result in rapid depressurization of the airplane.

(f) Compliance

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

(g) Affected Airplanes for Retained Paragraphs

    Paragraphs (h), (i), (j), (k), and (l) of this AD are restated 
from AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 
2001). These paragraphs apply to Model 737-200 and -200C series 
airplanes, line numbers 6 through 873 inclusive; and Model 737-200, 
-200C, -300, and -400 series airplanes, line numbers 874 through 
1642 inclusive; equipped with an aft cargo door having Boeing part 
number (P/N) 65-47952-1 or P/N 65-47952-524, excluding airplanes 
identified in paragraphs (g)(1) and (g)(2) of this AD.
    (1) Those airplanes on which that door has been modified as 
specified in Boeing Service Bulletin 737-52-1079. Or,
    (2) Those airplanes on which the door assembly having P/N 65-
47952-524 includes four straps (P/Ns 65-47952-139, 65-47952-140, 65-
47952-141, and 65-47952-142) and a thicker lower cross beam web (P/N 
65-47952-157).

(h) Retained Inspections and Corrective Actions

    This paragraph restates the actions required by paragraph (a) of 
AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), 
with revised service information. For airplanes identified in 
paragraph (g) of this AD: Within 90 days or 700 flight cycles after 
December 24, 1998 (the effective date of AD 98-25-06, Amendment 39-
10931 (63 FR 67769, December 9, 1998)), whichever occurs later, 
perform an internal detailed visual inspection to detect cracking of 
the corners of the door frame and the cross beams of the aft cargo 
door, in accordance with Boeing Service Bulletin 737-52-1079, 
Revision 5, dated May 16, 1996; Boeing Alert Service Bulletin 737-
52A1079, Revision 6, dated November 18, 1999; or Boeing Alert 
Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. 
Accomplishment of the modification required by paragraph (l) of this 
AD constitutes terminating action for the repetitive inspection 
requirements of this paragraph. Doing the inspections required by 
paragraph (p) or (s) of this AD terminates the inspections required 
by this paragraph.
    (1) If no cracking is detected, accomplish the requirements of 
either paragraph (h)(1)(i) or (h)(1)(ii) of this AD.
    (i) Repeat the internal visual inspection thereafter at 
intervals not to exceed 4,500 flight cycles. Or
    (ii) Prior to further flight, modify the corners of the door 
frame and the cross beams of the aft cargo door, in accordance with 
Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; 
Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated 
November 18, 1999; or Boeing Alert Service Bulletin 737-52A1079, 
Revision 7, dated December 17, 2010. Accomplishment of such 
modification constitutes terminating action for the repetitive 
inspection requirements of paragraph (h)(1)(i) of this AD.
    (2) If any cracking is detected in the upper or lower cross 
beams, prior to further flight, modify the cracked beam, in 
accordance with Part I of the Accomplishment Instructions of Boeing 
Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Part I 
of the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-52A1079, Revision 6, dated November 18, 1999; or Part II of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 7, dated December 17, 2010. Accomplishment of such 
modification constitutes terminating action for the repetitive 
inspection requirements of paragraph (h)(1)(i) of this AD for the 
modified beam.
    (3) If any cracking is detected in the forward or aft upper door 
frame, prior to further flight, repair the frame and modify the 
corners of the door frame of the aft cargo door, in accordance with 
Part I of the Accomplishment Instructions of Boeing Service Bulletin 
737-52-1079, Revision 5, dated May 16, 1996; Part I of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 6, dated November 18, 1999; or Part II of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 7, dated December 17, 2010; except as provided by 
paragraph (i) of this AD. Accomplishment of such modification 
constitutes terminating action for the repetitive inspection 
requirements of paragraph (h)(1)(i) of this AD for the upper door 
frame.
    (4) If any cracking is detected in the forward or aft lower door 
frame, prior to further flight, replace the damaged frame with a new 
frame, and modify the corners of the door frame of the aft cargo 
door, in accordance with Part I of the Accomplishment Instructions 
of Boeing Service Bulletin 737-52-1079, Revision 5, dated May 16, 
1996; Part I of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-52A1079, Revision 6, dated November 18, 1999; 
or Part II of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. 
Accomplishment of such modification constitutes terminating action 
for the repetitive inspection requirements of paragraph (h)(1)(i) of 
this AD for the lower door frame.

