
[Federal Register: March 18, 2010 (Volume 75, Number 52)]
[Proposed Rules]               
[Page 13046-13049]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18mr10-21]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0232; Directorate Identifier 2009-NM-032-AD]
RIN 2120-AA64

 
Airworthiness Directives; The Boeing Company Model 747-200C, -
200F, -400, -400D, and -400F 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 747-200C, -200F, -400, -
400D, and -400F series airplanes. The existing AD currently requires 
repetitive inspections for cracks in the overlapping (upper) skin, 
upper fastener row of the lap joints of the fuselage skin in sections 
41, 42, and 46; and related investigative and corrective actions, if 
necessary. This proposed AD would expand the inspection area in the 
existing AD, and add a modification of certain lap joints and certain 
post-repair inspections of the lap joints. Accomplishing the 
modification would end the repetitive inspections required by the 
existing AD for the length of lap joint that is modified. This proposed 
AD results from a structural review of affected skin lap joints for 
widespread fatigue damage. We are proposing this AD to prevent fatigue 
cracking in certain lap joints, which could result in rapid 
depressurization of the airplane.

DATES: We must receive comments on this proposed AD by May 3, 2010.

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

[[Page 13047]]

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.

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-2010-0232; 
Directorate Identifier 2009-NM-032-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 February 27, 2006, we issued AD 2006-05-09, amendment 39-14506 
(71 FR 12122, March 9, 2006), for certain Model 747-200C, -200F, -400, 
-400D, and -400F series airplanes. That AD requires repetitive 
inspections for cracks in the overlapping (upper) skin, upper fastener 
row of the lap joints of the fuselage skin in sections 41, 42, and 46; 
and related investigative and corrective actions, if necessary. That AD 
resulted from fatigue tests and an analysis that identified areas of 
the fuselage lap joints where fatigue cracks can occur. We issued that 
AD to detect and correct fatigue cracks in the overlapping (upper) 
skin, upper fastener row of the lap joints of the fuselage skin in 
sections 41, 42, and 46, which could adversely affect the structural 
integrity of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 2006-05-09, the manufacturer has conducted a 
structural review of affected skin lap joints for widespread fatigue 
damage, and has identified additional necessary inspection and 
modification actions. It is recommended that all lap joints with an 
upper skin thickness of 0.09 inch or less should be inspected; 
therefore, the inspection area has been expanded to include a new Area 
2 (i.e., the lap joint at STA 450, S-0 to S1L and the S-4L lap joint 
between STA 1970 and STA 2000). It is also recommended that lap joints 
in sections 41 and 42 with an upper skin thickness of 0.071 inch or 
less should be modified; and post-repair inspections have been 
identified.

Revised Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2499, 
Revision 1, dated October 30, 2008. That service bulletin describes 
procedures for repetitive external surface high frequency eddy current 
(HFEC), external low frequency eddy current (LFEC), and internal LFEC 
inspections for cracks in the overlapping (upper) skin, upper fastener 
row of the lap joints of the fuselage skin in sections 41, 42, and 46; 
and related investigative and corrective actions, if necessary.
    For airplanes on which any crack is found, the related 
investigative actions include open-hole HFEC inspections of the 
fastener holes to find further cracking. The corrective actions include 
repairing any cracked lap joint and an open-hole HFEC inspection of the 
skin at all existing fastener locations common to the repair. The 
corrective actions also include repairing any crack found during 
accomplishment of the inspections.
    That service bulletin also describes a modification of the lap 
joints in sections 41 and 42. The modification includes fabricating and 
installing skin doublers on affected lap joints.
    The compliance time for accomplishing the new Area 2 inspections is 
before the accumulation of 22,000 total flight cycles, or within 3,000 
flight cycles after the last HFEC inspection of that area, as specified 
in the Boeing Model 747 Supplemental Structural Inspection Document, or 
within 1,000 flight cycles from the date on Revision 1 of the service 
bulletin; whichever occurs latest.
    For areas on which a lap joint repair was installed and the repair 
doubler is greater than or equal to 40 inches long, that service 
bulletin describes procedures for repetitive internal surface HFEC 
inspections of certain doublers of the lap joints for cracks. The 
compliance time for accomplishing the inspections is within 15,000 
flight cycles after the repair was installed.
    That service bulletin specifies repeating the applicable inspection 
every 3,000 flight cycles, or every 1,500 flight cycles for airplanes 
that have accumulated 30,000 total flight cycles or more.
    The compliance time for accomplishing the new lap joint 
modification is before the accumulation of 30,000 total flight cycles, 
or within 3,000 flight cycles from the date of Revision 1 of the 
service bulletin, whichever is later. Accomplishing this modification 
eliminates the need for the repetitive inspections for the length of 
lap joint that is modified.

