Airworthiness Directives; Airbus Helicopters

[Federal Register Volume 86, Number 36 (Thursday, February 25, 2021)]
[Rules and Regulations]
[Pages 11419-11421]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-03657]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0907; Product Identifier 2017-SW-072-AD; Amendment 
39-21429; AD 2021-04-08]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Airbus Helicopters Model AS350B3 helicopters. This AD requires 
modifying the electrical system of the throttle twist grip, inspecting 
the routing of a microswitch electrical harness, and correcting the 
electrical harness routing if it is incorrect. This AD was prompted by 
reports of the engine remaining in idle when the twist grip was turned 
from the ``forced idle'' position to the ``flight'' position. The 
actions of this AD are intended to address an unsafe condition on these 
products.

DATES: This AD is effective April 1, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain document listed in this AD as of April 1, 2021.

ADDRESSES: For 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 
https://www.airbus.com/helicopters/services/technical-support.html. You 
may view the 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0907.

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-2020-
0907; 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 AD, the European Aviation Safety Agency (now European Union 
Aviation Safety Agency) (EASA) AD, any service information that is 
incorporated by reference, any comments received, and other 
information. The street address for Docket Operations is 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: Ronnea Derby, Aviation Safety 
Engineer, Denver ACO Branch, FAA, 26805 E 68th Ave., Denver, CO 80249; 
telephone 303-342-1093; email [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to Airbus Helicopters 
Model AS350B3 helicopters with a Turbomeca ARRIEL 2B engine installed. 
The NPRM published in the Federal Register on October 15, 2020 (85 FR 
65285). The NPRM proposed to require, based on helicopter 
configuration, modifying the electrical system of the throttle twist 
grip. The proposed AD also proposed to require inspecting the routing 
of a microswitch electrical harness, and depending on the routing of 
that electrical harness, correcting the routing. The proposed 
requirements were intended to prevent failure of the electrical 
operation of the throttle twist grip, which can prevent switching from 
``IDLE'' mode to ``FLIGHT'' mode. During autorotation training or 
during governor failure training (when the throttle grip is turned in 
the low flow direction), this condition prohibits recovery from a 
practice autorotation and compels the pilot to continue the 
autorotation to the ground. This condition could result in unintended 
touchdown to the ground at a flight-idle power setting, damage to the 
helicopter, and injury to occupants.
    The NPRM was prompted by EASA AD No. 2017-0035, dated February 20, 
2017 (EASA AD 2017-0035), to correct an unsafe condition for Airbus 
Helicopters (formerly Eurocopter) Model AS 350 B3 helicopters with 
ARRIEL 2B engines installed. EASA advises of an initial report of the 
microswitch pin jammed in the pushed-in position resulting in the 
engine remaining in idle when the twist grip had been turned back to 
the ``flight'' position during an autorotation training exercise. This 
condition could also occur during governor failure training when the 
twist grip is turned in the low flow rate direction. EASA also advises 
of two later reports of this condition, with one of those reports 
related to an incorrectly routed electrical harness. EASA advises that 
this condition, if not detected and corrected, could lead to reduced 
control of the helicopter.
    EASA initially issued AD No. 2006-0094, dated April 21, 2006, which 
required repetitive testing of the microswitch and established a life 
limit for the microswitch. Subsequent EASA AD action required reducing 
that life limit, inspecting the travel of the collective lever, 
performing an additional check of the collective lever for free travel, 
and installing a terminating action modification that was available for 
certain helicopter configurations. That modification gave priority to 
the HydroMechanical Unit (HMU) flight position when the microswitch 
failed to operate correctly at forced idle. EASA most recently issued 
AD 2017-0035, which prompted this AD action, to include all of the 
previous AD requirements and expand the terminating action modification 
to other helicopter configurations.

[[Page 11420]]

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule, but the FAA did not receive any comments on 
the NPRM or on the determination of the cost to the public.

