
[Federal Register: February 26, 2009 (Volume 74, Number 37)]
[Rules and Regulations]               
[Page 8713-8715]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26fe09-4]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-29255; Directorate Identifier 2007-NM-085-AD; 
Amendment 39-15821; AD 2009-04-15]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This AD requires repetitive internal eddy current and 
detailed inspections to detect cracked stringer tie clips; measuring 
the fastener spacing and the edge margin if applicable, and doing 
applicable corrective and related investigative actions. As a temporary 
alternative to doing the actions described previously, this AD requires 
repetitive external general visual inspections of the skin and lap 
joints and repetitive external eddy current sliding probe inspections, 
as applicable, of the lap joints for cracks and evidence of overload 
resulting from cracked stringer tie clips, and applicable corrective 
actions if necessary. This AD results from a report of several cracked 
stringer tie clips. We are issuing this AD to detect and correct 
multiple adjacent cracked stringer tie clips and damaged skin and 
frames, which could lead to the skin and frame structure developing 
cracks and consequent decompression of the airplane.

DATES: This AD becomes effective April 2, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of April 2, 
2009.

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 me.boecom@boeing.com; 
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

    The FAA issued a supplemental notice of proposed rulemaking (NPRM) 
to amend 14 CFR part 39 to include an AD that would apply to certain 
Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. That supplemental NPRM was published in the Federal Register 
on August 29, 2008 (73 FR 50899). That supplemental NPRM proposed to 
require repetitive internal eddy current and detailed inspections to 
detect cracked stringer tie clips; measuring the fastener spacing and 
the edge margin if applicable, and doing applicable corrective and 
related investigative actions. That supplemental NPRM also proposed to 
require repetitive external eddy current sliding probe inspections of 
the lap joints for cracks and evidence of overload resulting from 
cracked stringer tie clips, and applicable corrective actions if 
necessary.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Clarify Effectivity

    Boeing asks that the affected airplanes specified in Note 3 of the 
supplemental NPRM be clarified. Boeing states that the original issue 
of Boeing Service Bulletin 737-53-1085, Revision 1, dated May 10, 1990 
(referred to in Note 3), contains an error in the affected airplanes 
shown in the summary section. Boeing notes that the error shows line 
numbers 1 through 1000. Boeing also states that in the planning 
information section of that service bulletin, it shows line number 
1000/part number 136 is not included in the Group 2 airplanes (all 
affected Model 737-200 airplanes). In addition, Boeing Service Bulletin 
737-53-1085, Revision 1, dated May 10, 1990, includes a change to the 
production line for line numbers 1000 and on. Boeing asks that Note 3 
of the supplemental NPRM be changed to replace line number 1000 with 
line number 999, and to replace line number 1001 with line number 1000. 
We agree for the reasons provided and have changed Note 3 for 
clarification.

Request To Clarify Paragraph (g)

    Boeing asks that we clarify the first sentence in paragraph (g) of 
the supplemental NPRM (paragraph (f) of the final rule) by adding ``as 
applicable'' after the inspection method. We agree because the 
inspection method depends on the type of stringer clip. We have changed 
paragraph (f) of the AD accordingly.

Request To Clarify Paragraph (h)

    Boeing asks that we clarify the first sentence in paragraph (h) of 
the supplemental NPRM (paragraph (g) of the final rule) by adding ``as 
applicable'' to that sentence. We agree because the inspection types 
are appropriate only for certain airplanes. We have changed paragraph 
(g) of the AD accordingly.

Request To Move Note 2

    Boeing asks that we move Note 2 of the supplemental NPRM from its 
current position below paragraph (h) of the supplemental NPRM 
(paragraph (g) of the final rule) to the position below paragraph (g) 
(paragraph (f) of the final rule) and Note 1 of the supplemental NPRM. 
Boeing states that Note 2 pertains to the optional/economic 
inspections, which are relative to those inspections specified in 
paragraph (g), not paragraph (h). Boeing notes that

[[Page 8714]]

Note 2 provides supplemental information about paragraph (g). Boeing 
adds that Note 2 should be moved to correspond with Inspection A, which 
is specified in paragraph (g). We agree for the reasons provided and we 
have moved Note 2 to the position below Note 1.

