[Federal Register Volume 84, Number 29 (Tuesday, February 12, 2019)]
[Rules and Regulations]
[Pages 3290-3297]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-01518]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0162; Product Identifier 2017-NM-116-AD; Amendment 
39-19542; AD 2019-01-03]
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 superseding Airworthiness Directive (AD) 2016-18-01, 
which applied to certain The Boeing Company Model 737-600, -700, -700C, 
-800, -900, and -900ER series airplanes. AD 2016-18-01 required 
repetitive lubrication of the forward and aft trunnion pin assemblies 
of the right and left main landing gears (MLGs); repetitive inspection 
of these assemblies for corrosion and chrome damage, and related 
investigative and corrective actions if necessary; and installation of

[[Page 3291]]

new or modified trunnion pin assembly components, which terminated the 
repetitive lubrication and repetitive inspections. Since we issued AD 
2016-18-01, we have determined that rotable parts were not addressed in 
that AD, and it is therefore necessary to include all airplanes of the 
affected models in the applicability. This AD retains the requirements 
of AD 2016-18-01, adds airplanes to the applicability, and prohibits 
the installation of a MLG or MLG trunnion pin assembly under certain 
conditions. We are issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective March 19, 2019.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 19, 
2019.

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 service information at the 
FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. 
For information on the availability of this material at the FAA, call 
206-231-3195. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0162.

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-2018-
0162; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations (phone: 800-647-
5527) is 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 Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; telephone and fax: 206-231-3527; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 2016-18-01, Amendment 39-18631 (81 FR 59830, 
August 31, 2016) (``AD 2016-18-01''). AD 2016-18-01 applied to certain 
The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes. The NPRM published in the Federal Register on March 
5, 2018 (83 FR 9238). The NPRM was prompted by a determination that 
rotable parts were not addressed in AD 2016-18-01, and that it was 
therefore necessary to include all airplanes of the affected models in 
the applicability. The NPRM proposed to retain all requirements of AD 
2016-18-01 and add airplanes to the applicability. The NPRM also 
proposed to prohibit the installation of a MLG or MLG trunnion pin 
assembly on any airplane identified in paragraph (c) of the proposed AD 
unless certain actions are accomplished. We are issuing this AD to 
address heavy corrosion and chrome damage on the forward and aft 
trunnion pin assemblies of the right and left MLGs, which could result 
in cracking of these assemblies and collapse of the MLGs.

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.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the installation 
of winglets using Supplemental Type Certificate (STC) ST00830SE does 
not affect compliance with the actions proposed in the NPRM.
    We concur with the commenter. We have redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) of this AD and added 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 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.

Request To Include Alternative Action to Inspection To Determine Part 
Number

    All Nippon Airways (ANA) requested that the inspection to determine 
the part numbers of the existing parts, as specified in paragraph (g) 
of the proposed AD, not be required if the repetitive lubrication and 
inspection, as specified in paragraphs (h) and (i) of the proposed AD, 
have already been performed.
    We agree with the commenter's request. The alternative action 
recommended by ANA will maintain an acceptable level of safety by 
continuing the lubrication and inspection requirements in this AD. We 
have revised paragraph (g) of this AD to state that operators may 
accomplish continued lubrication and inspection as required by 
paragraphs (h) and (i) of this AD, at the specified times, in lieu of 
the inspection to determine the existing part numbers.

Request To Clarify Purpose of Inspection To Determine Part Number

    Alaska Airlines (Alaska), Boeing, and Southwest Airlines (SWA) 
requested that paragraph (g) of the proposed AD be revised to clarify 
that the inspection is to determine if any of the ``existing'' part 
numbers identified in paragraph 2.C.3., ``Parts Modified and 
Reidentified,'' of Boeing Special Attention Service Bulletin 737-32-
1448, Revision 2, dated August 2, 2017 (``BSASB 737-32-1448, R2''), are 
installed. Alaska noted that paragraph 2.C.3. of BSASB 737-32-1448, R2, 
has two columns of part numbers, one for existing part numbers and one 
for new part numbers.
    The commenters noted that paragraph (g) of the proposed AD states 
that the purpose of the inspection is to determine if any of the MLG 
trunnion pin assembly part numbers identified in paragraph 2.C.3. of 
BSASB 737-32-1448, R2, are installed. The commenters pointed out that 
this requested change would align the wording in the proposed AD with 
the wording in paragraph 2.C.3. of BSASB 737-32-1448, R2.
    In addition, Boeing observed that the existing parts identified in 
paragraph 2.C.3. of BSASB 737-32-1448, R2, include outer cylinder 
assemblies and race and ball assemblies, as well as MLG trunnion pin 
assemblies. Boeing recommended that the header to paragraph (g) of the 
proposed AD be revised to clarify that this inspection is to determine 
part numbers for all assembly types, rather than specify the part 
number of only the MLG and MLG trunnion pin assembly.
    We agree with the commenters' requests for the reasons provided by 
the commenters. We have revised the header to paragraph (g) of this AD 
to specify ``Inspection to Determine Part Numbers.'' We have also 
revised paragraph (g) of this AD to state, `` . . . do an inspection to 
determine if any of

