Document ID: FAA-2008-0981-0012
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: The Boeing Company Model 747 Airplanes
Posted Date: 2010-07-01T04:00Z

[Federal Register: July 1, 2010 (Volume 75, Number 126)]
[Rules and Regulations]               
[Page 38001-38007]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jy10-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0981; Directorate Identifier 2008-NM-073-AD; 
Amendment 39-16352; AD 2010-14-07]
RIN 2120-AA64

 
Airworthiness Directives; The Boeing Company Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD), which applies to certain Model 747 airplanes. That AD currently 
requires repetitive inspections of the body station (BS) 2598 bulkhead, 
and corrective actions if necessary. That AD also currently requires a 
terminating modification for certain repetitive inspections and a post-
modification inspection of the modified area. This new AD continues to 
require those actions using revised service information. For certain 
airplanes, this AD requires new repetitive inspections, an interim 
modification, and post-interim modification inspections. For certain 
airplanes, this AD requires replacing any previously repaired aft inner 
chord and reinstalling the terminating modification. For airplanes that 
are converted to the Model 747-400 large cargo freighter (LCF) 
configuration, this new AD reduces the threshold and repeat intervals 
of certain post-modification inspections. For all airplanes, this new 
AD also requires certain inspections of the upper aft outer chords and 
diagonal brace attachment fittings, flanges, and rods to continue after 
the terminating modification. This AD results from reports of cracked 
aft inner chords on airplanes after certain requirements of the 
existing AD were done. We are issuing this AD to prevent fatigue 
cracking of the BS 2598 bulkhead structure, which could result in 
inability of the structure to carry horizontal stabilizer flight loads, 
and loss of controllability of the airplane.

DATES: This AD becomes effective August 5, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of August 5, 
2010.
    On April 13, 2006 (71 FR 12125, March 9, 2006), the Director of the 
Federal Register approved the incorporation by reference of certain 
other publications listed in the AD.

[[Page 38002]]

    On October 27, 2003 (68 FR 54990, September 22, 2003), the Director 
of the Federal Register approved the incorporation by reference of a 
certain other publication listed in the AD.
    On August 16, 2001 (66 FR 36443, July 12, 2001), the Director of 
the Federal Register approved the incorporation by reference of a 
certain other publication listed in the AD.

ADDRESSES: For service information identified in this 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.

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 AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

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:

Discussion

    The FAA issued a supplemental notice of proposed rulemaking (NPRM) 
to amend 14 CFR part 39 to include an AD that supersedes AD 2006-05-06, 
Amendment 39-14503 (71 FR 12125, March 9, 2006). The existing AD 
applies to certain Model 747 airplanes. That supplemental NPRM was 
published in the Federal Register on February 24, 2010 (75 FR 8279). 
That supplemental NPRM proposed to continue to require repetitive 
inspections of the body station (BS) 2598 bulkhead, and corrective 
actions if necessary; and a terminating modification for the repetitive 
inspections and a post-modification inspection of the modified area; 
using revised service information. For certain airplanes, the 
supplemental NPRM proposed to require new repetitive inspections, an 
interim modification, and post-interim modification inspections. For 
certain airplanes, the supplemental NPRM also proposed to require 
replacing any previously repaired aft inner chord and reinstalling the 
terminating modification. The supplemental NPRM proposed to reduce the 
threshold and repeat intervals of certain post-modification inspections 
for airplanes that are converted to the Model 747-400 large cargo 
freighter (LCF) configuration. For all airplanes, the supplemental NPRM 
proposed that certain inspections of the upper aft outer chords and 
diagonal brace attachment fittings, flanges, and rods continue after 
the terminating modification.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments that have been 
received on the supplemental NPRM.

Support for the Supplemental NPRM

    Boeing concurs with the contents of the supplemental NPRM.

