[Federal Register: September 27, 2005 (Volume 70, Number 186)]
[Rules and Regulations]
[Page 56361-56365]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27se05-8]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2005-18788; Directorate Identifier 2003-NM-203-AD;
Amendment 39-14296; AD 2005-20-03]
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 inspections of the intercostal
webs, attachment clips, and stringer splice channels for cracks; and
corrective action if necessary. This AD is prompted by reports of
fatigue cracks on several Boeing Model 737-200 series airplanes. 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 November 1, 2005.
The incorporation by reference of a certain publication listed in
the AD is approved by the Director of the Federal Register as of
November 1, 2005.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
Docket: The AD docket contains the proposed AD, comments, and any
final disposition. 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 U.S.
Department of Transportation, 400 Seventh Street, SW., room PL-401,
Washington, DC. This docket number is FAA-2005-18788; the directorate
identifier for this docket is 2003-NM-203-AD.
FOR FURTHER INFORMATION CONTACT: Howard Hall, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6430; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with an AD for certain Model 737-100, -200, -200C, -300, -400, and -500
series airplanes. That action, published in the Federal Register on
August 6, 2004 (69 FR 47808), proposed to require repetitive
inspections of the intercostal webs, attachment clips, and stringer
splice channels for cracks; and corrective action if necessary.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments that have been
submitted on the proposed AD.
Qualified Support for the Proposed AD
One commenter, an operator, stated that the proposed AD is
acceptable provided that the service bulletin referenced in the
proposed AD is corrected to reflect the proper work instructions and to
reference accurate figures for accomplishment.
The FAA cannot respond to the generality of the commenter's
statement. However, other commenters have requested clarification on
certain aspects of the work instructions and requested certain revision
of the ``Costs of Compliance'' section of this AD. Those comments are
specified and responded to in the appropriate paragraphs below.
Request for Clarification in Paragraph (k) of the Proposed AD
Two commenters request that paragraph (k) be revised to clarify
that the reference to using Figure 201 instead of Figure 202 of the
service bulletin only applies to Model 737-400 series airplanes.
We agree that paragraph (k) of the AD should be clarified and have
revised the AD accordingly.
Request To Withdraw the Proposed AD
One commenter, an operator, states that the Maintenance Planning
Document (MPD) is the logical document to accomplish the main
objectives of the inspections specified in the proposed AD. The
commenter suggests that it makes more sense to revise MPD Task S53-22-
A-2, rather than to issue an AD. We infer that the commenter is
requesting that the proposed AD be withdrawn.
We do not agree. We are obligated by part 39 of the Federal
Aviation Regulations (FAR) to appropriately address any identified
unsafe condition that is likely to exist on other airplanes. The MPD is
appropriate for addressing routine maintenance of critical structural
components. However, operators may submit their specific and particular
MPD task cards for consideration as an alternative method of compliance
(AMOC) if they wish, in accordance with paragraph (n) of the AD. No
change is necessary to the AD in this regard.
Request for More Information Regarding Paragraph (k) of the Proposed AD
One commenter, an operator, requests that inspection specifics be
added to paragraph (k) of the proposed AD for the stringer-16L (S-16L)
area in the post-repair configuration. The commenter does not believe
that Boeing Special Attention Service Bulletin 737-53-1204, dated June
19, 2003, referenced in the proposed AD as the appropriate source of
service information, provides sufficient inspection specifics in Figure
1.
The FAA does not agree that further inspection specifics are
necessary to clarify paragraph (k) of the AD. Figure
[[Page 56362]]
1 does not specifically show the repair/modification configurations at
S-16L, and is simply intended to show typical crack locations and to
identify the structural components that require inspection. Since the
general inspection details provided in Figure 1 are applicable to both
pre- and post-repair/modification configurations, no change to the AD
is necessary in this regard.
Request To Allow ``Credit'' for Certain Repairs
One commenter, an operator, requests that repairs on the affected
intercostals that are installed prior to the effective date of the AD
be addressed. The operator states that the proposed AD specifies that
certain repairs must be approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA; or per data meeting the type
certification basis of the airplane approved by a Boeing Designated
Engineering Representative (DER) who has been authorized by the
Manager, Seattle ACO, to make such findings. The operator requests that
the final rule allow credit for any repairs previously approved by the
Seattle ACO.