(i) Retained Exception for Certain Actions Specified in Paragraphs (h) 
and (l) of This AD

    This paragraph restates the requirement of paragraph (b) of AD 
2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). For 
actions required by paragraphs (h) and (l) of this AD: Where Boeing 
Service Bulletin 737-52-1079, Revision 5, dated May 16, 1996; Boeing 
Alert Service Bulletin 737-52A1079, Revision 6, dated November 18, 
1999; or Boeing Alert Service Bulletin 737-52A1079, Revision 7, 
dated December 17, 2010; specifies that certain repairs are to be 
accomplished in accordance with instructions received from Boeing, 
this AD requires that, prior to further flight, such repairs be 
accomplished in accordance with a method approved by the Manager, 
Seattle Aircraft Certification Office (ACO), FAA; or using a method 
approved in accordance with the procedures specified in paragraph 
(x) of this AD.

(j) Retained Corrective Actions for Certain Cracking Found During 
Inspection Required by Paragraph (h) of This AD

    This paragraph restates the corrective action required by 
paragraph (c) of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, 
July 11, 2001), with revised service information. If any cracking of 
the outer chord of the upper or lower cross beams of the aft cargo 
door is detected during any inspection required by paragraph (h) of 
this AD, prior to further flight, accomplish the repair specified in 
paragraph (j)(1), (j)(2), (j)(3), or (j)(4) of this AD. For a repair 
method to be approved, as required by paragraphs (j)(1), (j)(3), and 
(j)(4) of this AD, the approval letter must specifically reference 
this AD.
    (1) Repair in accordance with a method approved by the Manager, 
Seattle ACO.
    (2) Repair in accordance with Boeing Alert Service Bulletin 737-
52A1079, Revision 6, dated November 18, 1999; or Boeing Alert 
Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
    (3) Repair in accordance with data meeting the type 
certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative who has been authorized by the 
FAA to make such findings.
    (4) Repair in accordance with a method approved by the Boeing 
Commercial Airplanes Organization Designation Authorization (ODA) 
whom we have authorized to make those findings.

[[Page 71727]]

(k) Retained Inspections and Corrective Actions for Airplanes 
Identified in Paragraph (g) of This AD

    This paragraph restates the actions required by paragraph (d) of 
AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), 
with revised service information. For airplanes identified in 
paragraph (g) of this AD: Within 4,500 flight cycles or 1 year after 
May 9, 2000 (the effective date of AD 2000-06-13, amendment 39-11654 
(65 FR 17583, April 4, 2000), whichever occurs later, perform a high 
frequency eddy current inspection (HFEC) to detect cracking of the 
four corners of the door frame of the aft cargo door, using a method 
approved in accordance with the procedures specified in paragraph 
(x) of this AD, or in accordance with Boeing Alert Service Bulletin 
737-52A1079, Revision 6, dated November 18, 1999; or Boeing Alert 
Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010. 
Accomplishment of the modification required by paragraph (l) of this 
AD constitutes terminating action for the repetitive inspection 
requirements of this paragraph. Doing the inspections required by 
paragraph (p) or (s) of this AD terminates the inspections required 
by this paragraph.

    Note 1 to paragraph (k) of this AD: Additional guidance for the 
inspection can be found in Boeing 737 Nondestructive Test Manual, 
Part 6, Chapter 51-00-00 (Figure 4 or Figure 23).

    (1) If no cracking of the corners of the door frame of the aft 
cargo door is detected, repeat the HFEC inspections thereafter at 
intervals not to exceed 4,500 flight cycles until accomplishment of 
the modification specified in paragraph (l) of this AD.
    (2) If any cracking of the corners of the door frame of the aft 
cargo door is detected, prior to further flight, replace the damaged 
frame with a new frame, and modify the four corners of the door 
frame, in accordance with Part II and Part III of the Accomplishment 
Instructions of Boeing Service Bulletin 737-52-1079, Revision 5, 
dated May 16, 1996; Part II and Part III of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-52A1079, Revision 
6, dated November 18, 1999; or Part III and Part IV of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 7, dated December 17, 2010. Accomplishment of such 
modification constitutes terminating action for the repetitive 
inspection requirements of paragraph (k)(1) of this AD for that door 
frame.

