[Federal Register Volume 75, Number 7 (Tuesday, January 12, 2010)]
[Rules and Regulations]
[Pages 1527-1529]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-31288]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0788; Directorate Identifier 2009-NM-193-AD; 
Amendment 39-16167; AD 2010-01-09]
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.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Model 737-300, -400, and -500 series airplanes. This AD requires 
repetitive external non-destructive inspections to detect cracks in the 
fuselage skin along the chem-mill step at stringers S-1 and S-2 right, 
between station (STA) 827 and STA 847, and repair if necessary. This AD 
results from a report of a hole in the fuselage skin common to stringer 
S-1 and S-2 left, between STA 827 and STA 847 on an airplane that 
diverted to an alternate airport due to cabin depressurization and 
subsequent deployment of the oxygen masks. We are issuing this AD to 
detect and correct fatigue cracking of the fuselage skin panels at the 
chem-milled steps, which could result in sudden fracture and failure of 
the fuselage skin panels, and consequent rapid decompression of the 
airplane.

DATES: This AD is effective February 16, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of February 16, 
2010.

ADDRESSES: 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 [email protected]; 
Internet https://www.myboeingfleet.com.

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 address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Wayne Lockett, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6447; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
certain Model 737-300, -400, and -500 series airplanes. That NPRM was 
published in the Federal Register on September 15, 2009 (74 FR 47148). 
That NPRM proposed to require repetitive

[[Page 1528]]

external non-destructive inspections to detect cracks in the fuselage 
skin along the chem-mill step at stringers S-1 and S-2 right, between 
station (STA) 827 and STA 847, and repair if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the three commenters.

Support for the NPRM

    Boeing and the National Transportation Safety Board concur with the 
NPRM.

Request To Revise Criteria for Optional Terminating Action

    Southwest Airlines (SWA) requests that we revise paragraph (i) of 
the NPRM to remove the first criterion specified for the optional 
terminating action so that repairs installed prior to September 3, 
2009, would be allowed. SWA did not provide justification for this 
request.
    We do not agree to remove the criterion in paragraph (i) of this 
AD. As we stated in the NPRM, September 3, 2009, is the date Boeing 
Service Bulletin 737-53A1301 became available to operators to address 
the identified unsafe condition. However, affected operators may 
request approval to use a repair installed prior to September 3, 2009, 
as an alternative method of compliance, under the provisions of 
paragraph (j) of the final rule. We have made no change to this final 
rule in this regard.

Explanation of Changes Made to This AD

    We have revised this AD to identify the legal name of the 
manufacturer as published in the most recent type certificate data 
sheet for the affected airplane models.
    In addition, Boeing Commercial Airplanes has received an 
Organization Designation Authorization (ODA), which replaces their 
previous designation as a Delegation Option Authorization (DOA) holder. 
We have revised paragraphs (i)(2) and (j) of this AD to delegate the 
authority to approve an alternative method of compliance for any repair 
required by this AD to the Boeing Commercial Airplanes ODA.

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD with the changes described previously. We also determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Interim Action

    We consider this AD interim action. If final action is later 
identified, we might consider further rulemaking then.

Costs of Compliance

    We estimate that this AD affects 135 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S. operators to 
comply with this AD.

                                                                 Table--Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                           Number of U.S.-
              Action                  Work hours     Average labor     Cost per product       registered                     Fleet cost
                                                     rate per hour                            airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection.......................               2              $80   $160, per inspection             135   $21,600, per inspection cycle.
                                                                      cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

    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), and
    (3) 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2010-01-09 The Boeing Company: Amendment 39-16167. Docket No. FAA-
2009-0788; Directorate Identifier 2009-NM-193-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective February 16, 
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to The Boeing Company Model 737-300, -400, 
and -500 series airplanes, certificated in any category; as 
identified in Boeing Alert Service Bulletin 737-53A1301, dated 
September 3, 2009.

Subject

    (d) Air Transport Association (ATA) of America Code 53: 
Fuselage.

[[Page 1529]]

Unsafe Condition

    (e) This AD results from a report of a hole in the fuselage skin 
common to stringer S-1 and S-2 left, between STA 827 and STA 847 on 
an airplane that diverted to an alternate airport due to cabin 
depressurization and subsequent deployment of the oxygen masks. We 
are issuing this AD to detect and correct fatigue cracking of the 
fuselage skin panels at the chem-milled steps, which could result in 
sudden fracture and failure of the fuselage skin panels, and 
consequent rapid decompression of the airplane.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Initial and Repetitive Inspections

    (g) Before the accumulation of 35,000 total flight cycles, or 
within 500 flight cycles after the effective date of this AD, 
whichever occurs later: Except as provided by paragraph (i) of this 
AD, do an external non-destructive inspection (NDI) to detect cracks 
in the fuselage skin along the chem-mill steps at stringers S-1 and 
S-2 right, between STA 827 and STA 847, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1301, dated September 3, 2009. If no cracking is found, repeat 
the inspection thereafter at intervals not to exceed 500 flight 
cycles, except as provided by paragraph (i) of this AD.

Repair

    (h) If any crack is found during any inspection required by this 
AD, and Boeing Alert Service Bulletin 737-53A1301, dated September 
3, 2009, specifies to contact Boeing for repair instructions: Before 
further flight, repair the crack using a method approved in 
accordance with the procedures specified in paragraph (j) of this 
AD.

Optional Terminating Action for Repetitive Inspections

    (i) Installing an external repair doubler along the chem-milled 
steps at stringers S-1 and S-2 right, between STA 827 and STA 847, 
constitutes terminating action for the repetitive inspections 
required by paragraph (g) of this AD for the repaired area only, 
provided all of the conditions specified in paragraphs (i)(1), 
(i)(2), and (i)(3) of this AD are met. The initial inspection 
required by paragraph (g) of this AD must be accomplished.
    (1) The repair is installed after September 3, 2009;
    (2) The repair was approved by the FAA or by a Boeing Company 
Authorized Representative or the Boeing Commercial Airplanes 
Organization Designation Authorization (ODA) authorized by the FAA 
to make such findings; and
    (3) The repair extends a minimum of three rows of fasteners on 
each side of the chem-mill line in the circumferential direction.

Alternative Methods of Compliance (AMOCs)

    (j)(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. Send information to 
ATTN: Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6447; fax (425) 917-6590. Or, e-mail 
information to [email protected].
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (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.

Material Incorporated by Reference

    (k) You must use Boeing Alert Service Bulletin 737-53A1301, 
dated September 3, 2009, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (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; e-mail 
[email protected]; Internet https://www.myboeingfleet.com.
    (3) You may review copies of the 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 or 425-227-1152.
    (4) 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 NARA, 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 December 21, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-31288 Filed 1-11-10; 8:45 am]
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