DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0384; Product Identifier 2017-SW-061-AD]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-
365N1, and SA-366G1 helicopters. This proposed AD would require
repetitive inspections of the aft fuselage outer skin. This proposed AD
is prompted by several reports of aft fuselage outer skin disbonding.
The actions of this proposed AD are intended to address an unsafe
condition on these products.

DATES: We must receive comments on this proposed AD by July 9, 2018.

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-2018-
0384; 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 (EASA) AD, the
economic evaluation, any comments received, and other information. The
street address for Docket Operations (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
Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052;
telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at
http://www.helicopters.airbus.com/website/en/ref/Technical-Support_73.
html. 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. 2017-0165, dated September 5,
2017 (EASA AD 2017-0165), to correct an unsafe condition for Airbus
Helicopters Model SA 365 N1, AS 365 N2, AS 365 N3, SA 366 G1, EC 155 B
and EC 155 B1 helicopters. EASA advises of several reports of aft
fuselage (baggage compartment area) outer skin disbonding found during
a 600-hour inspection. EASA advises that most of the reports of
disbonding occurred on Model EC 155 helicopters and may occur in the
same area on Model AS 365, SA 365, and SA 366 helicopters due to design
similarity. According to EASA, the cause of the disbonding has not yet
been determined and the investigation is continuing. Airbus Helicopters
states possible causes that are being considered include exhaust gas
heat from the exhaust pipes and environmental conditions. EASA states
that this condition, if not detected and corrected, could reduce the
structural integrity of the aft fuselage, possibly affecting safe
flight and landing.

To address this unsafe condition, EASA AD 2017-0165 requires a
repetitive tap inspection of the aft fuselage outer skin for
disbonding, a repetitive visual inspection of the aft fuselage outer
skin for distortion, wrinkling, and corrosion, and contacting Airbus
Helicopters if there is any disbonding.

FAA's Determination

These helicopters have been approved by the aviation authority of
France and are approved for operation in the United States. Pursuant to
our bilateral agreement with France, 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 Airbus Helicopters Alert Service Bulletin (ASB) No.
AS365-05.00.77 for Model AS365 N, N1, N2, and N3 and non-FAA-
certificated Model AS365 F, Fs, Fi, K, and K2 helicopters; ASB No.
SA366-05.48 for Model SA366 G1 and non-FAA-certificated Model SA366 GA
helicopters; and ASB No. EC155-05A033 for Model EC155 B and B1
helicopters, all Revision 0 and all dated July 21, 2017. This service
information specifies repetitive tap and visual inspections between aft
fuselage outer skin frames X4630 and X6630 and defines the allowable
limit of disbonding for this area. If there is distortion, wrinkling,
or corrosion, this service information specifies performing a tap
inspection. If there is disbonding within the allowable limit, this
service information specifies reporting the inspection results to
Airbus Helicopters and performing the recurring tap inspection at a
shorter compliance time interval. If there is disbonding that exceeds
the allowable limit, this service information specifies contacting
Airbus Helicopters for repair before further flight.

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, within 110 hours time-in-service
(TIS), a tap inspection of the aft fuselage outer skin for disbonding.
If there is no disbonding, repeating the tap inspection at intervals
not to exceed 660 hours TIS would be required. If there is disbonding,
either repeating the tap inspections at intervals not to exceed 110
hours TIS or repairing or replacing the panel before further flight and
then tap inspecting the panel at intervals not to exceed 660 hours TIS
would be required. This proposed AD would also require, within 220
hours TIS and thereafter at intervals not to exceed 110 hours TIS,
cleaning the aft fuselage outer skin and visually inspecting for
distortion, wrinkling, and corrosion. If there is any distortion,
wrinkling, or corrosion, tap inspecting the area for disbonding would
be required before further flight.

Differences Between This Proposed AD and the EASA AD

If there is disbonding within the allowable limit, the EASA AD
specifies reporting the inspection results to Airbus Helicopters,
whereas this proposed AD would not. If there is disbonding that exceeds
the allowable limit, the EASA AD specifies contacting Airbus
Helicopters for approved skin panel repair or replacement instructions,
whereas this proposed AD would require repairing or replacing the panel
instead.

Interim Action

We consider this proposed AD to be an interim action. If final
action is later identified, we might consider further rulemaking then.

Costs of Compliance

We estimate that this proposed AD would affect 46 helicopters of
U.S. Registry. We estimate that operators may incur the following costs
in order to comply with this AD. Labor costs are estimated at $85 per
work-hour.

Tap inspecting the aft fuselage outer skin would take about 3 work-
hours for an estimated cost of $255 per helicopter and $11,730 for the
U.S. fleet per inspection cycle. Visually inspecting the aft fuselage
outer skin would take about 0.3 work-hour for an estimated cost of $26
per helicopter and $1,196 for the U.S. fleet per inspection cycle.
Repairing a panel would take about 5 work-hours and parts would cost
about $500 for an estimated cost of $925. Replacing a panel would take
about 10 work-hours and parts would cost about $20,000 for an estimated
cost of $20,850.

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):