FAA's Determination

    This helicopter has been approved by EASA and is 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 issuing this AD after 
evaluating all of the information provided by EASA and determining the 
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, except for a 
minor editorial change. The FAA has determined that this minor 
editorial change is consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition and does not add any 
additional burden upon the public than was already proposed in the 
NPRM.

Differences Between This AD and the EASA AD

    The EASA AD specifies a repetitive test of the microswitch, a life 
limit for the microswitch, and inspecting the travel of the collective 
lever, until the terminating action of modifying the electrical system 
of the throttle twist grip and inspecting the routing of a microswitch 
electrical harness are completed. This AD only requires modifying the 
electrical system of the throttle twist grip and inspecting the routing 
of a microswitch electrical harness. The EASA AD specifies performing 
that terminating action in a compliance time of calendar months. This 
AD requires performing the required actions before the next practice 
autorotation, before the next simulated governor failure, or within 330 
hours time-in service, whichever occurs first.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB) 
No. AS350-67.00.43, Revision 3, dated June 16, 2016, which specifies 
procedures, based on different configurations, to modify the electrical 
operation to give priority to the HMU flight position when the 
microswitch does not operate correctly at forced idle (corresponds to 
Airbus Helicopters Modification (MOD) 073357). This service information 
also specifies instructions to inspect the routing of microswitch 
electrical harness number ``53K''.
    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

    The FAA also reviewed Eurocopter ASB No. 05.00.49, Revision 3, 
dated March 8, 2012. This service information specifies procedures, for 
helicopters without MOD 073357 installed, for repetitive testing of the 
microswitch, a life limit for the microswitch, inspecting the travel of 
the collective lever, and verifying correct wiring harness 
installation.

Costs of Compliance

    The FAA estimates that this AD affects 517 helicopters of U.S. 
Registry. The FAA estimates that operators may incur the following 
costs in order to comply with this AD. Labor costs are estimated at $85 
per work-hour. Modifying the electrical system and inspecting the 
electrical harness routing takes about 30 work-hours and parts will 
cost about $9,692 for an estimated cost of $12,242 per helicopter and 
$6,329,114 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.
    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 helicopters identified in this rulemaking action.

Regulatory Findings

    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) Will not affect intrastate aviation in Alaska, and
    (3) 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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2021-04-08 Airbus Helicopters: Amendment 39-21429; Docket No. FAA-
2020-0907; Product Identifier 2017-SW-072-AD.

(a) Applicability

    This airworthiness directive (AD) applies to Airbus Helicopters 
Model AS350B3 helicopters, certificated in any category, with a 
Turbomeca ARRIEL 2B engine installed.

(b) Unsafe Condition

    This AD defines the unsafe condition as failure of the 
electrical operation of the throttle twist grip, which can prevent 
switching from ``IDLE'' mode to ``FLIGHT'' mode. During autorotation 
training or during governor failure training (when the throttle grip 
is turned in the low flow direction), this condition prohibits 
recovery from a practice autorotation and compels the pilot to 
continue the autorotation to the ground. This condition could result 
in unintended touchdown to the ground at a flight-idle power 
setting, damage to the helicopter, and injury to occupants.

(c) Effective Date

    This AD becomes effective April 1, 2021.

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    Before the next practice autorotation, before the next simulated 
governor failure, or

