Document ID: FAA-2006-26107-0006
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Carson Helicopters, Inc.; Croman Corporation; Sikorsky Aircraft Corporation; and Siller Helicopters
Posted Date: 2021-03-15T04:00Z

[Federal Register Volume 86, Number 48 (Monday, March 15, 2021)]
[Proposed Rules]
[Pages 14285-14289]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05150]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26107; Project Identifier 2004-SW-30-AD]
RIN 2120-AA64

Airworthiness Directives; Carson Helicopters, Inc.; Croman 
Corporation; Sikorsky Aircraft Corporation; and Siller 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 all Sikorsky 
Aircraft Corporation Model S-61 A, D, E, and V helicopters; Croman 
Corporation Model SH-3H helicopters, Carson Helicopters, Inc. Model S-
61L helicopters; and Siller Helicopters Model CH-3E and SH-3A 
helicopters. This action revises the notice of proposed rulemaking 
(NPRM) by adding camshaft and gear housing part numbers that need to be 
marked and clarifying the applicability and certain compliance times. 
The FAA is proposing this airworthiness directive (AD) to address the 
unsafe condition on these products. Since these actions would impose an 
additional burden over that 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 October 30, 2006 (71 FR 63272), is reopened.
    The FAA must receive comments on this SNPRM by April 29, 2021.

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.

[[Page 14286]]

     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 SNPRM, contact your 
local Sikorsky Field Representative or Sikorsky's Service Engineering 
Group at Sikorsky Aircraft Corporation, 124 Quarry Road, Trumbull, CT 
06611; telephone 1-800-Winged-S; email wcs_cust_service_eng.gr-sik@lmco.com. Operators may also log on to the Sikorsky 360 website at 
https://www.sikorsky360.com. You may view this service information at 
the FAA, Office of the Regional Counsel, Southwest Region, 10101 
Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. For information on 
the availability of this material at the FAA, call 817-222-5110.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2006-
26107; 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: Isabel Saltzman, Aviation Safety 
Engineer, Boston ACO Branch, FAA, 1200 District Avenue, Burlington, MA 
01803; telephone 781-238-7649; email Isabel.L.Saltzman@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2006-26107; Project 
Identifier 2004-SW-30-AD'' at the beginning of your comments. The most 
helpful comments reference a specific portion of the proposal, explain 
the reason for any recommended change, and include supporting data. The 
FAA will consider all comments received by the closing date and may 
amend this proposal because of those comments.
    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 post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposal.

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 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 NPRM, 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 Isabel Saltzman, Aviation Safety Engineer, Boston ACO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; telephone 781-
238-7649; email Isabel.L.Saltzman@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 an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to all Sikorsky Aircraft Corporation Model S-61 A, D, E, 
and V helicopters; Croman Corporation Model SH-3H helicopters, Carson 
Helicopters, Inc. Model S-61L helicopters; and Siller Helicopters Model 
CH-3E and SH-3A helicopters. The NPRM published in the Federal Register 
on October 30, 2006 (71 FR 63272). The NPRM proposed to require 
creating a component history card or equivalent record and recording 
the hours time-in-service (TIS) and the external lift cycles (lift 
cycles) for each affected main gearbox input left and right freewheel 
unit (IFWU) assembly. The NPRM also proposed to require determining if 
the IFWU assembly is a repetitive external lift (REL) or non-REL IFWU 
assembly. The determination includes calculating a moving average of 
lift cycles per hour TIS at specified intervals on each IFWU assembly. 
For REL IFWU assemblies, the NPRM proposed to require repetitive 
inspections, which include visual and dimensional inspections, of the 
IFWU assembly for wear, surface distress, and endplay, recording 
certain information, and replacing affected parts with an airworthy 
part. In addition, the NPRM proposed to require permanently marking the 
REL IFWU camshafts and gear housings with the letters ``REL'' on the 
surface of these parts.
    The NPRM was prompted by an accident in which the left and right 
IFWU assembly on a helicopter slipped or disengaged, resulting in both 
engines overspeeding, engine shutdowns, and loss of engine power to the 
transmissions. The FAA is proposing this AD to address slipping of the 
main gearbox IFWU assembly, loss of engine power, and subsequent loss 
of control of the helicopter.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, the FAA determined that additional 
camshaft and gear housing part numbers need to be marked and the 
applicability and certain compliance times need clarification.