[[Page 3292]]

the existing part numbers identified in . . . . A review of airplane 
maintenance records is acceptable in lieu of this inspection if the 
part number of each existing part number can be conclusively determined 
from that review.''

Request To Remove Inspection Requirement for Certain Airplanes

    SWA and Ryanair (RYR) requested that airplanes identified in 
paragraphs (c)(1) and (c)(4) of the proposed AD (paragraphs (c)(1)(i) 
and (c)(1)(iv) in this AD) be relieved from doing the inspection to 
determine part numbers, or the review of airplane maintenance records, 
specified in paragraph (g) of the proposed AD. RYR also stated that the 
airplanes identified in these paragraphs have not incorporated the 
actions in Boeing Special Attention Service Bulletin 737-32-1448, dated 
May 19, 2011 (``BSASB 737-32-1448'').
    SWA indicated that the affected MLGs would have already been 
identified, as required by AD 2016-18-01, and the inspection and 
lubrication actions described in Boeing Special Attention Service 
Bulletin 737-32-1448, Revision 1, dated May 29, 2015 (``BSASB 737-32-
1448, R1''), would have already started on those airplanes. RYR stated 
that all MLGs would need to have all required actions completed to 
verify AD compliance anyway, and a records check would not yield any 
further benefit and would not outweigh the amount of work required to 
complete the records check.
    In addition, RYR stated that if an inspection to determine a part 
number or a records check is completed on an airplane identified in 
paragraph (c)(1) or (c)(4) of the proposed AD (paragraph (c)(1)(i) or 
(c)(1)(iv) of this AD), and it is determined that the affected rotable 
parts are installed on the airplane, the rotable parts may incorrectly 
be assumed to be in compliance with the requirements specified in the 
proposed AD. RYR stated that there is no way to determine if the MLG 
forward trunnion pin seal and retainer are AD compliant because the 
details would not be included in documentation and could be verified 
only if the MLG was removed from the airplane and inspected. This would 
incur a requirement to remove every MLG from every airplane in an 
operator's fleet within 30 days after the effective date of the AD to 
determine if the installation is compliant with the requirements of the 
AD.
    RYR also stated that BSASB 737-32-1448, R2, does not clearly 
indicate for which airplanes operators would need to do the inspection 
to determine the part number or records check. RYR pointed out that 
page 7 of BSASB 737-32-1448, R2, indicates that only airplanes in Group 
1-3 that have accomplished the actions in BSASB 737-32-1448 or BSASB 
737-32-1448, R1, would need to do the inspection or records check, but 
page 42, Table 1, for Group 1-2 airplanes, configuration 1, states this 
configuration relates only to airplanes on which the actions in the 
service bulletin have not been completed. RYR mentioned that it 
submitted a service request to Boeing to clarify if the intent of this 
action is only for airplanes on which the actions in BSASB 737-32-1448 
or BSASB 737-32-1448, R1, have been completed.
    We do not agree with the commenters' requests. We appreciate the 
operators' concerns that this records check does not appear to be 
necessary. However, BSASB 737-32-1448, R1, which is the required 
service information for compliance with AD 2016-18-01, did not address 
part rotability. An operator might have complied with the requirements 
of AD 2016-18-01 on a given airplane, and then subsequently rotated a 
non-compliant MLG and installed it on that same airplane. Shortly after 
AD 2016-18-01 was issued, one operator with a large number of affected 
airplanes informed the FAA that three-fourths of those airplanes no 
longer had the same landing gear that was installed when the airplane 
was delivered.
    Therefore, as explained elsewhere in this AD, it is necessary to 
supersede AD 2016-18-01 to address the unsafe condition by addressing 
rotability. In order to do this, the actions required by paragraphs 
(h), (i), and (j) of this AD are contingent upon knowing what parts are 
installed. An inspection for parts modified and reidentified was not 
included in BSASB 737-32-1448, R1, and consequently was not mandated by 
AD 2016-18-01.
    Operators should have adequate maintenance records to determine if 
the MLG forward trunnion pin seal and retainer are AD compliant. If 
this is not the case, then it might be necessary, as indicated by RYR, 
to remove the MLG from the airplane to identify the part numbers.
    Our change to paragraph (g) of this AD, allowing repetitive 
lubrication and inspection instead of the inspection to determine the 
part numbers or the records check, may provide relief to operators. If 
operators choose to continue to perform the repetitive lubrication and 
inspection, then they are not required to do the inspection to 
determine the part number.
    In regard to RYR's observation of discrepancies in BSASB 737-32-
1448, R2, we note that the information on page 7 is part of the 
Revision Transmittal Sheet, which explains the effects of the actions 
described in BSASB 737-32-1448, R2, for airplanes on which the actions 
in BSASB 737-32-1448 or BSASB 737-32-1448, R1, were previously done. 
The information in the Revision Transmittal Sheet is related to but not 
mandated by this AD. RYR has correctly sent its concerns to Boeing to 
address inconsistencies in its service information.
    We have not changed paragraph (g) to this AD regarding these 
issues.

