
[Federal Register Volume 76, Number 211 (Tuesday, November 1, 2011)]
[Rules and Regulations]
[Pages 67343-67346]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-28053]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1162; Directorate Identifier 2011-NM-186-AD; 
Amendment 39-16856; AD 2011-23-05]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Model 737-300, -400, 
and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are superseding an existing airworthiness directive (AD) 
for certain Model 737-300, -400, and -500 series airplanes. That AD 
currently requires repetitive inspections for cracking of the 1.04-inch 
nominal diameter wire penetration hole, and applicable related 
investigative and corrective actions. This AD reduces the compliance 
times for those actions. This AD was prompted by reports of cracking in 
the frame, or in the frame and frame reinforcement, common to the 1.04-
inch nominal diameter wire penetration hole intended for wire routing; 
and recent reports of multiple adjacent frame cracking found before the 
compliance time required by the existing AD. Such cracking could reduce 
the structural capability of the frames to sustain limit loads, and 
result in cracking in the fuselage skin and subsequent rapid 
depressurization of the airplane. We are issuing this AD to correct the 
unsafe condition on these products.

DATES: This AD is effective November 16, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of November 16, 
2011.
    We must receive any comments on this AD by December 16, 2011.

ADDRESSES: You may send comments 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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, 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, Washington 98124-2207; telephone (206) 544-
5000, extension 1; fax (206) 766-5680; email me.boecom@boeing.com; 
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.

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 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, Seattle Aircraft Certification Office (ACO), 
FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 
917-6447; fax: (425) 917-6590; email: wayne.lockett@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    On August 26, 2009, we issued AD 2009-02-06 R1, Amendment 39-16015 
(74 FR 45979, September 8, 2009), for certain Model 737-300, -400, and 
-500 series airplanes. That AD requires repetitive inspections for 
cracking of the 1.04-inch nominal diameter wire penetration hole in the 
frame and in the frame reinforcement, between stringers S-20 and S-21, 
on both the left and right sides of the airplane, and applicable 
related investigative and corrective actions. That AD resulted from 
reports of cracking in the frame, or in the frame and frame 
reinforcement, common to the 1.04-inch nominal diameter wire 
penetration hole intended for wire routing. We issued that AD to detect 
and correct cracking in the fuselage frames and frame reinforcements, 
which could reduce the structural capability of the frames to sustain 
limit loads, and result in cracking in the fuselage skin and subsequent 
rapid depressurization of the airplane.

Actions Since AD Was Issued

    Since we issued AD 2009-02-06 R1, Amendment 39-16015 (74 FR 45979, 
September 8, 2009), we received a report of four adjacent cracked 
frames at body station (BS) 500B, BS 500C, BS 500D, and BS 520 in the 
forward cargo compartment between S-20L and S-21L on a Model 737-300 
series airplane. The cracks at BS 500B and BS 500C were completely 
through the frame and fail-safe chord. The BS 500B frame was also 
cracked on the right-hand side. The cracks were discovered when the 
airplane had accumulated 44,535 total flight cycles and 44,876 total 
flight hours--before the compliance time required by AD 2009-02-06 R1.

Relevant Service Information

    AD 2009-02-06 R1, Amendment 39-16015 (74 FR 45979, September 8, 
2009), referred to Boeing Alert Service Bulletin 737-53A1279, dated 
December 18, 2007, as the appropriate source of service information for 
the required actions. Boeing has since revised this service bulletin. 
We reviewed Boeing Alert Service Bulletin 737-53A1279, Revision 1, 
dated September 2, 2011, which shortens the compliance time to 30,000 
total flight cycles, with a grace period of 30 or 90 days, and reduces 
the repetitive interval from 14,000 to 4,500 flight cycles. The 
procedures are unchanged from those specified in

[[Page 67344]]

Boeing Alert Service Bulletin 737-53A1279, dated December 18, 2007.

FAA's Determination

    We are issuing 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.

AD Requirements

    This AD requires accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between the AD and the Service Information.''

