
[Federal Register: December 11, 2008 (Volume 73, Number 239)]
[Rules and Regulations]               
[Page 75305-75307]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11de08-1]                         


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Rules and Regulations
                                                Federal Register
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[[Page 75305]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0590; Directorate Identifier 2008-NM-057-AD; 
Amendment 39-15765; AD 2008-25-07]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, and 747SR Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-
200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. 
This AD requires repetitive inspections for cracks or fractures of the 
forward end attachment and the forward lower flange of the flap tracks 
of the trailing edge flaps, and corrective actions if necessary. For 
certain airplanes, this AD would also require modifying the fail-safe 
links of the main carriage. This AD results from a detailed structural 
analysis of the flap attach structural and fail-safe components, 
accomplished as a result of a dynamic stability and control analysis, 
which could not demonstrate continued safe flight and landing of the 
airplane after the loss of a trailing edge flap. We are issuing this AD 
to detect and correct cracks or fractures of the primary structural and 
fail-safe load paths of the inboard and outboard trailing edge flaps, 
which could result in the loss of a flap during takeoff or landing, 
reducing flightcrew ability to maintain the safe flight and landing of 
the airplane.

DATES: This AD is effective January 15, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 15, 
2009.

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: Gary Oltman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6443; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
all Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 
747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series 
airplanes. That NPRM was published in the Federal Register on May 23, 
2008 (73 FR 30003) That NPRM proposed to require repetitive inspections 
for cracks or fractures of the forward end attachment and the forward 
lower flange of the flap tracks of the trailing edge flaps, and 
corrective actions if necessary. For certain airplanes, that NPRM would 
also require modifying the fail-safe links of the main carriage.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received from the commenters.

Support for the NPRM

    Boeing has reviewed the NPRM and concurs with the content of the 
proposed rule.

Request To Extend Certain Compliance Times

    Northwest Airlines (NWA) asks that the repetitive inspection 
intervals for the Part 1 inspections, as required by paragraph (f) of 
the NPRM, be changed to specify intervals not to exceed 750 flight 
cycles after accomplishing the last inspection or within 750 flight 
cycles after the flap track overhaul, whichever occurs later. For Part 
3 inspections, NWA asks that the repetitive inspection interval be 
changed to intervals not to exceed 1,500 flight cycles after 
accomplishing the last inspection or within 1,500 flight cycles after 
flap track overhaul, whichever occurs later. NWA adds that the reason 
for the request is that, as part of its procedure for removing the 
track for overhaul, the attaching fuse pin is removed and inspected and 
the defined support fitting is inspected for condition; any failure of 
the track would be detected during the track overhaul.
    We do not agree with NWA's request to change the repetitive 
inspection interval. The structural analysis of the flap attach 
structural and fail-safe components supports the compliance time 
specified for the repetitive inspection interval. In developing an 
appropriate compliance time for this action, we considered the urgency 
associated with the subject unsafe condition and the practical aspect 
of accomplishing the required inspections within a period of time that 
corresponds to the normal scheduled maintenance for most affected 
operators. These maintenance schedules can vary greatly from operator 
to operator. In light of these items, we have determined that the 
repetitive inspection intervals specified in the service bulletin are 
appropriate. However, according to the provisions of paragraph (j) of 
this AD, we may approve requests to adjust the compliance time if the 
request includes data that prove that the new compliance time would 
provide an acceptable level

[[Page 75306]]

of safety. We have not changed the AD in this regard.
    NWA also asks that the FAA review the 750-flight-cycle repetitive 
inspection interval requirement, and if supported by new analysis, 
change it to 1,000 flight cycles. NWA states that a 1,000-flight-cycle 
interval would permit accomplishing the inspections in conjunction with 
scheduled airplane maintenance.
    We do not agree with the request to change the interval for the 
repetitive inspections to 1,000 flight cycles. Previous analysis 
supports the current 750-flight-cycle interval, and no new analysis is 
currently available. However, as noted in the response to the previous 
comment, we will consider requests for approval of an AMOC if 
sufficient data are submitted that the new compliance time would 
provide an acceptable level of safety. We have not changed the AD in 
this regard.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed.

Costs of Compliance

    We estimate that this AD affects 190 airplanes of U.S. registry. 
The following table provides the estimated costs for U.S. operators to 
comply with this AD.

                                                                     Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                       Number of
                                                             Average                                                     U.S.-
              Action                      Work hours        labor rate          Parts             Cost per product     registered        Fleet cost
                                                             per hour                                                  airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Part 1 Inspections................  4....................          $80  $0...................  $320 per inspection            190  $60,800 per
                                                                                                cycle.                              inspection cycle.
Part 3 Inspections................  4....................           80  $0...................  $320 per inspection            190  $60,800 per
                                                                                                cycle.                              inspection cycle.
Part 2 Modification for Groups 1-3  Between 3 and 7......           80  Between $212 and       Between $452 and               182  Between $82,264 and
 Airplanes.                                                              $7,934.                $8,494.                             $1,545,908.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

    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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 FAA amends Sec.  39.13 by adding the following new AD:

2008-25-07 Boeing: Amendment 39-15765. Docket No. FAA-2008-0590; 
Directorate Identifier 2008-NM-057-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective January 15, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 
747-400F, and 747SR series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a detailed structural analysis of the 
flap attach structural and fail-safe components accomplished as a 
result of a dynamic stability and control analysis, which could not 
demonstrate continued safe flight and landing of the airplane after 
the loss of a trailing edge flap. We are issuing this AD to detect 
and correct cracks or fractures of the primary structural and fail-
safe load paths of the inboard and outboard trailing edge flaps, 
which could result in the loss of a flap during takeoff or landing, 
reducing flightcrew ability to maintain the safe flight and landing 
of the airplane.

Compliance

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

Repetitive Inspections/Corrective Actions

    (f) For all airplanes: Except as provided by paragraph (h) of 
this AD, at the applicable times specified in paragraph 1.E. of 
Boeing Alert Service Bulletin 747-57A2323, dated February 21, 2008, 
inspect for cracks or fractures of the forward end attachment and 
the forward lower flange of the flap tracks of the trailing edge 
flaps, and do all applicable corrective actions, by doing all the 
actions specified in Parts 1 and 3 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2323, dated

[[Page 75307]]

February 21, 2008, except as provided by paragraph (i) of this AD. 
Do all applicable corrective actions before further flight. Repeat 
the applicable inspection at the applicable time specified in 
paragraph 1.E. of Boeing Alert Service Bulletin 747-57A2323, dated 
February 21, 2008.

Modification of Fail Safe Links of Main Carriage

    (g) For Groups 1, 2, and 3 airplanes: Within 24 months after the 
effective date of this AD, replace the fail-safe links, pins, and 
attachment hardware in accordance with Part 2 of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 747-57A2323, dated 
February 21, 2008.

Exception to Compliance Times

    (h) Where Boeing Alert Service Bulletin 747-57A2323, dated 
February 21, 2008, specifies counting the compliance time from ``* * 
* the date on this service bulletin,'' this AD requires counting the 
compliance time from the effective date of this AD.

Exception to Corrective Actions

    (i) If any fractured support fitting is found during any 
inspection required by this AD, and Boeing Alert Service Bulletin 
747-57A2323, dated February 21, 2008, specifies to contact Boeing 
for appropriate action: Before further flight, repair 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, ATTN: Gary Oltman, Aerospace Engineer, Airframe Branch, ANM-
120S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 
telephone (425) 917-6443; fax (425) 917-6590; has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

Material Incorporated by Reference

    (k) You must use Boeing Alert Service Bulletin 747-57A2323, 
dated February 21, 2008; to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) 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.
    (3) You may review copies of the service information that is 
incorporated by reference 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.
    (4) You may also review copies of the service information 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 November 28, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-29073 Filed 12-10-08; 8:45 am]

BILLING CODE 4910-13-P