Comments

    The FAA gave the public the opportunity to participate in 
developing this proposed AD. The FAA has considered the comments 
received.

Request To Fix Typographical Errors

    Sikorsky Aircraft Corporation (Sikorsky) requested that the FAA fix 
two typographical errors. Sikorsky stated that in the third paragraph 
of the Discussion section in the NPRM, the citation for the alert 
service bulletin should read ``. . . 61B35-67B . . .'' (not ``61835-
67B''), and the citation for the all operators letter should read ``. . 
. CCS-61-AOL-04-0005'' (not ``CCS-61AOL-04-0005'').
    The FAA agrees with the request. The FAA has revised the citations 
accordingly.

Request To Revise Etching Language

    Sikorsky requested that the etching language in paragraph (d) of 
the proposed AD (in the NPRM) (referred to as paragraph (j) of this 
proposed AD (in the SNPRM)) be revised from ``After etching neutralize 
the etched surface with oil to prevent corrosion'' to the following: 
``After etching, neutralize the etched surface and oil to prevent 
corrosion.''
    The FAA agrees with the request. The FAA has also clarified the 
compliance time by specifying ``Before further flight and after 
etching, neutralize the etched surface and oil to prevent corrosion'' 
in paragraph (j) of this proposed AD.

[[Page 14287]]

Request To Add Camshaft and Gear Housing Part Numbers

    Sikorsky requested that the FAA add camshaft and gear housing part 
numbers to the ``Compliance'' section of the proposed AD. Sikorsky 
stated that additional IFWU camshaft part numbers 61350-24052 and 
61350-24072 have been delivered in military versions of the S-61 and 
should be included on the assumption that some of these aircraft have 
been or may become certificated. Sikorsky also stated that additional 
IFWU gear housing part numbers 61350-24051 and 61350-24068 have been 
delivered in military versions of the S-61 and should be included on 
the assumption that some of these aircraft have been or may become 
certificated.
    The FAA agrees. Paragraph (j) of this proposed AD has been revised 
accordingly.

Request To Require Installation of Redesigned IFWUs

    Croman Corporation stated a redesigned #2 IFWU could be installed 
in the commercial gear box with minimal modifications, mostly to the 
oil system. The FAA infers that the commenter is requesting that the 
proposed AD require installing redesigned #2 IFWUs in lieu of 
accomplishing the proposed actions (i.e., creating a component history 
card or equivalent record and recording the hours TIS and the lift 
cycles for each affected main gearbox IFWU assembly; determining if the 
IFWU assembly is a REL or non-REL assembly; for REL IFWU assemblies, 
repetitive inspections of the IFWU assembly for wear, surface distress, 
and endplay, recording certain information, and replacing affected 
parts; and permanently marking the REL IFWU camshafts and gear 
housings).
    The FAA does not concur. The FAA has determined that the proposed 
actions adequately address the identified unsafe condition. However, 
the FAA might consider additional rulemaking if sufficient data is 
submitted to substantiate requiring the replacement of the IFWUs in 
lieu of doing the proposed actions.

Clarification of the Model Designations

    The applicability of the proposed AD (in the NPRM) refers to Model 
S-61 A, D, E, V, SH-3H, S-61L; CH-3E, and SH-3A helicopters. The FAA 
has revised the applicability of this proposed AD (in the SNPRM) to 
refer to the model designations as specified in the most recent U.S. 
type certificate data sheet: Carson Helicopters, Inc., Model S-61L 
helicopters; Carson Helicopters, Inc., Model SH-3H helicopters; Croman 
Corporation Model SH-3H helicopters; Sikorsky Aircraft Corporation 
Model S-61A, S-61D, S-61E, and S-61V helicopters; Siller Helicopters 
Model CH-3E helicopters; and Siller Helicopters Model SH-3A 
helicopters.