Request To Revise Parts Installation Limitation Paragraph

    Boeing and SWA requested that paragraph (m) of the proposed AD be 
revised to include all existing parts identified in paragraph 2.C.3, 
``Parts Modified and Reidentified,'' of BSASB 737-32-1448, R2, not just 
the MLG or MLG forward trunnion pin assembly. Boeing noted that in 
addition to the MLG and MLG forward trunnion pin assembly, the list of 
parts includes the outer cylinder assembly, and race and ball 
assemblies.
    We agree with the commenters' requests. We have revised paragraph 
(m) of this AD to state that ``As of the effective date of this AD, no 
person may install existing parts identified in paragraph 2.C.3., 
`Parts Modified and Reidentified,' of BSASB 737-32-1448, R2, on any 
airplane identified in paragraphs (c)(1)(i) through (c)(1)(vii) of this 
AD, unless the actions required by paragraph (j) or (k), as applicable, 
of this AD have been accomplished on the parts.''

Request To Revise Parts Installation Limitation Paragraph To Include 
Newly Purchased Parts

    Delta Air Lines (DAL) requested that paragraph (m) of the proposed 
AD be revised to allow operators to install any newly purchased spare 
parts that are not specified in paragraph 2.C.3., ``Parts Modified and 
Reidentified,'' of BSASB 737-32-1448, R2. DAL stated that paragraph (m) 
of the proposed AD does not include a provision for parts that are not 
affected by the part number inspection required by paragraph (g) of the 
proposed AD. DAL also mentioned that many airplanes have been delivered 
with parts for which paragraphs (j) and (k) of the proposed AD are not 
applicable, and with parts that are identified through the inspection 
or records review specified in paragraph (g) of the proposed AD.

[[Page 3293]]

    We do not agree with the commenter's request. Although we 
appreciate the commenter's concern, paragraph (m) of this AD already 
addresses this issue with the phrase ``as applicable.'' Paragraph (m) 
of this AD applies only to parts that are subject to the requirements 
of paragraphs (j) and (k) of this AD and does not apply to newly 
purchased spare parts. In addition, as previously mentioned, we have 
revised the wording in paragraph (m) of this AD in response to another 
comment, and this revised wording addresses the commenter's concern. We 
have not revised this AD further in regard to this issue.

Request To Provide Additional Credit for Previous Actions

    DAL observed that paragraph (n) of the proposed AD did not provide 
credit for previously accomplished actions that comply with the 
inspection to determine the part numbers, specified in paragraph (g) of 
the proposed AD. DAL contended that once the part numbers have been 
identified, through inspection or maintenance records review, it is not 
necessary to repeat the inspection. We infer that DAL is requesting a 
revision to paragraph (n) of the proposed AD to include credit for 
inspections for part number identification specified in paragraph (g) 
of the proposed AD.
    We do not agree with the commenter's request. Neither the original 
issue of BSASB 737-32-1448, nor BSASB 737-32-1448, R1, included either 
an inspection to determine part numbers or a maintenance records check. 
Also, AD 2016-18-01 did not include a parts installation limitation 
provision. Paragraph (f), ``Compliance,'' of this AD already accounts 
for actions accomplished prior to the effective date of this AD. 
Specifically, paragraph (f) of this AD states ``Comply with this AD 
within the compliance times specified, unless already done.'' If DAL 
has adequate records to demonstrate that the part number determination 
required by paragraph (g) of this AD has already been accomplished for 
an airplane, then it is not necessary to repeat this action. We have 
not changed this AD in regard to this issue.

