
[Federal Register Volume 82, Number 34 (Wednesday, February 22, 2017)]
[Rules and Regulations]
[Pages 11299-11304]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-03261]



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  Federal Register / Vol. 82, No. 34 / Wednesday, February 22, 2017 / 
Rules and Regulations  

[[Page 11299]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-5468; Directorate Identifier 2015-NM-021-AD; 
Amendment 39-18806; AD 2017-04-11]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) all The 
Boeing Company Model 737-600, -700, -700C, -800, and -900 series 
airplanes. This AD was prompted by reports of paint deterioration on 
the surface of the main landing gear (MLG) and the early onset of 
corrosion in the trunnion bore of the MLG outer cylinder. This AD 
requires identifying affected parts, repetitive external surface 
detailed inspections for damage of affected parts, and related 
investigative and corrective actions if necessary. For certain 
airplanes, this AD also requires a detailed inspection and bushing 
replacement of the trunnion bore, and related investigative and 
corrective actions if necessary. We are issuing this AD to address the 
unsafe condition on these products.

DATES: This AD is effective March 29, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of March 29, 
2017.

ADDRESSES: For service information identified in this final rule, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone: 562-797-1717; Internet: https://www.myboeingfleet.com. You may view this referenced service information 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., 
Renton, WA. For information on the availability of this material at the 
FAA, call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
5468.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
5468; 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 Docket 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: Alan Pohl, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6450; fax: 425-917-6590; email: alan.pohl@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all The Boeing Company 
Model 737-600, -700, -700C, -800, and -900 series airplanes. The NPRM 
published in the Federal Register on April 12, 2016 (81 FR 21497) 
(``the NPRM''). The NPRM was prompted by reports of paint deterioration 
on the surface of the MLG and the early onset of corrosion in the 
trunnion bore of the MLG outer cylinder. The NPRM proposed to require 
identifying affected parts, repetitive external surface detailed 
inspections for damage of affected parts, and related investigative and 
corrective actions, if necessary. For certain airplanes, the NPRM also 
proposed to require a detailed inspection and bushing replacement of 
the trunnion bore, and related investigative and corrective actions, if 
necessary. We are issuing this AD to prevent stress corrosion cracking 
of the external surfaces of the MLG, which could result in a fracture 
of the MLG and consequent MLG collapse.

Comments

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

Request To Withdraw the NPRM

    Messier Services Asia Pte Ltd (MS Asia) explained that this 
maintenance, repair, and overhaul (MRO) facility, located in Singapore, 
has disclosed to Boeing that between November 2007 and December 2011, 
painting performed by MS Asia on certain landing gear legs as part of 
its overhaul service for Boeing did not fully conform to Boeing 
instructions and specifications. MS Asia stated that this painting 
error was disclosed to Boeing for Model 737 airplane landing gears 
identified in Boeing Special Attention Service Bulletin 737-32-1486, 
dated November 6, 2014, as revised by Boeing Special Attention Service 
Bulletin 737-32-1486, Revision 1, dated April 1, 2015 (``SASB 737-32-
1486, R1'').
    MS Asia refuted and continues to refute that the painting has 
generated the potential onset of corrosion discovered on the MLG. MS 
Asia explained that it had the opportunity to demonstrate to Boeing the 
absence of links between these two events and is willing to reiterate 
its technical demonstration to the FAA. MS Asia asserted that the NPRM 
makes an incorrect statement and conclusion, and is without technical 
evidence that the root cause of the corrosion detected on the trunnion 
bore and the associated risk of fracture is the consequence of the 
incorrect paint scheme application.
    MS Asia also stated that the NPRM is creating confusion when it 
refers to SAFRAN Messier-Bugatti-Dowty, and that the painting issues 
only affect gears overhauled by MS Asia during the period of November 
2007 to December 2011. MS Asia asserted that no painting issues have 
affected landing gears overhauled by the MRO entity of Messier-Bugatti-
Dowty outside the

