[Federal Register Volume 74, Number 127 (Monday, July 6, 2009)]
[Proposed Rules]
[Pages 31894-31896]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-15811]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0608; Directorate Identifier 2008-NM-215-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing 747-200C and -200F 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 747-200C and -200F series airplanes. This proposed AD would 
require a high frequency eddy current inspection for cracks of certain 
fastener holes, and corrective action if necessary. This proposed AD 
would also require repetitive replacements of the upper chords, straps 
(or angles), and radius fillers of certain upper deck floor beams, and, 
for any replacement that is done, detailed and open-hole HFEC 
inspections for cracks of the modified upper deck floor beams, and 
corrective actions if necessary. This proposed AD results from a report 
from the manufacturer that the accomplishment of certain existing 
inspections, repairs, and modifications is not adequate to ensure the 
structural integrity of the affected 7075 series aluminum alloy upper 
deck floor beam upper chords on airplanes that have exceeded certain 
thresholds. We are proposing this AD to prevent cracking of the upper 
chords and straps (or angles) of the floor beams, which could lead to 
failure of the floor beams and consequent loss of controllability, 
rapid decompression, and loss of structural integrity of the airplane.

DATES: We must receive comments on this proposed AD by August 20, 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 proposed AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-
544-5000, extension 1, fax 206-766-5680; e-mail [email protected]; 
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-2009-0608; 
Directorate Identifier 2008-NM-215-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 that operators have found cracks in the 
upper chords and straps (or angles) of the upper deck floor beams. The 
airplanes had accumulated between 16,264 and 23,561 total flight 
cycles. In addition, we received a report from the manufacturer that 
the accomplishment of certain existing inspections, repairs, and 
modifications is not adequate to ensure the structural integrity of the 
affected 7075 series aluminum alloy upper deck floor beam upper chords 
on airplanes that have exceeded certain thresholds. Cracks in the upper 
chords or straps (or angles) of an upper deck floor beam that are not 
found and repaired could become large and fully sever the floor beam. A 
severed floor beam can lead to large deflection or deformation of the 
floor and of the adjacent body skin, frames, and stringers, and could 
result in damage and unintended inputs to the wire bundles and control 
cables routed through the floor beams which could affect airplane 
controllability. If not corrected, adjacent severed floor beams could 
result in consequent loss of controllability, rapid decompression, and 
loss of structural integrity of the airplane.

Related ADs

    As a result of these reports of cracks, Boeing issued Alert Service 
Bulletin 747-53A2439, dated July 5, 2001. Boeing Alert Service Bulletin 
747-53A2439 provides procedures for an open-hole high frequency eddy 
current (HFEC) or surface HFEC inspection to find fatigue cracking in 
the upper chord of the upper deck floor beams, and applicable related 
investigative and corrective actions. The actions in Boeing Alert 
Service Bulletin 747-53A2439, dated July 5, 2001, are required by AD 
2006-08-02, amendment 39-14556 (71 FR 18618, April 12, 2006).
    In addition, Boeing has received many reports of cracks in the 
upper chords and straps (or angles) of the affected floor beams at the 
fastener locations where the upper chords attach to the body frames. As 
a result of these reports of cracks, Boeing issued Alert Service 
Bulletin 747-53A2420, dated March 26, 1998; and Boeing Alert Service 
Bulletin 747-53A2429, dated March 22, 2001. Boeing Alert Service 
Bulletin 747-53A2420 provides procedures for detailed and open-hole 
HFEC

[[Page 31895]]

