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[Federal Register: February 25, 2010 (Volume 75, Number 37)]
[Proposed Rules]               
[Page 8554-8557]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25fe10-28]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0132; Directorate Identifier 2009-NM-096-AD]
RIN 2120-AA64

 
Airworthiness Directives; The Boeing Company Model 747-100, -
200B, and -200F Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to certain Model 747-100, 747-200B, and -
200F series airplanes. The existing AD currently requires inspections 
to detect cracking in the upper row of fasteners holes of the skin lap 
joints in the fuselage lower lobe, and repair, if necessary. This 
proposed AD would reduce the maximum interval of the post-modification 
inspections. This proposed AD results from reports of fatigue cracking 
on modified airplanes. We are proposing this AD to detect and correct 
fatigue cracking in the longitudinal lap joints of the fuselage lower 
lobe, which could lead to the rapid decompression of the airplane and 
the inability of the structure to carry fail-safe loads.

DATES: We must receive comments on this proposed AD by April 12, 2010.

ADDRESSES: You may send comments by any of the following methods:

[[Page 8555]]

     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 me.boecom@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-2010-0132; 
Directorate Identifier 2009-NM-096-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

    On August 4, 1994, we issued AD 94-17-01, Amendment 39-8996 (59 FR 
41653, August 15, 1994), for certain Model 747 series airplanes. That 
AD requires inspections to detect cracking in the upper row of fastener 
holes of the skin lap joints in the fuselage lower lobe, and repair if 
necessary. That AD resulted from reports of incidents involving fatigue 
cracking and corrosion of transport category airplanes that are 
approaching or have exceeded their design life goal. We issued that AD 
to prevent separation of fuselage skin and rapid loss of pressure in 
the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 94-17-01, Boeing has performed a fleet-wide 
evaluation of the skin panel lap joints for widespread fatigue damage 
(WFD) and determined that the post-modification inspection interval of 
AD 94-17-01 needs to be reduced. In addition, lap joints where the 
upper (overlapping) skin thickness at the upper row of fasteners is 
0.071 inch or less need to be further modified to preclude WFD. WFD of 
the lap joints can link up and result in large skin cracks, and 
possible rapid in-flight decompression of the airplane.

Relevant Service Information

    AD 94-17-01 referred to Boeing Service Bulletin 747-53A2267, 
Revision 3, dated March 26, 1992, as the appropriate source of service 
information. Boeing has since issued Alert Service Bulletin 747-
53A2267, Revision 4, dated March 26, 2009. This service bulletin 
reduces the repetitive interval for the post-modification inspections 
and references a structural modification for lap joints where the upper 
(overlapping) skin thickness at the upper row of fasteners is 0.071 
inch or less.

Related Rulemaking

    We are considering issuing related rulemaking to address the 
identified unsafe condition. We are in the process of issuing an AD 
that will refer to Revision 1 of Boeing Alert Service Bulletin 747-
53A2463, and is related to this issue. That AD will require further 
modification of all the affected lap joints with an upper skin 
thickness of 0.071 inch or less.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 94-17-01. This AD would retain the requirements of 
that AD using the revised service information, and reduce the maximum 
interval of the post-modification inspections from 3,000 flight cycles 
to 1,000 flight cycles.

Differences Between the Proposed AD and Service Bulletin

    Boeing Alert Service Bulletin 747-53A2267, Revision 4, dated March 
26, 2009, 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 the Boeing Commercial 
Airplanes Organization Designation Authorization that we have 
authorized to make those findings.

Changes to Existing AD

    This proposed AD would retain the requirements of AD 94-17-01. 
Since AD 94-17-01 was issued, the AD format has been revised, and 
certain paragraphs have been rearranged. As a result, the corresponding 
paragraph identifiers have changed in this proposed AD, as listed in 
the following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
                                      Corresponding  requirement in this
     Requirement in AD 94-17-01                  proposed AD
------------------------------------------------------------------------
             Paragraph (a)                       Paragraph (g).
             Paragraph (b)                       Paragraph (h).
             Paragraph (c)                       Paragraph (i).
------------------------------------------------------------------------

    This proposed AD identifies the legal name of the manufacturer as 
published in the most recent type certificate data sheet for the 
affected airplane models.

Costs of Compliance

    There are about 23 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

[[Page 8556]]



                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                       Number of
                                                     Average                                             U.S. -
               Action                  Work hours   labor rate     Parts        Cost per airplane      registered                Fleet cost
                                                     per hour                                          airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Inspection (required by AD 94-17-01)          244          $85           $0  $20,740 per inspection             7  $145,180 per inspection cycle.
                                                                              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 have 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 that the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

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 removing Amendment 39-8996 (59 FR 
41653, August 15, 1994) and adding the following new AD:

The Boeing Company: Docket No. FAA-2010-0132; Directorate Identifier 
2009-NM-096-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by April 12, 
2010.

Affected ADs

    (b) This AD supersedes AD 94-17-01, Amendment 39-8996.

Applicability

    (c) This AD applies to The Boeing Company Model 747-100, 747-
200B, and 747-200F series airplanes, certificated in any category, 
as identified in Boeing Alert Service Bulletin 747-53A2267, Revision 
4, dated March 26, 2009.

