[Federal Register Volume 77, Number 4 (Friday, January 6, 2012)]
[Rules and Regulations]
[Pages 731-735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-33351]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0415; Directorate Identifier 2007-NM-256-AD; 
Amendment 39-16904; AD 2011-27-03]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Model 737 airplanes. This AD was prompted by a report of extensive 
corrosion of a ballscrew used in the drive mechanism of the horizontal 
stabilizer trim actuator (HSTA). This AD requires repetitive 
inspections, lubrications, and repetitive overhauls of the ball nut and 
ballscrew and attachment (Gimbal) fittings for the trim actuator of the 
horizontal stabilizer; various modification(s); and corrective actions 
if necessary; as applicable. We are issuing this AD to prevent an 
undetected failure of the primary load path for the ballscrew in the 
drive mechanism of the HSTA and subsequent wear and failure of the 
secondary load path, which could lead to loss of control of the 
horizontal stabilizer and consequent loss of control of the airplane.

DATES: This AD is effective February 10, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of February 10, 
2012.

ADDRESSES: For Boeing 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; email 
[email protected]; Internet https://www.myboeingfleet.com.
    For Skytronics service information identified in this AD, contact 
Skytronics Inc., (cage 16553), P.O. Box 807, El Segundo, California 
90245; telephone (310) 322-6284; fax (310) 322-6160; Internet http://www.skytronicsinc.com.
    For Linear Motion service information identified in this AD, 
contact Linear Motion LLC, 628 North Hamilton Street, Saginaw, Michigan 
48602; telephone (989) 759-8300; Internet http://www.thomsonaerospace.com.
    For Umbra Cuscinetti service information identified in this AD, 
contact Umbra Cuscinetti S.p.A., Technical Publications Department; Via 
Piave 12, Foligno (PG) 06034, Italy; telephone +39 (0742) 348300; fax 
+39 (0742) 348277; email [email protected].
    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://

[[Page 732]]

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 (phone: (800) 647-5527) is 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: Kelly McGuckin, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; phone: (425) 917-6490; fax: (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a supplemental notice of proposed rulemaking (NPRM) to 
amend 14 CFR part 39 to include an airworthiness directive (AD) that 
would apply to the specified products. The supplemental NPRM was 
published in the Federal Register on April 19, 2011 (76 FR 21815). The 
original NPRM was published in the Federal Register on April 28, 2008 
(73 FR 22840). The supplemental NPRM proposed to require repetitive 
inspections, lubrications, and repetitive repairs/overhauls of the ball 
nut and ballscrew and attachment (Gimbal) fittings for the trim 
actuator of the horizontal stabilizer; various installation(s); and 
corrective actions if necessary; as applicable.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the proposal 
and the FAA's response to each comment.

Supportive Comments

    Boeing concurred with the content of the supplemental NPRM (76 FR 
21815, April 19, 2011). Continental Airlines is complying with the 
actions and supported the supplemental NPRM.

Requests To Change Certain Compliance Times

    US Airways and Southwest Airlines asked that the compliance time 
required by paragraph (g)(1) of the supplemental NPRM (76 FR 21815, 
April 19, 2011) be extended. US Airways stated that the compliance time 
for the modification is defined in Table 1 of paragraph 1.E., 
``Compliance'' of Boeing Alert Service Bulletin 737-27A1278, Revision 
1, dated January 7, 2010; that compliance time is within 24,000 flight 
hours since delivery or 24,000 flight hours since last overhaul, 
whichever comes first. US Airways added that this compliance time would 
put all airplanes having HSTAs with more than 24,000 flight hours since 
delivery immediately out of compliance. US Airways adds that this 
compliance time, coupled with the compliance time in the supplemental 
NPRM, would give operators only 12 months to modify all affected 
airplanes. US Airways noted that the compliance time specified in Table 
1 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-27A1277, Revision 2, dated January 8, 2010, specifies ``whichever 
occurs later.'' Southwest also stated that this compliance time would 
put its airplanes out of compliance because all its HSTAs have more 
than 24,000 flight hours since new.
    Senem Sevinic stated that the compliance times given in the 
referenced service information seem quite complicated, and asked that 
we specify the compliance times in the supplemental NPRM (76 FR 21815, 
April 19, 2011).
    We acknowledge the requests from US Airways and Southwest and 
provide the following information. We specified grace periods (i.e., 
compliance times after the effective date of the AD) in paragraph 
(g)(1)(ii) of the supplemental NPRM (76 FR 21815, April 19, 2011). 
However, we have extended the compliance time required by paragraph 
(g)(1)(ii)(C) of this AD to 24 months because this extension will 
provide an acceptable level of safety. We do not agree with the request 
to specify the compliance times in paragraph (g)(1)(i) of this AD; 
those compliance times adequately identify the time necessary to 
complete each task required by this AD. We have not changed the AD in 
this regard.

