[Federal Register: October 17, 2007 (Volume 72, Number 200)]
[Proposed Rules]
[Page 58768-58770]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17oc07-13]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-0045; Directorate Identifier 2007-NM-169- AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-200F, 747-300, 747-
400, and 747-400D 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 747-200F, 747-300, 747-400, and 747-400D
series airplanes. This proposed AD would require a detailed inspection
to detect missing fasteners from the shear clip at a certain stub frame
to auxiliary sill joint, and applicable related investigative and
corrective actions. This proposed AD results from reports of missing
fasteners from the shear clip of the stub frame to auxiliary sill joint
and cracking of the adjacent exterior skin and internal doubler. We are
proposing this AD to ensure that fasteners are installed in the shear
clip of the stub frame to auxiliary sill joint. Missing fasteners could
result in cracks in the adjacent exterior skin and internal doubler,
which can propagate and result in loss of structural integrity and
sudden in-flight decompression of the airplane.
DATES: We must receive comments on this proposed AD by December 3,
2007.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov.
Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for the service information identified in this
proposed AD.
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 proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.
FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437;
fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0045;
Directorate Identifier 2007-NM-169-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov
, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.
Discussion
We have received two reports of cracks found in the exterior skin
and internal doubler adjacent to the shear clip at the stub frame to
auxiliary sill joint at stringer 30 (left and right sides), body
station (BS) 488. In addition, on one of the airplanes, seven fasteners
were missing from the shear clip on the left side of the airplane. The
cause of the missing fasteners has been attributed to a manufacturing
process error. If any fastener is missing from the shear clip at the
stub frame to auxiliary sill joint, cracks could result in the exterior
skin and internal doubler. Such cracks can propagate and result in loss
of structural integrity and sudden in-flight decompression of the
airplane.
[[Page 58769]]
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2685, dated
May 31, 2007. The service bulletin describes procedures for doing a
detailed inspection to detect missing fasteners from the shear clip at
the stub frame to auxiliary sill joint at stringer 30 (left and right
sides), BS 488, and applicable related investigative and corrective
actions. The related investigative actions include doing an open hole
high frequency eddy current inspection to detect cracks at certain
fastener locations in the exterior skin and internal doubler, and
repetitive low frequency eddy current inspections to detect cracks at
the edge row fasteners of any skin repair doubler, as applicable. The
corrective actions include trimming out cracks, installing missing
fasteners, installing skin repair doublers, and contacting Boeing for
certain repair conditions, as applicable.
The service bulletin also specifies the following compliance times:
For the initial detailed inspection: Before 6,000 total
flight cycles, or within 3,000 flight cycles, whichever occurs later.
For the related investigative actions: Before further
flight (for an open hole high frequency eddy current inspection), and
within 15,000 flight cycles after installation of repair and thereafter
at intervals not to exceed 1,500 flight cycles (for low frequency eddy
current inspections).
For the corrective actions: Before further flight.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
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. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously, except as discussed under
``Differences Between the Proposed AD and Service Information.''
Differences Between the Proposed AD and Service Information
The service bulletin specifies to contact the manufacturer for
instructions on how to repair certain conditions, but this proposed AD
would require repairing those conditions in one of the following ways:
Using a method that we approve; or
Using data that meet the certification basis of the
airplane, and that have been approved by an Authorized Representative
for the Boeing Commercial Airplanes Delegation Option Authorization
Organization whom we have authorized to make those findings.
Costs of Compliance
There are about 98 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 8 airplanes of
U.S. registry. The proposed actions would take about 1 work hour per
airplane, at an average labor rate of $80 per work hour. Based on these
figures, the estimated cost of the proposed AD for U.S. operators is
$640, or $80 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 proposed AD would not have federalism
implications 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 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, 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-0045; Directorate Identifier 2007-NM-
169-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by December
3, 2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-200F, 747-300, 747-400,
and 747-400D series airplanes, certificated in any category; as
identified in Boeing Alert Service Bulletin 747-53A2685, dated May
31, 2007.
Unsafe Condition
(d) This AD results from two reports of cracks found in the
exterior skin and internal doubler adjacent to the shear clip at the
stub frame to auxiliary sill joint at stringer 30 (left and right
sides), body station (BS) 488. In addition, on one of the airplanes,
seven fasteners were missing from the shear clip on the left side of
the airplane. The cause of the missing fasteners has been attributed
to a manufacturing process error. We are issuing this AD to ensure
fasteners in the shear clip of the stub frame to auxiliary sill
joints (left and right sides) are installed. Missing fasteners could
result in cracks in the exterior skin and internal doubler, which
can propagate and result in loss of structural integrity and sudden
in-flight 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.
[[Page 58770]]
Inspection and Applicable Related Investigative and Corrective Actions
(f) At the applicable compliance time and repeat intervals
listed in Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of
Boeing Service Bulletin 747-53A2685, dated May 31, 2007; except that
where the service bulletin specifies a compliance time after the
date on the service bulletin, this AD requires compliance within the
specified compliance time after the effective date of this AD: Do
the inspection and applicable related investigative and corrective
actions by accomplishing all the applicable actions specified in the
Accomplishment Instructions of the service bulletin, except as
provided by paragraph (g) of this AD.
Repair of Cracks
(g) If any crack is found during any inspection required by this
AD, and Boeing Service Bulletin 747-53A2685, dated May 31, 2007,
specifies to contact Boeing for appropriate action: Before further
flight, repair the crack using a method approved in accordance with
the procedures specified in paragraph (h) 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) 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 appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
(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.
Issued in Renton, Washington, on October 9, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-20467 Filed 10-16-07; 8:45 am]
BILLING CODE 4910-13-P