[[Page 11421]]

within 330 hours time-in-service, whichever occurs first, modify the 
electrical operation of the throttle twist grip to give priority to 
the HydroMechanical Unit flight position when the microswitch does 
not operate correctly at forced idle (corresponds to Airbus 
Helicopters Modification (MOD) 073357) as follows:
    (1) For helicopters without MOD 073087 and without MOD 073135 
installed:
    (i) Install box ``69K'' on the Full Authority Digital Engine 
Control plate, relay ``81K'' on frame X1310, install fuses on the 
console end comprising circuit-breaker panels ``31 ALPHA'' and ``32 
ALPHA,'' and modify the electrical wiring by following the 
Accomplishment Instructions, paragraph 3.B.2.a. of Airbus 
Helicopters Alert Service Bulletin No. AS350-67.00.43, Revision 3, 
dated June 16, 2016 (ASB AS350-67.00.43), except you are not 
required to discard parts.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following paragraph 3.B.2.e. of 
ASB AS350-67.00.43. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.
    (2) For helicopters with MOD 073087 (series) and without MOD 
073135 installed:
    (i) Install relays ``54K'' and ``81K'' on frame X1310 and modify 
the electrical wiring by following paragraph 3.B.2.b. of ASB AS350-
67.00.43.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following paragraph 3.B.2.e. of 
ASB AS350-67.00.43. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.
    (3) For helicopters with MOD 073087 (retrofit) and without MOD 
073135 installed:
    (i) Install relay ``81K'' on frame X1310 and modify the 
electrical wiring by following paragraph 3.B.2.c. of ASB AS350-
67.00.43.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following paragraph 3.B.2.e. of 
ASB AS350-67.00.43. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.
    (4) For helicopters with MOD 073087 and with MOD 073135 
installed:
    (i) Install relay ``81K'' on frame X1310 and modify the 
electrical wiring by following paragraph 3.B.2.d. of ASB AS350-
67.00.43.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following paragraph 3.B.2.e. of 
ASB AS350-67.00.43. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.
    (5) For helicopters with MOD 073084 and with MOD 073222 
installed:
    (i) Install relay ``81K'' on frame X1310 and modify the 
electrical wiring by following paragraph 3.B.2.g. of ASB AS350-
67.00.43, except you are not required to scrap parts.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following paragraph 3.B.2.e. of 
ASB AS350-67.00.43. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.
    (6) For helicopters with optional Autopilot ``81K'' and without 
MOD 073222 installed:
    (i) Position relay ``81K'' on frame X1310 by following paragraph 
3.B.2.h. of ASB AS350-67.00.43.
    (ii) Inspect the routing of microswitch electrical harness 
``53K'' for correct installation by following ASB AS350- 67.00.43, 
paragraph 3.B.2.e. If the wiring routing is incorrect, before 
further flight, correct the wiring routing by following paragraph 
3.B.2.f. of ASB AS350-67.00.43.

(f) Special Flight Permits

    Special flight permits are prohibited.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Strategic Policy Rotorcraft Section, FAA, has 
the authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the Strategic Policy Rotorcraft Section, 
send it to: Manager, Strategic Policy Rotorcraft Section, FAA, 10101 
Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email 
[email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(h) Additional Information

    (1) Eurocopter Alert Service Bulletin No. 05.00.49, Revision 3, 
dated March 8, 2012, which is not incorporated by reference, 
contains additional information about the subject of this AD. For 
service information identified in this AD, 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 https://www.airbus.com/helicopters/services/technical-support.html. You may 
view the referenced service information at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-
321, Fort Worth, TX 76177.
    (2) The subject of this AD is addressed in European Aviation 
Safety Agency (now European Union Aviation Safety Agency) (EASA) AD 
No. 2017-0035, dated February 20, 2017. You may view the EASA AD on 
the internet at https://www.regulations.gov in the AD Docket.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 7697, Engine 
Control System Wiring.

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Airbus Helicopters Alert Service Bulletin No. AS350-
67.00.43, Revision 3, dated June 16, 2016.
    (ii) [Reserved]
    (3) For service information identified in this AD, Airbus 
Helicopters, 2701 N Forum Drive, Grand Prairie, TX 75052; telephone 
972-641-0000 or 800-232-0323; fax 972-641-3775; or at https://www.airbus.com/helicopters/services/technical-support.html.
    (4) 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on February 4, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-03657 Filed 2-24-21; 8:45 am]
BILLING CODE 4910-13-P

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