Request To Clarify Certain Actions

    Delta asked that the ``repair/overhaul'' phrase specified in 
paragraph (g)(1)(ii)(B) of the supplemental NPRM (76 FR 21815, April 
19, 2011) be changed to ``overhaul'' to match the language specified in 
Table 1 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-27A1277, Revision 2, dated January 8, 2010. Delta stated 
that paragraph (g)(1)(ii)(B) of the supplemental NPRM can lead to 
uncertainty with respect to the necessary time to accomplish a repair. 
Delta noted that the compliance time for repair/overhaul required by 
this paragraph is ``within 12 months of the effective date of this 
AD;'' however, Boeing Alert Service Bulletin 737-27A1277, Revision 2, 
dated January 8, 2010, specifies repair prior to further flight if 
damage is found. Delta also noted that Table 1 of paragraph 1.E., 
``Compliance,'' of that service bulletin does not include the word 
``repair'' when referring to the overhaul actions, and adds that the 
only compliance time specified for the repair is ``before further 
flight.''
    We agree that some clarification is necessary. Therefore, we have 
changed the ``repair/overhaul'' phrase specified in the preamble and 
paragraphs (g), (g)(1), and (g)(1)(ii)(B) of this AD to specify 
``overhaul,'' for the reasons provided by the commenter.
    Delta and US Airways asked that paragraph (g)(1)(ii)(C) of the 
supplemental NPRM (76 FR 21815, April 19, 2011) be changed to clarify 
the phrase ``for the installation'' to identify the individual 
installation and its applicability, or, in the case of multiple 
installations, to identify each individual installation and its 
applicability. Delta stated that the installation could be a single 
installation or multiple installations, and noted that the phrase could 
be referring to the ball nut tube retainer installation. US Airways 
infers that we are identifying many references in the service 
information about removing certain parts and installing improved parts. 
US Airways suggested using the word ``modification'' since using 
``installation'' could be confusing, and noted that ``installation'' 
could refer to installation of modifications or installation of the 
HSTA.
    We agree that clarification is necessary for the reasons provided 
by the commenters. Therefore, in paragraph (g)(1)(ii)(C) of this AD we 
have changed the phrase ``For the installation(s)'' to ``For the 
modification(s).'' In addition, we have changed ``installation(s)'' to 
``modification(s)'' in the Summary section and paragraphs (g) and 
(g)(1) of this AD.

Request To Change the Maintenance Planning Document (MPD) Task Cards

    Southwest asked that the work instructions in the MPD task cards be 
expanded to match the procedures for the detailed inspections specified 
in the service information specified in paragraph (g) of the 
supplemental NPRM (76 FR 21815, April 19, 2011). Southwest added that 
this would allow for one set of instructions to accomplish the 
inspections and would eliminate the human error factor involved with 
more than one set of inspection requirements since the task cards do 
not match the service information. Senem Sevinic asked that a note be 
added to the

[[Page 733]]

supplemental NPRM that specifies which MPD tasks meet which steps in 
Boeing Alert Service Bulletin 737-27A1277, Revision 2, dated January 8, 
2010, because it is difficult to follow both the steps in this service 
information and the MPD tasks.
    We disagree with adding a note to this AD. The actions required by 
this AD, and referred to in Boeing Alert Service Bulletin 737-27A1277, 
Revision 2, dated January 8, 2010, address a specific safety issue. 
Accomplishing the tasks in the MPD task cards does not satisfy the 
actions specified in this service information; however, accomplishing 
the actions specified in this service information does satisfy certain 
MPD tasks. Because the MPD is a Boeing document and is not maintained 
by the FAA, operators may request any change to a task related to an 
MRB item through the Industry Steering Committee, which would ensure 
that approved changes are made to the applicable MPD task. We have not 
changed the AD in this regard.

Request To Clarify Parts Installation Paragraph

    US Airways asked that we clarify the requirements in paragraph (i) 
of the supplemental NPRM (76 FR 21815, April 19, 2011) (the parts 
installation paragraph). US Airways reiterated the language used in 
this paragraph and asked if an operator may install a serviceable unit 
(i.e., inspected and lubricated) after the effective date of the AD, or 
if we are requiring only replacement units that are inspected and 
lubricated, and have zero time since overhaul and post-modification.
    We infer that the commenter is asking if unmodified ballscrew 
assemblies may be used on replacement HSTAs, provided that they are 
inspected and lubricated as required. For clarification, the ballscrew 
assembly in the drive mechanism of the HSTA may not be installed unless 
it has been inspected, and modified, as applicable, to ensure that 
HSTAs used as replacements are not exposed to the unsafe condition 
addressed in this AD. No change to the AD is necessary in this regard.

Change to Final Rule

    Boeing Alert Service Bulletin 737-27A1278, Revision 1, dated 
January 7, 2010; and Boeing Alert Service Bulletin 737-27A1277, 
Revision 2, dated January 8, 2010; refer to accomplishing certain 
actions as given in certain component maintenance manuals (CMMs). This 
AD includes a new Note 1 (and renumbers subsequent notes) identifying 
those CMMs as additional sources of guidance. The note also clarifies a 
typographical error in Boeing Alert Service Bulletin 737-27A1278, 
Revision 1, dated January 7, 2010, which referred to ``CMM 27-45-12,'' 
and should have referred to ``CMM 27-45-11'' as an additional source of 
guidance.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We also determined that 
these changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    We estimate that this AD affects 1,641 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 U.S.-
            Action \1\                Work hours \1\      Average labor          Parts         Cost per product \1\    registered       Fleet cost \1\
                                                          rate per hour                                                 airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Detailed inspections.............  2 or 4..............             $85  None................  $170 or $340, per              1,641  Between $278,970,
                                                                                                inspection cycle.                     and $557,940 per
                                                                                                                                      inspection cycle.
Lubrications.....................  1 or 3..............              85  None................  $85 or $255, per               1,641  Between $139,485,
                                                                                                lubrication cycle.                    and $418,455 per
                                                                                                                                      lubrication cycle.
Overhauls........................  40..................              85  None................  $3,400 per overhaul.           1,641  $5,579,400 per
                                                                                                                                      overhaul cycle.
Modifications (Installations)....  Between 1 and 3.....              85  $2,200..............  Between $2,285 and             1,352  Between $3,089,320
                                                                                                $2,455.                               and $3,319,160.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Depending on airplane configuration.

    The number of work hours, as indicated above, is presented as if 
the accomplishment of the actions in this AD is to be conducted as new 
``stand alone'' actions. However, in actual practice, the lubrications, 
detailed inspections, and overhauls are currently being done as part of 
normal airplane maintenance. The repair (if necessary) can be done 
coincidentally or in combination with the normally scheduled HSTA and 
ballscrew overhaul. Therefore, the actual number of necessary 
additional work hours will be minimal in many instances. Additionally, 
any costs associated with special airplane scheduling will be minimal.
    We estimate the following costs to do any necessary repairs/
replacements that would be required based on the results of the 
inspection. We have no way of determining the number of aircraft that 
might need these repairs/replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
               Action                      Labor cost        Parts cost              Cost per product
----------------------------------------------------------------------------------------------------------------
Remove/replace HSTA................  Between 3 and 8 work            $0  Between $255 and $680.
                                      hours x $85 per hour
                                      = between $255 and
                                      $680.
----------------------------------------------------------------------------------------------------------------


[[Page 734]]

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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    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 airworthiness 
directive (AD):

2011-27-03 The Boeing Company: Amendment 39-16904; Docket No. FAA-
2008-0415; Directorate Identifier 2007-NM-256-AD.

