[Federal Register: June 23, 2009 (Volume 74, Number 119)]
[Proposed Rules]
[Page 29630-29632]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23jn09-12]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2009-0553; Directorate Identifier 2008-NM-199-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
200B, 747-200C, 747-200F, and 747SR Series Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Boeing Model 747-100, 747-100B, 747-200B, 747-200C, 747-200F,
and 747SR series airplanes. This proposed AD would require a one-time
general visual inspection for missing fasteners in certain stringer-to-
stringer clip joints at the station (STA) 760 through STA 940 frames,
and related investigative and corrective actions if necessary. This
proposed AD results from a report of broken and cracked frame shear
ties, cracks on the frame doubler and frame web, and missing fasteners
in the stringer (S)-10L stringer-to-stringer clip joint at the STA 820
frame. We are proposing this AD to detect and correct missing fasteners
in the stringer-to-stringer clip joints, which could result in shear
tie and skin cracks and rapid in-flight decompression of the airplane.
DATES: We must receive comments on this proposed AD by August 7, 2009.
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.
For service information identified in this AD, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207;
telephone 206-544-9990; fax 206-766-5682; e-mail DDCS@boeing.com;
Internet https://www.myboeingfleet.com. You may review copies of the
referenced service information at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information
on the availability of this material at the FAA, call 425-227-1221 or
425-227-1152.
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-2009-0553;
Directorate Identifier 2008-NM-199-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy
[[Page 29631]]
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 a report indicating that, during routine
maintenance, two operators found broken and cracked frame shear ties at
the station (STA) 820 frame between stringer (S)-10AL and S-11L. Also,
cracks were found on the frame doubler and frame web near S-11L.
Further inspection showed missing fasteners in the S-10L stringer-to-
stringer clip joint at the STA 820 frame. The cracks and missing
fasteners were found on airplanes that had accumulated 16,087 and
16,421 total flight cycles.
Boeing analysis shows that the cracks were caused by increased load
on the shear ties because of the missing fasteners in the stringer-to-
stringer clip joint. Boeing investigation shows that similar cracking
could occur in the frames adjacent to the tension ties if the stringer
clip fasteners are not installed. Cracks in the shear ties, if not
detected and corrected, could result in skin cracks and rapid in-flight
decompression of the airplane.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin 747-53A2751, dated
October 9, 2008. The service bulletin describes procedures for a one-
time general visual inspection for missing fasteners in the S-10, S-
10A, and S-11 stringer-to-stringer clip joints at the STA 760 through
STA 940 frames, detailed and surface high frequency eddy current
inspections to detect cracking of the adjacent frame and skin
structure, installation of missing fasteners, and repairs of the shear
ties, frame web, and/or skin. For airplanes on which the repair was
done, the service bulletin describes procedures for detailed
inspections to detect cracks of the repairs and the adjacent structure
within 10 inches of the repairs. The service bulletin also specifies a
detailed inspection of the repair and adjacent structure every 3,000
flight cycles.
FAA's Determination and Requirements of this Proposed AD
We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
This proposed AD would require accomplishing the actions specified in
the service information described previously, except as discussed under
``Differences Between the Proposed AD and Service Bulletin.''
Differences Between the Proposed AD and Service Bulletin
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
We estimate that this proposed AD would affect 84 airplanes of U.S.
registry. The following table provides the estimated costs for U.S.
operators to comply with this proposed AD.
Estimated Costs
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Number of
Average U.S.-
Action Work hours labor rate Parts Cost per product registered Fleet cost
per hour airplanes
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection.............................. 4 $80 $0 $320 per inspection cycle....................... 84 $26,880 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 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 this 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, 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.
[[Page 29632]]
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new AD:
Boeing: Docket No. FAA-2009-0553; Directorate Identifier 2008-NM-
199-AD.
Comments Due Date
(a) We must receive comments by August 7, 2009.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-100, 747-100B, 747-200B,
747-200C, 747-200F, and 747SR series airplanes, certificated in any
category; as identified in Boeing Alert Service Bulletin 747-
53A2751, dated October 9, 2008.
Subject
(d) Air Transport Association (ATA) of America Code 53:
Fuselage.
Unsafe Condition
(e) This AD results from a report of broken and cracked frame
shear ties, cracks on the frame doubler and frame web, and missing
fasteners in the stringer (S)-10L stringer-to-stringer clip joint at
the station (STA) 820 frame. We are proposing this AD to detect and
correct missing fasteners at the stringer-to-stringer clip joints,
which could result in shear tie and skin cracks and rapid in-flight
decompression of the airplane.
Compliance
(f) Comply with this AD within the compliance times specified,
unless already done.
Inspection for Missing Fasteners
(g) Within 3,000 flight cycles after the effective date of this
AD: Do a one-time general visual inspection for missing fasteners in
the left and right side S-10, S-10A, and S-11 stringer-to-stringer
clip joints at the STA 760 through 940 frames, in accordance with
the Accomplishment Instructions of Boeing Alert Service Bulletin
747-53A2751, dated October 9, 2008. If any fasteners are missing,
before further flight, do detailed and surface high frequency eddy
current inspections to detect cracking of the adjacent frame and
skin structure in accordance with the Accomplishment Instructions of
the service bulletin. Install all missing fasteners before further
flight.
(h) If any crack is found during the inspection required by
paragraph (g) of this AD: Before further flight, repair any cracked
shear ties, frame web, and/or skin in accordance with Boeing Service
Bulletin 747-53A2751, dated October 9, 2008.
(i) If any repair is done in accordance with paragraph (h) of
this AD, before 20,000 total flight cycles or within 3,000 flight
cycles from the repair installation, whichever occurs later: Do a
detailed inspection of the repair(s) and the adjacent structure
within 10 inches of the repair(s) for cracking. Repeat the
inspection thereafter at intervals not to exceed 3,000 flight
cycles. If any crack is found during this inspection, before further
flight, repair using a method approved in accordance with the
procedures specified in paragraph (j) of this AD.
Alternative Methods of Compliance (AMOCs)
(j)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. Send information to
Attn: 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. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-
Requests@faa.gov.
(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 principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, in the FAA
Flight Standards District Office (FSDO), or lacking a principal
inspector, your local FSDO. The AMOC approval letter must
specifically reference this AD.
(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 June 15, 2009.
Dorr M. Anderson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-14677 Filed 6-22-09; 8:45 am]
BILLING CODE 4910-13-P