Federal Register / Vol. 83, No. 180 / Monday, September 17, 2018 / Proposed Rules 46895 

Material misalignment means 

divergence of at least three percentage 

points in the one-month CPR for a 

cohort, or a prolonged misalignment (as 

determined by FHFA), or divergence 

greater than the prevailing threshold set 

by FHFA, per § 1248.5(c). 

Misalign or misalignment means 

diverge by or a divergence of two 

percentage points or more (or more than 

the prevailing percentage threshold set 

by FHFA, per § 1248.5(c)), in the onemonth CPR for a cohort. 

Mortgage-backed security or MBS 

means securities collateralized by a pool 

or pools of single-family mortgages. 

Supers means single-class resecuritizations of UMBS. 

To-Be-Announced Eligible MortgageBacked Security (TBA-Eligible MBS) 

means Enterprise MBS (including 

Freddie Mac Participation Certificates, 

Giants, MBS, UMBS, and Supers; and 

Fannie Mae MBS, Megas, UMBS, and 

Supers) that meet criteria such that the 

market considers them sufficiently 

fungible to be forward traded in the 

TBA market. 

Uniform Mortgage Backed Security or 

UMBS means a single-class MBS backed 

by fixed-rate mortgage loans on 1–4 unit 

(single-family) properties issued by 

either Enterprise which has the same 

characteristics (such as payment delay, 

pooling prefixes, and minimum pool 

submission amounts) regardless of 

which Enterprise is the issuer. 

§ 1248.2 Purpose. 

The purpose of this part is to: 

(a) Enhance liquidity in the MBS 

marketplace, and to that end, enable 

adoption of the UMBS, by achieving 

sufficient similarity of cash flows on 

cohorts of TBA-eligible MBS such that 

investors will accept delivery of UMBS 

from either issuer in settlement of trades 

on the TBA market. 

(b) Provide transparency and 

durability into the process for creating 

alignment. 

§ 1248.3 General alignment. 

Each Enterprise’s covered programs, 

policies, and practices must align with 

the other Enterprise’s covered programs, 

policies, and practices. 

§ 1248.4 Enterprise consultation. 

When and in the manner instructed 

by FHFA, the Enterprises shall consult 

with each other on any issues, including 

changes to covered programs, policies, 

and practices that potentially or actually 

cause cash flows to TBA-eligible MBS 

investors to misalign. 

§ 1248.5 Misalignment. 

(a) The Enterprises must report any 

misalignment to FHFA. 

(b) The Enterprises must submit, in a 

timely manner, a written report to FHFA 

on any material misalignment 

describing, at a minimum, the likely 

cause of material misalignment and the 

Enterprises’ plan to address the material 

misalignment. 

(c) FHFA will temporarily adjust the 

percentages in the definitions of align, 

misalignment, and material 

misalignment, if FHFA determines that 

market conditions dictate that an 

adjustment is appropriate. 

(1) In adjusting the percentages, FHFA 

will consider: 

(i) The prevailing level and volatility 

of interest rates, 

(ii) The level of credit risk embedded 

in the Enterprises’ TBA-eligible MBS, 

and 

(iii) Such other factors as FHFA may, 

in consultation with the Enterprises, 

determine to be appropriate to promote 

market confidence in the alignment of 

cash flows to TBA-eligible MBS 

investors and to foster the efficiency and 

liquidity of the secondary mortgage 

market. 

(2) If adjusted percentages remain in 

effect for six months or more, FHFA will 

amend this Part’s definitions by Federal 

Register Notice, with opportunity for 

public comment. 

§ 1248.6 Covered programs, policies, and 

practices. 

(a) Enterprise Change Management 

Processes. Each Enterprise must 

establish and maintain an Enterprisewide governance process to ensure that 

any proposed changes to covered 

programs, policies, and practices that 

may cause misalignment are identified, 

reviewed, escalated, and submitted, in 

writing, to FHFA for review and 

approval in a timely manner. 

(1) Submissions to FHFA must 

include projections for prepayment rates 

and for removals of delinquent loans 

under a range of interest rate 

environments and assumptions 

concerning borrower defaults. 

(2) Submissions to FHFA must 

include an analysis of the impact on 

borrower demand and impact on the 

cheapest-to-deliver security down to the 

decile. 

