[Federal Register: May 9, 2005 (Volume 70, Number 88)]
[Proposed Rules]
[Page 24335-24338]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09my05-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-21138; Directorate Identifier 2004-NM-131-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, and -200C
Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 737-100, -200, and -200C series airplanes.
This proposed AD would require a one-time detailed inspection for
cracking of the lugs of the inboard attach fittings of the wing leading
edge slat tracks at slat numbers 2 and 5; prior or concurrent actions
for certain airplanes; repetitive high-frequency eddy current (HFEC)
inspections for cracking of the lug surfaces of those inboard attach
fittings if necessary; and replacement of the attach fittings with new,
improved fittings. This proposed AD is prompted by reports of damage to
the lugs of certain inboard attach fittings of the leading edge slat
tracks. We are proposing this AD to prevent a lifted slat, which, if
the airplane performs any non-normal maneuver during takeoff or landing
at very high angles of attack, could lead to the loss of the slat and
reduced control of the airplane.
DATES: We must receive comments on this proposed AD by June 23, 2005.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to http: //dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401,
Washington, DC 20590.
By fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m.
and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this proposed AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
[[Page 24336]]
You can examine the contents of this AD docket on the Internet at
http://dms.dot.gov, or at the Docket Management Facility, U.S.
Department of Transportation, 400 Seventh Street SW., room PL-401, on
the plaza level of the Nassif Building, Washington, DC. This docket
number is FAA-2005-21138; the directorate identifier for this docket is
2004-NM-131-AD.
FOR FURTHER INFORMATION CONTACT: Nancy Marsh, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6440; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any written relevant data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2005-21138;
Directorate Identifier 2004-NM-131-AD'' in the subject line of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments submitted by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You can review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
can visit http://dms.dot.gov.
Examining the Docket
You can examine the 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 DOT
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after the DMS receives them.
Discussion
We have received reports of damage to the lugs of the inboard
attach fittings of the wing leading edge slat tracks at slat numbers 2
and 5 on several Boeing Model 737-100, -200, and -200C series
airplanes. Two reports addressed damage that occurred during takeoff
and four reports addressed damage that occurred during flight. The
other damaged fittings were found during routine maintenance
inspections. In most of the reports, the lugs of the fittings had
fractured or cracked. Both lugs of one fitting had fractured and were
completely separated at the slat-to-track attach bolt. The auxiliary
track was also lifted and there was damage to the upper skin of the
leading edge cavity on each side. Boeing analysis has determined this
fitting damage was due to cyclic fatigue. This condition, if not
corrected, could result in a lifted slat, which, if the airplane
performs any non-normal maneuver during takeoff or landing at very high
angles of attack, could lead to loss of the slat and reduced control of
the airplane.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 737-57-
1273, Revision 2, dated October 30, 2003. The service bulletin
describes procedures for a one-time detailed visual inspection for
cracking of the lugs of the inboard attach fittings at slat tracks 2
and 5 of the wing leading edge, repetitive high-frequency eddy current
(HFEC) inspections for cracking of the lug surfaces of those inboard
attach fittings, and replacement of the aluminum inboard attach
fittings with new, improved steel inboard attach fittings. Replacement
of any aluminum inboard attach fitting with a new, improved steel
inboard attach fitting eliminates the need for the one-time detailed
inspection and the repetitive HFEC inspections for that fitting.
Accomplishing the actions specified in the service bulletin is intended
to adequately address the unsafe condition.
Service Bulletin 737-57-1273, Revision 2, specifies prior
accomplishment of portions of Boeing Service Bulletin 737-57-1080,
Revision 3, dated September 24, 1992 (applicable to Group 2 airplanes
only as listed in Service Bulletin 737-57-1273). Among other things,
Service Bulletin 737-57-1080, Revision 3, Figure 3, describes
procedures for inspecting the slat tab support clip on slats 2 and 5
for interference with the slat track inboard attach fittings and
trimming the subject slat tab support clips to eliminate any such
interference.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. Therefore, we are proposing this AD, which
would require a one-time detailed inspection for cracking of the lugs
of the inboard attach fittings at slat tracks 2 and 5 of the wing
leading edge, related investigative actions, trimming the slat tab
support clip on slats 2 and 5 to eliminate any interference with the
slat track inboard attach fittings if necessary, and replacing the
attach fittings with new, improved fittings. Replacement of any
aluminum inboard attach fitting with a new, improved steel inboard
attach fitting terminates the one-time detailed inspection and the
repetitive HFEC inspections for that fitting. The proposed AD would
require you to use the service information described previously to
perform these actions, except as discussed under ``Clarification of
Inspection Terminology.''
Clarification of Inspection Terminology
In this proposed AD, the ``detailed visual inspection'' specified
in the Boeing service bulletin is referred to as a ``detailed
inspection.'' We have included the definition for a detailed inspection
in the proposed AD.
