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
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:
alan.pohl@faa.gov.

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 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.

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
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

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

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]

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: