[Federal Register Volume 74, Number 149 (Wednesday, August 5, 2009)]
[Rules and Regulations]
[Pages 38901-38903]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-18419]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1213; Directorate Identifier 2007-NM-092-AD; 
Amendment 39-15987; AD 2009-16-14]
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 superseding an existing airworthiness directive 
(AD) that applies to certain Boeing Model 737-100, -200, -200C, -300, -
400, and -500 series airplanes. That AD currently requires repetitive 
inspections of the intercostal webs, attachment clips, and stringer 
splice channels for cracks; and corrective action if necessary. This 
new AD reduces the repetitive inspection intervals from 25,000 flight 
cycles to 6,000 flight cycles, and expands the inspection area for 
Model 737-200C series airplanes to include the area aft of the forward 
entry door. This AD results from additional reports of fatigue cracks. 
We are issuing this AD to detect and correct fatigue cracking of the 
intercostals on the forward and aft sides of the forward entry door, 
which could result in loss of the forward entry door and rapid 
decompression of the airplane.

DATES: This AD becomes effective September 9, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of September 9, 
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 [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: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6450; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2005-20-03, amendment 
39-14296 (70 FR 56361, September 27, 2005). The existing AD applies to 
certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. That NPRM was published in the Federal Register on November 
17, 2008 (73 FR 67815). That NPRM proposed to continue to require 
repetitive inspections of the intercostal webs, attachment clips, and 
stringer splice channels for cracks, at repetitive inspection intervals 
reduced from 25,000 flight cycles to 6,000 flight cycles; and 
corrective action if necessary. That NPRM also proposed to expand the 
inspection area for Model 737-200C series airplanes to include the area 
aft of the forward entry door.

Comments

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

Request to Increase Grace Period

    US Airways requests that we increase the threshold grace period 
from 3,000 flight cycles after the effective date of this AD to 4,500 
flight cycles. US Airways states that the new grace period it requests 
would allow operators to schedule more airplanes into appropriate 
maintenance tasks. US Airways explains that the inspection would affect 
its operation by requiring additional maintenance that is not presently 
scheduled.
    We do not agree with the commenter's request. In developing an 
appropriate compliance time for this AD, we considered not only the 
safety implications, but the manufacturer's recommendations, and the 
practical aspect of accomplishing the modification within an interval 
of time that corresponds to typical scheduled maintenance for affected 
operators. However, under the provisions of paragraph (m) of this AD, 
we may consider requests for adjustments to the compliance time if data 
are submitted to substantiate that such an adjustment would provide an 
acceptable level of safety. We have not changed this AD in this regard.

Explanation of Additional Changes to the AD

    We have clarified paragraphs (h), (i), and (l) of this AD to 
include the full citation for the service information referenced in 
those paragraphs. We made this change to ensure that it is clear which 
service information operators must use for a specific action.
    We have changed paragraph (j) of this AD to remove the reference to 
``Part 4 of the Work Instructions of Boeing

[[Page 38902]]

Special Attention Service Bulletin 737-53-1204, dated June 19, 2003,'' 
because that service bulletin does not contain a Part 4. Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007, does 
include Part 4 to provide procedures related to inspections and 
corrective actions for the intercostal webs and attachment clips 
located aft of the forward entry door. Boeing Special Attention Service 
Bulletin 737-53-1204, dated June 19, 2003, does not include any actions 
for this area of the airplane.

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

    There are about 3,132 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD.

                                                                     Estimated Costs
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                                                                                           Number of U.S.-
              Action                  Work hours     Average labor    Cost per airplane      registered                      Fleet cost
                                                     rate per hour                            airplanes
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Inspection of areas forward of the               2             $80  $160 per inspection               876  $140,160 per inspection cycle.
 aft entry door (required by AD                                      cycle.
 2005[dash]20[dash]03).
Inspection of areas aft of the                   1              80  80 per inspection                  19  1,520 per inspection cycle.
 forward entry door for Model                                        cycle.
 737[dash]200C series airplanes
 (new action).
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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 
removing amendment 39-14296 (70 FR 56361, September 27, 2005) and by 
adding the following new airworthiness directive (AD):

2009-16-14 Boeing: Amendment 39-15987. Docket No. FAA-2008-1213; 
Directorate Identifier 2007-NM-092-AD.

Effective Date

    (a) This AD becomes effective September 9, 2009.

Affected ADs

    (b) This AD supersedes AD 2005-20-03.

Applicability

    (c) This AD applies to Model 737-100, -200, -200C, -300, -400, 
and -500 series airplanes, certificated in any category; as 
identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, 
dated March 26, 2007.

Unsafe Condition

    (d) This AD results from reports of fatigue cracks. We are 
issuing this AD to detect and correct fatigue cracking of the 
intercostals on the forward and aft sides of the forward entry door, 
which could result in loss of the forward entry door and rapid 
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.

Initial Compliance Time

    (f) For all Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes: Before the accumulation of 15,000 total flight 
cycles, or within 4,500 flight cycles after November 1, 2005 (the 
effective date of AD 2005-20-03), whichever occurs later: Do the 
inspections required by paragraphs (h) and (i) of this AD.
    (g) For all Model 737-200C series airplanes: Before the 
accumulation of 15,000 total flight cycles, or within 4,500 flight 
cycles after the effective date of this AD, whichever occurs later: 
Do the inspection required by paragraph (j) of this AD.

Initial Inspection for Passenger Configuration Airplanes

    (h) For Group 1 passenger airplanes identified in Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: 
Perform a detailed inspection for

[[Page 38903]]

cracking of the intercostal web, attachment clips, and stringer 
splice channels; and a high frequency eddy current inspection for 
cracking of the stringer splice channels located forward and aft of 
the forward entry door; and do all applicable corrective actions 
before further flight; in accordance with Parts 1 and 2 of the Work 
Instructions of Boeing Special Attention Service Bulletin 737-53-
1204, dated June 19, 2003; or Boeing Alert Service Bulletin 737-
53A1204, Revision 1, dated March 26, 2007. After the effective date 
of this AD, only Boeing Alert Service Bulletin 737-53A1204, Revision 
1, dated March 26, 2007, may be used.

Initial Inspection for Cargo Configuration Airplanes (Forward of the 
Forward Entry Door)

    (i) For Group 2 cargo airplanes identified in Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: 
Perform a detailed inspection for cracking of the intercostal webs 
and attachment clips located forward of the forward entry door, and 
do all applicable corrective actions before further flight, in 
accordance with Part 3 of the Work Instructions of Boeing Special 
Attention Service Bulletin 737-53-1204, dated June 19, 2003; or 
Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 
26, 2007. After the effective date of this AD, only Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007, may 
be used.

Initial Inspection for Cargo Configuration Airplanes (Aft of the 
Forward Entry Door)

    (j) For Group 2 cargo airplanes identified in Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007: 
Perform a detailed inspection for cracking of the intercostal webs 
and attachment clips located aft of the forward entry door, and do 
all applicable corrective actions before further flight, in 
accordance with Part 4 of the Work Instructions of Boeing Alert 
Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007.

Repeat Inspections

    (k) Repeat the inspections required by paragraphs (h), (i), and 
(j) of this AD thereafter at intervals not to exceed 6,000 flight 
cycles after the previous inspection, or within 3,000 flight cycles 
after the effective date of this AD, whichever occurs later.

Exceptions

    (l) Do the actions required by this AD by accomplishing all the 
applicable actions specified in the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 737-53-1204, dated June 
19, 2003; or Boeing Alert Service Bulletin 737-53A1204, Revision 1, 
dated March 26, 2007; except as provided by paragraphs (l)(1) and 
(l)(2) of this AD. After the effective date of this AD, only Boeing 
Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 
2007, may be used.
    (1) Where Boeing Special Attention Service Bulletin 737-53-1204, 
dated June 19, 2003; or Boeing Alert Service Bulletin 737-53A1204, 
Revision 1, dated March 26, 2007; specifies to contact Boeing for 
repair instructions: Before further flight, repair using a method 
approved in accordance with the procedures specified in paragraph 
(m) of this AD.
    (2) Where Boeing Special Attention Service Bulletin 737-53-1204, 
dated June 19, 2003; or Boeing Alert Service Bulletin 737-53A1204, 
Revision 1, dated March 26, 2007; specifies a compliance time 
relative to the date of a service bulletin, this AD requires 
compliance relative to the effective date of this AD. Where Boeing 
Special Attention Service Bulletin 737-53-1204, dated June 19, 2003; 
or Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated 
March 26, 2007; specifies a compliance time relative to the date of 
the initial release of the service bulletin, this AD requires 
compliance relative to the effective date of AD 2005-20-03 (November 
1, 2005).

Alternative Methods of Compliance (AMOCs)

    (m)(1) The Manager, Seattle Aircraft Certification Office, 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: Alan 
Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle 
ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6450; fax (425) 917-6590.
    (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 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, and the approval must specifically refer to this 
AD.
    (4) AMOCs approved previously in accordance with AD 2005-20-03 
are approved as AMOCs for the corresponding provisions of this AD, 
provided the repetitive inspection intervals (if any) do not exceed 
6,000 flight cycles.
    (5) AMOCs approved previously in accordance with AD 2005-20-03 
are not approved as AMOCs for the provisions of paragraph (j) or (k) 
of this AD.

Material Incorporated by Reference

    (n) You must use Boeing Alert Service Bulletin 737-53A1204, 
Revision 1, dated March 26, 2007; as applicable; 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 Boeing Alert Service Bulletin 737-
53A1204, Revision 1, dated March 26, 2007, 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 July 23, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-18419 Filed 8-4-09; 8:45 am]
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