Request To Delay the AD Pending Revised Service Information

    All Nippon Airways requests that we delay issuing the AD until 
Boeing revises Service Bulletin 747-53A2427 to Revision 6 (we referred 
to Boeing Service Bulletin 747-53A2427, Revision 5, dated October 1, 
2009, in the supplemental NPRM as the appropriate source of service 
information for certain actions). All Nippon Airways explains that it 
has asked Boeing to clarify an alternate material and filler thickness, 
which it asserts were not reflected in Boeing Service Bulletin 747-
53A2427, Revision 5, dated October 1, 2009. All Nippon Airways also 
state that Boeing will make the necessary changes in Revision 6 of 
Boeing Service Bulletin 747-53A2427. All Nippon Airways states that not 
including this information in the AD will be a burden on operators, 
causing them to request alternative methods of compliance (AMOCs) once 
the supplemental NPRM is mandated.
    We do not agree to delay this AD until additional service 
information is issued. We do not consider that further delaying this 
action until after the release of the manufacturer's planned service 
bulletin is warranted, since sufficient information currently exists to 
accomplish the applicable required actions within the specified 
compliance time. However, under the provisions of paragraph (x) of the 
final rule, we will consider requests for approval of an AMOC if 
sufficient data are submitted to substantiate that the change would 
provide an acceptable level of safety. We have not changed the AD in 
this regard.

Request for Clarification of Certain Requirements

    Japan Airlines requests that we clarify the requirements specified 
in paragraph (q)(2)(ii) of the supplemental NPRM. Japan Airlines states 
that the inspection description specified in that paragraph is not 
clear, because Boeing Alert Service Bulletin 747-53A2473, Revision 2, 
dated August 28, 2009, contains many inspections. Therefore, Japan 
Airlines suggests that we use the same wording between the supplemental 
NPRM and the service information, that we add the table number 
containing the requirement in the service information into the 
supplemental NPRM, and that we more clearly state the purpose of the 
inspection in the supplemental NPRM.
    We recognize that the actions specified in Boeing Alert Service 
Bulletin 747-53A2473, Revision 2, dated August 28, 2009, and this AD 
are complex. We point out that the wording used in this AD was taken 
directly from Boeing Alert Service Bulletin 747-53A2473, Revision 2, 
dated August 28, 2009. Operators should note that paragraph (q)(2)(ii) 
of this AD must be read in concert with paragraph (q)(2) of this AD. 
The content of paragraph (q)(2)(ii) of this AD was meant to clarify the 
content of paragraph (q)(2) of this AD, which contains more detailed 
information. However, while there is no table number to associate with 
the requirements specified in paragraph (q)(2)(ii) of this AD, we can 
refer to the specific paragraph(s) of the Accomplishment Instructions 
of the service information, which contain the required actions. We have 
revised paragraphs (q)(2)(i) and (q)(2)(ii) of this AD to specify the 
applicable paragraph of the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2473, Revision 2, dated August 28, 2009, for 
accomplishing the required actions specified in those paragraphs. 
Because the purpose of the inspection provided in paragraph (q)(2)(ii) 
of this AD is provided in paragraph (q)(2) of this AD, we find that no 
additional clarification is necessary in that regard.

Conclusion

    We have carefully reviewed the available data, including the 
comments that have been received, and determined that air safety and 
the public interest require adopting the AD with the changes described 
previously. We have determined that these changes will

[[Page 38003]]

neither increase the economic burden on any operator nor increase the 
scope of the AD.

Explanation of Change to Costs of Compliance

    Since issuance of the supplemental NPRM, we have increased the 
labor rate used in the Costs of Compliance from $80 per work-hour to 
$85 per work-hour. The Costs of Compliance information, below, reflects 
this increase in the specified hourly labor rate.

Costs of Compliance

    There are about 998 airplanes of the affected design in the 
worldwide fleet. The following table provides the estimated costs for 
U.S. operators to comply with this AD. The average labor rate is $85 
per work hour.

