[Federal Register Volume 73, Number 30 (Wednesday, February 13, 2008)]
[Proposed Rules]
[Pages 8248-8249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-2588]



[[Page 8248]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0166; Directorate Identifier 2007-NM-329-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, 747-400D, 
747-400F, 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 all 
Boeing Model 747 airplanes listed above. This proposed AD would require 
repetitive inspections for broken or missing fasteners in the single-
row hinge fasteners of the forward and aft cargo doors, and related 
investigative/corrective actions. This proposed AD results from reports 
of broken and missing fasteners in the hinges of the forward and aft 
cargo doors in both the body hinge segments and the door hinge 
segments. We are proposing this AD to detect and correct broken or 
missing fasteners in the hinge segments with a single fastener row, 
which could lead to opening of the cargo door during flight and result 
in rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by March 31, 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-2008-0166; 
Directorate Identifier 2007-NM-329-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 broken fasteners in the hinge segments 
of the forward and aft cargo doors. Two operators have reported broken 
fasteners in both the body hinge segments and the door hinge segments. 
One operator of a Model 747-400 series airplane found three fractured 
fasteners at the aft cargo door, and a subsequent torque check showed 
that two other fasteners were also fractured. Another operator reported 
that all eight fasteners of a hinge segment at the forward cargo door 
of a Model 747-300 series airplane were fractured. This operator also 
reported finding four fractured fasteners in one hinge segment at the 
forward cargo door of a different airplane. Broken or missing fasteners 
in the hinge segments, if not detected and corrected, could lead to 
opening of the cargo door during flight and result in rapid 
decompression of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-52A2287, dated 
October 25, 2007. The service bulletin describes procedures for a 
repetitive detailed inspection for broken or missing fasteners of the 
single-row hinge fasteners of the forward and aft cargo door hinge 
segments, and related investigative and corrective actions. If no 
broken fastener is found, the service bulletin specifies the related 
investigative action of applying torque to all the fasteners at that 
segment to detect any broken fastener. If any inspection or torque 
application shows a broken fastener, the service bulletin specifies the 
corrective action of replacing all fasteners in the hinge segment where 
the broken fastener is found.

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 
``Difference Between the Proposed AD and the Service Bulletin.''

Difference Between the Proposed AD and the Service Bulletin

    The Accomplishment Instructions of the service bulletin do not 
state the action to take if there is a missing fastener. This proposed 
AD would require replacing all fasteners in any hinge segment that has 
one or more missing fasteners.

Interim Action

    A Boeing investigation has not determined a specific root cause for 
the unsafe condition; therefore, we consider this proposed AD interim 
action. If final action is later identified, we might consider further 
rulemaking then.

Costs of Compliance

    We estimate that this proposed AD would affect 165 airplanes of 
U.S. registry. The ``Estimated Costs'' table provides the estimated 
costs for U.S. operators to comply with this proposed AD.

[[Page 8249]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                               Average                        Number of U.S.-
            Action               Work hours   labor rate   Cost per product      registered        Fleet cost
                                               per hour                          airplanes
----------------------------------------------------------------------------------------------------------------
Detailed inspection...........            3          $80  $240, per          165..............  $39,600, per
                                                           inspection cycle.                     inspection
                                                                                                 cycle.
Torque application (for any               7           80  $560, per          Up to 165........  Up to $92,400,
 hinge segment with no broken                              inspection cycle.                     per inspection
 or missing fastener).                                                                           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, 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-2008-0166; Directorate Identifier 2007-NM-
329-AD.

Comments Due Date

    (a) We must receive comments by March 31, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all 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.

Unsafe Condition

    (d) This AD results from reports of broken and missing fasteners 
in the hinges of the forward and aft cargo doors in both the body 
hinge segments and the door hinge segments. We are issuing this AD 
to detect and correct broken or missing fasteners in the hinge 
segments, which could lead to the cargo door opening during flight 
and result in rapid decompression of the airplane.

Compliance

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

Repetitive Inspection and Related Investigative/Corrective Actions

    (f) Before the accumulation of 7,200 total flight cycles or 
within 3,000 flight cycles after the effective date of this AD, 
whichever occurs later: Do a detailed inspection for broken or 
missing fasteners of the single-row hinge fasteners of the forward 
and aft cargo door hinge segments, and do all applicable related 
investigative (torque application) and corrective actions by 
accomplishing all the actions specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-52A2287, dated 
October 25, 2007. Do all applicable related investigative and 
corrective actions before further flight. Repeat the inspection 
thereafter at intervals not to exceed 6,000 flight cycles. Where the 
service bulletin does not give an action to take if there is one or 
more fasteners missing from a hinge segment, replace all fasteners 
in the hinge segment before further flight in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
52A2287, dated October 25, 2007.

Alternative Methods of Compliance (AMOCs)

    (g)(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 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 February 4, 2008.
Kevin Hull,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-2588 Filed 2-12-08; 8:45 am]
BILLING CODE 4910-13-P