Clarification of Certain Compliance Times

    The FAA has clarified the compliance times specified in paragraphs 
(g), (h)(1), (i)(1), and (j) of this proposed AD.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Sikorsky Aircraft Corporation Alert Service 
Bulletin 61B35-67B, Revision B, dated August 11, 2003. This service 
information describes, among other actions, procedures for inspections, 
which includes visual and dimensional inspections, of the IFWU assembly 
for wear, surface distress, and endplay, and for recording certain 
information. 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

    The FAA also reviewed Sikorsky Aircraft Corporation All Operators 
Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004. This service 
information provides an example and additional information about 
tracking cycles and the moving average procedure.
    The FAA also reviewed Sikorsky Aircraft S-61L/N Overhaul Manual, 
SA4045-83, Revision 20, dated August 15, 2003, as revised by Temporary 
Revisions 65-193, -194, -195, and -196, which contains the overhaul 
procedures for the IFWU assembly.

FAA's Determination

    The FAA is proposing this AD because the agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design. Certain changes described above expand the scope of the 
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 would require creating a component history card or 
equivalent record and recording the hours TIS and the lift cycles for 
each affected main gearbox IFWU assembly; determining if the IFWU 
assembly is a REL or non-REL assembly; for REL IFWU assemblies, 
repetitive inspections of the IFWU assembly for wear, surface distress, 
and endplay, recording certain information, and replacing affected 
parts; and permanently marking the REL IFWU camshafts and gear 
housings.

Differences Between This Proposed AD and the Service Information

    The effectivity of Sikorsky Aircraft Corporation Alert Service 
Bulletin 61B35-67B, Revision B, dated August 11, 2003, includes Model 
S-61 L, N, NM, and R helicopters. However, for those helicopters, the 
unsafe condition is addressed in AD 2007-01-05, Amendment 39-14876 (72 
FR 1139, January 10, 2007). Therefore, those helicopters are not 
included in the applicability of this proposed AD.
    Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B, 
Revision B, dated August 11, 2003, specifies contacting Sikorsky and 
providing information to Sikorsky. This proposed AD does not require 
you to contact Sikorsky or provide information to Sikorsky.

Costs of Compliance

    The FAA estimates that this proposed AD affects 55 helicopters of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Creating history card;            Up to 8 work-hours  Up to $1,975......  Up to $2,655......  Up to $146,025.
 determining type of IFWU          x $85 per hour =
 assembly; inspecting IFWU         $680.
 assemblies; recording
 information; replacing parts;
 and marking certain parts.
----------------------------------------------------------------------------------------------------------------

[[Page 14288]]

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 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 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) 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 proposes 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):

Carson Helicopters, Inc.; Croman Corporation; Sikorsky Aircraft 
Corporation; and Siller Helicopters: Docket No. FAA-2006-26107; 
Project Identifier 2004-SW-30-AD.

(a) Comments Due Date

    The FAA must receive comments by April 29, 2021.

(b) Affected Airworthiness Directives (ADs)

    None.

(c) Applicability

    This AD applies to all helicopters identified in paragraphs 
(c)(1) through (6) of this AD, certificated in any category 
including restricted.
    (1) Carson Helicopters, Inc., Model S-61L helicopters.
    (2) Carson Helicopters, Inc., Model SH-3H helicopters.
    (3) Croman Corporation Model SH-3H helicopters.
    (4) Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and 
S-61V helicopters.
    (5) Siller Helicopters Model CH-3E helicopters.
    (6) Siller Helicopters Model SH-3A helicopters.

 (d) Subject

    Joint Aircraft System Component (JASC) Code 6310, Engine/
Transmission Coupling.