(3) Submissions to FHFA must 

include an analysis of identified risks 

and may include potential mitigating 

actions. 

(b) Enterprise Monitoring. Any 

changes to covered programs, policies, 

and practices that an Enterprise 

reasonably should identify as having 

been a likely cause of an unanticipated 

divergence between Enterprises in the 

one month CPR of the same cohort shall 

be reported promptly to FHFA in 

writing. 

(c) FHFA Monitoring. FHFA will 

monitor changes to covered programs, 

policies, and practices for effects on 

cash flows to TBA-eligible MBS 

investors. 

§ 1248.7 Remedial actions. 

(a) Based on its review of reports 

submitted by the Enterprises and reports 

issued by independent parties, FHFA 

may: 

(1) Require an Enterprise to undertake 

additional analysis, monitoring, or 

reporting to further the purposes of this 

part. 

(2) Require an Enterprise to change 

covered programs, policies, and 

practices that FHFA determines may 

conflict with the purposes of this part. 

(b) To address material misalignment, 

FHFA may require additional and 

expedient Enterprise actions based on: 

(1) Consultation with the Enterprises 

regarding the cause of the material 

misalignment; 

(2) Review of Enterprise compliance 

with previously agreed upon or FHFArequired actions; and 

(3) Review of the effectiveness of such 

actions to determine whether they are 

achieving the purpose of this part. 

§ 1248.8 De minimis exception. 

FHFA may exclude from the 

requirements of this Part, covered 

programs, policies, or practices that 

solely affect cohorts with unpaid 

principal balances below $5 billion. 

Dated: September 11, 2018. 

Melvin L. Watt, 

Director, Federal Housing Finance Agency. 

[FR Doc. 2018–20124 Filed 9–14–18; 8:45 am] 

BILLING CODE 8070–01–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2018–0792; Product 

Identifier 2018–NM–090–AD] 

RIN 2120–AA64 

Airworthiness Directives; Bombardier, 

Inc., Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

Bombardier, Inc., Model BD–100–1A10 

airplanes. This proposed AD was 


daltland on DSKBBV9HB2PROD with PROPOSALS
46896 Federal Register / Vol. 83, No. 180 / Monday, September 17, 2018 / Proposed Rules 

prompted by an incident of 

uncommanded nose wheel steering 

(NWS) in-service; subsequent 

investigation revealed that the steering 

selector valve (SSV) is susceptible to 

jamming in the open position due to 

particulate contamination of the 

hydraulic system. This proposed AD 

would require modifying the left-hand 

hydraulic system of the NWS control 

system and, for certain airplanes, 

torqueing the fittings on a certain tube 

assembly. We are proposing this AD to 

address the unsafe condition on these 

products. 

DATES: We must receive comments on 

this proposed AD by November 1, 

20181. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202–493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, 

M–30, West Building Ground Floor, 

Room W12–140, 1200 New Jersey 

Avenue SE, Washington, DC 20590. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

For service information identified in 

this NPRM, contact Bombardier, Inc., 

400 Coˆte-Vertu Road West, Dorval, 

Que ́bec H4S 1Y9, Canada; telephone 

514–855–5000; fax 514–855–7401; email 

thd.crj@aero.bombardier.com; internet 

http://www.bombardier.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. 

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– 

0792; 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 NPRM, the 

regulatory evaluation, any comments 

received, and other information. The 

street address for Docket Operations 

(phone: 800–647–5527) is in the 

ADDRESSES section. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Darren Gassetto, Aerospace Engineer, 

Mechanical Systems and Admin 

Services Section, FAA, New York ACO 

Branch, 1600 Stewart Avenue, Suite 

410, Westbury, NY 11590; telephone 

516–228–7323; fax 516–794–5531; email 

9-avs-nyaco-cos@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposal. Send your comments to 

an address listed under the ADDRESSES

section. Include ‘‘Docket No. FAA– 

2018–0792; Product Identifier 2018– 

NM–090–AD’’ at the beginning of your 

comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of this NPRM. We will consider 

all comments received by the closing 

date and may amend this NPRM 

because of those comments. 

We will post all comments we 

receive, without change, to http://

www.regulations.gov, including any 

personal information you provide. We 

will also post a report summarizing each 

substantive verbal contact we receive 

about this NPRM. 

