Document ID: FAA-2008-1239-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 747 Airplanes
Posted Date: 2008-11-26T05:00Z

[Federal Register: November 26, 2008 (Volume 73, Number 229)]
[Proposed Rules]               
[Page 71963-71965]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26no08-33]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1239; Directorate Identifier 2008-NM-131-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747 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 airplanes. This proposed AD would require 
repetitive external surface high frequency eddy current inspections to 
detect cracks in the radius detail of the upper lobe doubler on both 
sides of the airplane, and applicable corrective action. This proposed 
AD results from reports of cracks in the radius detail of the upper 
lobe doublers. We are proposing this AD to detect and correct cracks in 
the upper lobe doublers. Such cracks could result in significant 
degradation of the fuselage structure and reduce its ability to carry 
flight loads from the vertical stabilizer, which could adversely affect 
the controllability of the airplane.

DATES: We must receive comments on this proposed AD by January 12, 
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.

[[Page 71964]]

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-2008-1239; 
Directorate Identifier 2008-NM-131-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 reports of cracks in the radius detail of the 
upper lobe doublers on Boeing Model 747 airplanes. The upper lobe 
doublers are located between the fuselage skin and vertical stabilizer 
attach fittings. Cracks in the upper lobe doublers, if not detected and 
corrected, could result in significant degradation of the fuselage 
structure and reduce its ability to carry flight loads from the 
vertical stabilizer, which could adversely affect the controllability 
of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2651, dated 
June 12, 2008. The service bulletin describes procedures for repetitive 
external surface high frequency eddy current (HFEC) inspections to 
detect cracks in the radius detail of the upper lobe doubler on both 
sides of the airplane, and applicable corrective action. The corrective 
action involves either repairing or replacing any cracked upper lobe 
doubler with a new upper lobe doubler.
    The compliance time for the initial external surface HFEC 
inspection is at the later of the following times, depending on the 
airplane configuration:
     Before the accumulation of 9,000 or 10,000 total flight 
cycles, or
     Within 48 months or 1,000 or 4,000 flight cycles, 
whichever occurs first.

The compliance time for the repetitive external surface HFEC 
inspections is within 1,500 or 4,000 flight cycles after the initial 
inspection, and thereafter at intervals not to exceed 1,500 or 4,000 
flight cycles, depending on the airplane configuration.

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(se) same type 
design(s). This proposed AD would require accomplishing the actions 
specified in the service information described previously, except as 
discussed under ``Difference Between the Proposed AD and Service 
Bulletin.''

Difference Between Proposed Rule 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 164 airplanes of 
U.S. registry. We also estimate that it would take about 9 work-hours 
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 $118,080 or $720 per product, 
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:

[[Page 71965]]

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-2008-1239; Directorate Identifier 2008-NM-
131-AD.

Comments Due Date

    (a) We must receive comments by January 12, 2009.

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, 747-400D, 747-
400F, 747SR, and 747SP series airplanes, certificated in any 
category; as identified in Boeing Alert Service Bulletin 747-
53A2651, dated June 12, 2008.

Unsafe Condition

    (d) This AD results from reports of cracks in the radius detail 
of the upper lobe doublers. We are issuing this AD to detect and 
correct cracks in the upper lobe doublers. Such cracks could result 
in significant degradation of the fuselage structure and reduce its 
ability to carry flight loads from the vertical stabilizer, which 
could adversely affect the controllability of the airplane.

Compliance

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

Inspection(s) and Corrective Action

    (f) At the applicable times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2651, dated 
June 12, 2008, do repetitive external surface high frequency eddy 
current inspections to detect cracks in the radius detail of the 
upper lobe doubler on both sides of the airplane, and the applicable 
corrective action by accomplishing all the applicable actions 
specified in Accomplishment Instructions of the service bulletin, 
except as provided by paragraph (g) of this AD. The applicable 
corrective action must be done before further flight.
    (g) Where Boeing Alert Service Bulletin 747-53A2651, dated June 
12, 2008, specifies to contact Boeing for repair instructions 
instead of repairing or replacing any cracked upper lobe doubler in 
accordance with the service bulletin, this AD requires, before 
further flight, repairing any cracked upper lobe doubler 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, ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle ACO, 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 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 November 16, 2008.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E8-28167 Filed 11-25-08; 8:45 am]

BILLING CODE 4910-13-P