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Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Rules and Regulations more total hours time-in-service, whereas EASA AD 20170087 allows a longer compliance time for these affected M/R slip rings that are installed on Model AW189 helicopters. EASA
ADs 20170083 and 20170087 specify inspecting for the proper lock wire installed, while this AD specifies inspecting for correct installation of lock wire 0.20 CRES NAS 33540 P/N
MS20995C20 double-twist lock wire and any missing double-twist lock wire.
If a screw is missing from the inner diameter the connector flange of the upper end of the M/R slip ring, EASA
ADs 20170083 and 20170087 specify replacing the M/R slip ring with a serviceable part, whereas this AD
requires removing the M/R slip ring from service instead. If a screw is missing from the outer diameter of the upper end, from the inner diameter of the lower end shaft extension attachment area, or from the outer diameter of the lower end, this AD
requires installing a new screw and washer, applying torque, and installing lock wire, whereas corrective action for this condition is not specified in EASA
AD 20170083 or 20170087.

lotter on DSK11XQN23PROD with RULES1

Costs of Compliance The FAA estimates that this AD
affects 134 helicopters of U.S. Registry.
Labor rates are estimated at $85 per work-hour. Based on these numbers, the FAA estimates the following costs to comply with this AD.
Inspecting an M/R slip ring takes about 10 work-hours for an estimated cost of $850 per helicopter and $113,900
for the U.S. fleet. Marking an M/R slip ring takes a minimal amount of time and parts cost a nominal amount. Replacing an M/R slip ring takes about 3 workhours and parts cost about $65,000 for an estimated cost of $65,255 per helicopter. Removing any ferrule ended safety cable; replacing screws and washers; applying torque; and installing lock wire takes about 1 work-hour and parts cost a nominal amount for an estimated cost of $85 per helicopter.
Authority for This Rulemaking Title 49 of the United States Code specifies the FAAs 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 Agencys 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
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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 helicopters 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 39AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:

Authority: 49 U.S.C. 106g, 40113, 44701.
39.13

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

20211301 Leonardo S.p.a. Type Certificates Previously Held by Agusta S.p.A. and AgustaWestland S.p.A.:
Amendment 3921606; Docket No.
FAA20210304; Project Identifier 2017SW108AD.
a Effective Date This airworthiness directive AD is effective August 3, 2021.
b Affected ADs None.
c Applicability This AD applies to Leonardo S.p.a. Type Certificate previously held by Agusta S.p.A.

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Model AB139 and AW139 helicopters and Leonardo S.p.a. Type Certificate previously held by AgustaWestland S.p.A. Model AW189 helicopters, certificated in any category, with a main rotor M/R slip ring part number P/N 4G6220V00151 with a serial number S/N up to and including S/
N 0141, except those marked with an L
following the S/N, installed.
d Subject Joint Aircraft Service Component JASC
Code: 6200, Main Rotor System.
e Unsafe Condition This AD was prompted by reports of missing lock wire and loose fasteners. The FAA is issuing this AD to address failure of an M/R slip ring fastener. The unsafe condition, if not addressed, could result in failure of the M/R slip ring bearing inner race, reduced M/R control, and subsequent loss of control of the helicopter.
f Compliance Comply with this AD within the compliance times specified, unless already done.
g Required Actions 1 For an M/R slip ring that has accumulated 900 or more total hours time-inservice TIS, within 50 hours TIS after the effective date of this AD; and for an M/R slip ring that has accumulated less than 900 total hours TIS, within 300 hours TIS after the effective date of this AD or before accumulating 950 total hours TIS, whichever occurs first:
i With the M/R slip ring removed, visually inspect for the presence of each screw, the presence of any ferrule ended safety cable, the correct installation of lock wire 0.20 CRES NAS 33540 P/N
MS20995C20 double-twist lock wire, and any missing double-twist lock wire for each set of upper connecter end and lower pigtail or standpipe end fasteners of the M/R slip ring as depicted in Figures 1 and 2 of Annex A to Leonardo Helicopters Alert Service Bulletin ASB No. 139472, dated May 9, 2017 ASB 139472, or Leonardo Helicopters ASB No. 189138, dated May 12, 2017 ASB 189138, as applicable to your model helicopter. Figures 2 and 3 of Annex A to ASB 139472 and ASB 189138 also show examples of a ferrule ended safety cable installed that are not approved.
Note 1 to paragraph g1i: Annex A to ASB 139472 and ASB 189138 is Moog Service Bulletin SB 1601, Revision 5, undated.
ii If all of the screws are present, there is not any ferrule ended safety cable installed, the double-twist lock wire is correctly installed, and none of the double-twist lock wire is missing on each set of upper end and lower end fasteners of the M/R slip ring, before further flight, mark the letter L
following the S/N on the identification label by following the Compliance Instructions, paragraph 3 of Annex A to ASB 139472 or ASB 189138, as applicable to your model helicopter.
iii If a screw is missing from the inner diameter the connector flange of the upper
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