Airworthiness Directives; Sikorsky Aircraft and Sikorsky Aircraft Corporation Helicopters

[Federal Register Volume 86, Number 62 (Friday, April 2, 2021)]
[Rules and Regulations]
[Pages 17283-17285]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-06779]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0920; Project Identifier AD-2020-00662-R; 
Amendment 39-21462; AD 2021-05-19]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft and Sikorsky Aircraft 
Corporation Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Sikorsky Aircraft Model S-61L, S-61N, S-61NM, and S-61R helicopters and 
Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and S-61V 
restricted category helicopters. This AD was prompted by the 
manufacturer determining that there may be arm assemblies in service 
that have accumulated 15,000 or more hours time-in-service (TIS), which 
exceeds the service life limit for this component. This AD requires 
reviewing the mixer unit component log card or equivalent record and, 
depending on the number of hours TIS, calculating the remaining life of 
the arm assembly or removing the arm assembly from service. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective May 7, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 7, 2021.

ADDRESSES: For service information identified in this final rule, 
contact your local Sikorsky Field Representative or Sikorsky's Service 
Engineering Group at Sikorsky Aircraft Corporation, Mailstop K100, 124 
Quarry Road, Trumbull, CT 06611; telephone 1-800-946-4337 (1-800-
Winged-S); email [email protected]. 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. It is also available at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2020-0920.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-0920; 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, any 
comments received, and other information. The address for Docket 
Operations 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: Isabel L. Saltzman, Aerospace 
Engineer, Boston ACO Branch, FAA, 1200 District Avenue, Burlington, MA 
01803; phone: (781) 238-7649; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to Sikorsky Aircraft Model 
S-61L, S-61N, S-61NM, and S-61R helicopters and Sikorsky Aircraft 
Corporation Model S-61A, S-61D, S-61E, and S-61V restricted category 
helicopters, with an arm assembly part number S6140-62614-009, 
installed. The NPRM published in the Federal Register on October 26, 
2020 (85 FR 67692). The FAA learned from Sikorsky Aircraft Corporation 
that Sikorsky S-61 Helicopter Alert Service Bulletin (ASB) 61B General-
1, Revision No. Z, dated November 13, 2018, which is applicable to 
Sikorsky Model S-61L, S-61N, S-61NM, and S-61R helicopters, failed to 
include the life limit of the redesigned arm assembly. As a result, 
Sikorsky Aircraft Corporation determined that there may be arm 
assemblies in service with 15,000 or more hours TIS, which exceeds the 
service life limit for this component. In the NPRM, the FAA proposed to 
require reviewing the mixer unit component log card or equivalent 
record and, depending on the hours TIS of the arm assembly, calculating 
the remaining life of the arm assembly or removing the arm assembly 
from service. The proposed actions are intended to prevent an arm 
assembly from remaining in service beyond its life limit. This 
condition, if not addressed, could result in reduced or loss of tail 
rotor control and reduced control of the helicopter.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    The FAA reviewed the relevant data and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. Except for 
the minor editorial changes of updating the contact information to 
obtain service information identified in this final rule and updating 
the contact information for the FAA, this AD is adopted as proposed in 
the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Sikorsky S-61 Helicopter ASB 61B40-11, Basic 
Issue, dated March 2, 2020. This service information describes 
procedures for a one-time inspection of the mixer unit component log 
card to verify the arm assembly life limit and, if the life limit has 
been exceeded, to replace the arm assembly for Sikorsky Model S-61L, S-
61N, and S-61NM helicopters.
    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 ADDRESSES.

[[Page 17284]]

Other Related Service Information

    The FAA also reviewed Sikorsky S-61 Helicopter ASB 61B General-1, 
Revision AA, dated February 24, 2020. This service information 
summarizes and lists parts with mandatory retirement times and 
inspections for Sikorsky Model S-61L, S-61N, and S-61NM helicopters.

Differences Between This AD and the Service Information

    The ASB is effective only for Sikorsky Aircraft Model S-61L, S-61N, 
and S-61NM helicopters. In addition to these helicopters, the 
applicability of this AD also includes Sikorsky Aircraft Model S-61R 
helicopters and Sikorsky Aircraft Corporation Model S-61A, S-61D, S-
61E, and S-61V restricted category helicopters. The FAA is expanding 
the applicability to prevent the installation of arm assemblies that 
have exceeded their life limits on helicopters with a similar type 
design as those helicopters affected by the ASB.

