DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0507; Project Identifier 2018-SW-117-AD; Amendment
39-21712; AD 2021-18-11]
Airworthiness Directives; Leonardo S.p.a. Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Leonardo S.p.a. Model AB139 and AW139 helicopters. This AD was
prompted by a report that, during a post-flight inspection of an in-
service helicopter, a tail rotor slider assembly was found fractured,
and the bushing and the actuator rod in the tail rotor servo were
partially damaged. This AD requires an inspection of the rail rotor
tail rotor slider assembly for corrosion and signs of circumferential
refinishing and, depending on the findings, replacement of the tail
rotor slider assembly with a serviceable part or repetitive inspections
of the tail rotor slider assembly for corrosion and signs of
circumferential refinishing, as specified in a European Aviation Safety
Agency (now European Union Aviation Safety Agency) (EASA) AD, which is
incorporated by reference. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective November 1, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 1,
ADDRESSES: For material incorporated by reference (IBR) in this
contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone
+49 221 8999 000; email ADs@easa.europa.eu; internet
www.easa.europa.eu. You may find this IBR material on the EASA website
at https://ad.easa.europa.eu. You may view this material 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
in the AD docket at https://www.regulations.gov by searching for and
locating Docket No. FAA-2021-0507.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0507; 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, the
mandatory continuing airworthiness information (MCAI), 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: Andrea Jimenez, Aerospace Engineer,
COS Program Management Section, Operational Safety Branch, Compliance
Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY
11590; telephone (516) 228-7330; email email@example.com. nyaco-cos
The EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2018-0292, dated December 28, 2018
(EASA AD 2018-0292) (also referred to as the MCAI), to correct an
unsafe condition for Leonardo S.p.a. (formerly Finmeccanica S.p.A,
AgustaWestland S.p.A., Agusta S.p.A.; AgustaWestland Philadelphia
Corporation, formerly Agusta Aerospace Corporation) Model AB139 and
AW139 helicopters, all serial numbers. Although EASA AD 2018-0292
applies to all Model AB139 and AW139 helicopters, this AD applies to
helicopters with an affected part installed instead.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Leonardo S.p.a.
Model AB139 and AW139 helicopters. The NPRM published in the Federal
Register on June 24, 2021 (86 FR 33149). The NPRM was prompted by a
report that, during a post-flight inspection of an in-service
helicopter, a tail rotor slide assembly was found fractured, and the
bushing and the actuator rod in the tail rotor servo were partially
damaged. The subsequent investigation revealed that the failure was due
to fatigue, initiated from corroded areas (corrosion craters) on the
surface of the tail rotor slider assembly characterized by signs of
circumferential refinishing. The corrosion craters originated along
finishing signs consistent with low grit sanding operations, which can
remove the passivation corrosion protection from the tail rotor slider
assembly. Sanding is a maintenance activity that is not included in the
maintenance manual for Leonardo S.p.a. Model AB139 and AW139
helicopters and is not allowed on in-service helicopters. The NPRM
proposed to require an inspection of the rail rotor tail rotor slider
assembly for corrosion and signs of circumferential refinishing and,
depending on the findings, replacement of the tail rotor slider
assembly with a serviceable part or repetitive inspections of the tail
rotor slider assembly for corrosion and signs of circumferential
refinishing, as specified in EASA AD 2018-0292.
The FAA is issuing this AD to address corrosion in the tail rotor
slider assembly caused by improper refinishing (characterized by signs
of circumferential refinishing consistent with sanding). The unsafe
condition, if not addressed, could result in fatigue crack and fracture
of the tail rotor slider assembly, resulting in failure of the tail
rotor controls and consequent loss of yaw control of the helicopter.
See EASA AD 2018-0292 for additional background information.
Discussion of Final Airworthiness Directive
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
The FAA reviewed the relevant data and determined that air safety
requires adopting this AD as proposed. Except for minor editorial
changes, this AD is adopted as proposed in the NPRM. None of the changes
will increase the economic burden on any operator. Accordingly, the FAA
issuing this AD to address the unsafe condition on these products.
Related Service Information Under 1 CFR Part 51
EASA AD 2018-0292 requires a detailed inspection of the tail rotor
slide assembly for corrosion and sign of circumferential refinishing
and, depending on the findings, applicable corrective actions. If there
is any evidence of corrosion craters the corrective action is
replacement of the affected part with a serviceable part. If there is
any evidence of surface imperfections caused by circumferential
refinishing but no evidence of corrosion, the corrective action is
repetitive inspections of the tail rotor slide assembly for corrosion
and signs of circumferential refinishing. Replacement of an affected
part with a serviceable part is terminating action for the repetitive
This material 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.
Costs of Compliance
The FAA estimates that this AD affects 129 helicopters of U.S.
Registry. The FAA estimates the following costs to comply with this AD.
||1 work-hour x $85 per hour =
The FAA estimates the following costs
to do any necessary
replacement that would be required based on the results of the
inspection. The agency has no way of determining the number of aircraft
that might need this replacement:
||Cost per product
||Up to 10 work-hours x $85 per
hour = $850
||Up to $24,050
||1 work-hour x $85 per hour =
$85 per inspection cycle
||$85 per inspection cycle
The FAA has included all known costs
in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this AD may be covered under warranty, thereby reducing the cost impact
on affected operators.
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.
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
(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
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness