
[Federal Register: October 1, 2009 (Volume 74, Number 189)]
[Rules and Regulations]               
[Page 50686-50688]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01oc09-4]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0293; Directorate Identifier 2008-NM-221-AD; 
Amendment 39-16035; AD 2009-20-12]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Boeing Model 747 airplanes identified above. This AD requires replacing 
the inboard trailing edge (TE) flap transmission carbon disk no-back 
brakes with skewed roller no-back brakes at the TE flap transmission, 
positions 4 and 5. This AD results from reports of the inboard TE flaps 
blowing back due to the failure of a transmission carbon disk no-back 
brake. The no-back brake did not hold the TE flaps in the commanded 
position. We are issuing this AD to prevent a decrease of the 
aerodynamic controllability of the airplane, which could adversely 
affect the airplane's continued safe flight and landing.

DATES: This AD is effective November 5, 2009.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of November 5, 
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: Douglas Tsuji, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6487; 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 
certain Boeing Model 747 Airplanes. That NPRM was published in the 
Federal Register on April 1, 2009 (74 FR 14750). That NPRM proposed to 
require replacing the inboard trailing edge (TE) flap transmission 
carbon disk no-back brakes with skewed roller no-back brakes at the TE 
flap transmission, positions 4 and 5.

Comments

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

Support for the NPRM

    Boeing concurs with the contents of the NPRM.

Clarification of Criteria for AD

    Lufthansa has doubts that all criteria for the issuance of an AD 
are met. The commenter states that there is no comprehensible technical 
background.
    We infer that the commenter is requesting that we withdraw the 
NPRM. We disagree. Although Boeing Special Attention Service Bulletin 
747-27-2422, dated October 30, 2008, states that ``since 1999, four 
operators have reported that the inboard TE flaps blew back due to the 
failure of a transmission carbon disk no-back brake,'' there have been 
ten reports of failed inboard and outboard carbon disk no-back brakes 
since 1973, and six reports since 1999. Nine of the reports were for 
the inboard no-back, and one for an outboard no-back. All of the 
failures (i.e., uncommanded blowbacks) occurred at a sufficient 
altitude for the pilots to react and control the airplane. As a result 
of these events, Boeing conducted extensive lab tests to check the wear 
properties and friction characteristics of new and used carbon disk 
brakes. The tests revealed a wide variation in friction capability but 
no wear correlation between friction coefficient and the number of 
cycles. Therefore, the carbon brake may be ineffective regardless of 
wear. Because of the test results and the number of events that have 
occurred in the fleet, we find it was necessary to proceed with issuing 
this AD to ensure the safety of the fleet.

Request to Include an Optional Method of Compliance

    Lufthansa requests that we include a repetitive D-Check shop 
overhaul (with updated procedures, if necessary) as an optional method 
of compliance to the proposed modification. Lufthansa states that no-
back brakes are removed every 6 years during D-Check and are overhauled 
in accordance with the latest Boeing overhaul manuals. Lufthansa states 
that since 1995 there have been no failures of the brake system, or a 
flap blow back event (which Lufthansa states is extremely improbable 
due to the fact that a simultaneous double failure has to exist). With 
the above-mentioned overhaul and an additional maintenance task, 
Lufthansa states that it is reducing if not even excluding the risk of 
a double failure. Lufthansa requests a compliance time of 8 years for 
the first D-check, 8 years for the second D-check, and 6 years for 
subsequent D-checks.
    We do not agree with the commenter's request to include an optional 
method of compliance. Based on the results of Boeing's extensive 
testing of carbon disk brakes, the carbon brakes may be ineffective 
regardless of wear. Therefore, overhauling the carbon brakes at D-check 
intervals would not adequately address the unsafe condition. In 
addition, we do not consider that the brake system failure--which 
involves a latent failure of the no-back brake, combined with an active 
failure of the flap drive system--is extremely improbable. No change to 
this AD is necessary.

Request to Delay Issuing Final Rule

    Japan Airlines (JAL) requests that we issue the AD after Revision 1 
of Boeing Service Bulletin 747-27-2422 is available. The NPRM cited 
Boeing Special Attention Service Bulletin 747-27-2422, dated October 
30, 2008, as the appropriate source of service information for 
installing the skewed roller no-back brakes at the trailing edge flap 
transmission. JAL requests that Boeing amend Service Bulletin 747-27-
2422 to improve Figure 3 to show part

[[Page 50687]]

numbers and the assembly sequence. JAL adds that Boeing is considering 
issuing Revision 1.
    We agree that adding part numbers and the assembly sequence to 
Figure 3 in Boeing Service Bulletin 747-27-2422, dated October 30, 
2008, may be beneficial. However, we do not consider that delaying the 
final rule until after the release of a future service bulletin 
revision is warranted. Boeing Service Bulletin 747-27-2422, dated 
October 30, 2008, already includes sufficient information to install 
the skewed roller no-back brakes at the trailing edge flap transmission 
within the compliance time. However, paragraph (h) of the final rule 
provides operators the opportunity to request an AMOC or an extension 
of the compliance time if data are presented to justify such an 
extension.

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 would affect 249 airplanes of U.S. 
registry. The following table provides the estimated costs for U.S. 
operators to comply with this AD.

                                                                 Table--Estimated Costs
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                                                                                                                        Number of U.S.-
                      Action                           Work hours     Average labor        Parts             Cost          registered       Fleet cost
                                                                      rate per hour                                        airplanes
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Replacement.......................................              25              $80          $60,670          $62,670              249      $15,604,830
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Authority for this Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    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:

2009-20-12 Boeing: Amendment 39-16035. Docket No. FAA-2009-0293; 
Directorate Identifier 2008-NM-221-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective November 5, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, -
200B, -200C, -200F, -300, -400, -400D, -400F, and 747SR series 
airplanes, certificated in any category; as identified in Boeing 
Special Attention Service Bulletin 747-27-2422, dated October 30, 
2008.

Subject

    (d) Air Transport Association (ATA) of America Code 27: Flight 
controls.

Unsafe Condition

    (e) This AD results from reports of the inboard trailing edge 
(TE) flaps blowing back due to the failure of a transmission carbon 
disk no-back brake. The no-back brake did not hold the flaps in the 
commanded position. The Federal Aviation Administration is issuing 
this AD to prevent a decrease of the aerodynamic controllability of 
the airplane, which could adversely affect the airplane's continued 
safe flight and landing.

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.

Corrective Action

    (g) Within 5 years after the effective date of this AD, replace 
the trailing edge flap transmission no-back brakes with skewed 
roller no-back brakes at the trailing edge flap transmission, 
positions 4 and 5, in accordance with Boeing Special Attention 
Service Bulletin 747-27-2422, dated October 30, 2008.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
ATTN: Douglas Tsuji, Aerospace Engineer, Systems and Equipment 
Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 
Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6487; fax (425) 917-6590.
    (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

[[Page 50688]]

(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.

Material Incorporated by Reference

    (i) You must use Boeing Special Attention Service Bulletin 747-
27-2422, dated October 30, 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 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 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 September 18, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-23555 Filed 9-30-09; 8:45 am]

BILLING CODE 4910-13-P