Discussion 

Transport Canada Civil Aviation 

(TCCA), which is the aviation authority 

for Canada, has issued Canadian AD 

CF–2018–11, dated April 5, 2018 

(referred to after this as the Mandatory 

Continuing Airworthiness Information, 

or ‘‘the MCAI’’), to correct an unsafe 

condition for certain Bombardier, Inc., 

Model BD–100–1A10 airplanes. The 

MCAI states: 

An incident of uncommanded nose wheel 

steering occurred in-service. Subsequent 

investigation revealed that the steering 

selector valve (SSV) was vulnerable to 

jamming in the open position due to 

particulate contamination of the hydraulic 

system. If not corrected, a jam of the SSV, 

following the independent failure of a second 

component of the nose wheel steering 

system, could result in uncommanded nose 

wheel steering and a risk of runway 

excursion. 

This [Canadian] AD requires the 

incorporation of a hydraulic fluid filter in the 

line supplying pressure from the direct 

current motor pump to the nose wheel 

steering system [and, for certain airplanes, 

torqueing the fittings on a certain tube 

assembly]. 

You may examine the MCAI in the 

AD docket on the internet at http://

www.regulations.gov by searching for 

and locating Docket No. FAA–2018– 

0792. 

Related Service Information Under 1 

CFR Part 51 

Bombardier has issued Service 

Bulletins 100–32–31, Revision 03; and 

350–32–007, Revision 03; both dated 

March 27, 2018. This service 

information describes procedures for 

modifying the left-hand hydraulic 

system of the NWS control system by 

installing a hydraulic filter into the 

hydraulic line between the direct 

current motor pump and the SSV and, 

for certain airplanes, torqueing the 

fittings on a certain tube assembly. 

These documents are distinct since they 

apply to different airplane 

configurations. 

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. 

FAA’s Determination 

This product has been approved by 

the aviation authority of another 

country, and is approved for operation 

in the United States. Pursuant to our 

bilateral agreement with the State of 

Design Authority, we have been notified 

of the unsafe condition described in the 

MCAI and service information 

referenced above. We are proposing this 

AD because we evaluated all the 

relevant information and determined 

the unsafe condition described 

previously is likely to exist or develop 

on other products of the same type 

design. 

Proposed Requirements of This NPRM 

This proposed AD would require 

accomplishing the actions specified in 

the service information described 

previously. 

Costs of Compliance 

We estimate that this proposed AD 

affects 534 airplanes of U.S. registry. We 

estimate the following costs to comply 

with this proposed AD: 

ESTIMATED COSTS

Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

25 work-hours × $85 per hour = $2,125 ..................................................................................... $13,196 $15,321 $8,181,414 


daltland on DSKBBV9HB2PROD with PROPOSALS
Federal Register / Vol. 83, No. 180 / Monday, September 17, 2018 / Proposed Rules 46897 

According to the manufacturer, some 

or all of the costs of this proposed 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 known 

costs in our cost estimate. 

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 proposed 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 to the Director of the 

System Oversight Division. 

Regulatory Findings 

We determined that this proposed AD 

would not have federalism implications 

under Executive Order 13132. This 

proposed AD would 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 this proposed regulation: 

1. Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866; 

2. Is not a ‘‘significant rule’’ under the 

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. 

The Proposed Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA proposes to amend 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. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive (AD): 

Bombardier, Inc.: Docket No. FAA–2018– 

0792; Product Identifier 2018–NM–090– 

AD. 

(a) Comments Due Date 

We must receive comments by November 

1, 2018. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to Bombardier, Inc., 

Model BD–100–1A10 airplanes, certificated 

in any category, serial numbers 20002 

through 20744 inclusive. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 32, Landing Gear. 

(e) Reason 

This AD was prompted by an incident of 

uncommanded nose wheel steering (NWS) 

in-service; subsequent investigation revealed 

that the steering selector valve (SSV) is 

susceptible to jamming in the open position 

due to particulate contamination of the 

hydraulic system. We are issuing this AD to 

address jamming of the SSV after 

independent failure of a second component 

of the NWS control system, which could 

result in uncommanded NWS and a possible 

runway excursion. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Modify Hydraulic System 

Except for airplanes identified in 

paragraph (h) of this AD: Within 2,000 flight 

cycles or 60 months after the effective date 

of this AD, whichever occurs first, modify the 

left-hand hydraulic system of the NWS 

control system by installing a hydraulic filter 

into the hydraulic line between the direct 

current motor pump and the SSV, in 

accordance with the Accomplishment 

Instructions of Bombardier Service Bulletin 

100–32–31, Revision 03; or Bombardier 

Service Bulletin 350–32–007, Revision 03; 

both dated March 27, 2018; as applicable. 