Request To Allow Use of Serviceable Rotable Parts

    DAL requested that operators be permitted to use serviceable 
rotable parts in lieu of returning modified parts to the same airplane 
from which they were removed. DAL noted that paragraph (j) of the 
proposed AD would require modification of the left and right MLG 
trunnion pin assemblies in accordance with work package 3 of the 
Accomplishment Instructions of BSASB 737-32-1448, R2. DAL mentioned 
that many operators use pools of rotable spare parts to reduce the time 
necessary for maintenance. DAL explained that rotable parts are 
airplane parts and components that can be rebuilt or overhauled to be 
reinstalled on the same airplane or put in stock to be used on a 
different airplane.
    We agree with the intent of the commenter's request, but find it 
unnecessary to change this AD to address the concern. These parts are 
rotable. We are superseding AD 2016-18-01 because it did not address 
rotable parts. We appreciate DAL's concern regarding returning modified 
parts to the same airplane from which they were removed. This AD does 
not include that requirement, and operators may do as DAL suggested and 
use rotable parts, provided the parts are per type design and meet any 
other pertinent requirements prior to installation. In addition, the 
revision to paragraph (m) of this AD, discussed previously, addresses 
DAL's concern. We have not revised this AD further in regard to this 
issue.

Request for Clarification of Difference Between the Proposed AD and 
Service Information

    RYR asked how an operator would show compliance with the 
requirements specified in the proposed AD for an airplane that received 
a certificate of airworthiness one or two days before the effective 
date of the final rule. RYR asked if there would be an additional 
revision to BSASB 737-32-1448, R2, that expanded the line number 
applicability and if that revised service bulletin would be included in 
a subsequent AD. We infer that RYR is requesting clarification 
regarding the difference between the proposed AD and the service 
information regarding airplane applicability.
    We acknowledge the commenter's concern. For an issue that involves 
rotable parts, an AD Friendly service bulletin with respect to 
applicability would include all affected airplanes, in this case, all 
Model 737 NG airplanes, whether or not the airplanes have been 
delivered. However, the effectivity of BSASB 737-32-1448, R2 does not 
include all airplanes of the affected models. Since it is possible to 
remove a part from one airplane and install it without change on an 
airplane not identified in the service bulletin effectivity, we have 
determined it necessary to expand the applicability of this AD beyond 
that of the service information provided by Boeing so that installation 
of certain rotable parts, addressed in paragraph (m) of this AD, is 
restricted on all airplanes of the affected models. Boeing did not 
reflect this in the effectivity and airplane groups of BSASB 737-32-
1448, R2; therefore, the FAA had to re-define the airplane groups as 
described in paragraph (c), ``Applicability,'' of this AD.
    Regarding RYR's concern for demonstrating immediate AD compliance, 
immediate compliance is not required by this AD. Each of the required 
actions in paragraphs (g) through (k) of this AD state that the 
compliance time is `` . . . at the [applicable] time specified in Table 
. . . of paragraph 1.E., `Compliance,' of BSASB 737-32-1448, R2.'' 
These compliance times range from 30 days to 10 years.
    Regarding RYR's question whether there will be another revision to 
BSASB 737-32-1448, R2, to expand the effectivity to match the 
applicability in this AD, that determination would be made by Boeing. 
We agree it is beneficial to all concerned for the service information 
to match the content of the AD. We note that if Boeing would provide a 
revised service bulletin that addressed rotability, then this could be 
approved as an AMOC and would be less confusing to the operators.
    We have not revised this AD in regard to this issue.