                                      Table--Estimated Costs of Compliance
----------------------------------------------------------------------------------------------------------------
                                                                                Number of U.S.-
            Action                 Work          Parts            Cost per        registered       Fleet cost
                                  hours                           airplane         airplanes
----------------------------------------------------------------------------------------------------------------
Surface high frequency eddy             2  None.............  $170, per                    162  $27,540, per
 current (HFEC) inspections                                    inspection                        inspection
 (required by AD 2006-05-06)                                   cycle.                            cycle.
 and open-hole HFEC
 inspections (new required
 action).
Detailed inspections (required          2  None.............  170, per                     162  27,540, per
 by AD 2006-05-06).                                            inspection                        inspection
                                                               cycle.                            cycle.
Terminating modification              126  $52,218..........  62,928..........             162  10,194,336
 (partially required by AD
 2006-05-06; additional
 modification requirements in
 this new action).
Interim modification (new               4  $4,000...........  4,340...........             162  703,080
 required action).
Replacement of previously               2  None.............  170.............             162  27,540
 repaired aft inner chords
 (new required action).
Support Frame upper Corner              8  None.............  680.............             162  110,160
 Fastener Inspection (new
 required action).
Post-modification inspection            4  None.............  340.............             162  55,080
 (new required action).
----------------------------------------------------------------------------------------------------------------

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 AD will not have federalism 
implications under Executive Order 13132. This AD will 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing Amendment 39-14503 (71 FR 12125, March 9, 2006) and by adding 
the following new airworthiness directive (AD):

2010-14-07 The Boeing Company: Amendment 39-16352. Docket No. FAA-
2008-0981; Directorate Identifier 2008-NM-073-AD.

Effective Date

    (a) This AD becomes effective August 5, 2010.

[[Page 38004]]

Affected ADs

    (b) This AD supersedes AD 2006-05-06, Amendment 39-14503.

Applicability

    (c) This AD applies to The Boeing Company 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, line numbers 1 though 1307 inclusive.

Subject

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

Unsafe Condition

    (e) This AD results from reports of cracked aft inner chords on 
airplanes after certain requirements of the existing AD were done. 
We are issuing this AD to prevent fatigue cracking of the body 
station (BS) 2598 bulkhead structure, which could result in 
inability of the structure to carry horizontal stabilizer flight 
loads, and loss of controllability 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 2006-05-06

Repetitive High Frequency Eddy Current (HFEC) Inspections of the 
Bulkhead Frame Supports

    (g) Before the accumulation of 10,000 total flight cycles, or 
within 1,000 flight cycles after August 16, 2001 (the effective date 
of AD 2001-14-07, Amendment 39-12318, which was superseded by AD 
2006-05-06), whichever occurs later: Do an open-hole HFEC inspection 
to find cracking of the bulkhead frame support under the hinge 
support fittings of the horizontal stabilizer on the left and right 
sides at BS 2598, in accordance with Figure 2 of the Accomplishment 
Instructions of Boeing Service Bulletin 747-53A2449, Revision 1, 
dated May 24, 2001; or Revision 2, dated March 14, 2002. Repeat the 
inspection after that at intervals not to exceed 3,000 flight 
cycles. Inspections accomplished before August 16, 2001, per Boeing 
Alert Service Bulletin 747-53A2449, dated June 8, 2000, are 
considered acceptable for compliance with the applicable inspection 
specified in this paragraph.

Repair of Any Cracked Bulkhead Frame Support

    (h) If any cracking is found during any inspection required by 
paragraph (g) of this AD, before further flight, repair using a 
method approved in accordance with the procedures specified in 
paragraph (x) of this AD.

Repetitive Inspections of Inner Chords, Frame Support Fitting, and 
Splice Fitting

    (i) Do a surface HFEC inspection of the forward and aft inner 
chords, the frame support, and the splice fitting of the forward 
inner chord of the upper corners of the station 2598 bulkhead to 
find cracking, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2427, Revision 2, dated October 
5, 2000; Revision 3, dated September 27, 2001; or Boeing Service 
Bulletin 747-53A2427, Revision 5, dated October 1, 2009; at the 
latest of the times specified in paragraphs (i)(1) and (i)(2) of 
this AD, as applicable. Repeat the inspection after that at 
intervals not to exceed 1,500 flight cycles. After the effective 
date of this AD, Boeing Service Bulletin 747-53A2427, Revision 5, 
dated October 1, 2009, must be used.
    (1) For airplanes having line numbers 1 through 1241 inclusive:
    (i) Before the accumulation of 6,000 total flight cycles.
    (ii) Within 500 flight cycles after August 28, 2001 (the 
effective date of AD 2001-15-03, Amendment 39-12337, which was 
superseded by AD 2006-05-06).
    (iii) For airplanes inspected before August 28, 2001, in 
accordance with Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998 (including inspections of the splice fitting); or 
Revision 1, dated October 28, 1999: Within 1,500 flight cycles after 
accomplishment of the last inspection done in accordance with the 
original service bulletin or Revision 1, as applicable.
    (2) For airplanes having line numbers 1242 through 1307 
inclusive:
    (i) Before the accumulation of 16,000 total flight cycles.
    (ii) Within 500 flight cycles after August 28, 2001.
    (iii) For airplanes inspected before August 28, 2001, in 
accordance with Boeing Alert Service Bulletin 747-53A2427, dated 
December 17, 1998 (including inspections of the splice fitting), or 
Revision 1, dated October 28, 1999: Within 1,500 flight cycles after 
accomplishment of the last inspection done in accordance with Boeing 
Alert Service Bulletin 747-53A2427, dated December 17, 1998; or 
Revision 1, dated October 28, 1999; as applicable.

Repair of Any Cracked Inner Chord, Frame Support, or Splice Fitting

    (j) If any cracking is found during the inspections required by 
paragraph (i) of this AD, before further flight, repair in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2427, Revision 2, dated October 5, 2000; 
Revision 3, dated September 27, 2001; or Boeing Service Bulletin 
747-53A2427, Revision 5, dated October 1, 2009. After the effective 
date of this AD, Boeing Service Bulletin 747-53A2427, Revision 5, 
dated October 1, 2009, must be used. Where Boeing Alert Service 
Bulletin 747-53A2427, Revision 2, dated October 5, 2000; Revision 3, 
dated September 27, 2001; or Boeing Service Bulletin 747-53A2427, 
Revision 5, dated October 1, 2009; specifies that the manufacturer 
may be contacted for disposition of certain repair conditions, 
before further flight, repair using a method approved in accordance 
with the procedures specified in paragraph (x) of this AD.

Repetitive Detailed Inspections of BS 2598 Bulkhead

    (k) Before the accumulation of 10,000 total flight cycles, or 
within 1,000 flight cycles after October 27, 2003 (the effective 
date of AD 2003-19-08, Amendment 39-13311, which was superseded by 
AD 2006-05-06), whichever is later: Do a detailed inspection of the 
BS 2598 bulkhead for discrepancies (cracking, elongated fastener 
holes) of the areas specified in paragraphs (k)(1) and (k)(2) of 
this AD, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2467, dated July 26, 2001; or 
Boeing Service Bulletin 747-53A2467, Revision 1, dated April 28, 
2005. Repeat the inspections after that at intervals not to exceed 
3,000 flight cycles, except as required by paragraph (m) of this AD. 
Doing the modification specified in paragraph (m) or (q) of this AD 
terminates the inspection of the area specified in paragraph (k)(1) 
of this AD.
    (1) The lower aft inner chords.
    (2) The upper aft outer chords, and the diagonal brace 
attachment fittings, flanges, and rods.

