[Federal Register Volume 71, Number 153 (Wednesday, August 9, 2006)]
[Rules and Regulations]
[Pages 45367-45368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-12825]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24698; Directorate Identifier 2006-NM-026-AD; 
Amendment 39-14711; AD 2006-16-11]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-700 and 737-800 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 737-700 and 737-800 series airplanes. This AD 
requires performing a one-time high frequency eddy current inspection 
for cracking of the backup intercostals located above the cutout for 
the forward airstair door; doing related investigative and corrective 
actions if any crack is found; and doing other specified corrective 
actions if no crack is found. This AD results from a report of fatigue 
cracks discovered during a full-scale fatigue test conducted by the 
manufacturer. We are issuing this AD to detect and correct such 
cracking, which could result in more extensive fatigue cracking and 
lead to possible loss of cabin pressure.

DATES: This AD becomes effective September 13, 2006.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of September 13, 
2006.

ADDRESSES: You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street, SW., Nassif Building, 
Room PL-401, Washington, DC.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Howard Hall, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6430; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Examining the Docket

    You may examine the airworthiness directive (AD) docket on the 
Internet at http://dms.dot.gov or in person at the Docket Management 
Facility office between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Management Facility office 
(telephone (800) 647-5227) is located on the plaza level of the Nassif 
Building at the street address stated in the ADDRESSES section.

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that would apply to certain Boeing Model 
737-700 and 737-800 series airplanes. That NPRM was published in the 
Federal Register on May 9, 2006 (71 FR 26873). That NPRM proposed to 
require performing a one-time high frequency eddy current (HFEC) 
inspection for cracking of the backup intercostals located above the 
cutout for the forward airstair door; doing related investigative and 
corrective actions if any crack is found; and doing other specified 
corrective actions if no crack is found.

Comment

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the single comment received. 
The commenter, Boeing, supports the NPRM.

Clarification to NPRM

    The first reference to Boeing Special Attention Service Bulletin 
737-53-1236, Revision 1, dated November 10, 2005, in paragraph (f) of 
the NPRM was unintentionally omitted, and has been added to that 
paragraph of this AD.

Conclusion

    We have carefully reviewed the available data, including the 
comment received, and determined that air safety and the public 
interest require adopting the AD with the change described previously. 
We have determined that this change will neither increase the economic 
burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 146 airplanes of the affected design in the 
worldwide fleet. This AD will affect about 54 airplanes of U.S. 
registry. The required HFEC inspection will take about 2 work hours per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the AD for U.S. operators is $8,640, or 
$160 per airplane.

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:

[[Page 45368]]

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):

2006-16-11 Boeing: Amendment 39-14711. Docket No. FAA-2006-24698; 
Directorate Identifier 2006-NM-026-AD.

Effective Date

    (a) This AD becomes effective September 13, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-700 and 737-800 series 
airplanes, certificated in any category; as identified in Boeing 
Special Attention Service Bulletin 737-53-1236, Revision 1, dated 
November 10, 2005.

Unsafe Condition

    (d) This AD results from a report of fatigue cracks discovered 
during a full-scale fatigue test conducted by the manufacturer. We 
are issuing this AD to detect and correct such cracking, which could 
result in more extensive fatigue cracking and lead to possible loss 
of cabin pressure.

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 of Backup Intercostals

    (f) Before the accumulation of 24,000 total flight cycles, or 
within 4,500 flight cycles after the effective date of this AD, 
whichever comes later: Perform a high frequency eddy current (HFEC) 
inspection for cracking of the backup intercostals located above the 
cutout for the forward airstair door, in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-53-1236, Revision 1, dated November 10, 2005; and, 
before further flight, do related investigative actions and 
applicable corrective actions if any crack is found, and other 
specified corrective actions if no crack is found. Related 
investigative actions, applicable corrective actions, and other 
specified corrective actions must be done in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-53-1236, Revision 1, dated November 10, 2005; except 
where the service bulletin specifies to contact Boeing for repair 
instructions, repair all cracks using a method approved in 
accordance with the procedures specified in paragraph (h) of this 
AD.

Actions Accomplished Using Original Issue of Service Bulletin

    (g) Actions accomplished before the effective date of this AD in 
accordance with Boeing Service Bulletin 737-53-1236, dated July 11, 
2002, are considered acceptable for compliance with the 
corresponding requirements of this AD.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
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 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.

Material Incorporated by Reference

    (i) You must use Boeing Special Attention Service Bulletin 737-
53-1236, Revision 1, dated November 10, 2005, 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. Contact Boeing Commercial Airplanes, P.O. Box 3707, 
Seattle, Washington 98124-2207, for a copy of this service 
information. You may review copies at the Docket Management 
Facility, U.S. Department of Transportation, 400 Seventh Street, 
SW., Room PL-401, Nassif Building, Washington, DC; on the Internet 
at http://dms.dot.gov; or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at the 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 31, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-12825 Filed 8-8-06; 8:45 am]
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