Request To Clarify Certain Requirements

    MNGJET requested that the NPRM include a clarification of the 
differences between BSASB 737-32-1448 and BSASB 737-32-1448, R1, which 
were the service bulletins referred to in AD 2016-18-01. MNGJET 
specifically pointed out the difference between these service bulletin 
revisions regarding the MLG forward trunnion seal and retainer 
configuration.
    We do not agree with the commenter's request. The revisions to the 
service information are in regard to AD 2016-18-01, which is being 
superseded by this AD. This AD refers to BSASB 737-32-1448, R2, as the 
service information.
    Furthermore, the reason for the difference between BSASB 737-32-
1448 and BSASB 737-32-1448, R1, concerning the MLG forward trunnion 
seal and retainer configuration, is explained in paragraph 1.C, 
``Reason,'' of both BSASB 737-32-1448, R1, and BSASB 737-32-1448, R2. 
It is not necessary to either reiterate or explain the differences 
between different revisions of a service bulletin. Suggestions for 
improvement of the related service information should be

[[Page 3294]]

directed to Boeing. Also, FAA ADs have been written using AD Friendly 
standards since 2005. The requirements of ADs are written at a higher 
level, and the detailed information is in the related service 
information.
    No change has been made to this AD in regard to these issues.

Request To Extend Compliance Time for Certain Airplanes

    AMES, a continued airworthiness management organization (CAMO) for 
Boeing Business Jets (BBJs), requested that the compliance time for the 
replacement of the MLG forward trunnion pin housing assembly, seal, and 
retainer, in paragraph (k) of the proposed AD, be extended for BBJs. 
Specifically, AMES asked that for only BBJs on a low utilization 
maintenance program (LUMP) program, with a 12-year landing gear 
overhaul interval, the compliance time in the proposed AD be extended 
from 10 years to 12 years after the last landing gear overhaul. AMES 
highlighted that these are low-utilization airplanes, flying less than 
1,200 flight hours per year, and the MLG overhaul interval is every 12 
years. AMES observed that the compliance time for the actions in the 
proposed AD is 10 years after the effective date of AD 2016-18-01 
(October 5, 2026), which is before the next scheduled maintenance 
check. AMES stated that a limited number of BBJs would be affected and 
there would be limited impact.
    AMES also suggested that because the BBJs have low-time landing 
gears, owners do not want to exchange the low-time gears with high-time 
gears from airlines. AMES expressed that the 12-year check ground time 
is the best time to send the gears for overhaul.
    We disagree with the commenter's request. The commenter did not 
provide definitive supporting data that would justify the requested 
extension of the compliance time. In addition, Boeing's service 
information, BSASB 737-32-1448, R2, retains the same 10-year compliance 
time for BBJs.
    Regarding the commenter's concern of receiving a high-time MLG in 
exchange for a low-time MLG, presumably from sending these MLGs to a 
repair facility and receiving an exchange unit from a pool of MLGs, it 
is unclear how this would be prevented by having a 12-year compliance 
time instead of a 10-year compliance time.
    We have not made any changes to this AD in regard to these issues.

Concern Regarding Possible Parts Shortage

    United Airlines expressed concern that Boeing may not have an 
adequate stock of MLG forward trunnion pin seals and retainers to meet 
the requirement for operators to replace these parts. United Airlines 
noted that a parts shortage did arise from October 2016 to March 2017 
when Boeing could not supply operators with required parts. United 
Airlines observed that a parts shortage would lead to unnecessarily 
grounding airplanes.
    We appreciate the commenter's concern. However, as mentioned by the 
commenter, this issue has been ongoing since October 2016. Boeing is 
aware of operator concerns and should ensure that an adequate supply of 
required parts is available. Because of the identified unsafe 
condition, further delay of this final rule is not appropriate. In 
addition, the FAA has issued an AMOC for AD 2016-18-01 to a spare parts 
supplier for installation of its split ball assembly in lieu of the 
corresponding part specified in BSASB 737-32-1448, R1. That AMOC is 
still applicable to the corresponding provisions of this AD, as noted 
in paragraph (o)(4) of this AD. We have not revised this AD in regard 
to this issue.

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 addressing 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 BSASB 737-32-1448, R2. This service information 
describes procedures for determining the part numbers of the forward 
and aft trunnion pin assemblies installed on the right and left MLGs, 
inspections for corrosion and damage on the forward and aft trunnion 
pin assemblies and related investigative and corrective actions, 
repetitive lubrication of these assemblies, and installation of new or 
modified trunnion pin assembly components. 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 up to 1,814 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
----------------------------------------------------------------------------------------------------------------
Lubrication (retained actions  2 work-hours x $85                 $0  $170 per lubrication  $173,910, per
 from AD 2016-18-01).           per hour = $170 per                    cycle.                lubrication cycle
                                lubrication cycle.                                           (1,023 airplanes).
Inspection (Groups 1 and 2,    51 work-hours x $85                 0  $4,335 per            $4,282,980 per
 Configuration 1 airplanes;     per hour = $4,335                      inspection cycle.     inspection cycle
 retained actions from AD       per inspection cycle.                                        (988 airplanes).
 2016-18-01).
Inspection (Group 3            93 work-hours x $85                 0  $7,905 per            $276,675 per
 airplanes; retained actions    per hour = $7,905                      inspection cycle.     inspection cycle
 from AD 2016-18-01).           per inspection cycle.                                        (35 airplanes).
Replacement/overhaul (Groups   84 work-hours x $85                 0  $7,140..............  $7,054,320 (988
 1 and 2 airplanes; retained    per hour = $7,140.                                           airplanes).
 actions from AD 2016-18-01).
Replacement/overhaul (Group 3  86 work-hours x $85                 0  $7,310..............  $255,850 (35
 airplanes retained actions     per hour = $7,310.                                           airplanes).
 from AD 2016-18-01).