(h) Additional Action for Certain Airplanes 

For airplanes that have incorporated 

Bombardier Service Bulletin 100–32–31, 

dated January 4, 2018; Bombardier Service 

Bulletin 100–32–31, Revision 01, dated 

January 23, 2018; Bombardier Service 

Bulletin 100–32–31, Revision 02, dated 

March 14, 2018; Bombardier Service Bulletin 

350–32–007, dated January 4, 2018; 

Bombardier Service Bulletin 350–32–007, 

Revision 01, dated January 23, 2018; or 

Bombardier Service Bulletin 350–32–007, 

Revision 02, dated March 14, 2018; as 

applicable, as of the effective date of this AD: 

Within 50 flight hours after the effective date 

of this AD, torque the fittings on any tube 

assembly having part number K1000070395– 

401, in accordance with the ‘‘Retroactive 

Action’’ instructions of Bombardier Service 

Bulletin 100–32–31, Revision 03, or 

Bombardier Service Bulletin 350–32–007, 

Revision 03, both dated March 27, 2018, as 

applicable. 

(i) Other FAA AD Provisions 

The following provisions also apply to this 

AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, New York 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 ATTN: Program Manager, 

Continuing Operational Safety, FAA, New 

York ACO Branch, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; telephone 

516–228–7300; fax 516–794–5531. Before 

using any approved AMOC, notify your 

appropriate principal inspector, or lacking a 

principal inspector, the manager of the local 

flight standards district office/certificate 

holding district office. 

(2) Contacting the Manufacturer: For any 

requirement in this AD to obtain corrective 

actions from a manufacturer, the action must 

be accomplished using a method approved 

by the Manager, New York ACO Branch, 

FAA; or Transport Canada Civil Aviation 

(TCCA); or Bombardier, Inc.’s TCCA Design 

Approval Organization (DAO). If approved by 

the DAO, the approval must include the 

DAO-authorized signature. 

(j) Related Information 

(1) Refer to Mandatory Continuing 

Airworthiness Information (MCAI) Canadian 

AD CF–2018–11, dated April 5, 2018, for 

related information. This MCAI may be 

found in the AD docket on the internet at 

http://www.regulations.gov by searching for 

and locating Docket No. FAA–2018–0792. 

(2) For more information about this AD, 

contact Darren Gassetto, Aerospace Engineer, 

Mechanical Systems and Admin. Services 

Section, FAA, New York ACO Branch, 1600 


daltland on DSKBBV9HB2PROD with PROPOSALS
46898 Federal Register / Vol. 83, No. 180 / Monday, September 17, 2018 / Proposed Rules 

Stewart Avenue, Suite 410, Westbury, NY 

11590; telephone 516–228–7323; fax 516– 

794–5531; email 9-avs-nyaco-cos@faa.gov. 

(3) For service information identified in 

this AD, contact Bombardier, Inc., 400 CoˆteVertu Road West, Dorval, Que ́bec H4S 1Y9, 

Canada; telephone 514–855–5000; fax 514– 

855–7401; email thd.crj@

aero.bombardier.com; internet http://

www.bombardier.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. 

Issued in Des Moines, Washington, on 

August 30, 2018. 

Jeffrey E. Duven, 

Director, System Oversight Division, Aircraft 

Certification Service. 

[FR Doc. 2018–19841 Filed 9–14–18; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2018–0739; Product 

Identifier 2015–NE–07–AD] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Canada Corp. Turboshaft 

Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to supersede 

airworthiness directive (AD) 2015–20– 

04, which applies to certain Pratt & 

Whitney Canada Corp. (P&WC) PT6B– 

37A turboshaft engines. AD 2015–20–04 

requires initial and repetitive 

inspections until replacement of the No. 