[[Page 11300]]

period of November 2007 to December 2011.
    From these statements, we infer that MS Asia is requesting we 
withdraw the NPRM. We do not agree.
    Landing gear components include materials that are very sensitive 
to corrosion and cracking and are not tolerant of improper maintenance. 
In particular, high strength steel, once corroded, can readily develop 
cracks which could then propagate very rapidly and render inspection 
programs ineffectual. This is why it is imperative that protective 
finishes be applied as specified.
    The determination of a connection between improper finish 
application and the potential onset of corrosion was made by Boeing in 
Boeing Special Attention Service Bulletin 737-32-1486, dated November 
6, 2014, with review and concurrence by the FAA. This connection has 
also been validated by extensive fleet experience.
    MS Asia provided no definitive data to substantiate its statement 
that there is not such a connection between its painting (application 
of unqualified primer) and corrosion. It should also be noted that this 
painting was only one of several discrepancies noted that indicated 
improper maintenance. There is no refutation of the finding that the 
components were not overhauled in accordance with Boeing instructions 
and specifications. These instructions and specifications, or their 
equivalent, are in turn included in operators' maintenance programs 
that are approved by the governing regulatory authority.
    We are willing to review data MS Asia might wish to submit 
regarding this AD. However, this issue has been determined to be a 
safety issue by both Boeing and the FAA, and the FAA has also 
determined that it is not appropriate to withdraw the NPRM. If a future 
review of submitted data substantiates MS Asia's claim that the root 
cause of the corrosion detected on the trunnion bore and the associated 
risk of fracture is not the consequence of the incorrect paint scheme 
application, then we may grant relief through either additional 
rulemaking or a global alternative method of compliance (AMOC).
    We have not revised this final rule regarding a connection between 
improper finish application and the potential onset of corrosion.
    We note that the dates of the discrepant overhaul specified in 
paragraph (g) of this AD differ from the dates given in Boeing Special 
Attention Service Bulletin 737-32-1486, dated November 6, 2014, and in 
MS Asia's comments. The dates in paragraph (g) of this AD were 
determined by an investigation of MS Asia's maintenance records by an 
FAA inspector. After that review of maintenance records by an FAA field 
office, we concur with MS Asia's statement that this improper rework is 
limited to their facility in Singapore. We have revised this final rule 
to refer to MS Asia instead of SAFRAN Messier-Bugatti-Dowty to avoid 
confusion regarding affected parts.

Requests for Clarification Regarding the Nose Landing Gear (NLG)

    Boeing and the European Aviation Safety Agency (EASA) requested 
that we clarify why the NPRM did not address actions specified in the 
service information for the NLG.
    We agree that there is a need to clarify. The discrepant rework 
described in the Boeing service information does specify the NLG as 
well as the MLG. We note that in the Boeing service information, 
inspections of the MLG were specified for safety and were so labeled. 
However, inspections of the NLG were not determined by Boeing to be a 
safety issue. Those NLG inspections were labeled as economic 
inspections. This determination is consistent with the FAA's safety 
determination. Issues involving potential collapse of the NLG are 
evaluated on a case-by-case basis, but are typically determined not to 
be safety issues. In the event of failure of the NLG, the flight crew 
normally retains adequate directional control of the airplane via 
differential braking, engine thrust, and/or rudder. This is not the 
case for MLG collapses. We have not changed this AD in this regard.

Request To Revise Corrective Action in Paragraph (i) of the Proposed AD

    Boeing requested that we include Part 7 of the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-32-1486, 
dated November 6, 2014, in the applicable investigative and corrective 
actions identified in paragraph (i) of the proposed AD. Boeing stated 
that the replacement of the MLG outer cylinder in accordance with Part 
7 should be allowed as an option for compliance with the requirements 
of paragraph (i) of the proposed AD.
    We have confirmed that Boeing's requested change to paragraph (i) 
of this AD is not needed since Part 7 of the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 737-32-1486, 
dated November 6, 2014, is already cited in paragraph (j)(3) of this AD 
as terminating action for the actions required by paragraph (i) of this 
AD. We have not changed this AD in this regard.

Request To Clarify ``New'' Part

    EASA stated that the NPRM does not explicitly state that 
replacement with a new part is acceptable unless the new part belongs 
to ``Appendix D (wrong batch).''
    We are not sure what EASA intended by the term ``new.'' This would 
ordinarily indicate a brand new part obtained from the design approval 
holder or authorized supplier that has never previously been placed 
into service. However, we infer from EASA's statement that it intends 
the term to mean a different part than what is currently installed on 
the airplane. If this is the case, then this issue is already addressed 
in the service information. For example, for replacement of the entire 
MLG, Part 8 of the Accomplishment Instructions of Boeing Special 
Attention Service Bulletin 737-32-1486, dated November 6, 2014, 
specifies that such replacement be accomplished with a serviceable MLG. 
By definition, the components listed in Appendix D of SASB 737-32-1486, 
R1 are not serviceable. We have not changed this AD in this regard.

Requests To Clarify/Revise Overhaul Procedures and Clarify Component 
Installations

    SunExpress requested clarification that overhaul of affected 
components/assemblies specified in the service information is 
terminating action for inspections. SunExpress stated that the service 
information has a note specifying to not reinstall a removed component 
and/or MLG on another airplane until overhaul is completed.
    United Airlines (UAL) requested that we revise paragraph (l) of the 
proposed AD to allow operators to install affected parts as long as 
they have been overhauled using the component maintenance manual and 
Boeing Special Attention Service Bulletin 737-32-1486, dated November 
6, 2014, as revised by SASB 737-32-1486, R1. UAL stated that the 
wording in paragraph (l) of the proposed AD implies that all affected 
serial numbers would need FAA approval for repair/overhaul.
    In addition, SunExpress requested clarification as to whether each 
sub-part or sub-assembly under an MLG component installation is also 
affected individually. SunExpress asked if, for example, a sub-part 
(e.g., inner cylinder) that was previously installed on an MLG assembly 
affected by the proposed AD would be subject to the AD requirements if 
it is installed on a different unaffected MLG assembly.

[[Page 11301]]

    We partially agree with the commenters' requests. We find that the 
instructions in the service information for overhaul, as specified in 
the NPRM, already address the commenters' concerns. However, we agree 
that additional clarification would be helpful. We have revised 
paragraph (l) of this AD to specify, in part, that an MLG may not be 
installed unless that MLG has been overhauled as specified in the 
applicable corrective actions of paragraphs (h) and (i) of this AD, or 
using a method approved in accordance with the procedures specified in 
paragraph (m) of this AD.
    In addition, to address SunExpress's comment concerning component 
installations, we provide the following clarification. Based on 
accepted maintenance practices, a part number would include all of the 
components that make up that part. It is incumbent upon the operator to 
either inspect or do a records review to identify those parts affected 
by this AD. Any parts identified, including all components of those 
parts, are affected. As stated previously, we have revised paragraph 
(l) of this AD to provide clarification.