[[Page 3295]]

 
Lubrication pin assemblies     2 work-hours x $85                  0  $170 per lubrication  Up to $308,380, per
 (new action, Work Packages 1   per hour = $170 per                    cycle.                lubrication cycle
 and 2).                        lubrication cycle.                                           (up to 1,814
                                                                                             airplanes).
Inspection (new action;        51 work-hours x $85                 0  $4,335 per            Up to $7,594,920 per
 Groups 1, 2, 4, and 5,         per hour = $4,335                      inspection cycle.     inspection cycle
 Configuration 1 airplanes;     per inspection cycle.                                        (up to 1,752
 Work Package 2).                                                                            airplanes).
Inspection (new action;        93 work-hours x $85                 0  $7,905 per            Up to $490,110 per
 Groups 3 and 6 airplanes;      per hour = $7,905                      inspection cycle.     inspection cycle
 Work Package 2).               per inspection cycle.                                        (Up to 62
                                                                                             airplanes).
Replacement/overhaul trunnion  84 work-hours x $85                 0  $7,140..............  Up to $12,509,280
 pin assembly (Groups 1, 2,     per hour = $7,140.                                           (up to 1,752
 4, and 5 airplanes; new                                                                     airplanes).
 action; Work Package 2).
Replacement/overhaul trunnion  86 work-hours x $85                 0  $7,310..............  Up to $453,220 (Up
 pin assembly (Groups 3 and 6   per hour = $7,310.                                           to 62 airplanes).
 airplanes; new action; Work
 Package 2).
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that will enable us to provide 
cost estimates for the on-condition actions specified in 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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to transport category airplanes and 
associated appliances to the Director of the System Oversight Division.

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 removing Airworthiness Directive (AD) 
2016-18-01, Amendment 39-18631 (81 FR 59830, August 31, 2016), and 
adding the following new AD:

2019-01-03 The Boeing Company: Amendment 39-19542; Docket No. FAA-
2018-0162; Product Identifier 2017-NM-116-AD.

(a) Effective Date

    This AD is effective March 19, 2019.

(b) Affected ADs

    This AD replaces AD 2016-18-01, Amendment 39-18631 (81 FR 59830, 
August 31, 2016) (``AD 2016-18-01'').

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-600, -
700, -700C, -800, -900, and -900ER series airplanes, certificated in 
any category. These airplanes are specified in paragraphs (c)(1)(i) 
through (c)(1)(vii) of this AD.
    (i) Airplanes in Groups 1 and 2, Configuration 1, as identified 
in Boeing Special Attention Service Bulletin 737-32-1448, Revision 
2, dated August 2, 2017 (``BSASB 737-32-1448, R2'').
    (ii) Airplanes in Groups 1 and 2, Configuration 2, as identified 
in BSASB 737-32-1448, R2.
    (iii) Airplanes in Group 3, as identified in BSASB 737-32-1448, 
R2.
    (iv) Airplanes in Groups 4 and 5, Configuration 1, as identified 
in BSASB 737-32-1448, R2, except where this service bulletin 
specifies the groups as line numbers 3527 through 6510 inclusive, 
this AD specifies those groups as line number 3527 through any line 
number of an airplane with an original Certificate of Airworthiness 
or an original Export Certificate of Airworthiness dated on or 
before the effective date of this AD.
    (v) Airplanes in Groups 4 and 5, Configuration 2, as identified 
in BSASB 737-32-1448, R2, except where this service bulletin 
specifies the groups as line numbers 3527 through 6510 inclusive, 
this AD specifies those groups as line number 3527