    Note 1:  For the purposes of this AD, a detailed inspection is 
``an intensive examination of a specific item, installation, or 
assembly to detect damage, failure, or irregularity. Available 
lighting is normally supplemented with a direct source of good 
lighting at an intensity deemed appropriate. Inspection aids such as 
mirrors magnifying lenses, etc. may be necessary. Surface cleaning 
and elaborate procedures may be required.''

Repair of Any Cracked BS 2598 Bulkhead

    (l) If any discrepancy is found during any inspection required 
by paragraph (k) of this AD: Before further flight, repair in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2467, dated July 26, 2001; or Boeing Service 
Bulletin 747-53A2467, Revision 1, dated April 28, 2005. If Boeing 
Alert Service Bulletin 747-53A2467, dated July 26, 2001; or Boeing 
Service Bulletin 747-53A2467, Revision 1, dated April 28, 2005; 
specifies to contact Boeing for appropriate action: Before further 
flight, repair using a method approved in accordance with the 
procedures specified in paragraph (x) of this AD.

Terminating Modification With New Compliance Time for Certain 
Airplanes for the Inspection Specified in Paragraph (k)(2) of This 
AD

    (m) Except as provided by paragraph (q) of this AD: Before the 
accumulation of 20,000 total flight cycles, or within 48 months 
after April 13, 2006 (the effective date of AD 2006-05-06), 
whichever occurs later, modify the bulkhead by doing all applicable 
actions including surface and open-hole HFEC inspections for 
cracking of the upper forward inner chords, aft inner chords, upper 
splice fittings, and frame support fittings, as specified in the 
Accomplishment Instructions of Boeing Service Bulletin 747-53-2473, 
dated March 24, 2005; Revision 1, dated February 20, 2007; or Boeing 
Alert Service Bulletin 747-53A2473, Revision 2, dated August 28, 
2009. Repair any cracks

[[Page 38005]]

before further flight, in accordance with Boeing Service Bulletin 
747-53-2473, dated March 24, 2005; Revision 1, dated February 20, 
2007; or Boeing Alert Service Bulletin 747-53A2473, Revision 2, 
dated August 28, 2009. Where Boeing Service Bulletin 747-53-2473, 
dated March 24, 2005; Revision 1, dated February 20, 2007; or Boeing 
Alert Service Bulletin 747-53A2473, Revision 2, dated August 28, 
2009; specifies that the manufacturer may be contacted for 
disposition of certain repair conditions: Before further flight, 
repair the cracks using a method approved in accordance with the 
procedures specified in paragraph (x) of this AD. Accomplishment of 
the modification terminates the requirements of paragraphs (g), (i), 
and (k)(1) of this AD. After the effective date of this AD, Boeing 
Alert Service Bulletin 747-53A2473, Revision 2, dated August 28, 
2009, must be used for the actions specified in this paragraph. For 
airplanes that are converted to the Model 747-400 Large Cargo 
Freighter (LCF) configuration, repeat the inspection specified in 
paragraph (k)(2) of this AD thereafter at intervals not to exceed 
1,800 flight cycles.

Post-Modification Inspection and Repair

    (n) Except as provided by paragraphs (q) and (r) of this AD: 
Within 20,000 flight cycles after doing the modification required by 
paragraph (m) of this AD, inspect the BS 2598 bulkhead for cracks, 
and repair any cracks before further flight, in accordance with a 
method approved by the Manager, Seattle Aircraft Certification 
Office (ACO).

New Requirements of This AD

Terminating Repair for Repetitive Surface HFEC Inspections

    (o) As of the effective date of this AD, accomplishing the aft 
inner chord repair required by paragraph (j) of this AD in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2427, Revision 5, dated October 1, 2009, ends the 
repetitive surface HFEC inspections required by paragraph (i) of 
this AD for that side of the bulkhead only.

