
[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]                         

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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).

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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
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                                                                                                                                    Number of
                                                         Average                                                                      U.S.-
                 Action                    Work hours   labor rate     Parts                     Cost per product                   registered                     Fleet cost
                                                         per hour                                                                   airplanes
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Inspection..............................            4          $80           $0  $320 per inspection cycle.......................           84  $26,880 per inspection cycle.
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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 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