Change to Final Rule

    We have removed the ``Service Bulletin Reference'' paragraph from 
this AD, and re-identified subsequent paragraphs accordingly. (That 
paragraph was identified as paragraph (f) in the supplemental NPRM.) 
Instead, we have spelled out the service bulletin citations throughout 
this AD.

Conclusion

    We reviewed the relevant data, considered the comments 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.

Costs of Compliance

    We estimate that this AD affects 787 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S. operators to 
comply with this AD.

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                 Number of U.S.-
            Action              Work hours \1\   Average labor      Cost per       registered     Fleet cost \1\
                                                 rate per hour    airplane \1\      airplanes
----------------------------------------------------------------------------------------------------------------
Inspection A.................  Between 40 and              $80  Between $3,200              787  Between
                                103.                             and $8,240,                      $2,518,400 and
                                                                 per inspection                   $6,484,880,
                                                                 cycle.                           per inspection
                                                                                                  cycle.
Inspection B (temporary        Between 2 and                80  Between $160                787  Between
 alternative to Inspection A).  109.                             and $8,720.                      $125,920 and
                                                                                                  $6,862,640,
                                                                                                  per inspection
                                                                                                  cycle.
----------------------------------------------------------------------------------------------------------------
\1\ Depending on the airplane configuration.

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 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2009-04-15 Boeing: Amendment 39-15821. Docket No. FAA-2007-29255; 
Directorate Identifier 2007-NM-085-AD.

Effective Date

    (a) This AD becomes effective April 2, 2009.

Affected ADs

    (b) AD 93-08-04, amendment 39-8551.

Applicability

    (c) This AD applies to Boeing Model 737-100, -200, -200C, -300, 
-400, and -500 series airplanes, certificated in any category; as 
identified in Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006.

Unsafe Condition

    (d) This AD results from a report of several cracked stringer 
tie clips. We are issuing this AD to detect and correct multiple 
adjacent cracked stringer tie clips and damaged skin and frames, 
which could lead to the skin and frame structure developing cracks 
and consequent decompression of the airplane.

Compliance

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

Inspection A: Required Internal Inspections, Applicable Corrective and 
Related Investigative Actions, and Measurement

    (f) Do repetitive internal eddy current and detailed 
inspections, as applicable, to detect cracked stringer tie clips; 
measure the fastener spacing and the edge margin if applicable; and 
do applicable corrective and related investigative actions. Do all 
applicable actions at the applicable compliance times and repeat 
intervals identified in Tables 2 through 8 inclusive of paragraph 
1.E., ``Compliance,'' of Boeing Special Attention Service Bulletin 
737-53-1268, dated August 25, 2006 (``the service bulletin''); 
except as provided by paragraphs (h) through (k) of this AD. Do all 
applicable actions in accordance with the Accomplishment 
Instructions of the service bulletin, except as provided by 
paragraph (l) of this AD.


[[Page 8715]]


    Note 1: Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006, refers to Boeing Service Bulletin 737-
53A1177, Revision 6, dated May 31, 2001, as an additional source of 
service information for doing an internal eddy current inspection of 
the lap joint for certain airplane configurations.


    Note 2: The eddy current inspections along the stringer tie clip 
radius to detect damage and replacement, as applicable, specified in 
paragraph 3.B.5. of the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 737-53-1268, dated August 25, 
2006, are not required by this AD. The actions are optional and can 
be done in addition to and at the same time as the actions required 
by paragraph (f) of this AD.