Request To Extend Proposed Compliance Time

    SunExpress requested that we revise the proposed compliance time 
for the MLG inspections from 24 months to 36 months to accommodate its 
maintenance schedule. SunExpress pointed out that the longer compliance 
time would be financially beneficial for operators.
    We do not agree with SunExpress's request to extend the compliance 
time. The operator provided no technical justification for revising 
this compliance time. Stress corrosion cracking of the external 
surfaces of the MLG is a significant safety issue, and we have 
determined that the proposed inspection threshold is warranted, based 
on the effectiveness of the inspection procedure and the FAA transport 
airplane risk assessment.
    In developing an appropriate compliance time for this AD, we 
considered the safety issues as well as the recommendations of the 
manufacturer, the availability of necessary parts, and the practical 
aspect of accomplishing the required inspection within an interval of 
time that corresponds to the normal maintenance schedules of most 
affected operators. We considered the manufacturer's recommendation as 
well as the time necessary to complete the rulemaking process, and 
found that a 24-month initial compliance time should fall well within 
the time that the majority of operators have regular maintenance visits 
scheduled. In light of these factors, we have determined that the 24-
month initial compliance time, as proposed, is appropriate. We have not 
changed this AD in this regard.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing Supplemental 
Type Certificate (STC) ST00830SE does not affect the actions specified 
in the NPRM.
    We concur with the commenter. We have redesignated paragraph (c) of 
the proposed AD as (c)(1) and added new paragraph (c)(2) to this AD to 
state that installation of STC ST00830SE does not affect the ability to 
accomplish the actions required by this final rule. Therefore, for 
airplanes on which STC ST00830SE is installed, a ``change in product'' 
AMOC approval request is not necessary to comply with the requirements 
of 14 CFR 39.17.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Special Attention Service Bulletin 737-32-1486, 
dated November 6, 2014, as revised by SASB 737-32-1486, R1. The service 
information describes procedures for identifying affected parts, 
repetitive external surface detailed inspections for damage of affected 
parts, and related investigative and corrective actions if necessary. 
For certain airplanes, the service information describes procedures for 
a detailed inspection and bushing replacement of the trunnion bore, and 
related investigative and corrective actions. The service information 
also describes procedures for certain airplanes for a detailed 
inspection of the trunnion bore, and corrective actions. This service 
information is reasonably available because the interested parties have 
access to it through their normal course of business or by the means 
identified in the ADDRESSES section.

Costs of Compliance

    We estimate that this AD affects 33 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                     Labor cost          Parts cost     Cost per product        operators
----------------------------------------------------------------------------------------------------------------
External surface detailed        Up to 16 work-hours x                $0  $1,360 per          Up to $44,880 per
 inspection.                      $85 per hour = $1,360                    inspection cycle.   inspection cycle.
                                  per inspection cycle.
Outer cylinder assembly          70 work-hours x $85 per      Negligible  $5,950............  $196,350.
 trunnion bore detailed           hour = $5,950.
 inspection and bushing
 replacement (Groups 1-2,
 configuration 1).
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the inspections. We have 
no way of determining the number of aircraft that might need this 
replacement.

[[Page 11302]]



                           On-Condition Costs
------------------------------------------------------------------------
                                                             Cost per
             Action                    Labor cost            product
------------------------------------------------------------------------
Outer cylinder assembly          28 work-hours x $85             $2,380
 replacement (if required as a    per hour = $2,380.
 result of the outer cylinder
 assembly trunnion bore
 detailed inspection).
------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for certain on-condition actions (MLG external surface 
repair, MLG component replacement, outer cylinder repair, and MLG 
replacement) specified in this AD.
    According to the manufacturer, some of the costs of this AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.
    The previous information is based on known affected airplanes. 
However, the MLG may have been overhauled outside of the Boeing 
Exchange Program as specified in the ``Clarification of Affected MLGs'' 
section of this AD.

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),
    (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):

2017-04-11 The Boeing Company: Amendment 39-18806; Docket No. FAA-
2016-5468; Directorate Identifier 2015-NM-021-AD.

(a) Effective Date

    This AD is effective March 29, 2017.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-600, -
700, -700C, -800, and -900 series airplanes, certificated in any 
category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/184DE9A71EC3FA5586257EAE00707DA6?OpenDocument&Highlight=st00830se) 
does not affect the ability to accomplish the actions required by 
this AD. Therefore, for airplanes on which STC ST00830SE is 
installed, a ``change in product'' alternative method of compliance 
(AMOC) approval request is not necessary to comply with the 
requirements of 14 CFR 39.17.

(d) Subject

    Air Transport Association (ATA) of America Code 32, Landing 
Gear.

