DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0826; Product Identifier 2016-SW-084-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 supersede airworthiness directive (AD) 2015-22-
53 for Airbus Helicopters (Airbus) Model AS350B3 helicopters. AD 2015-
22-53 requires revising the rotorcraft flight manual (RFM) to perform
the yaw load compensator check after rotor shut-down and to state that
the yaw servo hydraulic switch must be in the "ON" position before
taking off. Since we issued AD 2015-22-53, Airbus developed a
modification of the ACCU TST switch. This proposed AD would retain the
requirements of AD 2015-22-53 and require modifying the yaw servo
hydraulic switch (collective switch) and replacing the ACCU TST button.
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 November 7, 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-2017-0826;
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
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: George Schwab, Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110;
email george.schwab@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

On November 13, 2015, we issued AD 2015-22-53, Amendment 39-18331
(80 FR 74982, December 1, 2015), which was sent previously as an
emergency AD to all known U.S. owners and operators of Airbus
Helicopters Model AS350B3 helicopters. AD 2015-22-53 requires revising
the pre-flight and post-flight procedures in the RFM to perform the yaw
load compensator check (ACCU TST switch) after rotor shut-down instead
of during preflight procedures and to state that the yaw servo
hydraulic switch (collective switch) must be in the "ON" (forward)
position before taking off. AD 2015-22-53 was prompted by two accidents
and one incident of Model AS350B3 helicopters with a dual hydraulic
system installed, and which also prompted EASA, which is the Technical
Agent for the Member States of the European Union, to issue EASA AD No.
2015-0178, dated August 26, 2015. EASA advised these occurrences may
have resulted from improperly performing the T/R hydraulic preflight
check (a pilot forgetting to put the yaw servo hydraulic switch
(collective switch) in the "ON" position or put the ACCU TST switch
in the "OFF" position before flight)--and not from equipment failure.
According to EASA, these conditions significantly increase the control
load necessary to generate sufficient tail rotor thrust for take-off.

Actions Since AD 2015-22-53 Was Issued

Since we issued AD 2015-22-53, Airbus Helicopters issued SB No.
AS350-67.00.65, Revision 0, dated August 25, 2016, which specifies
procedures to alter the ACCU TST switch. Subsequently, EASA issued AD
No. 2016-0220, dated November 4, 2016. EASA advises that further
analysis of the incidents resulted in the recognition that a pilot
could forget to activate a switch despite the RFM changes and that the
modifications developed by Airbus Helicopters are necessary.
Accordingly, EASA AD No. 2016-0220 requires installing a caution
indication to the pilot when the yaw servo hydraulic switch (collective
switch) is in the "OFF" position, installing an additional indicator
light on the caution and warning panel, and replacing the bistable push
button (push-on, push-off) ACCU TST switch with a monostable push
button (push-on, timer-off) switch.

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 SB No. AS350-67.00.64, Revision 0,
dated February 25, 2015, which specifies procedures to install a timer
relay and an additional indicator light on the caution and warning
panel. This modification provides an "OFF" status indication of the
yaw servo hydraulic switch (collective switch) by flashing a newly
installed "HYD2" indicator light on the caution and warning panel.
Airbus Helicopters identifies performance of this SB as modification
074622. This modification was available when AD 2015-22-53 was issued;
however, it was determined unnecessary to address the unsafe condition
at that time.

We also reviewed Airbus Helicopters SB No. AS350-67.00.65, Revision
0, dated August 25, 2016, which specifies procedures to replace the
bistable push button ACCU TST switch with a monostable push button
switch. Airbus Helicopters identifies performance of this SB as
modification 074719.

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.

Other Related Service Information

We reviewed Airbus SB No. AS350-67.00.66, Revision 1, dated October
22, 2015, which specifies inserting specific pages of the SB into the
rotorcraft flight manual. These pages revise the preflight and post-
flight hydraulic checks by moving the tail rotor yaw load compensator
check from preflight to post-flight. These pages also revise
terminology within the flight manuals for the different engine
configurations.

Proposed AD Requirements

This proposed AD would retain the RFM revision that moves the yaw
load compensator check (ACCU TST switch) from preflight procedures to
post-flight procedures after rotor shut-down. This proposed AD would
also retain the RFM revision that requires the yaw servo hydraulic
switch (collective switch) to be in the "ON" (forward) position
before taking off.

Additionally, this proposed AD would require, within 350 hours
time-in-service, installing a timer relay for the yaw servo hydraulic
switch (collective switch) and installing an additional light on the
caution and warning panel. This proposed AD would also require
replacing the bistable ACCU TST button with a monostable button.

Costs of Compliance

We estimate that this proposed AD would affect 86 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.

Revising an RFM would take about 0.5 work-hour for a cost of $43
per helicopter and $3,698 for the U.S. fleet. Installing a timer relay
for the yaw servo hydraulic switch (collective switch) and an indicator
light would take about 9 work-hours and parts would cost about $2,224.
Replacing the ACCU TST button would take about 1 work-hour and parts
would cost about $2,244.

Based on these figures, we estimate a total cost of $5,361 per
helicopter and $461,046 for the U.S. fleet.

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 removing airworthiness directive (AD)
2015-22-53, Amendment 39-18331 (80 FR 74982, December 1, 2015), and
adding the following new AD: