[Federal Register: March 30, 2006 (Volume 71, Number 61)]
[Rules and Regulations]
[Page 16019-16021]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30mr06-2]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-20110; Directorate Identifier 2004-NM-114-AD;
Amendment 39-14531; AD 2006-07-04]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 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 737-600, -700, -700C, -800, and -900 series
airplanes. This AD requires repetitive general visual inspections for
dirt, debris, and drain blockage and cleaning of the aft fairing
cavities of the engine struts; and modification of the aft fairings,
which terminates the repetitive general visual inspections. This AD
results from a report indicating that water had accumulated in the
cavities of the engine strut aft fairings. We are issuing this AD to
prevent drain blockage by debris that, when combined with leaking,
flammable fluid lines passing through the engine strut aft fairing,
could allow flammable fluids to build up in the cavity of the aft
fairing, and consequently could be ignited by the engine exhaust nozzle
located below the engine strut, resulting in an explosion or
uncontrolled fire.
DATES: This AD becomes effective May 4, 2006.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of May 4, 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: Doug Pegors, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone
(425) 917-6504; 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
737-600, -700, -700C, -800, and -900 series airplanes. That NPRM was
published in the Federal Register on January 24, 2005 (70 FR 3320).
That NPRM proposed to require repetitive general visual inspections for
dirt, debris, and drain blockage and cleaning of the aft fairing
cavities of the engine struts; and modification of the aft fairings,
which would terminate the repetitive general visual inspections.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Support for NPRM
Southwest Airlines and AirTran Airways support the NPRM.
Request To Revise Dimension Between Certain Fastener Holes
Alaska Airlines requests that we revise the dimension between
certain fastener holes specified in Figures 3, 4, 5, and 6 of Boeing
Special Attention Service Bulletin 737-54-1041, dated January 22, 2004.
Alaska Airlines states that the dimension between an existing fastener
hole and the new fastener hole is called out in the ten-thousandths
(1.6772 inches); any deviation from this exact measurement would
require approval of an alternative method of compliance (AMOC). Alaska
Airlines suggests dimensions of 1.67 or 1.68 inches with a standard
tolerance of 0.03 inch. If we cannot revise the dimension,
the commenter instead requests that we clarify why such a tight
tolerance would be required.
We agree with Alaska Airlines' request, since there is no technical
justification for requiring such a tight tolerance between fastener
holes. Since issuance of the NPRM, Boeing has published Service
Bulletin 737-54-1041, Revision 1, dated December 1, 2005. The
procedures in Revision 1 of the service bulletin are essentially the
same as those in the original issue, dated January 22, 2004, which we
referenced in the NPRM as the appropriate source of service
information. Revision 1 allows a dimension of 1.647 inches to 1.707
inches between fastener holes. Therefore, we have revised this AD to
also allow use of Revision 1 for accomplishing the actions specified in
this AD. We have also revised paragraph (c) of this AD to reference
Revision 1. Since the effectivity of Revision 1 is the same as the
effectivity of the original issue, the applicability of this AD has not
changed.
Clarification of AMOC Paragraph
We have revised this action to clarify the appropriate procedure
for notifying the principal inspector before using any approved AMOC on
any airplane to which the AMOC applies.
Conclusion
We have carefully reviewed the available data, including the
comments received, and determined that air safety and the public
interest require adopting the AD with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
[[Page 16020]]
Costs of Compliance
This AD affects about 1,406 airplanes worldwide and about 549 U.S.-
registered airplanes. The following table provides the estimated costs
for U.S. operators to comply with this AD.
Estimated Costs
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Number of
Average U.S.-
Action Work hours labor rate Parts Cost per airplane registered Fleet cost
per hour airplanes
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Inspection, per inspection cycle..... 2 $65 None.................... $130, per inspection 549 $71,370, per inspection
cycle. cycle.
Modification......................... 5 65 $294.................... $619................... 549 $339,831.
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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
adding the following new airworthiness directive (AD):
2006-07-04 Boeing: Amendment 39-14531. Docket No. FAA-2005-20110;
Directorate Identifier 2004-NM-114-AD.