(e) Unsafe Condition

    This AD was prompted by reports of paint deterioration on the 
surface of the main landing gear (MLG) and early onset of corrosion 
in the trunnion bore of the MLG outer cylinder. We are issuing this 
AD to prevent stress corrosion cracking of the external surfaces of 
the MLG, which could result in a fracture of the MLG and consequent 
MLG collapse.

(f) Compliance

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

(g) Inspection for Affected Part/Serial Numbers

    At the applicable time specified in table 1 of paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 737-32-
1486, dated November 6, 2014, as revised by Boeing Special Attention 
Service Bulletin 737-32-1486, Revision 1, dated April 1, 2015 
(``SASB 737-32-1486, R1''), except as required by paragraph (k)(1) 
of this AD: Do the actions specified in paragraphs (g)(1) and (g)(2) 
of this AD in order to identify affected parts.
    (1) Inspect the MLG to determine if it has any component 
installation or side strut assembly having a part number and serial 
number listed in Appendix D of Boeing Special Attention Service 
Bulletin 737-32-1486, dated November 6, 2014, as revised by SASB 
737-32-1486, R1; except that the ``Variable Number'' column of 
Appendix D is to be disregarded in determining affected part and 
serial numbers. An MLG that has any MLG component installation or 
side strut assembly having a part number and serial number listed in 
Appendix D of Boeing Special Attention Service Bulletin 737-32-1486, 
dated November 6, 2014, as revised by SASB 737-32-1486, R1 is an 
affected part. A review of airplane maintenance records is 
acceptable in lieu of this inspection if the part number and serial 
number of the MLG component installation and side strut assembly can 
be conclusively identified from that review.
    (2) Do a records review to determine if the MLG has been 
overhauled by Messier Services Asia Pte Ltd (MS Asia) outside of the 
Boeing Exchange program from June 1, 2009, to July 31, 2013. If it 
is determined that the MLG has been overhauled by MS Asia outside of 
the Boeing Exchange program from

[[Page 11303]]

June 1, 2009, to July 31, 2013, that MLG is an affected part. If 
from the records review it cannot be conclusively determined that an 
overhauled MLG was overhauled by a maintenance, repair, and overhaul 
(MRO) facility other than MS Asia, or if from the records review it 
cannot be conclusively determined that an MLG overhauled by MS Asia 
was part of the Boeing Exchange Program from June 1, 2009, to July 
31, 2013, that MLG is an affected part.

(h) Requirements for Affected Parts

    If any affected part is identified during the inspection or 
records review required by paragraph (g) of this AD: At the 
applicable time specified in table 3 of paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 737-32-
1486, dated November 6, 2014, as revised by SASB 737-32-1486, R1, 
except as required by paragraph (k)(1) of this AD, do detailed 
inspections of the external surfaces of the MLG, and do all 
applicable related investigative and corrective actions, in 
accordance with Parts 1, 3, and 4 of the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 737-32-1486, dated 
November 6, 2014, as revised by SASB 737-32-1486, R1, except as 
required by paragraph (k)(2) of this AD. Repeat the inspections 
thereafter at the applicable time specified in table 3 of paragraph 
1.E., ``Compliance,'' of Boeing Special Attention Service Bulletin 
737-32-1486, dated November 6, 2014, as revised by SASB 737-32-1486, 
R1. All applicable related investigative and corrective actions must 
be done before further flight.