[[Page 3296]]

through any line number of an airplane with an original Certificate 
of Airworthiness or an original Export Certificate of Airworthiness 
dated on or before the effective date of this AD.
    (vi) Airplanes in Groups 6 as identified in BSASB 737-32-1448, 
R2, except where this service bulletin specifies the groups as line 
numbers 3527 through 6510 inclusive, this AD specifies those groups 
as line number 3527 through any line number of an airplane with an 
original Certificate of Airworthiness or an original Export 
Certificate of Airworthiness dated on or before the effective date 
of this AD.
    (vii) All Model 737-600, -700, -700C, -800, -900 and -900ER 
series airplanes with an original Certificate of Airworthiness or an 
original Export Certificate of Airworthiness dated after the 
effective date of this AD.
    (2) Installation of Supplemental Type Certificate (STC) 
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 heavy corrosion and chrome 
damage on the forward and aft trunnion pin assemblies of the right 
and left main landing gears (MLGs). We are issuing this AD to 
address heavy corrosion and chrome damage on the forward and aft 
trunnion pin assemblies of the right and left MLGs, which could 
result in cracking of these assemblies and collapse of the MLGs.

(f) Compliance

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

(g) Inspection To Determine Part Numbers

    For airplanes identified in paragraphs (c)(1)(i), (c)(1)(iii), 
(c)(1)(iv), or (c)(1)(vi) of this AD: Except as required by 
paragraph (l) of this AD, at the applicable time specified in Table 
1, Table 2, Table 4, or Table 5, of paragraph 1.E., ``Compliance,'' 
of BSASB 737-32-1448, R2, do an inspection to determine if any of 
the existing part numbers identified in paragraph 2.C.3., ``Parts 
Modified and Reidentified,'' of BSASB 737-32-1448, R2, are 
installed. A review of airplane maintenance records is acceptable in 
lieu of this inspection if the part number of each existing part 
number can be conclusively determined from that review. Repetitive 
lubrication and inspection as required by and at the times specified 
in paragraphs (h) and (i) of this AD are also acceptable in lieu of 
this inspection to determine the MLG trunnion pin assembly part 
number.

(h) Repetitive Lubrication of MLG Trunnion Pin Assemblies

    For airplanes identified in paragraphs (c)(1)(i), (c)(1)(iii), 
(c)(1)(iv), or (c)(1)(vi) of this AD, having any part number 
identified in paragraph 2.C.3., ``Parts Modified and Reidentified,'' 
of BSASB 737-32-1448, R2, installed: Except as required by paragraph 
(l) of this AD, at the applicable time specified in Table 1, Table 
2, Table 4, or Table 5, of paragraph 1.E., ``Compliance,'' of BSASB 
737-32-1448, R2, lubricate the applicable forward and aft trunnion 
pin assemblies of the right and left MLGs, in accordance with Work 
Package 1 of the Accomplishment Instructions of BSASB 737-32-1448, 
R2. Repeat the lubrication thereafter at intervals not to exceed 
those specified in Table 1, Table 2, Table 4, or Table 5, of 
paragraph 1.E., ``Compliance,'' of BSASB 737-32-1448, R2. 
Accomplishment of the actions specified in paragraph (j) of this AD 
terminates the repetitive lubrication required by this paragraph.

(i) Repetitive Inspections, Corrective Actions, and Lubrication

    For airplanes identified in paragraphs (c)(1)(i), (c)(1)(iii), 
(c)(1)(iv), or (c)(1)(vi) of this AD, having any part number 
identified in paragraph 2.C.3., ``Parts Modified and Reidentified,'' 
of BSASB 737-32-1448, R2, installed: Except as required by paragraph 
(l) of this AD, at the applicable time specified in Table 1, Table 
2, Table 4, or Table 5, of paragraph 1.E., ``Compliance,'' of BSASB 
737-32-1448, R2, do a general visual inspection of the left and 
right MLGs at the forward and aft trunnion pin locations and the 
visible surfaces of the forward and aft trunnion pin assemblies for 
discrepancies including signs of corrosion or chrome plating damage, 
and lubricate the forward and aft trunnion pin assemblies as 
applicable, in accordance with Work Package 2 of the Accomplishment 
Instructions of BSASB 737-32-1448, R2. Repeat the general visual 
inspection thereafter at intervals not to exceed those specified in 
paragraph 1.E., ``Compliance,'' of BSASB 737-32-1448, R2. If any 
discrepancy is found during any inspection required by this 
paragraph, before further flight, do all applicable related 
investigative and corrective actions in accordance with Work Package 
2 of the Accomplishment Instructions of BSASB 737-32-1448, R2. 
Accomplishment of the actions required by paragraph (j) of this AD 
terminates the repetitive inspections required by this paragraph.

