Document ID: FAA-2017-0682-0005
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Robinson Helicopter Co. Helicopters
Posted Date: 2020-07-28T04:00Z

[Federal Register Volume 85, Number 145 (Tuesday, July 28, 2020)]
[Proposed Rules]
[Pages 45360-45363]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-16188]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0682; Product Identifier 2017-SW-028-AD]
RIN 2120-AA64

Airworthiness Directives; Robinson Helicopter Company Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: The FAA is revising an earlier proposal for Robinson 
Helicopter Company (Robinson) Model R66 helicopters that proposed to 
require replacing a certain part-numbered tail rotor (T/R) drive shaft 
yoke assembly (yoke assembly) and inspecting for sealant. The NPRM was 
prompted by reports of T/R drive shaft forward hanger bearing failures. 
This action revises the NPRM by expanding the applicability, changing 
the proposed requirements, and correcting nomenclature. Since this 
imposes an additional burden over that proposed in the NPRM, the FAA is 
reopening the comment period to allow the public the chance to comment 
on these changes.

DATES: The comment period for the NPRM published in the Federal 
Register on March 30, 2018 (83 FR 13706), is reopened.
    The FAA must receive comments on this SNPRM by September 11, 2020.

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 https://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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this SNPRM, contact Robinson 
Helicopter Company, 2901 Airport Drive, Torrance, CA 90505; telephone 
310-539-0508; fax 310-539-5198; or at https://www.robinsonheli.com. You 
may view this referenced service information at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, 
Fort Worth, TX 76177.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov in Docket No. FAA-2017-0682; 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 SNPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Danny Nguyen, Aerospace Engineer, Los 
Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood, California 
90712; telephone 562-627-5247; email danny.nguyen@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to participate in this rulemaking by submitting 
written comments, data, or views. The most helpful comments reference a 
specific portion of the proposal, explain the reason for any 
recommended change, and include supporting data. To ensure the docket 
does not contain duplicate comments, commenters should send only one 
copy of written comments, or if comments are filed electronically, 
commenters should submit only one time.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will file in the docket all comments received, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this proposed rulemaking. Before acting on this 
proposal, the FAA will consider all comments received on or before the 
closing date for comments. The FAA will consider comments filed after 
the comment period has closed if it is possible to do so without 
incurring expense or delay. The FAA may change this proposal in light 
of the comments received.

Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
this SNPRM

[[Page 45361]]

contain commercial or financial information that is customarily treated 
as private, that you actually treat as private, and that is relevant or 
responsive to this SNPRM, it is important that you clearly designate 
the submitted comments as CBI. Please mark each page of your submission 
containing CBI as ``PROPIN.'' The FAA will treat such marked 
submissions as confidential under the FOIA, and they will not be placed 
in the public docket of this SNPRM. Submissions containing CBI should 
be sent to Danny Nguyen, Aerospace Engineer, Los Angeles ACO Branch, 
FAA, 3960 Paramount Blvd., Lakewood, California 90712; telephone 562-
627-5247; email danny.nguyen@faa.gov. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking.

