DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0348; Project Identifier 2018-SW-076-AD]
RIN 2120-AA64

Airworthiness Directives; Leonardo S.p.a. (Type Certificate
Previously Held by Agusta S.p.A.) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2011-18-52 for certain Agusta S.p.A. (now Leonardo S.p.a.) Model AB139
and AW139 helicopters. AD 2011-18-52 requires revising the life limit
for certain part-numbered tail rotor (T/R) blades, updating the
helicopter's historical records, repetitively inspecting each T/R blade
for a crack or damage, and depending on the results, replacing the T/R
blade. Since the FAA issued AD 2011-18-52, the manufacturer developed im-
proved T/R blades using different materials and established life limits
for each improved blade. This proposed AD would retain certain require-
ments from AD 2011-18-52, revise certain requirements from AD 2011-18-52,
and expand the applicability to include the newly-designed T/R blades.
The actions of this proposed AD are intended to address an unsafe con-
dition on these products.

DATES: The FAA must receive comments on this proposed AD by June 24,
2021.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: (202) 493-2251.

Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.

Hand Delivery: Deliver to the "Mail" address between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Leonardo
S.p.a. Helicopters, Emanuele Bufano, Head of Airworthiness, Viale
G.Agusta 520, 21017 C.Costa di Samarate (Va) Italy; telephone +39-0331-
225074; fax +39-0331-229046; or at https://www.leonardocompany.com/en/
home. 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-2021-0348;
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 proposed AD, the European Aviation Safety Agency (now European
Union Aviation Safety Agency) (EASA) AD, any comments received and
other information. The street address for Docket Operations is listed
above.

FOR FURTHER INFORMATION CONTACT: Matt Fuller, AD Program Manager,
Operational Safety Branch, Airworthiness Products Section, General
Aviation & Rotorcraft Unit, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone (817) 222-5110; email Matthew.Fuller@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-2021-0348; Project Identifier
2018-SW-076-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 NPRM 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 NPRM. Submissions containing CBI should be sent to, Matt
Fuller, AD Program Manager, Operational Safety Branch, Airworthiness
Products Section, General Aviation & Rotorcraft Unit, FAA, 10101
Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email
Matthew.Fuller@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.

Background

The FAA issued Emergency AD 2011-18-52 on August 25, 2011, which
was published as a Final rule; request for comments, on April 18, 2012
(77 FR 23109) (AD 2011-18-52). AD 2011-18-52 applies to Agusta S.p.A.
(now Leonardo S.p.a.) Model AB139 and AW139 helicopters with a T/R
blade part number (P/N) 3G6410A00131 or P/N 4G6410A00131 installed. AD
2011-18-52 requires, within 5 hours time-in-service (TIS), establishing
a life limit of 600 hours TIS or 1,500 takeoff and landing cycles
(cycles), whichever occurs first, on the affected T/R blades and
updating the helicopter's historical records. If a T/R blade's total
number of cycles is unknown, determining the T/R blade cycles by
multiplying the T/R blade's hours TIS by 4 is required. For a T/R blade
that, on the effective date of the AD, has already exceeded 600 hours
TIS or 1,500 cycles, the AD requires replacing the T/R blade with an
airworthy T/R blade within 5 hours TIS.

AD 2011-18-52 also requires, within 25 hours TIS, and thereafter at
intervals not to exceed 25 hours TIS, inspecting the T/R blade for a
crack or damage that exceeds the limits of the applicable maintenance
manual. The inspection must be accomplished using a mirror, magnifying
glass (5X or greater), and light source; or borescope. If there is a
crack, or if there is damage that exceeds the limits of the applicable
maintenance manual, AD 2011-18-52 requires, before further flight,
replacing the T/R blade with an airworthy T/R blade.

AD 2011-18-52 was prompted by a fatal accident involving an Agusta
Model AW139 helicopter, which may have been caused by cracks in a T/R
blade. EASA, which is the Technical Agent for the Member States of the
European Union, issued EASA Emergency AD 2011-0156-E, dated August 25,
2011 (EASA AD 2011-0156-E) to require repetitive inspections and
reducing the life limit of the T/R blades. According to EASA, this
condition, if not detected and corrected, could result in failure of a
T/R blade and subsequent loss of control of the helicopter.

Actions Since AD 2011-18-52 Was Issued

Since the FAA issued AD 2011-18-52, EASA issued a series of ADs as
follows:

EASA AD 2012-0030, dated February 17, 2012 (EASA AD 2012-
0030), which superseded Emergency AD 2011-0156-E, advised that the
manufacturer developed improved, newly-designed T/R blades P/N
3G6410A00132 and P/N 4G6410A00132, established life limits for each
improved T/R blade, added repetitive inspections for the improved T/R
blades, and advised that each T/R blade P/N had its own individual life
limit.