(a) Effective Date

    This AD is effective February 10, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Model 737 airplanes; certificated in any 
category.

(d) Subject

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

(e) Unsafe Condition

    This AD results from a report of extensive corrosion of a 
ballscrew used in the drive mechanism of the horizontal stabilizer 
trim actuator (HSTA). We are issuing this AD to prevent an 
undetected failure of the primary load path for the ballscrew in the 
drive mechanism of the HSTA and subsequent wear and failure of the 
secondary load path, which could lead to loss of control of the 
horizontal stabilizer and consequent loss of control of the 
airplane.

(f) Compliance

    You are responsible for having the actions required by this AD 
performed within the compliance times specified, unless the actions 
have already been done.

(g) Inspections, Lubrications, Overhauls, Modification(s), and 
Applicable Corrective Actions

    At the applicable compliance time and repeat intervals listed in 
Tables 1 and 2 of paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-27A1278, Revision 1, dated January 7, 2010; or 
Boeing Alert Service Bulletin 737-27A1277, Revision 2, dated January 
8, 2010; as applicable (depending on airplane configuration): Do the 
inspections, lubrications, overhauls, modification(s), and 
applicable corrective actions, by accomplishing all the applicable 
actions specified in the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-27A1278, Revision 1, dated January 7, 2010; or 
Boeing Alert Service Bulletin 737-27A1277, Revision 2, dated January 
8, 2010; as applicable; except as provided by paragraphs (g)(1) and 
(g)(2) of this AD.

    Note 1:  Boeing Alert Service Bulletin 737-27A1277, Revision 2, 
dated January 8, 2010; and Boeing Alert Service Bulletin 737-
27A1278, Revision 1, dated January 7, 2010; refer to the following 
component maintenance manuals (CMMs) as additional sources of 
guidance for accomplishing the applicable specified actions: Boeing 
CMM 27-45-11, dated November 1, 2011; Boeing CMM 27-45-12, dated 
November 1, 2011; Skytronics CMM 27-40-03, Revision 1, dated 
September 1, 2006; Umbra Cuscinetti CMM 27-41-01, Revision 5, dated 
September 27, 2005; and Linear Motion CMM 27-41-01, Revision 8, 
dated May 21, 2008; as applicable.


    Note 2:  Boeing Alert Service Bulletin 737-27A1278, Revision 1, 
dated January 7, 2010, refers to Umbra Cuscinetti Service Bulletin 
07322-27-01, dated December 21, 2004; Linear Motion Service Bulletin 
7901708, Revision A, and Revision B, both dated July 26, 2005; 
Boeing 737 Service Bulletin 27-1046, Revision 1, dated April 5, 
1974; and SKYTRONICS Service Bulletin 93004, dated September 1, 
2005; as additional sources of guidance for accomplishing the 
applicable specified actions.


    Note 3:  Boeing Alert Service Bulletin 737-27A1277, Revision 2, 
dated January 8, 2010, refers to Umbra Cuscinetti Service Bulletin 
07322-27-01, dated December 21, 2004, as an additional source of 
guidance for accomplishing the applicable specified actions.