Discussion

    The FAA issued a Notice of proposed rulemaking (NPRM), which 
proposed to amend 14 CFR part 39 by adding an AD that would apply to 
Robinson Model R66 helicopters, serial numbers 0003 through 0752, with 
a T/R drive shaft assembly part number (P/N) D224-3 or D224-4 
installed. The NPRM published in the Federal Register on March 30, 2018 
(83 FR 13706). The NPRM proposed to require replacing the yoke 
assembly, visually inspecting for sealant, and applying sealant if 
needed to prevent seal rotation.
    The NPRM was prompted by two incidents of forward hanger bearing 
failure of the T/R drive shaft assembly because the bearing was 
undersized for its housing. Consequently, the bearing was spinning at a 
speed that caused excessive heating of the bearing during operation and 
led to the breakdown of the bearing's grease and ultimately seizure of 
the C647-16 bearing.
    To correct this condition, Robinson initially issued R66 Service 
Bulletin SB-14, dated June 25, 2015 (SB-14), for certain serial-
numbered helicopters, which specified installing a temperature recorder 
on the T/R drive shaft forward hanger bearing assembly and inspecting 
the temperature recorder during preflight checks and during each 100-
hour inspection. If the bearing was found running hot, then Robinson 
advised upgrading the bearing to a newer design.
    Following additional reports of overheating forward hanger bearing 
assemblies, Robinson superseded SB-14 with R66 Service Bulletin SB-20, 
dated November 7, 2016 (SB-20), which affected additional serial-
numbered helicopters and specified modifying T/R drive shaft assembly 
P/Ns D224-3 and D224-4 by using kit Robinson KI-235 R66 TRDS Forward 
Yoke Assembly and Hanger Installation Kit Instructions, Revision A, 
dated June 23, 2015 (KI-235) and installing yoke assembly P/N D224-5. 
This installation has an improved, larger bearing that spins with less 
friction. SB-20 also specified inspecting the forward and aft sides of 
the hanger and damper bearings for a minimum of 0.5 inch in length of 
sealant on the junction of the black seal and bearing outer race and 
applying sealant if there was less than 0.5 inch in length of sealant.
    Robinson revised SB-20 with R66 Service Bulletin SB-20A, dated June 
6, 2017 (SB-20A), to clarify that helicopters with either T/R drive 
shaft assembly P/N D224-3 with modification B900-11 or P/N D224-4 
installed include the upgraded bearing and do not require kit KI-235.
    Robinson later revised SB-20A with R66 Service Bulletin SB-20B, 
dated December 20, 2017 (SB-20B), which updates writing practices and 
organizes the procedures into two separate sections, clarifies the 
``Rotorcraft Affected'' section, and reduces the helicopters that need 
to perform the inspection and sealant application procedures to just 
helicopters without the latest version damper and housing bearings.
    The actions proposed by the NPRM were intended to prevent failure 
of the T/R drive shaft forward bearing and subsequent loss of 
helicopter control.

Comments

    After the NPRM was published, the FAA received comments from 
Robinson. The following presents the comments received on the NPRM and 
the FAA's response to each comment.

Request for Changes to the Preamble and Nomenclature

    Request: Robinson requested the description of what prompted this 
AD in the SUMMARY section be revised from reports of T/R drive shaft 
failures to reports of bearing failures because there have been no T/R 
drive shaft failures, only bearing failures.
    FAA Response: The FAA agrees and has revised that statement in this 
SNPRM.
    Request: Robinson requested standardizing nomenclature by changing 
instances of ``yoke assembly'' to ``hanger bearing'' throughout the AD 
to minimize confusion. Robinson stated that although the bearing is 
pressed onto a yoke, the important point is to upgrade the bearing.
    FAA Response: The FAA agrees to clarify nomenclature pertaining to 
the forward hanger bearing when discussing T/R drive shaft assembly P/N 
D224-3 and P/N D224-4. However, the FAA continues to use the 
nomenclature of yoke assembly for T/R drive shaft assembly P/N D224-5 
to match nomenclature stated in Robinson service information.
    Request: Robinson requested numerous changes to the Discussion 
section to provide a simplified explanation of the bearing failure--
noting that the explanation as published in the NPRM has technical 
errors and that the C647 callout is not beneficial because there was no 
customer visibility of the C647 P/N until data plates were added 
recently, and to provide a description of the upgraded bearing design, 
clarify the explanation of SB-20 and SB-20A, add an explanation of SB-
20B, identify that the sealant inspection and application aspects of 
the SB are separate from this AD, and state that bearing failure does 
not cause loss of helicopter control.
    FAA Response: The purpose of the Discussion section is to explain 
the unsafe condition and the FAA's justification for issuing AD action. 
It may include, but is not limited to, providing the following types of 
information: the circumstances that created the need to correct the 
unsafe condition, historical information, consequences if the unsafe 
condition is not corrected, and any other information that supports the 
AD action. Robinson's requested language that corrects information in 
the Discussion section has been incorporated in this SNPRM. Any 
requested changes that do not correct information have not been 
incorporated.
    Request: Robinson proposed changes to the Related Service 
Information section that delete the pilot caution reference. Robinson 
stated it is peripheral to the bearing upgrade and obsolete due to 
supersedure of SB-14. Robinson also requested adding a reference to SB-
20B, adding clarification that the bearing upgrade is only for T/R 
drive shaft assembly P/N D223-3, and removing information related to 
the sealant inspection and application.
    FAA Response: The purpose of the Related Service Information 
section is to describe service information that is relevant to the AD 
action and give a brief description of the specified procedures. 
Service information documents that are relevant to an AD action may 
contain other information as well. Any proposed changes that correct 
information in the Related Service Information section have been 
incorporated in this SNPRM. Any

[[Page 45362]]

proposed changes that do not correct information have not been 
incorporated.