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 2006-05-09 and would retain the requirements of the 
existing AD. This proposed AD would also require accomplishing the 
actions specified in the service information described previously.

Explanation of Change Made to This Proposed AD

    Boeing Commercial Airplanes has received an Organization 
Designation Authorization (ODA), which replaces the previous 
designation as a Delegation Option Authorization (DOA) holder. We have 
revised paragraph (n)(3) of this proposed AD to add delegation of 
authority to Boeing Commercial Airplanes ODA to approve an alternative 
method of compliance for any repair required by this AD.

Change to Existing AD

    This proposed AD would retain all requirements of AD 2006-05-09. 
Since AD 2006-05-09 was issued, we have

[[Page 13048]]

added a new paragraph to include the ATA code. 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 2006-05-09                 proposed AD
------------------------------------------------------------------------
             paragraph (f)                        paragraph (g)
             paragraph (g)                        paragraph (h)
             paragraph (h)                        paragraph (l)
------------------------------------------------------------------------

Costs of Compliance

    There are about 735 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 96 airplanes of 
U.S. registry.
    The actions that are required by AD 2006-05-09 and retained in this 
proposed AD take about 541 work hours per airplane, at an average labor 
rate of $85 per work hour. Based on these figures, the estimated cost 
of the currently required actions is $45,985 per airplane, per 
inspection cycle.
    The new proposed Area 2 inspections would take about 124 work hours 
per airplane, at an average labor rate of $85 per work hour. Based on 
these figures, the estimated cost of the new inspections specified in 
this proposed AD for U.S. operators is $1,011,880, or $10,540 per 
airplane, per inspection cycle.
    The new proposed modification would take about 4,799 work hours per 
airplane, at an average labor rate of $85 per work hour. Required parts 
costs per airplane would be minimal. Based on these figures, the 
estimated cost of the new actions specified in this proposed AD for 
U.S. operators is $39,159,840, or $407,915 per airplane.

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 39-14506 (71 FR 
12122, March 9, 2006) and adding the following new AD:

The Boeing Company: Docket No. FAA-2010-0232; Directorate Identifier 
2009-NM-032-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by May 3, 
2010.

Affected ADs

    (b) This AD supersedes AD 2006-05-09.

Applicability

    (c) This AD applies to The Boeing Company Model 747-200C, -200F, 
-400, -400D, and -400F series airplanes, certificated in any 
category; as identified in Boeing Alert Service Bulletin 747-
53A2499, Revision 1, dated October 30, 2008.

Subject

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

Unsafe Condition

    (e) This AD results from a structural review of affected skin 
lap joints for widespread fatigue damage. The Federal Aviation 
Administration is issuing this AD to prevent fatigue cracking in 
certain lap joints, which could result in rapid depressurization of 
the airplane.

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 2006-05-09, With Revised Service 
Information

Initial Inspections and Related Investigative and Corrective Actions

    (g) For airplanes identified in Boeing Alert Service Bulletin 
747-53A2499, dated August 11, 2005: At the applicable time specified 
in Table 1 of this AD, do an external surface high frequency eddy 
current (HFEC), external low frequency eddy current (LFEC), and 
internal LFEC inspection, as applicable, for cracks in the 
overlapping (upper) skin, upper fastener row of the lap joints of 
the fuselage skin in sections 41, 42, and 46, and any applicable 
related investigative and corrective actions by doing all of the 
actions in accordance with the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2499, dated August 11, 2005; or 
Revision 1, dated October 30, 2008. Do any applicable related 
investigative and corrective actions before further flight. As of 
the effective date of this AD, only Revision 1, dated October 30, 
2008, of Boeing Alert Service Bulletin 747-53A2499 may be used.

