
[Federal Register: October 8, 2008 (Volume 73, Number 196)]
[Proposed Rules]               
[Page 58901-58903]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08oc08-25]                         

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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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[[Page 58901]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1072; Directorate Identifier 2008-NM-109-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 
747SP 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, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747-400, 747SR, and 747SP series airplanes. 
This proposed AD would require inspecting for skin cracks at the shear 
tie end fastener locations of the fuselage frames, and repair if 
necessary. This proposed AD results from a wide-spread fatigue damage 
assessment of Model 747 airplanes. We are proposing this AD to detect 
and correct cracks in the fuselage skin that can propagate and grow, 
resulting in a loss of structural integrity and a sudden decompression 
of the airplane during flight.

DATES: We must receive comments on this proposed AD by November 24, 
2008.

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.

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-2008-1072; 
Directorate Identifier 2008-NM-109-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

    As part of a recent wide-spread fatigue damage (WFD) assessment of 
Boeing Model 747 airplanes, the manufacturer revealed that an 
inspection for skin cracks at certain shear tie end fastener locations 
of the fuselage frames is necessary. This is one of the structural 
areas determined by analysis and fleet history to be susceptible to WFD 
and requires service action in the form of inspections and/or a 
modification. Cracks in the fuselage skin can propagate and grow, 
resulting in loss of structural integrity and a sudden decompression of 
the airplane during flight.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2682, dated 
May 8, 2008. The service bulletin describes procedures for an external 
detailed inspection, or an alternative external high frequency eddy 
current (HFEC) inspection, for skin cracks at the shear tie end 
fastener locations of the fuselage frames between Station (STA) 540 to 
980 (STA 780 on 747SP airplanes), Stringers 23 through 47 on the left 
and right sides, and repair if necessary. If no skin crack is found, 
the applicable inspection is repeated. If any skin crack is found, the 
crack must be repaired, as specified in the 747 Structural Repair 
Manual (SRM). If any crack is found in an SRM skin repair, the service 
bulletin recommends contacting Boeing for repair data.
    The compliance time for the external detailed inspections and the 
alternative external HFEC inspections is before 22,000 total flight 
cycles or within 2,000 flight cycles after the date on the service 
bulletin, whichever occurs later. If no skin crack is found during the 
external detailed inspection, the inspection is repeated within 3,000 
flight cycles after the initial inspection is done, and thereafter at 
intervals not to exceed 3,000 flight cycles. If no skin crack is found 
during the alternative external HFEC inspection, the inspection is 
repeated within 6,000 flight cycles after the initial inspection is 
done, and thereafter at intervals not to exceed 6,000 flight cycles. If 
any crack is found in the skin or skin repair during any inspection, 
the repair is done before further flight.

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

[[Page 58902]]

develop in other products of the same type designs. This proposed AD 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between Proposed AD and Service Information.''

Differences Between 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.
    Although the service bulletin specifies that the repetitive 
inspections are optional, this proposed AD requires the repetitive 
inspections. We find repeating the inspections at regular intervals 
will ensure an acceptable level of safety for all airplanes affected by 
the proposed AD. This difference has been coordinated with Boeing.

Costs of Compliance

    We estimate that this proposed AD would affect 147 airplanes of 
U.S. registry. We also estimate that it would take about 30 work-hours 
for the detailed inspection, or 49 work hours for the HFEC inspection, 
per product, to comply with this proposed AD. The average labor rate is 
$80 per work-hour. Based on these figures, we estimate the cost of this 
proposed AD to the U.S. operators to be $352,800 or $576,240, or $2,400 
or 3,920 per product.

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, 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 AD:

Boeing: Docket No. FAA-2008-1072; Directorate Identifier 2008-NM-
109-AD.

Comments Due Date

    (a) We must receive comments by November 24, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 
747SP series airplanes, certificated in any category; as identified 
in Boeing Alert Service Bulletin 747-53A2682, dated May 8, 2008.

Unsafe Condition

    (d) This AD results from a wide-spread fatigue damage assessment 
of Model 747 airplanes. We are issuing this AD to detect and correct 
cracks in the fuselage skin that can propagate and grow, resulting 
in a loss of structural integrity and sudden decompression of the 
airplane during flight.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Inspections/Repair

    (f) Except as provided by paragraphs (g) and (h) of this AD: At 
the applicable compliance times specified in paragraph 1.E. of 
Boeing Alert Service Bulletin 747-53A2682, dated May 8, 2008, do an 
external detailed inspection or external high frequency eddy current 
inspection for skin cracks at the shear tie end fastener locations 
of the fuselage frames, and repair any skin cracks before further 
flight, by accomplishing all of the applicable actions specified in 
the Accomplishment Instructions of the service bulletin. Repeat the 
applicable inspection thereafter at the applicable interval 
specified in paragraph 1.E. of the service bulletin.

Exceptions to the Service Bulletin

    (g) Where paragraph 1.E. of Boeing Alert Service Bulletin 747-
53A2682, dated May 8, 2008, specifies counting the compliance time 
from ``* * * the date on this service bulletin,'' this AD requires 
counting the compliance time from the effective date of this AD.
    (h) If any crack is found in a structural repair manual skin 
repair during any inspection required by paragraph (f) of this AD, 
and Boeing Alert Service Bulletin 747-53A2682, dated May 8, 2008, 
specifies to contact Boeing for repair: Before further flight, 
repair using a method approved in accordance with the procedures 
specified in paragraph (i) of this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, 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; has the authority to approve AMOCs for this AD, if 
requested using 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

[[Page 58903]]

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 September 26, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-23821 Filed 10-7-08; 8:45 am]

BILLING CODE 4910-13-P