Request for Changes to the Applicability

    Request: Robinson requested the FAA revise the applicability of 
this AD by removing the aircraft S/N. Robinson further stated that the 
aircraft S/N may be included for reference.
    FAA Response: The FAA agrees and has revised the applicability in 
this SNPRM accordingly.
    Request: Robinson requested the FAA remove T/R drive shaft assembly 
P/N D224-4 from the applicability of this AD because T/R drive shaft 
assembly P/N D224-4 incorporates the improved bearing and does not 
require an upgrade. Robinson also proposed adding a note stating that 
T/R drive shaft assembly P/N D224-3 with modification data plate P/N 
B900-11 has previously been upgraded and does not require action per 
this AD.
    FAA Response: The FAA agrees except T/R drive shaft assembly P/N 
D224-3 with B900-11 modification installed cannot be included in a note 
because notes are for informational purposes and are not regulatory 
text. This exception will be included in the applicability paragraph 
instead.

Request To Change the Unsafe Condition

    Request: Robinson proposed the FAA change the possible result of 
the unsafe condition from ``failure of the T/R drive shaft and 
subsequent loss of helicopter control'' to ``forced landing of the 
helicopter.''
    FAA Response: The FAA disagrees. Failure of the T/R drive shaft 
bearing results in loss of T/R control, which could result in scenarios 
ranging from a forced landing of the helicopter to loss of helicopter 
control.

Request for Changes to the Required Actions

    Request: Robinson requested the FAA change the Required Actions 
paragraph to delete the requirements to install T/R drive shaft 
assembly P/N D224-5 and inspect and apply sealant. Robinson requested 
the FAA require upgrading an affected T/R drive shaft assembly P/N 
D224-3 using Robinson KI-235 or replacing an affected T/R drive shaft 
assembly P/N D224-3 with T/R drive shaft assembly P/N D224-4 instead.
    FAA Response: The FAA agrees, except for using the wording Robinson 
KI-235, as this SNPRM specifically specifies installing Robinson KI-235 
using KI-235 R66 TRDS Forward Yoke Assembly and Hanger Installation Kit 
Instructions, Revision A, dated June 23, 2015.

Additional Changes Since the NPRM Was Issued

    Since the FAA issued the NPRM, the fleet size has increased from 
249 helicopters to 290 helicopters and the website address for Robinson 
has changed. This SNPRM updates this information.
    Additionally, the FAA has determined that it is necessary to 
prevent installation of an affected T/R drive shaft assembly on any 
Model R66 helicopter as a replacement part. Accordingly, this SNPRM 
proposes to prohibit this installation.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed KI-235. This service information provides 
instructions for installing the newly designed yoke assembly, P/N D224-
5.
    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.

Related Service Information

    The FAA has reviewed SB-14, which specifies installing a 
temperature recorder on the T/R drive shaft forward hanger bearing 
assembly and inspecting the temperature during preflight checks and 
during each 100-hour inspection. If the temperature of the bearing is 
found running hot, then Robinson advises upgrading the bearing to a 
newer design (kit P/N KI-235). This service information also specifies 
adding a caution page to the Pilot Operating Handbook regarding the 
overheating bearing assemblies. This service information was superseded 
by SB-20.
    The FAA has reviewed SB-20, SB-20A, and SB-20B, which specify 
upgrading the forward hangar bearing assembly of certain T/R drive 
shaft assemblies to the newer design with kit P/N KI-235 if not 
previously done. For certain installations, this service information 
contains procedures for inspecting for sealant and applying sealant to 
the damper and hanger bearings if needed to prevent seal rotation. This 
service information also specifies removing the caution page from the 
Pilot Operating Handbook regarding the overheating bearing assemblies 
that was added by SB-14.

FAA's Determination

    The FAA is proposing this SNPRM after evaluating all known relevant 
information and determining that an unsafe condition is likely to exist 
or develop on other helicopters of the same type design. Certain 
changes described above expand the scope of the original NPRM. As a 
result, the FAA has determined that it is necessary to reopen the 
comment period to provide additional opportunity for the public to 
comment on this SNPRM.

Proposed Requirements of This SNPRM

    This SNPRM proposes to require, within 100 hours TIS, either 
installing Robinson field kit P/N KI-235 or replacing an affected T/R 
drive shaft assembly with T/R drive shaft assembly P/N D224-4. This 
SNPRM also proposes to prohibit installing an affected T/R drive shaft 
assembly on any helicopter.

Differences Between This AD and the Service Information

    SB-20 specifies replacing the yoke assembly and applying sealant to 
the bearing seals within the next 100 flight hours or by January 31, 
2017, whichever comes first, and SB-20A and SB-20B continue the 
compliance time of no later than January 31, 2017. This proposed AD 
does not have a calendar time compliance requirement. SB-20, SB-20A, 
and SB-20B specify inspecting for sealant and applying sealant to the 
damper and hanger bearings if needed, while this proposed AD does not.

Costs of Compliance

    The FAA estimates that this proposed AD affects 290 helicopters of 
U.S. Registry. Labor rates are estimated at $85 per work-hour. Based on 
these estimates, the FAA estimates that operators may incur the 
following costs in order to comply with this proposed AD.
    Installing Robinson field kit KI-235 would take about 6 work-hours 
and parts would cost about $950, for an estimated cost of $1,460 per 
helicopter. As an option, replacing an affected T/R drive shaft 
assembly P/N D224-3 with T/R drive shaft assembly P/N D224-4 would take 
about 5 work-hours and parts cost about $4,400, for an estimated cost 
of $4,825 per helicopter.

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.
    The FAA is 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

[[Page 45363]]

with promoting safe flight of civil aircraft in air commerce by 
prescribing regulations for practices, methods, and procedures the 
Administrator finds necessary for safety in air commerce. This 
regulation is within the scope of that authority because it addresses 
an unsafe condition that is likely to exist or develop on products 
identified in this rulemaking action.

Regulatory Findings

    The FAA has determined that this proposed AD will not have 
federalism implications under Executive Order 13132. This proposed 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 proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) 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 proposed to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

Robinson Helicopter Company: Docket No. FAA-2017-0682; Product 
Identifier 2017-SW-028-AD.

(a) Applicability

    This AD applies to Robinson Helicopter Company (Robinson) Model 
R66 helicopters with a tail rotor (T/R) drive shaft assembly part 
number (P/N) D224-3 without B900-11 modification installed, 
certificated in any category.

    Note 1 to paragraph (a) of this AD: Helicopters with S/Ns 0753 
and subsequent had T/R drive shaft forward yoke assembly P/N D224-5 
installed during production.

(b) Unsafe Condition

    This AD defines the unsafe condition as failure of a T/R drive 
shaft forward hanger bearing. This condition could result in failure 
of the T/R drive shaft and subsequent loss of helicopter control.

(c) Comments Due Date

    The FAA must receive comments by September 11, 2020.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Within 100 hours time-in-service, do one of the following:
    (i) Install Robinson kit P/N KI-235 using KI-235 R66 TRDS 
Forward Yoke Assembly and Hanger Installation Kit Instructions, 
Revision A, dated June 23, 2015, except you are not required to 
discard nuts or palnuts, or
    (ii) Replace the entire T/R drive shaft assembly with T/R drive 
shaft assembly P/N D224-4.
    (2) As of the effective date of this AD, do not install a T/R 
drive shaft assembly P/N D224-3 without B900-11 modification on any 
helicopter.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles ACO Branch, FAA, may approve AMOCs 
for this AD. Send your proposal to: Danny Nguyen, Aerospace 
Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., 
Lakewood, California 90712; telephone 562-627-5247; email 9-ANM-LAACO-AMOC-REQUESTS@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, the FAA suggests 
that you notify your principal inspector, or lacking a principal 
inspector, the manager of the local flight standards district office 
or certificate holding district office, before operating any 
aircraft complying with this AD through an AMOC.

(g) Additional Information

    For service information identified in this AD, contact Robinson 
Helicopter Company, 2901 Airport Drive, Torrance, CA 90505; 
telephone 310-539-0508; fax 310-539-5198; or at https://www.robinsonheli.com. You may view a copy of information at the FAA, 
Office of the Regional Counsel, Southwest Region, 10101 Hillwood 
Pkwy., Room 6N-321, Fort Worth, TX 76177.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6510, Tail Rotor 
Drive Shaft.

    Issued on July 22, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-16188 Filed 7-27-20; 8:45 am]
BILLING CODE 4910-13-P