    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-27A1278, Revision 1, dated January 7, 2010; or 
Boeing Alert Service Bulletin 737-27A1277, Revision 2, dated January 
8, 2010; as applicable; specifies an initial compliance time for 
accomplishing the initial inspection, lubrication, overhaul, or 
modification, this AD requires doing the applicable initial 
action(s) at the later of the times specified in paragraphs 
(g)(1)(i) and (g)(1)(ii) of this AD.
    (i) At the applicable compliance time specified in paragraph 
1.E, ``Compliance,'' of Boeing Alert Service Bulletin 737-27A1278, 
Revision 1, dated January 7, 2010; or Boeing Alert Service Bulletin 
737-27A1277, Revision 2, dated January 8, 2010; as applicable.
    (ii) Within the applicable compliance time specified in 
paragraph (g)(1)(ii)(A), (g)(1)(ii)(B), or (g)(1)(ii)(C) of this AD.
    (A) For the initial detailed inspection and lubrication: Within 
6 months after the effective date of this AD.
    (B) For the initial overhaul: Within 12 months after the 
effective date of this AD.
    (C) For the modification(s): Within 24 months after the 
effective date of this AD.
    (2) Where Table 2 of paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 737-27A1277, Revision 2, dated January 8, 
2010, specifies a compliance time of ``* * * within 25,000 Flight 
Hours since the latest horizontal stabilizer trim actuator (HSTA) 
Overhaul from the date of Revision 1 of this Service Bulletin * * 
*,'' this AD requires compliance within 25,000 flight hours since 
the last overhaul of the trim actuator of the horizontal stabilizer.

(h) Credit for Actions Accomplished in Accordance With Previous Service 
Information

    Actions accomplished before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 737-27A1277, Revision 
1, dated July 25, 2007; or Boeing Alert Service Bulletin 737-
27A1278, dated May 24, 2007; as applicable; are considered 
acceptable for compliance with the corresponding actions specified 
in this AD.

[[Page 735]]

(i) Parts Installation

    As of the effective date of this AD, no person may install a 
ballscrew assembly in the drive mechanism of the HSTA on any 
airplane, unless it has been inspected and modified, as applicable, 
in accordance with paragraph (g) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    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. In accordance with 14 CFR 
39.19, send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the ACO, send it to the attention of the 
person identified in the Related Information section of this AD. 
Information may be emailed to: [email protected].
    (1) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD if it is approved by the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that has been authorized by the Manager, Seattle ACO to make 
those findings. For a repair method to be approved, the repair must 
meet the certification basis of the airplane.

(k) Related Information

    (1) For more information about this AD, contact Kelly McGuckin, 
Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, 
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, 
Washington 98057-3356; phone: (425) 917-6490; fax: (425) 917-6590.
    (2) Boeing 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; email 
[email protected]; Internet https://www.myboeingfleet.com.
    (3) For Skytronics service information identified in this AD, 
contact Skytronics Inc., (cage 16553), P.O. Box 807, El Segundo, 
California 90245; phone: (310) 322-6284; fax: (310) 322-6160; 
Internet: http://www.skytronicsinc.com.
    (4) For Linear Motion service information identified in this AD, 
contact Linear Motion LLC, 628 North Hamilton Street, Saginaw, 
Michigan 48602; phone: (989) 759-8300; Internet: http://www.thomsonaerospace.com.
    (5) For Umbra Cuscinetti service information identified in this 
AD, contact Umbra Cuscinetti S.p.A., Technical Publications 
Department; Via. Piave 12, Foligno (PG) 06034, Italy; phone: +39 
(0742) 348300; fax: +39 (0742) 348277; email: 
[email protected].

(l) Material Incorporated by Reference

    (1) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise. The 
Director of the Federal Register approved the incorporation by 
reference (IBR) of the following service information under 5 U.S.C. 
552(a) and 1 CFR part 51:
    (i) Boeing Alert Service Bulletin 737-27A1278, Revision 1, dated 
January 7, 2010.
    (ii) Boeing Alert Service Bulletin 737-27A1277, Revision 2, 
dated January 8, 2010.
    (2) For Boeing 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; email: 
[email protected]; 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.
    (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 an NARA facility, 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 December 14, 2011.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-33351 Filed 1-5-12; 8:45 am]
BILLING CODE 4910-13-P