We do not agree that previous repairs need to be addressed other
than through the normal process as stated above by the commenter. Other
than the repairs already identified at S-16L, we are not aware of any
specific pre-existing repair configurations that should be addressed in
the final rule. The Manager, Seattle ACO, can approve design data for
previously installed or newly installed repair configurations prior to
the issuance of this AD. However, approval as an AMOC with the AD
cannot be given until the date the final rule is effective. No change
is necessary to the AD in this regard.
Requests To Address Previously Accomplished Modification/Repairs
Two commenters, both operators, request that provision for
``previous or newly accomplished'' installations of the repair be added
to paragraph (k) of the proposed AD.
We acknowledge the commenters' concern and partially agree.
Paragraph (k) of the AD, as worded in the AD, simply permits deferring
the repetitive inspections if the installation of the repair as a
preventative modification or corrective action is accomplished in
accordance with Part 1 of the Work Instructions of the service
bulletin. We did not specify that installation of the repair must be
performed either before or after the effective date of the AD, since,
in this case, it does not matter when it is accomplished. No change is
necessary to the AD in this regard.
Requests To Extend Initial Compliance Time of Paragraph (g) of the
Proposed AD
Several commenters request that the grace period specified in
paragraph (g), ``4,500 flight cycles after the effective date of the
AD,'' be extended to 7,500 or 8,000 flight cycles. One commenter states
that the most critical area (STR 16L between Body Station (BS) 348.2
and BS 360) can only be inspected correctly by accessing additional
areas, which may include removing lavatories or galleys. The commenters
contend that extending the grace period of the initial compliance time
would allow most operators to accomplish the requirements of paragraph
(g) during normal scheduled maintenance.
We do not agree that the grace period should be extended beyond
4,500 flight cycles. We have determined that the grace period of 4,500
is appropriate and adequate to maintain an acceptable level of safety.
The grace period represents more than two years of average operation,
during which time most operators will have accomplished regularly
schedule maintenance. The commenter has provided no technical data to
show that extending the grace period compliance time to 7,500 or 8,000
flight cycles would continue to provide an acceptable level of safety.
However, under the provisions of paragraph (n) of the AD, we may
consider requests for adjustments to the grace period for the initial
compliance time if sufficient data are submitted to substantiate that
such an extension of the grace period would provide an acceptable level
of safety. No change is necessary to the AD in this regard.
Request To Extend Initial Compliance Time of Paragraph (g) of the
Proposed AD for Certain Areas
One commenter requests that, for areas that are non-critical, the
compliance time be extended from 15,000 total flight cycles to 25,000
total flight cycles. The commenter notes that it is not clear why the
non-critical areas have the same initial threshold as the critical area
(S-16L). The commenter contends that the compliance time should be
extended for those areas other than S-16L.
We do not agree. We have received recent service reports of cracked
structure occurring at locations other than S-16L as early as 18,910
total flight cycles. No change is necessary to the AD in this regard.
Request for Credit for Similar Inspections
One commenter, an operator, notes that certain inspections similar
to the inspections in the proposed AD are already required under the
Corrosion Prevention and Control Program (CPCP). Although the commenter
acknowledges that the intensity and type of inspection is not identical
to the inspections specified in the proposed AD, the commenter requests
that some relief of the compliance time should be considered if the
CPCP inspections have been performed recently.
We do not agree to extend the compliance time. In developing this
AD, we considered the inspections of the baseline CPCP program, but
also noted that certain operators may be using different CPCP programs.
However, under the provisions of paragraph (n) of the AD, we may
approve requests for adjustments to the compliance time if data are
submitted to substantiate that such an adjustment would provide an
acceptable level of safety. No change is necessary to the AD in this
regard.
Request To Clarify the Failure Mechanism
One commenter, an operator, requests that we explain why the FAA
and the manufacturer disagree on the potential failure mechanism. The
commenter points out that the manufacturer does not indicate that the
fatigue cracking could result in loss of the forward entry door, only
that incorporation of the service bulletin would prevent possible
decompression and unscheduled down time.