(j) Modification of MLG Trunnion Pin Assemblies

    For airplanes identified in paragraphs (c)(1)(i), (c)(1)(iii), 
(c)(1)(iv), or (c)(1)(vi) of this AD, having any part number 
identified in paragraph 2.C.3., ``Parts Modified and Reidentified,'' 
of BSASB 737-32-1448, R2, installed: Except as required by paragraph 
(l) of this AD, at the time specified in Table 1, Table 2, Table 4, 
or Table 5, as applicable, of paragraph 1.E., ``Compliance,'' of 
BSASB 737-32-1448, R2, modify the left and right MLG trunnion pin 
assemblies, including all applicable related investigative and 
corrective actions, in accordance with Work Package 3 of the 
Accomplishment Instructions of BSASB 737-32-1448, R2. All applicable 
related investigative and corrective actions must be done at the 
time specified in paragraph 1.E., ``Compliance,'' of BSASB 737-32-
1448, R2. Accomplishment of the actions in Work Package 3 of the 
Accomplishment Instructions of BSASB 737-32-1448, R2, terminates the 
repetitive lubrication required by paragraph (h) of this AD and the 
repetitive inspections required by paragraph (i) of this AD.

(k) Replacement of MLG Forward Trunnion Pin Housing Assembly, Seal, and 
Retainer

    For airplanes identified in paragraphs (c)(1)(ii) and (c)(1)(v) 
of this AD: Except as required by paragraph (l) of this AD, at the 
time specified in Table 3 or Table 6, as applicable, of paragraph 
1.E., ``Compliance,'' of BSASB 737-32-1448, R2, replace the seal, 
retainer, and support ring assembly with a new seal and retainer 
configuration; install the forward trunnion pin assembly into the 
housing assembly; and lubricate the forward and aft trunnion pin 
assemblies for the left and right MLGs; in accordance with Work 
Package 4 of the Accomplishment Instructions of BSASB 737-32-1448, 
R2.

(l) Exception to Service Information Specification

    Where paragraph 1.E., ``Compliance,'' of BSASB 737-32-1448, R2, 
specifies a compliance time ``after the Revision 2 date of this 
service bulletin,'' this AD requires compliance within the specified 
compliance time after the effective date of this AD.

(m) Parts Installation Limitation

    As of the effective date of this AD, no person may install 
existing parts identified in paragraph 2.C.3., ``Parts Modified and 
Reidentified,'' of BSASB 737-32-1448, R2, on any airplane identified 
in paragraphs (c)(1)(i) through (c)(1)(vii) of this AD, unless the 
actions required by paragraph (j) or (k), as applicable, of this AD 
have been accomplished on the parts.

(n) Credit for Previous Actions

    (1) This paragraph provides credit for the requirements of 
paragraph (h) of this AD, if those actions were performed before the 
effective date of this AD using Boeing Special Attention Service 
Bulletin 737-32-1448, dated May 19, 2011; or Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015.
    (2) This paragraph provides credit for the requirements of 
paragraphs (i), (j), and (k) of this AD, if those actions were 
performed before the effective date of this AD using Boeing Special 
Attention Service Bulletin 737-32-1448, Revision 1, dated May 29, 
2015.

(o) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO Branch, 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 certification office, send it to the attention of the 
person identified in paragraph (p)(1) of this AD. Information may be 
emailed to: [email protected].

[[Page 3297]]

    (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 Branch, FAA, 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) AMOCs approved previously for AD 2016-18-01 are approved as 
AMOCs for the corresponding provisions of this AD.

(p) Related Information

    (1) For more information about this AD, contact Alan Pohl, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; telephone and fax: 206-231-
3527; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (q)(3) and (q)(4) of this AD.

(q) 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 737-32-1448, 
Revision 2, dated August 2, 2017.
    (ii) [Reserved].
    (3) For 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 
Standards Branch, 2200 South 216th St., Des Moines, WA. For 
information on the availability of this material at the FAA, call 
206-231-3195.
    (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.

    Issued in Des Moines, Washington, on December 21, 2018.
Jeffrey E. Duven,
Director, System Oversight Division, Aircraft Certification Service.
[FR Doc. 2019-01518 Filed 2-11-19; 8:45 am]
BILLING CODE 4910-13-P