(l) Retained Terminating Action for Inspections Specified in Paragraphs 
(h) and (k) of This AD

    This paragraph restates the action required by paragraph (e) of 
AD 2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001), 
with revised service information. For airplanes identified in 
paragraph (g) of this AD: Within 4 years or 12,000 flight cycles 
after August 15, 2001 (the effective date of AD 2000-06-13 R1), 
whichever occurs later, modify the four corners of the door frame 
and the cross beams of the aft cargo door, in accordance with Part 
II of the Accomplishment Instructions of Boeing Service Bulletin 
737-52-1079, Revision 5, dated May 16, 1996; Part II of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 6, dated November 18, 1999; or Part III of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
52A1079, Revision 7, dated December 17, 2010. Accomplishment of that 
modification constitutes terminating action for the repetitive 
inspection requirements of paragraphs (h) and (k) of this AD.

(m) Retained Method of Compliance

    This paragraph restates the method of compliance of Note 3 of AD 
2000-06-13 R1, Amendment 39-12317 (66 FR 36146, July 11, 2001). 
Accomplishment of the modification required by paragraph (a) of AD 
90-06-02, Amendment 39-6489 (55 FR 8372, March 7, 1990), is 
considered acceptable for compliance with the requirements of 
paragraph (l) of this AD.

(n) Retained Credit for Previous Actions

    This paragraph restates the credit given for service information 
specified in Note 4 of AD 2000-06-13 R1, Amendment 39-12317 (66 FR 
36146, July 11, 2001). This paragraph provides credit for the 
modification of the corners of the door frame and the cross beams of 
the aft cargo door required by paragraph (l) of this AD, if the 
modification was accomplished prior to August 15, 2001 (the 
effective date of AD 2000-06-13 R1), using Boeing Service Bulletin 
737-52-1079, dated December 16, 1983; Revision 1, dated December 15, 
1988; Revision 2, dated July 20, 1989; Revision 3, dated May 17, 
1990; or Revision 4, dated February 21, 1991.

(o) New Requirement for Determining Door Configuration

    At the applicable time specified in Table 1 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-52A1153, dated 
July 13, 2011, except as provided by paragraph (u)(1) of this AD: 
Inspect the door to determine the configuration, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-52A1153, dated July 13, 2011.

(p) New Requirements for Certain Doors Subject to Boeing Alert Service 
Bulletin 737-52A1079, Revision 7, Dated December 17, 2010

    If, during the inspection required by paragraph (o) of this AD, 
any door is determined to be from any airplane having line numbers 6 
through 873 inclusive, and neither the modification nor the repair 
specified in any service bulletin identified in paragraphs (p)(1) 
through (p)(7) of this AD has been done as of the effective date of 
this AD: Do a one-time HFEC and a one-time ultrasonic inspection for 
cracking of the upper and lower corner frames and the upper and 
lower cross beams, and do all applicable related investigative and 
corrective actions, in accordance with Parts II, III, IV, and VI of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-52A1079, Revision 7, dated December 17, 2010; and, as 
applicable, the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-52-1154, dated December 17, 2010, as 
revised by Boeing Special Attention Service Bulletin 737-52-1154, 
Revision 1, dated August 3, 2011; except as provided by paragraphs 
(u)(2) and (u)(3) of this AD. Do the inspections at the applicable 
time specified in Table 1 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010; except as provided by paragraph (u)(4) of this 
AD. Do all applicable related investigative and corrective actions 
before further flight. If no cracking is found during the initial 
inspections, before further flight, do the modification in 
accordance with Part III of the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010. Doing the inspection specified in this paragraph 
terminates the inspections required by paragraphs (h) and (k) of 
this AD.
    (1) Boeing Service Bulletin 737-52-1079, dated December 16, 
1983.
    (2) Boeing Service Bulletin 737-52-1079, Revision 1, dated 
December 15, 1988.
    (3) Boeing Service Bulletin 737-52-1079, Revision 2, dated July 
20, 1989.
    (4) Boeing Service Bulletin 737-52-1079, Revision 3, dated May 
17, 1990.
    (5) Boeing Service Bulletin 737-52-1079, Revision 4, dated 
February 21, 1991.
    (6) Boeing Service Bulletin 737-52-1079, Revision 5, dated May 
16, 1996.
    (7) Boeing Service Bulletin 737-52A1079, Revision 6, dated 
November 18, 1999.

(q) Requirements for All Doors Subject to Boeing Alert Service Bulletin 
737-52A1079, Revision 7, Dated December 17, 2010

    If, during the inspection required by paragraph (o) of this AD, 
any door is determined to be from any airplane having line numbers 6 
through 873 inclusive: At the applicable time specified in Table 2 
of paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-52A1079, Revision 7, dated December 17, 2010, except as provided 
by paragraph (u)(4) of this AD, inspect the lower corner frames to 
determine if the door has reinforcement angles, P/N 65C25180-9, -43, 
-10, -11, or -12, that were installed as specified in any service 
bulletin identified in paragraphs (q)(1) through (q)(5) of this AD. 
If any affected reinforcement angle is found, do a one-time general 
visual inspection for edge margin and do a detailed inspection for 
cracks; in accordance with Part V of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010.
    (1) Boeing Service Bulletin 737-52-1079, dated December 16, 
1983.
    (2) Boeing Service Bulletin 737-52-1079, Revision 1, dated 
December 15, 1988.
    (3) Boeing Service Bulletin 737-52-1079, Revision 2, dated July 
20, 1989.
    (4) Boeing Service Bulletin 737-52-1079, Revision 3, dated May 
17, 1990.
    (5) Boeing Service Bulletin 737-52-1079, Revision 4, dated 
February 21, 1991.

(r) Corrective Actions for Inspections Specified in Paragraph (q) of 
This AD

    If, during any inspection required by paragraph (q) of this AD, 
any crack is found, or if any edge margin does not meet the 
specification identified in Part V of the Accomplishment 
Instructions of Boeing Alert

[[Page 71728]]

Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010, 
before further flight, do the actions specified in paragraphs 
(r)(1), (r)(2), and (r)(3) of this AD.
    (1) Replace the corner reinforcement angle, in accordance with 
Part III of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-52A1079, Revision 7, dated December 17, 2010.
    (2) Do a one-time detailed inspection or HFEC inspection for 
cracking at the forward and aft ends of cross beam D, in accordance 
with Part 1 of the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-52-1154, dated December 17, 2010. If 
any cracking is found, before further flight, do all applicable 
repairs in accordance with the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 737-52-1154, dated December 17, 
2010, except as provided by paragraph (u)(2) of this AD.
    (3) Do a one-time detailed inspection or ultrasonic inspection 
for cracking on the frames, in accordance with Part 2 (detailed 
inspection) or Part 8 (ultrasonic inspection) of the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-52-
1154, dated December 17, 2010, as revised by Boeing Special 
Attention Service Bulletin 737-52-1154, Revision 1, dated August 3, 
2011. If any cracking is found, before further flight, replace the 
frame in accordance with the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-52A1079, Revision 7, dated December 17, 
2010.

(s) Requirements for Doors Subject to Boeing Alert Service Bulletin 
737-52A1153, Dated July 13, 2011

    If, during the action required by paragraph (o) of this AD, a 
door is determined to be from an airplane having line numbers 874 
and subsequent: At the applicable time specified in Tables 1 and 2 
of paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-52A1153, dated July 13, 2011, except as provided by paragraph 
(u)(1) of this AD, do high frequency and detailed inspections for 
cracks in the forward and aft ends of cross beam E, and do all 
applicable related investigative and corrective actions, in 
accordance with Parts 1, 3, 4, 5, and 6 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-52A1153, dated 
July 13, 2011; and, as applicable, the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 737-52-1154, dated 
December 17, 2010, as revised by Boeing Special Attention Service 
Bulletin 737-52-1154, Revision 1, dated August 3, 2011; except as 
provided by paragraph (u)(2) of this AD. Do all applicable related 
investigative and corrective actions at the applicable time 
specified in Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of 
Boeing Service Bulletin 737-52A1153, dated July 13, 2011, except as 
provided by paragraph (u)(1) of this AD. If no cracking is found 
during the inspections specified in Boeing Alert Service Bulletin 
737-52A1153, dated July 13, 2011, at the applicable time specified 
in Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-52A1153, dated July 13, 2011, except as 
provided by paragraph (u)(1) of this AD, do the modification in 
accordance with Parts 5 and 6, as applicable, of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-52A1153, dated 
July 13, 2011. Repeat the inspections thereafter at the times 
specified in Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011, 
until the preventative modification or repair is done to both ends 
of cross beam E in accordance with the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011. 
Doing the inspection specified in this paragraph terminates the 
inspections required by paragraphs (h) and (k) of this AD.