EASA AD 2012-0076, dated May 2, 2012 (EASA AD 2012-0076),
which superseded EASA AD 2012-0030 and was issued after the
manufacturer developed another version of improved T/R blades P/N
3G6410A00133 and P/N 4G6410A00133 with different materials. AD 2012-
0076 required interim life limits for the new improved version of the
T/R blades while also retaining the inspection requirements of EASA AD
2012-0030.

EASA AD 2012-0076R1, dated July 13, 2012 (EASA AD 2012-
0076R1), which revised EASA AD 2012-0076 after a modification was
developed to allow installation of certain part-numbered T/R blades
under certain conditions.

EASA AD 2012-0076R2, dated February 20, 2014 (EASA AD
2012-0076R2), which revised EASA AD 2012-0076R1, was issued after
another modification was developed. EASA AD 2012-0076R2 requires
removing the 25 hours TIS inspection of certain part-numbered T/R
blades, extending the life limit of certain part-numbered T/R blades,
retaining the repetitive inspections of certain part-numbered T/R
blades and depending on the inspection results, performing certain
applicable corrections.

Also, after AD 2011-18-52 was issued, the FAA issued an NPRM (78 FR
54596), which published in the Federal Register on September 5, 2013.
The NPRM proposed to require retaining the inspection requirements for
certain part-numbered blades and expand the applicability to include
the newly designed blades and establish life limits for those blades.
The NPRM also proposed to require replacing any cracked blade or any
blade that has reached its life limit. That NPRM was prompted by
improved modifications of the T/R blades. However, because the FAA
determined that the NPRM does not adequately address the identified
unsafe condition, the NPRM was withdrawn on February 25, 2021 (86 FR
11477).

Additional review also revealed necessary changes to address the
unsafe condition. This proposed AD clarifies the repetitive inspection
for T/R blade P/Ns 3G6410A00131 and P/N 4G6410A00131 from, "visually
inspect the T/R blade for a crack or damage" to "visually inspect the
T/R blade for a crack and damage." This proposed AD further revises
that repetitive inspection from "damage that exceeds the limits of the
applicable maintenance manual" to "damage that exceeds allowable
limits" to meet current publishing requirements. This proposed AD
clarifies the inspection area for that repetitive inspection by
proposing to require using a figure in the related service information
instead of using a figure in the body of this AD action. This proposed
AD also revises the requirements by removing unnecessary information,
including the special flight permits paragraph.

FAA's Determination

These helicopters have been approved by EASA and are approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Union, EASA has notified the FAA of the
unsafe condition described in its AD. The FAA is proposing this AD
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.

Related Service Information Under 1 CFR Part 51

The FAA reviewed AgustaWestland S.p.A Mandatory Bollettino Tecnico
No. 139-265, Revision B, dated February 18, 2014. This service
information specifies a precautionary inspection for a crack, a life
limit for the affected T/R blades, and a quarantine of T/R blades that
have exceeded their life limit. This service information also provides
instructions for mixed usage of the affected T/R blades and sending
certain data to the manufacturer.

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.

Proposed AD Requirements

This proposed AD would retain the inspection requirements of AD
2011-18-52 for certain part-numbered T/R blades, expand the
applicability to include the improved T/R blades, require determining
each T/R blade's total hours TIS or landing cycles, and establish life
limits for certain T/R blades. This proposed AD would require removing
from service any T/R blade that has a crack or damage beyond allowable
limits or any T/R blade that has reached its life limit.

Differences Between This Proposed AD and EASA AD

The EASA AD does not list the T/R blade life limits and instead
references the Airworthiness Limitations Section of 139 AMPI Chapter 4,
while this proposed AD would include the life limits in the AD. The
EASA AD requires reporting information to Product Support Engineering,
whereas this proposed AD would not. The EASA AD requires contacting
AgustaWestland if a crack or damage is found during the inspection,
whereas this proposed AD would require removing the T/R blade from
service.

Costs of Compliance

The FAA estimates that this proposed AD would affect 130 helicopters
of U.S. Registry. The FAA estimates that operators may incur the
following costs in order to comply with this proposed AD.
Labor costs are estimated at $85 per work-hour.

Inspecting one T/R blade for a crack would take about 1 work-hour
for an estimated cost of $85 per T/R blade per inspection cycle and up
to $44,200 for the U.S. fleet per inspection cycle.

Replacing one T/R blade would take about 8 work-hours and parts
would cost about $40,560 for an estimated cost of $41,240 per
replacement.

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, I certify this proposed regulation:

1. Is not a "significant regulatory action" under Executive Order
12866,

2. Would not affect intrastate aviation in Alaska, and

3. Would 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

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:

a. Removing Airworthiness Directive 2011-18-52, Amendment 39-17020 (77
FR 23109, April 18, 2012); and

b. Adding the following new airworthiness directive: