
[Federal Register Volume 77, Number 216 (Wednesday, November 7, 2012)]
[Proposed Rules]
[Pages 66757-66760]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-27141]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1161; Directorate Identifier 2011-NM-277-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to certain The Boeing Company Model 737-200, -200C, -
300, -400 and -500 series airplanes. The existing AD currently requires 
a one-time mid-frequency eddy current (MFEC) inspection, a low 
frequency eddy current (LFEC) inspection, and a detailed inspection for 
damage or cracking of stringer S-4L and S-4R lap joints and stringer 
clips between body station (BS) 540 and BS 727, and follow-on 
inspections and repair if necessary. Since we issued that AD, we have 
received reports of cracking of the lap joint lower row. This proposed 
AD would instead require repetitive external eddy current inspections 
for cracking of certain fuselage crown lap joints and corrective 
actions; internal eddy current and detailed inspections for cracking of 
certain fuselage crown lap joints, and repair if necessary; and 
detailed inspections of certain stringer clips, and replacement with 
new stringer clips if necessary. This proposed AD would also add 
airplanes to the applicability. We are proposing this AD to detect and 
correct cracking of the fuselage lap joints, which could result in 
sudden decompression of the airplane.

DATES: We must receive comments on this proposed AD by December 24, 
2012.

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 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: Wayne Lockett, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6447; fax: 
425-917-6590; email: wayne.lockett@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-2012-1161; 
Directorate Identifier 2011-NM-277-AD'' at the beginning of

[[Page 66758]]

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 April 18, 2003, we issued AD 2003-08-15, Amendment 39-13128 (68 
FR 20341, April 25, 2003), for certain The Boeing Company Model 737-
200, -200C, -300, -400 and -500 series airplanes. That AD requires a 
one-time MFEC, LFEC, and detailed inspection for damage or cracking of 
stringer S-4L and S-4R lap joints and stringer clips between BS 540 and 
BS 727, and follow-on inspections and repair if necessary. That AD 
resulted from a report indicating that, during a walk-around inspection 
on a Model 737-200 series airplane with 60,333 total flight cycles, a 
23-inch-long crack was found in the lower row of the stringer S-4L lap 
joint between BS 616 and BS 639. Cracking was also found between the 
tear straps and in the skin locations common to the tear straps. 
Additionally, we received a report of significant cracking on stringer 
S-4R of the lap joint between BS 600 and BS 727 on a Model 737-300 
series airplane having 52,400 total flight cycles. We issued that AD to 
detect and correct cracking of the fuselage lap joints, which could 
result in sudden decompression of the airplane.

Actions Since Existing AD 2003-08-15, Amendment 39-13128 (68 FR 20341, 
April 25, 2003) Was Issued

    Since we issued AD 2003-08-15, Amendment 39-13128 (68 FR 20341, 
April 25, 2003), we have received reports of lap joint lower row 
cracking on airplanes that were not subject to inspections in AD 2002-
07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002). We are 
proposing to supersede AD 2003-08-15 to provide inspections for these 
airplanes.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin 737-53A1255, Revision 2, 
dated August 7, 2012. For information on the procedures and compliance 
times, see this service information at http://www.regulations.gov by 
searching for Docket No. FAA-2012-* * *.

Other Relevant Rulemaking

    These crown lap joint inspections are currently also contained in 
the following service bulletins, which are mandated by AD 2002-07-08, 
Amendment 39-12702 (67 FR 17917, April 12, 2002):
     Boeing Service Bulletin 737-53A1177, Revision 4, dated 
September 2, 1999;
     Boeing Service Bulletin 737-53A1177, Revision 5, dated 
February 15, 2001; and
     Boeing Service Bulletin 737-53A1177, Revision 6, dated May 
31, 2001.
    Boeing chose to add the needed inspections for the airplanes not 
covered by AD 2002-07-08 to the service information included in AD 
2003-08-15, Amendment 39-13128 (68 FR 20341, April 25, 2003), due to 
the large scope of changes that would be needed to revise Boeing 
Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001. We are 
considering further rulemaking to remove reference to those crown lap 
joint inspections from that AD.

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 none of the requirements of AD 2003-
08-15, Amendment 39-13128 (68 FR 20341, April 25, 2003). This proposed 
AD would include new inspection requirements, reduce certain inspection 
thresholds, and add repetitive inspections. This proposed AD would also 
add airplanes to the applicability statement of the existing AD. This 
proposed AD would require accomplishing the actions specified in the 
service information described previously.
    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.

Costs of Compliance

    We estimate that this proposed AD affects 307 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                     Cost per        Number of     Cost on U.S.
            Action                 Labor cost       Parts cost        product        airplanes       operators
----------------------------------------------------------------------------------------------------------------
Internal inspection...........  Up to 303 work-               $0         $25,755             307      $7,906,785
                                 hours x $85 per
                                 hour = $25,755.
External inspection...........  Up to 10 work-                 0             850             307         260,950
                                 hours x $85 per
                                 hour = $850.
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    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

[[Page 66759]]

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 this AD:
    (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) 2003-08-15, Amendment 39-13128 (68 FR 20341, April 25, 2003), and 
adding the following new AD:

The Boeing Company: Docket No. FAA-2012-1161; Directorate Identifier 
2011-NM-277-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by December 24, 
2012.

(b) Affected ADs

    This AD supersedes AD 2003-08-15, Amendment 39-13128 (68 FR 
20341, April 25, 2003).

(c) Applicability

    This AD applies to The Boeing Company Model 737-200, -200C, -
300, -400, and -500 series airplanes; certificated in any category; 
as specified in Boeing Alert Service Bulletin 737-53A1255, Revision 
2, dated August 7, 2012.

(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 of the lap joint 
lower row. We are issuing this AD to detect and correct cracking of 
the fuselage lap joints, which could result in sudden decompression 
of the airplane.

(f) Compliance

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

(g) External Crown Lap Joint Inspection and Repair

    For airplanes on which the lap splice modification specified in 
AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), has 
not been accomplished, except as required by paragraph (l)(1) and 
(l)(2) of this AD: At the applicable times specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-53A1255, 
Revision 2, dated August 7, 2012, do an external eddy current 
inspection for cracking in the crown lap joints, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1255, Revision 2, dated August 7, 2012. At the intervals 
specified in paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-53A1255, Revision 2, dated August 7, 2012, repeat the 
inspections, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-53A1255, Revision 2, dated August 
7, 2012. If any cracking is found in a lap joint, before further 
flight, repair, in accordance with the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-53A1255, Revision 2, dated 
August 7, 2012.

(h) Optional Internal Inspections for Mid-Bay Fastener Locations

    As an option to confirm cracks found during the inspections 
required by paragraph (g) of this AD, do an internal mid-frequency 
eddy current (MFEC) inspection for cracking in the lap joint 
fastener row between tear straps of the crown lap and do a detailed 
inspection of the lap joint lower fastener row for cracking, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1255, Revision 2, dated August 7, 2012.

(i) Internal Crown Lap Joint Inspection and Repair

    For airplanes on which the lap splice modification specified in 
AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002) has 
not been accomplished: At the times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1255, 
Revision 2, dated August 7, 2012, except as required by paragraphs 
(l)(1) and (l)(2) of this AD, do an internal MFEC, low frequency 
eddy current (LFEC), and detailed inspection for cracking in the 
crown lap joints and stringer clips, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1255, Revision 2, dated August 7, 2012.
    (1) If any cracking is found in any lap joint, before further 
flight, repair, in accordance with the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-53A1255, Revision 2, dated 
August 7, 2012.
    (2) If any cracking is found in any stringer clip, before 
further flight, replace the stringer clip with a new stringer clip, 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-53A1255, Revision 2, dated August 7, 2012.
    (3) Repeat the inspections at the intervals specified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-53A1255, Revision 2, dated August 7, 2012.

(j) Optional Inspections for Tear Strap Locations Only

    As an option to confirm cracks found while doing the inspections 
required by paragraph (i) of this AD, do an open-hole inspection for 
cracking at the tear strap locations, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1255, Revision 2, dated August 7, 2012.

(k) Terminating Action

    (1) Accomplishing a repair of a crown lap joint in accordance 
with Boeing Alert Service Bulletin 737-53A1255, Revision 2, dated 
August 7, 2012, terminates the inspections required by paragraphs 
(g) and (i) of this AD for the repaired area only.
    (2) Accomplishing the modification of the crown lap joints in 
accordance with any of the service bulletins specified in paragraphs 
(k)(2)(i), (k)(2)(ii), and (k)(2)(iii) of this AD terminates the 
inspections required by paragraphs (g) and (i) of this AD for the 
modified area only.
    (i) Boeing Service Bulletin 737-53A1177, Revision 4, dated 
September 2, 1999.
    (ii) Boeing Service Bulletin 737-53A1177, Revision 5, dated 
February 15, 2001.
    (iii) Boeing Service Bulletin 737-53A1177, Revision 6, dated May 
31, 2001.

(l) Exceptions

    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1255, Revision 2, dated August 7, 2012, 
states a compliance time ``from the Revision 1 date of this service 
bulletin,'' this AD requires a compliance time ``after the effective 
date of this AD.''
    (2) Where the ``condition'' column, in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1255, 
Revision 2, dated August 7, 2012, specifies airplanes with certain 
flight cycles ``at the Revision 1 date of this service bulletin,'' 
for this AD the condition is for airplanes with corresponding flight 
cycles ``as of the effective date of this AD.''

(m) Credit for Previous Actions

    This paragraph provides credit for the actions required by 
paragraphs (g), (h), (i), and (j) of this AD, if those actions were 
performed before the effective date of this AD

[[Page 66760]]

using Boeing Alert Service Bulletin 737-53A1255, Revision 1, dated 
November 7, 2011, which is not incorporated by reference in this AD.

(n) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in the Related Information 
section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO, to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) AMOCs approved for paragraphs (a), (b), (c), (d), and (e) of 
AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002) 
before the effective date of this AD, are approved for the 
corresponding requirements of paragraphs (g), (i), and (k) of this 
AD.
    (5) As of the effective date of this AD, any AMOCs approved for 
paragraphs (g) and (i) of this AD are approved as AMOCs for the 
corresponding requirements of paragraphs (a), (b), (c), (d), and (e) 
of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002).

(o) Related Information

    (1) For more information about this AD, contact Wayne Lockett, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; 
phone: 425-917-6447; fax: 425-917-6590; email: 
wayne.lockett@faa.gov.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-
5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com.You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, WA. For information on the availability of 
this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on October 31, 2012.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-27141 Filed 11-6-12; 8:45 am]
BILLING CODE 4910-13-P