(i) Additional Actions for Groups 1 and 2, Configuration 1 Airplanes

    For airplanes that are identified as Groups 1 and 2, 
Configuration 1, in Boeing Special Attention Service Bulletin 737-
32-1486, dated November 6, 2014, as revised by SASB 737-32-1486, R1, 
and that have an affected part identified during the inspection or 
records review required by paragraph (g) of this AD: At the 
applicable time specified in table 4 of paragraph 1.E, 
``Compliance,'' of Boeing Special Attention Service Bulletin 737-32-
1486, dated November 6, 2014, as revised by SASB 737-32-1486, R1, 
except as required by paragraph (k)(1) of this AD, do a detailed 
inspection and bushing replacement of the MLG trunnion bore, and do 
all applicable related investigative and corrective actions, in 
accordance with Parts 2, 5, and 6 of the Accomplishment Instructions 
of Boeing Special Attention Service Bulletin 737-32-1486, dated 
November 6, 2014, as revised by SASB 737-32-1486, R1, except as 
required by paragraph (k)(2) of this AD.

(j) Terminating Action

    (1) MLG replacement in accordance with Part 8 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-32-1486, dated November 6, 2014, as revised by SASB 
737-32-1486, R1, terminates the requirements of paragraphs (g), (h), 
and (i) of this AD for that MLG only.
    (2) MLG component replacement in accordance with Part 4 of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-32-1486, dated November 6, 2014, as revised by SASB 
737-32-1486, R1, terminates the requirements of paragraph (h) of 
this AD for that component only.
    (3) MLG outer cylinder replacement in accordance with Part 7 of 
the Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 737-32-1486, dated November 6, 2014, as revised by SASB 
737-32-1486, R1, terminates the requirements of paragraph (i) of 
this AD for that component only.

(k) Exceptions to Service Information Specifications

    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Special 
Attention Service Bulletin 737-32-1486, dated November 6, 2014, as 
revised by SASB 737-32-1486, R1, specifies a compliance time ``after 
the original issue date of this service bulletin,'' this AD requires 
compliance within the specified compliance time after the effective 
date of this AD.
    (2) Although Boeing Special Attention Service Bulletin 737-32-
1486, dated November 6, 2014, as revised by SASB 737-32-1486, R1, 
specifies to contact Boeing for repair instructions, and specifies 
that action as ``RC'' (Required for Compliance), this AD requires 
repair before further flight using a method approved in accordance 
with the procedures specified in paragraph (m) of this AD.

(l) Parts Installation Prohibition

    As of the effective date of this AD, no person may install the 
following on any airplane identified in paragraph (c)(1) of this AD, 
unless either the MLG or MLG component has first been overhauled as 
specified in the corrective actions of paragraphs (h) and (i), as 
applicable, of this AD, or the MLG or MLG component has been 
overhauled using a method approved in accordance with the procedures 
specified in paragraph (m) of this AD.
    (1) An MLG or MLG component having a part number and serial 
number identified in Appendix D of SASB 737-32-1486, R1.
    (2) An MLG that was overhauled between June 1, 2009, and July 
31, 2013, by MS Asia.

(m) Alternative Methods of Compliance (AMOCs)

    (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. 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 paragraph (n) of this AD. 
Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (2) 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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration 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. To be approved, the 
repair method, modification deviation, or alteration deviation must 
meet the certification basis of the airplane, and the approval must 
specifically refer to this AD.
    (4) Except as required by paragraph (k)(2) of this AD: For 
service information that contains steps that are labeled as RC, the 
provisions of paragraphs (m)(4)(i) and (m)(4)(ii) of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(n) Related Information

    For more information about this AD, contact Alan Pohl, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle ACO, 1601 Lind 
Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 425-
917-6590; email: alan.pohl@faa.gov.

(o) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Special Attention Service Bulletin 737-32-1486, dated 
November 6, 2014.
    (ii) Boeing Special Attention Service Bulletin 737-32-1486, 
Revision 1, dated April 1, 2015.
    (3) For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone: 562-797-1717; Internet: https://www.myboeingfleet.com.
    (4) You may view this service information at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For 
information on the availability of this material at the FAA, call 
425-227-1221.
    (5) You may view this 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/cfr/ibr-locations.html.


[[Page 11304]]


    Issued in Renton, Washington, on February 8, 2017.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2017-03261 Filed 2-21-17; 8:45 am]
BILLING CODE 4910-13-P