[[Page 13049]]



                    Table 1--Initial Compliance Time
------------------------------------------------------------------------
    For airplanes on which
 Structural Significant Items
 (SSIs) F-25G, F-25H, and F-                   Inspect--
            25I--
------------------------------------------------------------------------
(1) Have not been inspected    Before the accumulation of 22,000 total
 in accordance with paragraph   flight cycles, or within 1,000 flight
 (i) of AD 2004-07-22 R1,       cycles after April 13, 2006 (the
 amendment 39-15326, using      effective date of AD 2006-05-09),
 the HFEC method.               whichever occurs later.
(2) Have been inspected in     Within 3,000 flight cycles after the most
 accordance with paragraph      recent supplemental structural
 (i) of AD 2004-07-22 R1,       inspection document (SSID) inspection of
 using the HFEC method.         each applicable structural significant
                                item (as given in Boeing Document D6-
                                35022, ``SSID for Model 747 Airplanes,''
                                Revision G, dated December 2000), or
                                within 1,000 flight cycles after April
                                13, 2006, whichever occurs later.
------------------------------------------------------------------------

Repetitive Inspections

    (h) Repeat the applicable inspections required by paragraph (g) 
of this AD thereafter at intervals not to exceed those specified in 
paragraph 1.E., ``Compliance,'' (including the note) of Boeing Alert 
Service Bulletin 747-53A2499, dated August 11, 2005; or Revision 1, 
dated October 30, 2008. As of the effective date of this AD, only 
Revision 1, dated October 30, 2008, of Boeing Alert Service Bulletin 
747-53A2499 may be used.

New Requirements of This AD

Repetitive Inspections/Investigative and Corrective Actions

    (i) For all airplanes: Do an external HFEC inspection of the lap 
joints in Sections 41, 42, and 46 for cracks, by doing all the 
actions, including all applicable related investigative and 
corrective actions, specified in the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2499, Revision 1, dated October 
30, 2008. Do the inspection at the applicable time specified in 
paragraph 1.E. of Boeing Alert Service Bulletin 747-53A2499, 
Revision 1, dated October 30, 2008; except as required by paragraph 
(m) of this AD. Do all applicable related investigative and 
corrective actions before further flight. Repeat the inspection 
thereafter at the times specified in paragraph 1.E. of Boeing Alert 
Service Bulletin 747-53A2499, Revision 1, dated October 30, 2008. 
Accomplishment of the inspections required by this paragraph 
terminates the inspections required by paragraphs (g) and (h) of 
this AD.
    (j) For areas on which a lap joint repair was installed and the 
repair doubler is greater than or equal to 40 inches long: Do 
initial and repetitive internal HFEC inspections for cracks by doing 
all the actions, including all applicable corrective actions, 
specified in the Accomplishment Instructions of Boeing Alert Service 
Bulletin 747-53A2499, Revision 1, dated October 30, 2008, except as 
required by paragraph (l) of this AD. Do the inspections and 
corrective actions at the times specified in paragraph 1.E. of 
Boeing Alert Service Bulletin 747-53A2499, Revision 1, dated October 
30, 2008, except as required by paragraph (m) of this AD.

Terminating Action

    (k) Modify the applicable lap joints in sections 41 and 42 by 
doing all the applicable actions specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2499, Revision 
1, dated October 30, 2008, at the time specified in paragraph 1.E. 
of Boeing Alert Service Bulletin 747-53A2499, Revision 1, dated 
October 30, 2008; except as required by paragraphs (l) and (m) of 
this AD. Accomplishing this modification terminates the repetitive 
inspections of the skin lap joints in sections 41 and 42 required by 
paragraphs (i) and (j) of this AD for the length of lap joint that 
is modified.

Exceptions to Service Bulletin Procedures

    (l) Where Boeing Alert Service Bulletin 747-53A2499, Revision 1, 
dated October 30, 2008, specifies to contact Boeing for appropriate 
action, before further flight, repair the crack using a method 
approved in accordance with the procedures specified in paragraph 
(n) of this AD.
    (m) Where Boeing Alert Service Bulletin 747-53A2499, Revision 1, 
dated October 30, 2008, specifies a compliance time after the date 
of the service bulletin, this AD requires compliance within the 
specified compliance time after the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

    (n)(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 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. Information may be e-mailed 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) or other person 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 2006-05-09 
are approved as alternative methods of compliance with the 
corresponding requirements of this AD.

    Issued in Renton, Washington, on March 10, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-5940 Filed 3-17-10; 8:45 am]
BILLING CODE 4910-13-P