Effective Date
(a) This AD becomes effective May 4, 2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737-600, -700, -700C, -800,
and -900 series airplanes, certificated in any category; as listed
in Boeing Service Bulletin 737-54-1041, Revision 1, dated December
1, 2005.
Unsafe Condition
(d) This AD was prompted by a report indicating that water had
accumulated in the cavities of the engine strut aft fairings. We are
issuing this AD to prevent drain blockage by debris that, when
combined with leaking, flammable fluid lines passing through the
engine strut aft fairing, could allow flammable fluids to build up
in the cavity of the aft fairing, and consequently could be ignited
by the engine exhaust nozzle located below the engine strut,
resulting in an explosion or uncontrolled fire.
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.
Service Bulletin Reference
(f) The term ``service bulletin,'' as used in this AD, means the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-54-1041, dated January 22, 2004; or Boeing Service
Bulletin 737-54-1041, Revision 1, dated December 1, 2005.
Repetitive Inspections of the Engine Strut Aft Fairings
(g) Within 4,000 flight cycles or within 30 months after the
effective date of this AD, whichever occurs first: Do the actions
specified in paragraphs (g)(1) and (g)(2) of this AD.
(1) Do a general visual inspection for dirt, debris, and drain
blockage and clean the aft fairing cavity of the left engine strut,
in accordance with Part I of the service bulletin, except as
provided by paragraph (h) of this AD. Thereafter at intervals not to
exceed 4,000 flight cycles or 30 months, whichever occurs first:
Repeat the inspection until the aft fairing of the left engine strut
has been modified in accordance with paragraph (i)(1) of this AD.
(2) Do a general visual inspection for dirt, debris, and drain
blockage and clean the aft fairing cavity of the right engine strut,
in accordance with Part II of the service bulletin, except as
provided by paragraph (h) of this AD. Thereafter at intervals not to
exceed 4,000 flight cycles or 30 months, whichever occurs first:
Repeat the inspection until the aft fairing of the right engine
strut has been modified in accordance with paragraph (i)(2) of this
AD.
Note 1: For the purposes of this AD, a general visual inspection
is: ``A visual examination of an interior or exterior area,
installation, or assembly to detect obvious damage, failure, or
irregularity. This level of inspection is made from within touching
distance unless otherwise specified. A mirror may be necessary to
ensure visual access to all surfaces in the inspection area. This
level of inspection is made under normally available lighting
conditions such as daylight, hangar lighting, flashlight, or
droplight and may require removal or opening of access panels or
doors. Stands, ladders, or platforms may be required to gain
proximity to the area being checked.''
[[Page 16021]]
Approved Equivalent Procedure
(h) If the service bulletin specifies that the general visual
inspection and cleaning of the aft fairing cavity of the left or
right engine strut may be accomplished per an ``approved equivalent
procedure'': The general visual inspection or cleaning must be
accomplished in accordance with the chapter of the Boeing 737-600/
700/800/900 Airplane Maintenance Manual specified in the service
bulletin.
Modification of the Engine Strut Aft Fairings
(i) Within 9,000 flight cycles after the effective date of this
AD, do the actions specified in paragraphs (i)(1) and (i)(2) of this
AD.
(1) Modify the aft fairing of the left engine strut, in
accordance with Part III of the service bulletin; and after
accomplishing the modification but before further flight, inspect
and clean the drain system of the aft fairing in accordance with
Part I of the service bulletin. This modification terminates the
repetitive inspections required by paragraph (g)(1) of this AD.
(2) Modify the aft fairing of the right engine strut, in
accordance with Part IV of the service bulletin; and after
accomplishing the modification but before further flight, inspect
and clean the drain system of the aft fairing in accordance with
Part II of the service bulletin. This modification terminates the
repetitive inspections required by paragraph (g)(2) of this AD.
Alternative Methods of Compliance (AMOCs)
(j)(1) The Manager, Seattle Aircraft Certification Office, 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 14 CFR
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.
Material Incorporated by Reference
(k) You must use Boeing Special Attention Service Bulletin 737-
54-1041, dated January 22, 2004; or Boeing Service Bulletin 737-54-
1041, Revision 1, dated December 1, 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 these documents 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 March 17, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 06-2958 Filed 3-29-06; 8:45 am]
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