We acknowledge that the manufacturer's service bulletin does not
specifically advise that ``loss of the forward entry door'' could occur
as a result of the identified unsafe condition. However, the
manufacturer and the FAA agree that several potential failure
scenarios, such as loss of the forward entry door, could occur. Both
the manufacturer and the FAA agree that an unsafe condition has been
identified and is likely to exist or to develop in other airplanes.
Therefore, the actions specified in the AD are necessary to detect and
correct fatigue cracking of the intercostals of the forward entry door.
No change is necessary to the AD in this regard.
Request To Revise the Costs of Compliance
Several commenters request that the ``Costs of Compliance'' section
be revised to reflect the number of work hours required for access.
We do not agree that the cost estimate provided in the proposed AD
should be revised. Based on the best data available, the manufacturer
provided the number of work hours (two) necessary to do the required
actions.
[[Page 56363]]
This number represents the time necessary to perform only the actions
actually required by this AD. We recognize that, in doing the actions
required by an AD, operators may incur incidental costs in addition to
the direct costs. The cost analysis in AD rulemaking actions, however,
typically does not include incidental costs such as the time required
to gain access and close up, time necessary for planning, or time
necessitated by other administrative actions. Those incidental costs,
which may vary significantly among operators, are almost impossible to
calculate. No change is necessary to the AD in this regard.
Request To Replace Parts Without FAA Approval
One commenter, an operator, asks that allowance be made in
paragraph (m) for the replacement of parts without the need to contact
the FAA for approval.
We do not agree with the commenter's request. Since the service
bulletin referenced in this AD does not provide specific instructions
for repair (replacing the parts), operators must perform the repair in
accordance with a method approved as specified in paragraph (m) of this
AD.
Explanation of Change Made to This AD
Since the issuance of the proposed AD, Boeing has received a
Delegation Option Authorization (DOA). We have revised this AD to
delegate the authority to approve an alternative method of compliance
for any repair required by this AD to the Authorized Representative for
the Boeing DOA Organization rather than the Designated Engineering
Representative.
Conclusion
We have carefully reviewed the available data, including the
comments that have been submitted, 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.
Costs of Compliance
This AD will affect about 3,113 airplanes worldwide and 876
airplanes of U.S. registry. The required actions will take about 2 work
hours per airplane, at an average labor rate of $65 per work hour.
Based on these figures, the estimated cost of the AD for U.S. operators
is $113,880, or $130 per airplane, per inspection cycle.
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. 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 FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2005-20-03 Boeing: Amendment 39-14296. Docket No. FAA-2005-18788;
Directorate Identifier 2003-NM-203-AD.
Effective Date
(a) This AD becomes effective November 1, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Model 737-100, -200, -200C, -300, -400,
and -500 series airplanes, as identified in Boeing Special Attention
Service Bulletin 737-53-1204, dated June 19, 2003; certificated in
any category.
Unsafe Condition
(d) This AD was prompted by reports of fatigue cracks on several
Boeing Model 737-200 series airplanes. 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.
Service Bulletin Definition
(f) The term ``service bulletin,'' as used in this AD, means
Boeing Special Attention Service Bulletin 737-53-1204, dated June
19, 2003.
Initial Compliance Time
(g) 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 inspections specified in paragraph
(h) or (i) of this AD, as applicable.
Inspection for Passenger Configuration Airplanes
(h) For Group 1 passenger airplanes identified in the service
bulletin: Perform a detailed inspection of the intercostal web,
attachment clips, and stringer splice channels for cracks; and a
high frequency eddy current inspection of the stringer splice
channels, located forward and aft of the forward entry door, for
cracks; per Parts 1 and 2 of the Work Instructions of the service
bulletin.
Inspection for Cargo Configuration Airplanes
(i) For Group 2 cargo airplanes identified in the service
bulletin: Perform a detailed inspection of the intercostal webs and
attachment clips located forward of the forward entry door for
cracks, per Part 3 of the Work Instructions of the service bulletin.
[[Page 56364]]
Repetitive Inspections
(j) If no crack is found during any inspection required by
paragraph (h) or (i) of this AD, repeat the inspections in paragraph
(h) or (i) of this AD at the applicable time specified in Table 1 of
this AD, except as provided by paragraph (k) of this AD.
Table 1.--Repetitive Inspection Interval
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Repeat inspections at intervals not to
Airplane group number in Service Bulletin For intercostal location-- exceed--
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Group 1.................................. Stringer-16L (S-16L), from 4,500 flight cycles.
Body Stringer 348.2 to BS
360 (aft of door).
Group 1.................................. S-7L through S-15L, from BS 25,000 flight cycles.
348.2 to BS 360 (aft of
door).
Group 1 and 2............................ S-7L through S-16L, from BS 25,000 flight cycles.
294.5 to BS 303.9 (forward
of door).
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Deferral of Certain Repetitive Inspections
(k) For intercostal webs at S-16L from BS 348.2 to BS 360:
Installation of the repair as a preventative modification or
corrective action per Part 1 of the Work Instructions of the service
bulletin defers the repetitive inspections to intervals not to
exceed 25,000 flight cycles. For Model 737-400 series airplanes, use
737-400 Structural Repair Manual (SRM) 53-10-04, Figure 201, instead
of Figure 202.
Corrective Actions
(l) If any crack is found during any inspection required by
paragraph (h) or (i) of this AD, perform the actions specified in
paragraphs (l)(1) through (l)(3) of Table 2 of this AD, as
applicable. Repeat the inspections at the applicable time specified
in Table 1 of this AD, except as provided by paragraph (k) of this
AD.
Table 2.--Corrective Actions
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If any crack is found At intercostal
During any inspection specified in-- in-- location-- Before further flight--
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(1) Part 1 of the Work Instructions (i) The intercoastal S-16L, from BS 348.2 to Repair per Part 1 of
of the service bulletin. web. BS 360 (aft of door). the Work Instructions
of the service
bulletin, except the
service bulletin
specifies to contact
Boeing for repair
instructions, before
further flight, do the
repair specified in
paragraph (m) of this
AD. Use 737-400 SRM 53-
10-04, Figure 201,
instead of Figure 202,
as applicable (see
Note 1).
(ii) An attachment clip S-16L, from BSDo 348.2 Do the repair specified
or stringer splice to BS 360 (aft of in paragraph (m) of
channel. door). this AD.
(2) Part 2 of the Work Instructions An intercoastal web, S-7L through S-16L, Do the repair specified
of the service bulletin. attachment clip, or from BS 294.5 to BS in paragraph (m) of
stringer splice 303.9 (forward of this AD.
channel. door); and S-7L
through S-15L, from BS
348.2 to BS 360 (aft
of door).
(3) Part 3 of the Work Instructions An intercoastal web or S-7L through S-16L, Do the repair specified
of the service bulletin. attachment clip. from BS 294.5 to BS in paragraph (m) of
303.9 (forward of this AD.
door).
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Note 1: The service bulletin specifies to repair any crack
found at the S-16L intercostal (BS 348.2-360) on Boeing Model 737-
400 series airplanes per 737-400 SRM 53-10-04, Figure 202. Figure
202 does not exist; the correct figure is 737-400 SRM 53-10-04,
Figure 201.
Repair
(m) At the time specified in Table 2 of this AD, repair per a
method approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA; or per data meeting the type certification basis
of the airplane approved 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.
Alternative Methods of Compliance (AMOCs)
(n)(1) The Manager, Seattle ACO, 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 corrective actions per data meeting the type certification
basis of the airplane approved by a Boeing DOA Organization AR who
has been authorized by the Manager, Seattle ACO, to make those
findings. For a repair method to be approved, the approval must
specifically reference this AD.
Material Incorporated by Reference
(o) You must use Boeing Special Attention Service Bulletin 737-
53-1204, dated June 19, 2003, to perform the actions that are
required by this AD, unless the AD specifies otherwise. The Director
of the Federal Register approves the incorporation by reference of
this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.
To get copies of the service information, contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. To view
the AD docket, go to the Docket Management Facility, U.S. Department
of Transportation, 400 Seventh Street SW., room PL-401, Nassif
Building, Washington, DC. To review copies of the service
information, go to 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.
[[Page 56365]]
Issued in Renton, Washington, on September 16, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-19143 Filed 9-26-05; 8:45 am]
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