DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0826; Product Identifier 2016-SW-084-AD; Amendment
39-19153; AD 2018-01-12]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding Airworthiness Directive (AD) 2015-22-53 for
Airbus Helicopters Model AS350B3 helicopters. AD 2015-22-53 required
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 Helicopters developed a
modification of the ACCU TST switch. This new AD retains the
requirements of AD 2015-22-53 and requires modifying the yaw servo
hydraulic switch (collective switch) and replacing the ACCU TST button.
The actions of this AD are intended to address an unsafe condition on
these products.

DATES: This AD is effective February 20, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of February 20,
2018.

ADDRESSES: For Airbus Helicopters service information identified in
this final 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 view this referenced service
information at the FAA, Office of the Regional Counsel, Southwest
Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. It is
also available on the internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2017-0826.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.
gov in Docket No. FAA-2017-0826; or in person at the
Docket Management Facility between 9 a.m. and 5 p.m., Monday through
Friday, except Federal holidays. The AD docket contains this AD, the
European Aviation Safety Agency (EASA) AD, any incorporated-by-
reference information, the economic evaluation, any comments received,
and other information. The address for the Docket Office (phone: 800-
647-5527) is Document Management Facility, 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: 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:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to remove AD 2015-22-53, Amendment 39-18331 (80 FR 74982,
December 1, 2015) and add a new AD. AD 2015-22-53 applied to Airbus
Helicopters Model AS350B3 helicopters with a dual hydraulic system
installed. AD 2015-22-53 required 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.
The NPRM published in the Federal Register on September 8, 2017 (82
FR 42487). The NPRM was prompted by AD No. 2016-0220, dated November 4,
2016, issued by EASA, which is the Technical Agent for the Member
States of the European Union, to correct an unsafe condition for Airbus
Helicopters Model AS 350 B3 helicopters. EASA advises that further
analysis resulted in the recognition that a pilot could forget to
activate a switch despite the RFM changes and that altering the
bistable push button (push-on, push-off) ACCU TST switch is necessary.
Accordingly, the NPRM proposed to retain the requirements of AD
2015-22-53 and also proposed to require, within
350 hours time-in-service, installing a timer relay for the yaw servo
hydraulic switch, installing an additional light on the caution and
warning panel, and replacing the bistable ACCU TST button with a
monostable button. The proposed requirements were intended to prevent
takeoff without hydraulic pressure in the tail rotor (T/R) hydraulic
system, loss of T/R flight control, and subsequent loss of control of
the helicopter.

Comments

After our NPRM was published, we received comments from two
commenters.

Requests

The National Transportation Safety Board (NTSB) requested that the
AD address the need for an alert when there is insufficient pressure in
the T/R hydraulic system, which results in increased pedal loads. In
support of this request, the NTSB stated that, for at least four events
it investigated in which the yaw servo hydraulic switch was likely not
returned to its correct position before takeoff, a salient alert could
have cued the pilots of insufficient T/R hydraulic pressure.
We partially agree. We agree that an aural and visual alert to the
pilot to indicate loss of T/R hydraulic pressure would address this
unsafe condition. However, Airbus Helicopters has not developed an
alteration that provides such an alert. The FAA has determined the
requirements proposed by the NPRM are appropriate to address this
unsafe condition at this time. Should an aural and visual alert to the
pilot to indicate loss of T/R hydraulic pressure be developed and
approved, we might consider additional rulemaking at that time. We did
not change the AD based on this comment.
The NTSB also requested that we eliminate the requirement to move
the yaw load compensator check (ACCU TST switch) to post-flight
procedures instead of preflight procedures. In support of this request,
the NTSB stated that performing this check post-flight does not ensure
the yaw load compensator will remain functional for the next flight.
We disagree. We determined that requiring this check post-flight
with the RFM procedure to have the yaw servo hydraulic switch in the
``ON'' position before takeoff, along with the alterations to the yaw
servo hydraulic switch and replacement of the ACCU TST button, reduces
the risk of takeoff with the switch in the incorrect position to an
acceptable level. We did not change the AD based on this comment.
Eagle Copters requested we change the AD to address helicopters
that have replaced the factory console with a Geneva Aviation P122 or
P132 electrical console under Eagle Copters USA, Inc. Supplemental Type
Certificate No. SH4747NM. In support of this request, Eagle Copters
noted that operators of these helicopters will need to request an
Alternative Method of Compliance to comply with the AD, because the
Airbus Helicopters service information required for replacing the
bistable ACCU TST button does not apply to these helicopters. Eagle
Copters proposed adding a requirement to the AD to replace the HYD
TEST/ACCU TEST ESN-11 switch on the console from the locking bistable
toggle switch to a locking momentary (monostable) toggle switch part
number (P/N) MS24658-16F.
We agree. We revised the AD to require helicopters with a P122 or
P132 electrical console installed to replace the bistable ACCU TEST
switch (which may be marked ``HYD TEST'') with monostable toggle switch
P/N MS24658-16F.

FAA's Determination

We have reviewed the relevant information and determined that an
unsafe condition exists and is likely to exist or develop on other
helicopters of the same type design and that air safety and the public
interest require adopting the AD requirements as proposed with the
change previously described. This change is consistent with the intent
of the proposals in the NPRM and will not increase the economic burden
on any operator nor increase the scope of the AD.

Related Service Information Under 1 CFR Part 51

We reviewed Airbus Helicopters Service Bulletin (SB) No. AS350-
67.00.64, Revision 0, dated February 25, 2015. This service information
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
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. This service information 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 Helicopters SB No. AS350-67.00.66, Revision 1,
dated October 22, 2015. This service information 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 T/R
yaw load compensator check from preflight to post-flight. These pages
also revise terminology within the flight manuals for the different
engine configurations.

Costs of Compliance

We estimate that this AD affects 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 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 have determined that 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
Order 12866,
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska to the extent
that a regulatory, 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

Adoption of the Amendment

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