10 bearing, and eventual replacement of 

the No. 9 bearing, both located in the 

engine reduction gearbox (RGB) 

assembly. Since we issued AD 2015–20– 

04, P&WC has determined that the 

repetitive inspection of the bearings has 

an associated risk of gearbox damage or 

contamination and that the bearing 

installation required by AD 2015–20–04 

does not adequately address the issue of 

bearing axial movement. This proposed 

AD would require removal from service 

and replacement of the No. 9 and No. 

10 position bearings. We are proposing 

this AD to address the unsafe condition 

on these products. 

DATES: We must receive comments on 

this proposed AD by November 1, 2018. 

ADDRESSES: You may send comments, 

using the procedures found in 14 CFR 

11.43 and 11.45, by any of the following 

methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202–493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue SE, 

Washington, DC 20590. 

• Hand Delivery: Deliver to Mail 

address above between 9 a.m. and 5 

p.m., Monday through Friday, except 

Federal holidays. 

For service information identified in 

this NPRM, contact Pratt & Whitney 

Canada Corp., 1000 Marie-Victorin, 

Longueuil, Quebec, Canada, J4G 1A1; 

phone: 800–268–8000; fax: 450–647– 

2888; website: http://www.pwc.ca. You 

may view this service information at the 

FAA, Engine & Propeller Standards 

Branch, 1200 District Avenue, 

Burlington, MA 01803. For information 

on the availability of this material at the 

FAA, call 781–238–7759. 

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– 

0739; or in person at the Docket 

Operations between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal 

holidays. The AD docket contains this 

NPRM, the mandatory continuing 

airworthiness information, regulatory 

evaluation, any comments received, and 

other information. The street address for 

Docket Operations (phone: 800–647– 

5527) is listed above. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Barbara Caufield, Aerospace Engineer, 

ECO Branch, FAA, 1200 District 

Avenue, Burlington, MA 01803; phone: 

781–238–7146; fax: 781–238–7199; 

email: barbara.caufield@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposed AD. Send your comments 

to an address listed under the 

ADDRESSES section. Include ‘‘Docket No. 

FAA–2018–0739; Product Identifier 

2015–NE–07–AD’’ at the beginning of 

your comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of this NPRM. We will consider 

all comments received by the closing 

date and may amend this NPRM 

because of those comments. 

We will post all comments we 

receive, without change, to http://

www.regulations.gov, including any 

personal information you provide. We 

will also post a report summarizing each 

substantive verbal contact we receive 

about this proposed AD. 

Discussion 

We issued AD 2015–20–04, 

Amendment 39–18282 (80 FR 61717, 

October 14, 2015), (‘‘AD 2015–20–04’’), 

for certain P&WC PT6B–37A turboshaft 

engines. AD 2015–20–04 requires initial 

and repetitive inspections until 

replacement of the No. 10 bearing, and 

eventual replacement of the No. 9 

bearing, both located in the engine RGB 

assembly. AD 2015–20–04 resulted from 

reports of incorrect engine torque for 

PT6B–37A engines. We issued AD 

2015–20–04 to prevent axial movement 

at the No. 10 bearing position in the 

engine RGB assembly, which could 

result in engine overtorque, failure of 

the engine, in-flight shutdown, and loss 

of the helicopter. 

Actions Since AD 2015–20–04 Was 

Issued 

Since we issued AD 2015–20–04, 

P&WC has determined that the 

repetitive inspection of the bearings in 

P&WC Service Bulletin (SB) PT6B–72– 

39095, Revision No. 3, dated December 

29, 2014, has an associated risk of 

gearbox damage or contamination. 

P&WC also determined that the bearing 

installation in P&WC SB No. PT6B–72– 

39092, Revision No. 4, dated December 

29, 2014, as required by AD 2015–20– 

04, does not adequately address the 

issue of bearing axial movement. 

Related Service Information Under 1 

CFR Part 51 

We reviewed P&WC SB No. PT6B–72– 

39108, dated September 30, 2016. The 

SB describes procedures for replacing 

affected bearings. 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. 

Other Related Service Information 

We reviewed P&WC SB No. PT6B–72– 

39092, Revision No. 4, dated December 

29, 2014. The service information 

describes procedures for removing 

affected bearings. 

FAA’s Determination 

We are proposing this AD because we 

evaluated all the relevant information 

and determined the unsafe condition 

described previously is likely to exist or 


daltland on DSKBBV9HB2PROD with PROPOSALS