Costs of Compliance
This proposed AD would affect about 909 airplanes worldwide. The
following table provides the estimated costs for U.S. operators to
comply with this proposed AD.
Estimated Costs
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Number of U.S.-
Action Work Average labor Parts cost Cost per airplane registered Fleet cost
hours rate per hour airplanes
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Detailed inspection................. 1 $65 None................... $65.................... 522 $33,930
[[Page 24337]]
HFEC Inspection..................... 4 65 None................... 230, per inspection 522 120,060, per inspection
cycle.. cycle.
Replace fitting..................... 2 65 $1,674................. 1,804.................. 522 941,688
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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 proposed AD would not have federalism
under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the 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 proposed AD. 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, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive (AD):
Boeing: Docket No. FAA-2005-21138; Directorate Identifier 2004-NM-
131-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this AD action by June 23, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737-100, -200, and -200C
series airplanes; line numbers 1 through 1585 inclusive;
certificated in any category.
Unsafe Condition
(d) This AD was prompted by reports of damage to the lugs of
certain inboard attach fittings of the leading edge slat tracks. We
are issuing this AD to prevent a lifted slat, which, if the airplane
performs any non-normal maneuver during takeoff or landing at very
high angles of attack, could lead to the loss of the slat and
reduced control 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.
Service Bulletin Reference
(f) The term ``service bulletin,'' as used in this AD, means the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-57-1273, Revision 2, dated October 30, 2003; unless
otherwise specified in this AD.
Inspections
(g) Prior to the accumulation of 7,000 total flight cycles or
within 12 months after the effective date of this AD, whichever
occurs later, perform a one-time detailed inspection for cracking
and damage of the inboard attach fittings at slats 2 and 5 of the
wing leading edge in accordance with the Accomplishment Instructions
of the service bulletin.
Note 1: For the purposes of this AD, a detailed inspection is
``An intensive visual examination of a specific structural area,
system, installation, or assembly to detect damage, failure, or
irregularity. Available lighting is normally supplemented with a
direct source of good lighting at intensity deemed appropriate by
the inspector. Inspection aids such as mirror, magnifying lenses,
etc., may be used. Surface cleaning and elaborate access procedures
may be required.''
(1) If any crack or damage is found, replace the cracked inboard
attach fitting in accordance with paragraph (h) of this AD.
(2) If no crack or damage is found, within 4,500 flight cycles
or 18 months after the detailed inspection required by paragraph (g)
of this AD, whichever occurs first, perform a high-frequency eddy
current (HFEC) inspection for cracking of the lugs of the inboard
attach fittings in accordance with the Accomplishment Instructions
of the service bulletin. If no crack is found, repeat the HFEC
inspection at intervals not to exceed 4,500 flight cycles.
Replacement of Fittings
(h) Replace the aluminum inboard attach fittings with new,
improved steel fittings at the applicable compliance time in
paragraph (h)(1) or (h)(2) of this AD in accordance with the
Accomplishment Instructions of the service bulletin. Replacement of
any aluminum fitting with a new, improved steel fitting terminates
the one-time detailed inspection and the repetitive HFEC inspections
required by paragraph (g) of this AD for that fitting.
(1) If any crack or damage is found during any inspection
required by paragraphs (g) or (i) of this AD, before further flight.
(2) If no crack or damage is found during any inspection
required by paragraph (g) or (i) of this AD, within 30,000 flight
cycles or within 120 months after the effective date of this AD,
whichever occurs first.
Concurrent Service Bulletin
(i) For airplanes listed in Group 2 of Boeing Special Attention
Service Bulletin 737-57-1273, Revision 2: Prior to or during the
one-time detailed inspection for cracking or damage required by
paragraph (g) of this AD or during replacement of the fitting
required by paragraph (h) of this AD, whichever occurs first,
perform a detailed inspection on slats 2 and 5 for interference of
the slat tab
[[Page 24338]]
support clips with the slat track attach fittings and trim the
support clips to eliminate any interference with the attach fittings
as applicable; in accordance with the Accomplishment Instructions of
Boeing Service Bulletin 737-57-1080, Revision 3, Figure 3, dated
September 24, 1992; and replace any cracked or damaged aluminum
attach fitting with a new, improved steel fitting in accordance with
paragraph (h) of this AD.
Actions Accomplished Per Previous Issue of Service Bulletin
(j) Actions accomplished before the effective date of this AD in
accordance with Boeing Service Bulletin 737-57-1080, dated September
10, 1973; Boeing Service Bulletin 737-57-1080, Revision 1, dated
February 25, 1983; and Boeing Service Bulletin 737-57-1080, Revision
2, dated August 24, 1989; are considered acceptable for compliance
with the corresponding actions specified in paragraph (i) of this
AD.
Alternative Methods of Compliance (AMOCs)
(k)(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) 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 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.
Issued in Renton, Washington, on April 29, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-9187 Filed 5-6-05; 8:45 am]
BILLING CODE 4910-13-P