(e) Unsafe Condition

    This AD was prompted by an accident in which the left and right 
input freewheel unit (IFWU) assembly on a helicopter slipped or 
disengaged, resulting in both engines overspeeding, engine 
shutdowns, and loss of engine power to the transmissions. The FAA is 
issuing this AD to address slipping of the main gearbox IFWU 
assembly, loss of engine power, and subsequent loss of control of 
the helicopter.

(f) Compliance

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

(g) Creation of History Card or Equivalent and Daily Actions

    Within 10 hours time-in-service (TIS) after the effective date 
of this AD, do the actions specified in paragraphs (g)(1) and (2) of 
this AD.
    (1) Create an external lift component history card or equivalent 
record for each IFWU assembly, part number (P/N) 61074-35000-041 
through 61074-35000-063 inclusive.
    (2) Count and, at the end of each day's operations, record the 
number of external lift cycles (lift cycles) performed and the hours 
TIS for each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive. A ``lift cycle'' is defined as the lifting of an 
external load and subsequent release of the load. Record the lift 
cycles and hours TIS on the external lift component history card or 
equivalent record.

(h) Determination of IFWU Assembly Type and Calculations

    (1) Upon reaching 250 hours TIS after the effective date of this 
AD on each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive, determine whether the IFWU assembly is a repetitive 
external lift (REL) or non-REL IFWU assembly by using a 250-hour TIS 
moving average. To perform the calculation, divide the total number 
of lift cycles performed during the first 250 hours TIS by 250. The 
result will be the first moving average calculation of lift cycles 
per hour TIS.
    (i) If the calculation specified in paragraph (h)(1) of this AD 
results in more than 6 lift cycles per hour TIS, the IFWU assembly 
is an REL IFWU assembly.
    (ii) If the calculation specified in paragraph (h)(1) of this AD 
results in 6 or less lift cycles per hour TIS, the IFWU assembly is 
a Non-REL IFWU assembly.
    (2) For each IFWU assembly determined to be a Non-REL IFWU 
assembly based on the first calculation of the 250-hour TIS moving 
average for lift cycles specified in paragraph (h)(1) of this AD: 
Within 50 hours TIS after the determination, and thereafter at 
intervals of 50 hours TIS, recalculate the average lift cycles per 
hour TIS to determine whether the IFWU assembly is an REL or non-REL 
IFWU assembly. To perform the calculation, subtract the total number 
of lift cycles performed during the first 50-hour TIS interval used 
in the previous moving average calculation from the total number of 
lift cycles performed on the IFWU assembly during the previous 300 
hours TIS. Divide this result by 250. The result will be the next or 
subsequent moving average calculation of lift cycles per hour TIS.
    (i) If any calculation specified in paragraph (h)(2) of this AD 
results in more than 6 lift cycles per hour TIS, the IFWU assembly 
is an REL IFWU assembly.
    (ii) If any calculation specified in paragraph (h)(2) of this AD 
results in 6 or less lift cycles per hour TIS, the IFWU assembly is 
a Non-REL IFWU assembly.

    Note 1 to paragraph (h)(2): Sikorsky Aircraft Corporation All 
Operators Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004, 
provides an example and additional information about tracking cycles 
and the moving average procedure.

    Note 2 to paragraph (h)(2):  The following is a sample 
calculation for subsequent 50 hour TIS intervals. Assume the total 
number of lift cycles for the first 50 hour TIS interval used in the 
previous moving average calculation = 450 lift cycles and the total 
number of lift cycles for the previous 300 hours TIS = 2,700 lift 
cycles. The subsequent moving average of lift cycles per hour TIS = 
(2,700-450) divided by 250 = 9 lift cycles per hour TIS.