inspections of the upper chords of the floor beams, and applicable 
corrective actions. Boeing Alert Service Bulletin 747-53A2429 provides 
procedures for detailed and open-hole HFEC inspections and modification 
of the upper chords of the floor beams, and applicable corrective 
actions. The actions in Boeing Alert Service Bulletin 747-53A2420, 
dated March 26, 1998; and Boeing Alert Service Bulletin 747-53A2429, 
dated March 22, 2001, are required by AD 2005-07-21, amendment 39-14046 
(70 FR 18277, April 11, 2005).
    To preclude widespread fatigue damage, we have determined that we 
should not rely solely on the inspections required by AD 2006-08-02 and 
AD 2005-07-21 indefinitely. We have determined to mandate a 
modification of the floor beams and related investigative actions in 
this separate AD action, rather than superseding the related ADs.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2696, dated 
October 16, 2008. This service bulletin describes procedures for 
removing the upper chords from the upper deck floor beams at stations 
(STA) 340 to 440 inclusive, 500, and 520, an open-hole HFEC inspection 
for cracks of all the fastener holes accessed for upper chord removal, 
and if any cracking is found, contacting Boeing for repair information, 
and doing the repair. This service bulletin also describes procedures 
for fabricating and installing new upper chords and straps (or angles) 
of the upper deck floor beams at STA 340 to 440 inclusive, 500, and 520 
with new upper chords, straps (or angles), and radius fillers.
    For any airplane on which a replacement is done, the service 
bulletin recommends detailed and HFEC inspections for cracks of the 
modified upper deck floor beams, and for airplanes on which any 
cracking is found, contacting Boeing for repair instructions and 
repairing if necessary. For all airplanes, this service bulletin 
specifies to do detailed and HFEC inspections for cracks of the upper 
deck floor beams within 15,000 flight cycles after the replacement is 
done, or within 1,500 flight cycles, whichever occurs later. This 
service bulletin also specifies replacing the upper chords and straps 
(or angles) of the upper deck floor beams within 6,000 flight cycles 
after doing the detailed and HFEC inspections. The service bulletin 
also specifies repetitive detailed and HFEC inspections within 15,000 
flight cycles after the upper chord replacement modification.
    Boeing Alert Service Bulletin 747-53A2696 refers to Boeing Alert 
Service Bulletin 747-53A2429, Revision 2, dated October 16, 2008; and 
Boeing Alert Service Bulletin 747-53A2439, Revision 2, dated July 17, 
2008; as additional sources of information for doing the post-
modification inspections.

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 the Service Bulletin.''

Differences Between the Proposed AD and the Service Bulletin

    Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008, 
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 25 airplanes of U.S. 
registry. The following table provides the estimated costs for U.S. 
operators to comply with this proposed AD.

                                             Table--Estimated Costs
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                       Average                                                  Number of
                        labor                                                     U.S.-
     Work hours        rate per          Parts            Cost per product     registered        Fleet cost
                         hour                                                   airplanes
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663.................        $80  None................  $53,040 per inspection/         25  $1,326,000 per
                                                        replacement cycle.                  inspection/
                                                                                            replacement 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.

[[Page 31896]]

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.


Sec.  39.13   [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new AD:

Boeing: Docket No. FAA-2009-0608; Directorate Identifier 2008-NM-
215-AD.

Comments Due Date

    (a) We must receive comments by August 20, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 747-200C and -200F 
series airplanes, certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 53: 
Fuselage.

Unsafe Condition

    (e) This AD results from a report from the manufacturer that the 
accomplishment of certain existing inspections, repairs, and 
modifications is not adequate to ensure the structural integrity of 
the affected 7075 series aluminum alloy upper deck floor beam upper 
chords on airplanes that have exceeded certain thresholds. We are 
issuing this AD to prevent cracking of the upper chords and straps 
(or angles) of the floor beams, which could lead to failure of the 
floor beams and consequent loss of controllability, rapid 
decompression, and loss of structural integrity of the airplane.

Compliance

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

Initial Inspection and Replacement

    (g) Before the accumulation of 21,000 total flight cycles, or 
within 1,500 flight cycles after the effective date of this AD, 
whichever occurs later: Do an open hole high frequency eddy current 
(HFEC) inspection of all the fastener holes accessed for upper chord 
removal for cracks, and replace upper chords, straps (or angles), 
and radius fillers of the upper deck floor beams, in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
747-53A2696, dated October 16, 2008.

Repetitive Replacements and Post-Replacement Inspections

    (h) Within 15,000 flight cycles after doing the replacement 
required by paragraph (g) of this AD, or within 1,500 flight cycles 
after the effective date of this AD, whichever occurs later: Do 
detailed and HFEC inspections for cracks of the modified upper deck 
floor beams, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2696, dated October 16, 2008. 
Within 6,000 flight cycles after doing the detailed and HFEC 
inspections, do the replacement specified in paragraph (g) of this 
AD. Repeat the post-replacement inspections and replacement at the 
applicable times specified in paragraph 1.E. of Boeing Alert Service 
Bulletin 747-53A2696, dated October 16, 2008.

Repair of Cracks

    (i) If any crack is found during any inspection required by this 
AD: Before further flight, repair the crack 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, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 
Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6437; fax (425) 917-6590. Or, e-mail information to [email protected].
    (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, or lacking a 
principal inspector, your local Flight Standards District Office. 
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 25, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-15811 Filed 7-2-09; 8:45 am]
BILLING CODE 4910-13-P