Differences Between the AD and the Service Information

    Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions in one of the following ways:
     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.
    Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, specifies compliance with the Part 4 inspection by 
the later of 4,500 flight cycles or 90 days--both after the date on 
this service bulletin. In some cases, this compliance time might occur 
before the Part 2 inspection. This AD (in paragraph (h)) therefore 
requires the Part 4 inspection within 4,500 flight cycles after 
accomplishment of the most recent Part 2 or Part 4 inspection, with a 
grace period of 90 days. We have coordinated this difference with 
Boeing.
    For certain airplanes that have accumulated 40,000 or more total 
flight cycles, Boeing Alert Service Bulletin 737-53A1279, Revision 1, 
dated September 2, 2011, specifies a 30-day compliance time for the 
Part 2 inspection. Paragraph (k)(2) of this AD extends that compliance 
time to 90 days for those airplanes, if the original chem.-milled 
fuselage skins have been replaced with solid skins. This difference has 
been coordinated with Boeing.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
cracking in multiple adjacent fuselage frames and frame reinforcements 
reduces the structural capability of the frames to sustain limit loads, 
and result in cracking in the fuselage skin and subsequent rapid 
depressurization of the airplane. Therefore, we find that notice and 
opportunity for prior public comment are impracticable and that good 
cause exists for making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
the Docket No. FAA-2011-1162 and directorate identifier 2011-NM-186-AD 
at the beginning of your comments. We specifically invite comments on 
the overall regulatory, economic, environmental, and energy aspects of 
this AD. We will consider all comments received by the closing date and 
may amend this 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 AD.

Costs of Compliance

    We estimate that this AD affects 605 airplanes of U.S. registry. We 
estimate the following costs to comply with this AD:

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Action                        Labor cost               Parts cost           Cost per product                Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection........................  16 work-hours x $85 per     None...............  $1,360 per inspection       $822,800 per inspection cycle.
                                     hour = $1,360 per                                cycle.
                                     inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                       Cost per
                 Action                              Labor cost                   Parts cost           product
----------------------------------------------------------------------------------------------------------------
On-condition inspection.................  2 work-hours x $85 per hour =    None....................         $170
                                           $170.
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     We have received no definitive data that would enable us to 
provide a cost estimate for the on-condition repair or optional 
modification specified in this 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

[[Page 67345]]

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends part 39 of the Federal Aviation 
Regulations (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) 
2009-02-06 R1, Amendment 39-16015 (74 FR 45979, September 8, 2009), and 
adding the following new AD:

2011-23-05 The Boeing Company: Amendment 39-16856; Docket No. FAA-
2011-1162; Directorate Identifier 2011-NM-186-AD.

(a) Effective Date

    This AD is effective November 16, 2011.

(b) Affected ADs

    This AD supersedes AD 2009-02-06 R1, Amendment 39-16015 (74 FR 
45979, September 8, 2009).

(c) Applicability

    This AD applies to The Boeing Company Model 737-300, -400, -500 
series airplanes, certificated in any category; as identified in 
Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of four cracked frames at 
certain body stations (BS) in the forward cargo compartment. We are 
issuing this AD to detect and correct cracking in the fuselage 
frames and frame reinforcements, which could reduce the structural 
capability of the frames to sustain limit loads, and result in 
cracking in the fuselage skin and subsequent rapid depressurization 
of the airplane.

(f) Compliance

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

(g) Inspection

    At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1279, 
Revision 1, dated September 2, 2011, except as required by 
paragraphs (k)(1), (k)(2), and (k)(4) of this AD: Do a high 
frequency eddy current (HFEC) surface or HFEC hole/edge inspection 
for any cracking of the 1.04-inch nominal diameter wire penetration 
hole in the frame and frame reinforcement between stringer S-20 and 
S-21, in accordance with Part 2 of the Accomplishment Instructions 
of Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011.

(h) Repetitive Inspection

    Within 4,500 flight cycles after accomplishment of the most 
recent inspection specified in Part 2 or Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1279, Revision 1, dated September 2, 2011, or within 90 days 
after the effective date of this AD, whichever occurs later: Do an 
HFEC hole/edge inspection for cracking of the 1.04-inch nominal 
diameter wire penetration hole in the frame and frame reinforcement 
between S-20 and S-21, in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1279, Revision 1, dated September 2, 2011. Repeat the inspection 
thereafter at intervals not to exceed 4,500 flight cycles.

(i) Repair

    If any cracking is found during any inspection required by 
paragraph (g) or (h) of this AD: Before further flight, repair the 
crack including doing all related investigative and applicable 
corrective actions, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1279, Revision 
1, dated September 2, 2011, except as required by paragraph (k)(3) 
of this AD. All related investigative and applicable corrective 
actions must be done before further flight. Accomplishment of the 
requirements of this paragraph terminates the repetitive inspection 
requirements of paragraph (h) of this AD for the repaired location 
of that frame.

(j) Optional Terminating Action

    Accomplishment of the preventive modification, including doing 
all related investigative and applicable corrective actions, 
specified in Part 5 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-53A1279, Revision 1, dated September 2, 
2011, except as required by paragraph (k)(3) of this AD, terminates 
the repetitive inspection requirements of paragraph (h) of this AD 
for the modified location of that frame, provided the modification 
is done before further flight after an inspection required by 
paragraph (g) or (h) of this AD has been done, and no cracking was 
found on that frame location during that inspection.

(k) Exceptions to Service Bulletin Specifications

    The following exceptions apply in this AD.
    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1279, Revision 1, dated September 2, 2011, 
refers to a compliance time ``from date on Revision 1 of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.
    (2) For airplanes meeting all of the criteria specified in 
paragraphs (k)(2)(i), (k)(2)(ii), and (k)(2)(iii) of this AD: The 
compliance time for the initial inspection specified in Part 2 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-53A1279, Revision 1, dated September 2, 2011, and required by 
paragraph (g) of this AD, may be extended to 90 days after the 
effective date of this AD.
    (i) Model 737-300 series airplanes in Group 1, line numbers 1001 
through 2565 inclusive;
    (ii) Airplanes that have accumulated 40,000 or more total flight 
cycles as of the effective date of this AD; and
    (iii) Airplanes on which the modification specified in Boeing 
Service Bulletin 737-53-1273, dated September 20, 2006; Revision 1, 
dated December 21, 2006; Revision 2, dated June 4, 2007; Revision 3, 
dated December 7, 2009; or Revision 4, dated July 23, 2010; has been 
done, including any configuration or deviation that has been 
approved as an AMOC during accomplishment of these service 
bulletins, by the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA) that has been authorized by the 
Manager, Seattle Aircraft Certification Office (ACO) to make those 
findings.
    (3) Where Boeing Alert Service Bulletin 737-53A1279, Revision 1, 
dated September 2, 2011 specifies to contact Boeing for appropriate 
repair instructions: Before further flight, repair the crack using a 
method approved in accordance with the procedures specified in 
paragraph (m) of this AD.

[[Page 67346]]

    (4) The ``Condition'' column of paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, refers to total flight cycles, ``at the date of/
on this service bulletin.'' However, this AD applies to the 
airplanes with the specified total flight cycles as of the effective 
date of this AD.

(l) Credit for Actions Accomplished in Accordance With Previous Service 
Information

    Actions done in accordance with Boeing Alert Service Bulletin 
737-53A1279, dated December 18, 2007, before the effective date of 
this AD are acceptable for compliance with the corresponding actions 
required by paragraphs (g), (h), (i), and (j) of this AD.

(m) 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 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 for paragraphs (h) and (i) of AD 2009-02-06 
R1, Amendment 39-16015 (74 FR 45979, September 8, 2009), are 
approved as AMOCs for the corresponding provisions of paragraphs 
(g), (h), and (i) of this AD.

(n) Related Information

    For more information about this AD, contact Wayne Lockett, 
Aerospace Engineer, Airframe Branch, ANM-120S, Seattle ACO, FAA, 
1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: (425) 
917-6447; fax: (425) 917-6590; email: wayne.lockett@faa.gov.

(o) Material Incorporated by Reference

    (1) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise. The 
Director of the Federal Register approved the incorporation by 
reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51 of the 
following service information on the date specified:
    (i) Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, approved for IBR November 16, 2011.
    (2) If you accomplish the optional actions specified by this AD, 
you must use the following service information to perform those 
actions, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference (IBR) of 
the following service information on the date specified:
    (i) Boeing Alert Service Bulletin 737-53A1279, Revision 1, dated 
September 2, 2011, approved for IBR November 16, 2011.
    (3) 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; e-mail 
me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
    (4) You may review copies of the service information at the FAA, 
1601 Lind Avenue SW., Renton, Washington. For information on the 
availability of this material at the FAA, call (425) 227-1221.
    (5) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at an NARA facility, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on October 20, 2011.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-28053 Filed 10-31-11; 8:45 am]
BILLING CODE 4910-13-P