(t) One Time Inspections for Doors Subject to Boeing Alert Service 
Bulletin 737-52A1153, Dated July 13, 2011

    If, during the actions required by paragraph (o) of this AD, a 
door is determined to be from an airplane having line numbers 874 
and subsequent: At the applicable time specified in Tables 3 and 4 
of paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-52A1153, dated July 13, 2011, except as provided by paragraph 
(u)(1) of this AD, do a one-time ultrasonic inspection of the frame 
and a detailed inspection of the reinforcing angle for cracks of the 
forward and aft ends of cross beam E, and do all applicable related 
investigative and corrective actions, in accordance with Parts 1, 3, 
4, 7, and 8 of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-52A1153, dated July 13, 2011; and, as 
applicable; the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-52-1154, dated December 17, 2010, as 
revised by Boeing Special Attention Service Bulletin 737-52-1154, 
Revision 1, dated August 3, 2011; except as provided by paragraph 
(u)(2) of this AD. Do all applicable related investigative and 
corrective actions before further flight.

(u) Service Information Exceptions

    The following exceptions apply to this AD.
    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-52A1153, dated July 13, 2011, specifies a 
compliance time ``after the original issue date of this service 
bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.
    (2) Where Boeing Special Attention Service Bulletin 737-52-1154, 
dated December 17, 2010, specifies to contact Boeing for repair, 
before further flight, repair using a method approved in accordance 
with the procedures specified in paragraph (x) of this AD.
    (3) Where Boeing Alert Service Bulletin 737-52A1079, Revision 7, 
dated December 17, 2010, specifies to contact Boeing for repair, 
before further flight, repair using a method approved in accordance 
with the procedures specified in paragraph (x) of this AD.
    (4) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-52A1079, Revision 7, dated December 17, 2010, 
specifies a compliance time ``from the date of Revision 7 to this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.

(v) Supplemental Structural Inspections

    The supplemental structural inspections specified in Tables 5 
and 6 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-52A1153, dated July 13, 2011; and Tables 3 and 4 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-52A1079, Revision 7, dated December 17, 2010; are not required 
by this AD.

    Note 2 to paragraph (v) of this AD:  The damage tolerance 
inspections specified in Tables 5 and 6 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-52A1153, dated 
July 13, 2011; and Tables 3 and 4 of paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010; may be used in support of compliance with section 
121.1109(c)(2) or 129.109(b)(2) of the Federal Aviation Regulations 
(14 CFR 121.1109(c)(2) or 14 CFR 129.109(b)(2)). The corresponding 
actions specified in the Accomplishment Instructions and figures of 
Boeing Alert Service Bulletin 737-52A1153, dated July 13, 2011; and 
Boeing Alert Service Bulletin 737-52A1079, Revision 7, dated 
December 17, 2010; are not required by this AD.

(w) Credit for Previous Actions

    This paragraph provides credit for actions required by 
paragraphs (p), (q), and (r) of this AD, if the actions were 
accomplished before the effective date of this AD using any service 
information specified in paragraph (w)(1), (w)(2), (w)(3), (w)(4), 
(w)(5), (w)(6), or (w)(7) of this AD.
    (1) Boeing Service Bulletin 737-52-1079, dated December 16, 
1983.
    (2) Boeing Service Bulletin 737-52-1079, Revision 1, dated 
December 15, 1988.
    (3) Boeing Service Bulletin 737-52-1079, Revision 2, dated July 
20, 1989.
    (4) Boeing Service Bulletin 737-52-1079, Revision 3, dated May 
17, 1990.
    (5) Boeing Service Bulletin 737-52-1079, Revision 4, dated 
February 21, 1991.
    (6) Boeing Service Bulletin 737-52-1079, Revision 5, dated May 
16, 1996.
    (7) Boeing Alert Service Bulletin 737-52A1079, Revision 6, dated 
November 18, 1999.

(x) 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.

[[Page 71729]]

    (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 2000-06-13, 
Amendment 39-11654 (65 FR 17583, April 4, 2000); and AD 2000-06-13 
R1, Amendment 39-12317 (66 FR 36146, July 11, 2001); are approved as 
AMOCs for the corresponding requirements of this AD.

(y) 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.

    Issued in Renton, Washington, on November 21, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-29170 Filed 12-3-12; 8:45 am]
BILLING CODE 4910-13-P