Replacement of Previously Repaired Aft Inner Chord and 
Reinstallation of Terminating Modification

    (p) For airplanes on which the terminating modification required 
by paragraph (m) of this AD has been done in accordance with Boeing 
Service Bulletin 747-53-2473, dated March 24, 2005: Within 1,500 
flight cycles after doing the modification, or within 1,000 flight 
cycles after the effective date of this AD, whichever occurs later, 
do a one-time general visual inspection for repairs installed 
previously on the left and right side aft inner chords. For 
airplanes with previously installed repairs, before further flight, 
do rework (i.e., replace any previously repaired aft inner chord 
with a new aft inner chord and reinstall the terminating 
modification), using a method approved in accordance with the 
procedures specified in paragraph (x) of this AD.

Revised Terminating Modification

    (q) Doing the applicable modification required by paragraph 
(q)(1) or (q)(2) of this AD at the applicable time terminates the 
requirements of paragraph (m) of this AD and the repetitive 
inspections required by paragraphs (g), (i), and (k)(1) of this AD. 
For airplanes that are converted to the Model 747-400 LCF 
configuration, the inspection specified in paragraph (k)(2) of this 
AD must be repeated thereafter at intervals not to exceed 1,800 
flight cycles.
    (1) For airplanes on which the terminating modification required 
by paragraph (m) of this AD has not been done as of the effective 
date of this AD: Before the accumulation of 20,000 total flight 
cycles, or within 18 months after the effective date of this AD, 
whichever occurs later, modify the bulkhead, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
53A2473, Revision 2, dated August 28, 2009; except that where Boeing 
Alert Service Bulletin 747-53A2473, Revision 2, dated August 28, 
2009, specifies to contact Boeing for modification data, the 
modification data must be approved in accordance with the procedures 
specified in paragraph (x) of this AD, and the modification must be 
done within the times specified in this paragraph.
    (2) For airplanes on which the terminating modification required 
by paragraph (m) of this AD has been done in accordance with Boeing 
Service Bulletin 747-53-2473, dated March 24, 2005; or Revision 1, 
dated February 20, 2007; as of the effective date of this AD: Within 
1,000 flight cycles after the effective date of this AD, or within 
1,500 flight cycles after doing the modification, whichever occurs 
later, do a general visual inspection of the applicable areas 
specified in paragraph (q)(2)(i) and (q)(2)(ii) of this AD to 
determine if certain fasteners are installed, and, before further 
flight, do all applicable related investigative and corrective 
actions, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 747-53A2473, Revision 2, dated August 
28, 2009; except where Boeing Alert Service Bulletin 747-53A2473, 
Revision 2, dated August 28, 2009, specifies to contact Boeing for 
repair or rework data, the data must be approved in accordance with 
the procedures specified in paragraph (x) of this AD and the repair 
or rework must be done before further flight.
    (i) For airplanes modified in accordance with Boeing Service 
Bulletin 747-53-2473, dated March 24, 2005: Inspect the upper 
forward inner chord, frame support fitting, and splice fitting, in 
accordance with paragraph 3.B.7.d. of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2473, Revision 
2, dated August 28, 2009.
    (ii) For airplanes modified in accordance with Boeing Service 
Bulletin 747-53-2473, Revision 1, dated February 20, 2007: Inspect 
the frame web and upper shear deck aft side, and the upper forward 
inner chord, frame support fitting, and splice fitting, in 
accordance with paragraphs 3.B.7.c and 3.B.7.d of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2473, Revision 
2, dated August 28, 2009.

Post-Modification Inspection and Repair

    (r) For airplanes on which the terminating modification has been 
done in accordance with paragraph (m) or (q) of this AD: Perform 
post-modification inspections of the BS 2598 bulkhead for cracking, 
in accordance with Parts 1, 2, and 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-53A2473, Revision 
2, dated August 28, 2009. Do the inspections at the applicable times 
specified in Tables 6 through 9 of paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 747-53A2473, Revision 2, dated 
August 28, 2009; except where Boeing Alert Service Bulletin 747-
53A2473, Revision 2, dated August 28, 2009, specifies a compliance 
time after the date of that service bulletin, this AD requires 
compliance within the specified compliance time after the effective 
date of this AD. If any cracking is found during any inspection 
required by this paragraph, before further flight, repair using a 
method approved in accordance with the procedures specified in 
paragraph (x) of this AD. Repeat the inspections thereafter at the 
applicable times specified in Tables 6 through 9 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 747-53A2473, 
Revision 2, dated August 28, 2009. Accomplishing the applicable 
inspections required by this paragraph terminates the requirements 
of paragraph (n) of this AD.

Open-Hole HFEC Inspection(s) and Terminating Repair

    (s) For airplanes on which the terminating modification required 
by paragraph (m) or (q) of this AD has not been done: Do an initial 
open-hole HFEC inspection to detect cracks in the bulkhead splice 
fitting, frame support fitting, and forward and aft inner chords on 
the left and right sides of the BS 2598 bulkhead, in accordance with 
the Accomplishment Instructions of Boeing Service Bulletin 747-
53A2427, Revision 5, dated October 1, 2009. Do the initial 
inspection at the applicable time specified in Table 1 or 3 of 
paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 747-
53A2427, Revision 5, dated October 1, 2009; except where Boeing 
Service Bulletin 747-53A2427, Revision 5, dated October 1, 2009, 
specifies a compliance time after the date on that service bulletin, 
this AD requires compliance within the specified compliance time 
after the effective date of this AD.
    (1) If no crack is detected, repeat the open-hole HFEC 
inspection thereafter at intervals not to exceed 1,500 flight 
cycles.
    (2) If any crack is detected, before further flight, repair it 
in accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2427, Revision 5, dated October 1, 2009; except 
where Boeing Service Bulletin 747-53A2427, Revision 5, dated October 
1, 2009, 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 (x) of this 
AD. Accomplishing the aft inner chord repair in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2427, 
Revision 5, dated October 1, 2009, ends the repetitive surface and 
open-hole HFEC inspections required by paragraphs (i) and (s)(1), 
respectively, of this AD for that side of the bulkhead only.

[[Page 38006]]

Interim Modification

    (t) For Group 1 airplanes, as identified in Boeing Service 
Bulletin 747-53A2427, Revision 5, dated October 1, 2009, on which 
the repair required by paragraph (j) or (s)(2) of this AD has not 
been done; and on which the terminating modification required by 
paragraph (m) or (q) of this AD has not been done: Before the 
accumulation of 12,000 total flight cycles, or within 1,500 flight 
cycles after the effective date of this AD, whichever occurs later, 
install the interim modification for the aft inner chords, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2427, Revision 5, dated October 1, 2009. 
Accomplishing the interim modification ends the repetitive surface 
and open-hole HFEC inspections required by paragraphs (i) and 
(s)(1), respectively, of this AD.

Post-Interim Modification/Repair Repetitive Surface and Open-Hole 
HFEC Inspections

    (u) For airplanes on which the interim modification required by 
paragraph (t) of this AD has been done or the repair required by 
paragraph (j) or (s)(2) of this AD has been done; and on which the 
terminating modification required by paragraph (m) or (q) of this AD 
has not been done: At the applicable times specified in Table 1, 2, 
or 3 of paragraph 1.E., ``Compliance,'' of Boeing Service Bulletin 
747-53A2427, Revision 5, dated October 1, 2009, do a surface HFEC 
inspection to detect cracks on the forward side (unmodified area) of 
the bulkhead, and open-hole and surface HFEC inspections to detect 
cracks in the modified or repaired area, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-53A2427, 
Revision 5, dated October 1, 2009. Repeat the open-hole and surface 
HFEC inspections thereafter at intervals not to exceed 1,500 flight 
cycles, until the modification required by paragraph (q) of this AD 
is done, as applicable; except that for airplanes on which the 
repair of any cracked aft inner chord has been done on only one side 
of the bulkhead in accordance with the applicable requirements 
specified in paragraph (j) or (s)(2) of this AD, the repetitive 
surface and open-hole HFEC inspections required by paragraphs (i) 
and (s)(1), respectively, of this AD must continue to be done for 
the other side of the bulkhead.

Repair of Any Cracked Inner Chord, Splice Fitting, or Frame Support 
Fitting

    (v) If any crack is detected during any surface or open-hole 
HFEC inspection required by paragraph (u) of this AD, before further 
flight, repair any cracked inner chord, splice fitting, or frame 
support fitting, in accordance with the Accomplishment Instructions 
of Boeing Service Bulletin 747-53A2427, Revision 5, dated October 1, 
2009; except where Boeing Service Bulletin 747-53A2427, Revision 5, 
dated October 1, 2009, 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 
(x) of this AD.

Actions Accomplished According to Previous Issue of Service Bulletin

    (w) Inspections, interim modification, and repairs accomplished 
before the effective date of this AD in accordance with Boeing Alert 
Service Bulletin 747-53A2427, Revision 4, dated March 6, 2008, are 
considered acceptable for compliance with the corresponding action 
specified paragraphs (i), (j), (s), (t), (u), and (v) of this AD.

Alternative Methods of Compliance (AMOCs)

    (x)(1) The Manager, Seattle 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, 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 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 2006-05-06 
are approved as AMOCs for the corresponding provisions of this AD.

Material Incorporated by Reference

    (y) You must use the service information contained in Table 1 of 
this AD, as applicable, to do the actions required by this AD, 
unless the AD specifies otherwise.

             Table 1--All Material Incorporated by reference
------------------------------------------------------------------------
            Document                   Revision              Date
------------------------------------------------------------------------
Boeing Alert Service Bulletin     Original..........  July 26, 2001.
 747-53A2467.
Boeing Alert Service Bulletin     2.................  August 28, 2009.
 747-53A2473.
Boeing Service Bulletin 747-      5.................  October 1, 2009.
 53A2427.
Boeing Service Bulletin 747-      1.................  May 24, 2001.
 53A2449.
Boeing Service Bulletin 747-      2.................  March 14, 2002.
 53A2449.
Boeing Service Bulletin 747-      1.................  April 28, 2005.
 53A2467.
------------------------------------------------------------------------

     (1) The Director of the Federal Register approved the 
incorporation by reference of the service information contained in 
Table 2 of this AD under 5 U.S.C. 552(a) and 1 CFR part 51.

             Table 2--New Material Incorporated by Reference
------------------------------------------------------------------------
              Document                 Revision            Date
------------------------------------------------------------------------
Boeing Alert Service Bulletin 747-             2  August 28, 2009.
 53A2473.
Boeing Service Bulletin 747-53A2427            5  October 1, 2009.
------------------------------------------------------------------------

     (2) On April 13, 2006 (71 FR 12125, March 9, 2006), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Service Bulletin 747-53A2449, Revision 2, dated 
March 14, 2002; and Boeing Service Bulletin 747-53A2467, Revision 1, 
dated April 28, 2005.
    (3) On October 27, 2003 (68 FR 54990, September 22, 2003), the 
Director of the Federal Register approved the incorporation by 
reference of Boeing Alert Service Bulletin 747-53A2467, dated July 
26, 2001.
    (4) On August 16, 2001 (66 FR 36443, July 12, 2001), the 
Director of the Federal Register approved the incorporation by 
reference of

[[Page 38007]]

Boeing Service Bulletin 747-53A2449, Revision 1, dated May 24, 2001.
    (5) For service information identified in this 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.
    (6) You may review copies of the 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.
    (7) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Renton, Washington, on June 17, 2010.
Robert D. Breneman,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-15654 Filed 6-30-10; 8:45 am]
BILLING CODE 4910-13-P