Subject

    (d) Air Transport Association (ATA) of America Code 53: 
Fuselage.

Unsafe Condition

    (e) This AD results from reports of fatigue cracking. The 
Federal Aviation Administration is issuing this AD to detect and 
correct fatigue cracking in the fuselage lower lobe longitudinal lap 
joints, which could lead to the rapid decompression of the airplane 
and the inability of the structure to carry fail-safe loads.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.
    Restatement of Requirements of AD 94-17-01, with Revised 
Compliance Times for Post-Modification Inspection and Revised 
Service Information:

Initial External High Frequency Eddy Current Inspection

    (g) Perform an external high frequency eddy current inspection 
to detect cracks in the upper row of fasteners in the modified lap 
joints in accordance with Boeing Service Bulletin 747-53A2267, 
Revision 3, dated March 26, 1992; or Revision 4, dated March 26, 
2009; at the time specified in paragraph (g)(1) or (g)(2) or (g)(3) 
of this AD, as applicable. As of the effective date of this AD, only 
Revision 4 may be used.
    (1) For airplanes on which the full modification required by AD 
90-06-06, Amendment 39-6490, has been accomplished in accordance 
with Revision 2 of Boeing Service Bulletin 747-53A2267, dated March 
29, 1990; or Revision 3, dated March 26, 1992; or Revision 4, dated 
March 26, 2009: Prior to the accumulation of 10,000 flight cycles 
after accomplishment of the full modification.
    (2) For airplanes on which the full modification required by AD 
90-06-06 has been accomplished in accordance with Boeing Service 
Bulletin 747-53A2267, dated March 28, 1986; or Revision 1, dated 
September 25, 1986: Prior to the accumulation of 7,000 flight cycles 
after accomplishment of the full modification.
    (3) For airplanes on which the optional modification has been 
accomplished in accordance with Boeing Service Bulletin 747-53A2267, 
Revision 2, dated March 29, 1990; or Revision 3, dated March 26, 
1992; or Revision 4, dated March 26, 2009: Prior to the accumulation 
of 7,000 flight cycles after accomplishment of the optional 
modification.

Repetitive External High Frequency Eddy Current Inspections

    (h) If no cracking is detected during the inspection required by 
paragraph (g) of this AD, repeat the inspection required by 
paragraph (g) of this AD at the earlier of the times specified in 
paragraphs (h)(1) and (h)(2) of this AD, and thereafter at intervals 
not to exceed 1,000 flight cycles.
    (1) Within 3,000 flight cycles after the last inspection 
required by paragraph (g) of this AD.
    (2) Within 1,000 flight cycles after the last inspection 
required by paragraph (g) of this AD or 500 flight cycles after the 
effective date of this AD, whichever occurs later.

Repair

    (i) If any cracking is detected during any inspection required 
by paragraph (g) of this

[[Page 8557]]

AD, prior to further flight, repair in accordance with Section 53-
30-03 of the Boeing 747 Structural Repair Manual (SRM); or Boeing 
Alert Service Bulletin 747-53A2267, Revision 4, dated March 26, 
2009; except as required by paragraph (j) of this AD; and repeat the 
inspection required by paragraph (g) of this AD at the times 
specified in paragraph (i)(1) of this AD. After the effective date 
of this AD, use only Boeing Alert Service Bulletin 747-53A2267, 
Revision 4, dated March 26, 2009.
    (1) As of the effective date of this AD: If the repair specified 
in the Boeing 747 SRM does not include removing the lap joint and 
the upper row of countersunk fasteners, repeat the inspection 
required by paragraph (g) of this AD at the earlier of the times 
specified in paragraphs (i)(1)(i) and (i)(1)(ii) of this AD, and 
thereafter at intervals not to exceed 1,000 flight cycles.
    (i) Within 3,000 flight cycles after the last inspection 
required by paragraph (g) of this AD.
    (ii) Within 1,000 flight cycles after the last inspection 
required by paragraph (g) of this AD, or within 500 flight cycles 
after the effective date of this AD, whichever occurs later.
    (2) If the repair specified in the 747 SRM includes removing the 
lap joint and the upper row of countersunk fasteners, such repair 
constitutes terminating action for the inspection requirements of 
this AD.

Exception to the Service Bulletin

    (j) If any cracking is found during any inspection required by 
this AD, and Boeing Alert Service Bulletin 747-53A2267, Revision 4, 
dated March 26, 2009, specifies contacting Boeing for appropriate 
action: Before further flight, repair the cracking using a method 
approved in accordance with the procedures specified in paragraph 
(k) of this AD. For a repair method to be approved by the Manager, 
Seattle ACO, as required by this paragraph, the Manager's approval 
letter must specifically refer to this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office, 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, 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 the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that 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.
    (4) AMOCs approved previously in accordance with AD 94-17-01 are 
approved as AMOCs for the corresponding provisions of this AD.

    Issued in Renton, Washington, on February 17, 2010.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-3819 Filed 2-24-10; 8:45 am]
BILLING CODE 4910-13-P
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