    (3) Once an IFWU assembly is determined to be an REL IFWU 
assembly, it remains an REL IFWU assembly for the rest of its 
service life and is subject to the inspection for REL IFWU 
assemblies required by paragraph (i) of this AD.
    (4) Once an IFWU assembly is determined to be an REL IFWU 
assembly, you no longer need to perform the 250-hour TIS moving

[[Page 14289]]

average calculation required by paragraph (h)(2) of this AD, but you 
must continue to count and record the lift cycles as required by 
paragraph (g)(2) of this AD.

(i) Repetitive Inspections of REL IFWU Assemblies and Replacement

    For each REL IFWU assembly, as determined by paragraph (h)(1) or 
(2) of this AD:
    (1) Within 500 hours TIS or 7,500 lift cycles, whichever occurs 
first since the assembly was determined to be a REL IFWU assembly, 
and thereafter at intervals not to exceed 500 hours TIS or 7,500 
lift cycles, whichever occurs first, inspect for wear, surface 
distress, and endplay by following paragraphs B.(1) through B.(6) of 
the Accomplishment Instructions of Sikorsky Aircraft Corporation 
Alert Service Bulletin 61B35-67B, Revision B, dated August 11, 2003. 
Record all the information specified in Figures 1 through 3 of the 
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B, 
Revision B, dated August 11, 2003. You may record this information 
on any suitable maintenance record, or you may use the Sikorsky 
evaluation forms provided in Sikorsky Aircraft Corporation Alert 
Service Bulletin 61B35-67B, Revision B, dated August 11, 2003. This 
AD does not require you to contact Sikorsky or provide information 
to Sikorsky.
    (2) If during any inspection required by paragraph (i)(1) of 
this AD, any IFWU assembly part is found whose average wear, wear 
marks, surface distress, or endplay exceeds the limits specified in 
paragraphs B.(1) through B.(6) of the Accomplishment Instructions of 
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B, 
Revision B, dated August 11, 2003, before further flight, replace 
the affected part with an airworthy IFWU assembly part.

    Note 3 to paragraph (i)(2): Sikorsky Aircraft S-61L/N Overhaul 
Manual, SA4045-83, Revision 20, dated August 15, 2003, as revised by 
Temporary Revisions 65-193, -194, -195, and -196, contains the 
overhaul procedures for the IFWU assembly.

(j) Part Marking

    For each REL IFWU assembly, as determined by paragraph (h)(1) or 
(2) of this AD: Before further flight after the assembly was 
determined to be an REL IFWU assembly, permanently mark IFWU 
camshafts, P/N 61350-24052, 61350-24072, S6135-20611, S6135-20614 
and S6137-23075, and IFWU gear housings, P/N 61350-24051, 61350-
24068, S6135-20695, and S6137-23057, with the letters ``REL''. Mark 
the camshafts by applying etching ink on the surface of the part 
that is 0.5-inch square with the depth of the letters not to exceed 
0.001 inch. Before further flight and after etching, neutralize the 
etched surface and oil to prevent corrosion.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Strategic Policy Rotorcraft Section, 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 Strategic Policy Rotorcraft Section, 
send it to: Manager, Strategic Policy Rotorcraft Section, FAA, 10101 
Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110. 
Information may be emailed to: 9-ASW-FTW-AMOC-Requests@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(l) Related Information

    (1) For more information about this AD, contact Isabel Saltzman, 
Aviation Safety Engineer, Boston ACO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803; telephone 781-238-7649; email 
Isabel.L.Saltzman@faa.gov.
    (2) For service information identified in this AD, contact your 
local Sikorsky Field Representative or Sikorsky's Service 
Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road, 
Trumbull, CT 06611; telephone 1-800-Winged-S; email 
wcs_cust_service_eng.gr-sik@lmco.com. Operators may also log on to 
the Sikorsky 360 website at https://www.sikorsky360.com. You may 
view this service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort 
Worth, TX 76177. For information on the availability of this 
material at the FAA, call 817-222-5110.

    Issued on March 8, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-05150 Filed 3-12-21; 8:45 am]
BILLING CODE 4910-13-P