Costs of Compliance

    The FAA estimates that this AD affects 13 helicopters of U.S. 
Registry. Labor rates are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates that operators may incur the following 
costs in order to comply with this AD.
    Reviewing the mixer unit component log or equivalent record takes 
about 1 work-hour for an estimated cost of $85 per helicopter and 
$1,105 for the U.S. fleet. Adding the arm assembly entry and determine 
the remaining life takes about 1 work-hour for an estimated cost of $85 
per helicopter and $1,105 for the U.S. fleet. Replacing the arm 
assembly takes about 9 work-hours and parts cost about $5,035, for an 
estimated cost of $5,800 per arm assembly.
    According to the manufacturer, some of the costs of this AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. The FAA does not control warranty coverage by the 
manufacturer; accordingly, the FAA has included all costs in this 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.
    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

    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) 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

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


Sec.  39.13  [Amended]

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

2021-05-19 Sikorsky Aircraft and Sikorsky Aircraft Corporation: 
Amendment 39-21462; Docket No. FAA-2020-0920; Project Identifier AD-
2020-00662-R.

(a) Effective Date

    This airworthiness directive (AD) is effective May 7, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Sikorsky Aircraft Model S-61L, S-61N, S-61NM, 
and S-61R helicopters and Sikorsky Aircraft Corporation Model S-61A, 
S-61D, S-61E, and S-61V helicopters, certificated in any category 
including restricted, with an arm assembly part number S6140-62614-
009, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 6720, Tail Rotor 
Control System.

(e) Unsafe Condition

    This AD was prompted by the manufacturer determining that there 
may be arm assemblies in service with 15,000 or more hours time-in-
service (TIS), which exceeds the life limit for this component. The 
FAA is issuing this AD to prevent reduced or loss of tail rotor 
control. This unsafe condition, if not addressed, could result in 
reduced control of the helicopter.

(f) Compliance

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

(g) Required Action

    (1) Within 90 days after the effective date of this AD, review 
the mixer unit component log card or equivalent record to determine 
if the affected arm assembly is entered with the appropriate 15,000 
hours TIS life limit.
    (2) If the affected arm assembly is not included on the mixer 
unit component log card or equivalent record, within 90 days after 
the effective date of this AD, add the arm assembly entry to the 
mixer unit component log card or equivalent record and determine the 
remaining life of the arm assembly using the Accomplishment 
Instructions, Section 3.A.(3) of Sikorsky S-61 Helicopter Alert 
Service Bulletin (ASB) 61B40-11, Basic Issue, dated March 2, 2020 
(the ASB).
    (3) If, based on the review required by paragraphs (g)(1) and 
(2) of this AD, the arm assembly has accumulated 15,000 or more 
hours TIS, before further flight, remove the arm assembly from 
service. If the hours TIS for the affected arm assembly cannot be 
determined, before further flight, remove the affected arm assembly 
from service.
    (4) For arm assemblies that have not accumulated 15,000 or more 
hours TIS, thereafter, continue to determine the remaining life of 
the arm assembly and remove the arm assembly from service before it 
accumulates 15,000 hours TIS.

(h) Credit for Previous Actions

    You may take credit for adding the arm assembly entry to the 
mixer unit component log card or equivalent record and determining 
the remaining life of the arm assembly required by paragraphs (g)(1) 
and (2) of this AD if you performed these actions before the 
effective date of this AD using Sikorsky S-61 Helicopter ASB 61B 
General-1, Revision AA, dated February 24, 2020.

(i) Special Flight Permit

    Special flight permits, as described in Section 21.197 and 
Section 21.199 of the Federal Aviation Regulations (14 CFR 21.197

[[Page 17285]]

and 21.199), are subject to the requirements of paragraph (g)(3) of 
this AD. Operators who are prohibited from further flight due to 
exceeding the life limit in paragraph (g)(3) of this AD, may only 
perform a maintenance check or a one-time ferry flight to a location 
where the affected arm assembly can be removed from service. This 
ferry flight must be performed with only essential flight crew.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Boston ACO Branch, FAA, has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request 
to your principal inspector or local Flight Standards District 
Office, as appropriate. If sending information directly to the 
manager of the certification office, send it to the attention of the 
person identified in paragraph (k) of this AD.
    (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.

(k) Related Information

    For more information about this AD, contact Isabel Saltzman, 
Aerospace Engineer, Boston ACO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7649; email: 
[email protected].

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Sikorsky S-61 Helicopter Alert Service Bulletin 61B40-11, 
Basic Issue, dated March 2, 2020.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact your 
local Sikorsky Field Representative or Sikorsky's Service 
Engineering Group at Sikorsky Aircraft Corporation, Mailstop K100, 
124 Quarry Road, Trumbull, CT 06611; telephone 1-800-946-4337 (1-
800-Winged-S); email [email protected]. Operators 
may also log on to the Sikorsky 360 website at https://www.sikorsky360.com.
    (4) 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on March 1, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-06779 Filed 4-1-21; 8:45 am]
BILLING CODE 4910-13-P

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