Inspection B: Temporary Alternative External Inspections and Corrective 
Actions

    (g) As a temporary alternative to doing the actions required by 
paragraph (f) of this AD, do repetitive external general visual 
inspections of the skin and lap joints and repetitive external eddy 
current sliding probe inspections, as applicable, of the lap joints 
for cracks and evidence of overload resulting from cracked stringer 
tie clips, and applicable corrective actions if necessary. Do all 
applicable actions at the applicable compliance times and repeat 
intervals identified in Tables 9 through 12 inclusive of paragraph 
1.E., ``Compliance,'' of Boeing Special Attention Service Bulletin 
737-53-1268, dated August 25, 2006 (``the service bulletin''), but 
not to exceed the flight cycles in the ``Inspection Period Allowed'' 
column of the tables; except as provided by paragraphs (h) and (k) 
of this AD. Do all applicable actions in accordance with the 
Accomplishment Instructions of the service bulletin, except as 
provided by paragraph (l) of this AD.

    Note 3: Inspection B may be used on affected airplanes having 
line numbers 1 through 999 inclusive on which the terminating action 
(i.e., replacement of stringer tie clips) specified in Boeing 
Service Bulletin 737-53-1085, Revision 1, dated May 10, 1990, has 
been done; and on affected airplanes having line numbers 1000 and 
subsequent. Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006, contains a similar note.

Exceptions to Service Information

    (h) Where Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006 (``the service bulletin''), specifies a 
compliance time after the date of the service bulletin, this AD 
requires compliance within the specified compliance time after the 
effective date of this AD.
    (i) For Model 737-100, -200, and -200C series airplanes, on 
which Boeing Service Bulletin 737-53-1085, Revision 1, dated May 10, 
1990, has not been done in accordance with AD 93-08-04: As of the 
effective date of this AD, do the applicable inspections from 
station (STA) 559 to STA 887 in accordance with paragraph (f) of 
this AD, at the applicable compliance times specified in paragraph 
(b) of AD 93-08-04.
    (j) In the first row of Tables 5 and 6 of paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 737-53-
1268, dated August 25, 2006 (``the service bulletin''), where the 
service bulletin specifies a compliance time of before 25,000 total 
airplane flight cycles, this AD requires a compliance time of before 
the accumulation of 25,000 total flight cycles, or within 2 years 
after the effective date of this AD, whichever occurs later.
    (k) Where Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006, specifies no starting point (e.g., ``after 
the date on the service bulletin'') for a grace period, this AD 
requires compliance within the specified grace period after the 
effective date of this AD.
    (l) Where Boeing Special Attention Service Bulletin 737-53-1268, 
dated August 25, 2006, specifies to contact Boeing for appropriate 
action: Before further flight, repair the discrepancy using a method 
approved in accordance with the procedures specified in paragraph 
(n) of this AD.

Certain Actions End Certain Requirements of AD 93-08-04

    (m) Accomplishment of the internal eddy current and detailed 
inspections for STA 559 to STA 887 in accordance with paragraph (f) 
of this AD constitutes compliance with the inspections required by 
paragraph (a) of AD 93-08-04, as it pertains to Boeing Service 
Bulletin 737-53-1085, Revision 1, dated May 10, 1990. Accomplishment 
of the internal eddy current and detailed inspections does not 
terminate the remaining requirements of AD 93-08-04, as it applies 
to other service bulletins. Operators are required to continue to 
inspect and/or modify per the other service bulletins listed in that 
AD.

Alternative Methods of Compliance (AMOCs)

    (n)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, 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; has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (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 an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who 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.

Material Incorporated by Reference

    (o) You must use Boeing Special Attention Service Bulletin 737-
53-1268, dated August 25, 2006, to perform the actions that are 
required by this AD, unless the AD specifies otherwise. The Director 
of the Federal Register approved the incorporation by reference of 
this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
    (1) 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.
    (2) You may review copies of the service information that is 
incorporated by reference 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.
    (3) You may also review copies of the service information 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 January 30, 2009.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E9-3621 Filed 2-25-09; 8:45 am]

BILLING CODE 4910-13-P
