DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0103; Product Identifier 2016-SW-086-AD]
RIN 2120-AA64

Airworthiness Directives; Agusta S.p.A. Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for
Agusta S.p.A. Model AB139 and Model AW139 helicopters. This proposed AD
would require inspecting the thickness of the tail gearbox (TGB)
central housing (housing). This proposed AD is prompted by reports that
the housing thickness does not conform to its type design. The actions
of this proposed AD are intended to detect and correct an unsafe
condition on these products.

DATES: We must receive comments on this proposed AD by November 21,
2017.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to http://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.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2017-
0103; or in person at the Docket Operations Office 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 (EASA)
AD, the economic evaluation, any comments received, and other
information. The street address for the Docket Operations Office
(telephone 800-647-5527) is in the ADDRESSES section. Comments will be
available in the AD docket shortly after receipt.

For service information identified in this proposed rule, contact
Leonardo S.p.A., Matteo Ragazzi, Head of Airworthiness, Viale G.Agusta
520, 21017 C.Costa di Samarate (Va) Italy; telephone +39-0331-711756;
fax +39-0331-229046; or at http://www.leonardocompany.com/-/bulletins.
You may review the referenced service information at the FAA, Office of
the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-
321, Fort Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: Matt Fuller, Senior Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy, Fort Worth, TX 76177; telephone (817) 222-5110;
email matthew.fuller@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to participate in this rulemaking by submitting
written comments, data, or views. We also invite comments relating to
the economic, environmental, energy, or federalism impacts that might
result from adopting the proposals in this document. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. To
ensure the docket does not contain duplicate comments, commenters
should send only one copy of written comments, or if comments are filed
electronically, commenters should submit only one time.
We will file in the docket all comments that we receive, as well as
a report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal, we
will consider all comments we receive on or before the closing date for
comments. We will consider comments filed after the comment period has
closed if it is possible to do so without incurring expense or delay.
We may change this proposal in light of the comments we receive.

Discussion

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD No. 2016-0246, dated December 13,
2016, to correct an unsafe condition for Leonardo S.p.A. (formerly
Finmeccanica S.p.A. and Agusta S.p.A.) Model AB139 and Model AW139
helicopters.
EASA advises that the thickness of some sections of the housing do
not conform to the type design. According to EASA, this condition, if
not detected and corrected, could lead to premature cracks in the
housing, resulting in failure of the tail gear rotor transmission and
reduced control of the helicopter. The EASA AD consequently requires a
one-time inspection to determine the thickness of the housing wall, and
depending on the findings, replacing the housing or TGB assembly with
an airworthy part.
The FAA is in the process of updating Agusta S.p.A.'s name change
to Leonardo S.p.A. on its FAA type certificate. Because this name
change is not yet effective, this AD specifies Agusta S.p.A. as the
type certificate holder.

FAA's Determination

These helicopters have been approved by the aviation authority of
Italy and are approved for operation in the United States. Pursuant to
our bilateral agreement with Italy, EASA, its technical representative,
has notified us of the unsafe condition described in its AD. We are
proposing this AD because we evaluated all known relevant information
and determined that an unsafe condition is likely to exist or develop
on other products of the same type design.

Related Service Information Under 1 CFR Part 51

We reviewed Leonardo Bollettino Tecnico No. 139-274, dated
September 14, 2016 (BT 139-274), which specifies procedures for a
dimensional check of the housing or TGB to determine the thickness of
the housing wall. For housings with fewer than 7,500 flight hours, BT
139-274 specifies compliance with the dimensional check by measurement
during the next repair or overhaul, and replacing the housing if it
does not meet its thickness requirement. For housings with 7,500 or
more flight hours, BT 139-274 specifies compliance with the dimensional
check by ultrasonic inspection within 300 flight hours, and replacing
the TGB if it does not meet its thickness requirement. BT 139-274
excludes certain serial-numbered housings from the applicability
because they were inspected before delivery to customers.
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 require the following:
If a housing has fewer than 7,500 hours time-in-service
(TIS), before reaching 7,500 hours TIS, inspecting the housing wall to
determine the thickness and replacing the housing if the thickness is
less than 2.65 mm (0.104 inch).
If a housing has 7,500 or more hours TIS, within 300 hours
TIS, ultrasonic inspecting the TGB to determine the thickness and
replacing the TGB if the thickness is less than 2.65 mm (0.104 inch).

Differences Between This Proposed AD and the EASA AD

If a housing has fewer than 7,500 hours TIS, the EASA AD requires a
dimensional inspection of the housing wall at a helicopter's first
return to a shop or service station for a TGB overhaul or repair after
the EASA AD's effective date but no later than 7,500 hours TIS. This
proposed AD would require such an inspection only before reaching 7,500
hours TIS.

Costs of Compliance

We estimate that this proposed AD would affect 103 helicopters of
U.S. Registry and that labor costs average $85 per work-hour. Based on
these estimates, we expect the following costs:
Measuring the thickness of the housing would require .5
work-hour and no parts would be needed for a cost of $43 per
helicopter.
Ultrasonic inspecting the thickness of the housing would
require 2 work-hours and no parts would be needed for a cost of $170
per helicopter.
Replacing the TGB housing would require 5 work-hours, and
parts would cost $11,185 for a cost of $11,610 per helicopter.

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.
We are 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

We 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. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979);
3. Will not affect intrastate aviation in Alaska to the extent that
it justifies making a regulatory distinction; and
4. 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.
We prepared an economic evaluation of the estimated costs to comply
with this proposed AD and placed it in the AD docket.

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 adding the following new airworthiness
directive (AD):