Document ID: FAA-2017-1036-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Airbus Helicopters
Posted Date: 2020-08-07T04:00Z

[Federal Register Volume 85, Number 153 (Friday, August 7, 2020)]
[Proposed Rules]
[Pages 47925-47928]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-17271]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-1036; Product Identifier 2018-SW-015-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: The FAA proposes to adopt a new airworthiness directive (AD) 
for Airbus Helicopters Model AS-365N2, AS 365 N3, SA-365N, SA-365N1 
helicopters. This proposed AD would require replacing the main gearbox 
(MGB), or as an alternative, replacing the epicyclic reduction gear 
module for certain serial numbered planet gear assemblies installed on 
the MGB. This proposed AD would also require inspecting the MGB 
magnetic plugs and oil filter for particles. Depending on the outcome 
of the inspections, this proposed AD would require further inspections, 
and replacing certain parts. This proposed AD is prompted by the 
failure of an MGB second stage planet gear. The actions of this 
proposed AD are intended to correct an unsafe condition on these 
helicopters.

DATES: The FAA must receive comments on this proposed AD by September 
21, 2020.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to https://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 https://www.regulations.gov by searching for and locating Docket No. FAA-2017-
1036; 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 (now European 
Union Aviation Safety Agency) (EASA) AD, any comments received, and 
other information. The street address for Docket Operations is listed 
above. 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 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.

FOR FURTHER INFORMATION CONTACT: Rao Edupuganti, Aviation Safety 
Engineer, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort 
Worth, TX 76177; telephone 817-222-5110; email rao.edupuganti@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to participate in this rulemaking by submitting 
written comments, data, or views. 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.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will file in the docket all comments received, as well 
as a report summarizing each substantive public contact with FAA 
personnel concerning this proposed rulemaking. Before acting on this 
proposal, the FAA will consider all comments received on or before the 
closing date for comments. The FAA will consider comments filed after 
the comment period has closed if it is possible to do so without 
incurring expense or delay. The FAA may change this proposal in light 
of the comments received.

Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act

[[Page 47926]]

(FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your 
comments responsive to this NPRM contain commercial or financial 
information that is customarily treated as private, that you actually 
treat as private, and that is relevant or responsive to this NPRM, it 
is important that you clearly designate the submitted comments as CBI. 
Please mark each page of your submission containing CBI as ``PROPIN.'' 
The FAA will treat such marked submissions as confidential under the 
FOIA, and they will not be placed in the public docket of this NPRM. 
Submissions containing CBI should be sent to Rao Edupuganti, Aviation 
Safety Engineer, Rotorcraft Standards Branch, FAA, 10101 Hillwood 
Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email 
rao.edupuganti@faa.gov. Any commentary that the FAA receives which is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Discussion

    EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA AD No. 2017-0116, Revision 2, dated 
March 2, 2018, (EASA AD 2017-01162R2) to correct an unsafe condition 
for Airbus Helicopters Model AS 365 N2, AS 365 N3, SA 365 N, and SA 365 
N1 helicopters. EASA advises that after an accident on a Model EC225 
helicopter, an investigation revealed the failure of a second stage 
planet gear of the MGB. EASA states that one of the two types of planet 
gear assemblies used in the MGB epicyclic module is subject to higher 
outer race contact pressures and therefore is more susceptible to 
spalling and cracking. Airbus Helicopters reviewed its range of 
helicopters with regard to this issue and provided instructions to 
improve the reliability of the installed MGB. Therefore, EASA AD 2017-
01162R2 requires repetitive inspections of the MGB magnetic plugs and 
corrective action if any particles are detected. EASA AD 2017-01162R2 
also requires, if certain MGB planet gear assemblies are installed, 
replacing the planet gear assemblies. Finally, the EASA AD prohibits 
installing an MGB with a Type X or Type Y planet gear assembly on any 
helicopter.

FAA's Determination

    These helicopters have been approved by EASA and are 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 proposing this AD 
after evaluating all known relevant information and determining that an 
unsafe condition is likely to exist or develop on other products of the 
same type designs.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB) 
No. AS365-05.00.78, Revision 3, dated March 2, 2018, for Model SA-365N, 
SA-365N1, AS-365N2, and AS 365 N3 helicopters. This service information 
specifies performing periodic inspections of the MGB magnetic plugs for 
particles. This service information also specifies identifying the type 
of gear assembly installed in the MGB and replacing any Type X assembly 
within 50 hours time-in-service (TIS). For Type Y gear assemblies, the 
service information requires replacing the assembly within 50 hours TIS 
or within 300 hours TIS, depending on the time since new. The service 
information specifies Type Z gear assemblies should be left as is.
    The FAA also reviewed Airbus Helicopters Service Bulletin No. 
AS365-63.00.21, Revision 3, dated July 26, 2018 for Model AS365 
helicopters. This service information contains procedures for replacing 
the MGB epicyclic reduction gear as an option to replacing the MGB.
    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 before further flight, for 
helicopters with a Type X planet gear assembly with a certain S/N 
installed, replacing the MGB. This proposed AD would require, for 
helicopters with no Type X planet gear assembly installed but at least 
one Type Y planet gear assembly with a certain S/N installed, replacing 
the MGB within 300 hours TIS or before any planet gear assembly 
accumulates 1,300 hours TIS since new, whichever occurs first. As an 
alternative to replacing the MGB, this proposed AD would allow 
replacing the epicyclic reduction gear module in the affected MGB.
    This proposed AD would prohibit installing a MGB with Type Y or 
Type X planet gear assembly installed on any helicopter.
    This proposed AD also would require within 10 hours TIS and 
thereafter before the first flight of the day or at intervals not to 
exceed 10 hours TIS, whichever occurs first, inspecting the lower MGB 
magnetic plugs for particles. If there are particles, the proposed AD 
would require replacing the MGB, depending on the type and the size of 
particles.

Differences Between This Proposed AD and the EASA AD

    The EASA AD requires a 50-hour or 300-hour TIS compliance time or 
by June 30, 2019, whichever occurs first, to determine the type of 
planet gear installed in the MGB, and depending on the outcome, to 
replace the MGB. This proposed AD would set compliance deadlines based 
only on hours TIS or before further flight. The EASA AD allows a pilot 
to inspect the MGB magnetic plugs for particles, while this proposed AD 
would not.

Costs of Compliance

    The FAA estimates that this proposed AD affects 34 helicopters of 
U.S. Registry. The FAA estimates that operators may incur the following 
costs in order to comply with this proposed AD. Labor costs are 
estimated at $85 per work-hour.
    Inspecting the magnetic plugs and oil filter for particle deposits 
would take about 1 work-hour for an estimated cost of $85 per 
inspection cycle.
    Replacing an MGB would take about 42 work-hours for cost of $3,570 
and parts would cost about $295,000 (overhauled) for a total cost of 
$298,570 per helicopter.
    Replacing the epicyclic reduction gear would take about 56 work-
hours for an estimated cost of $4,760 and parts would cost about 
$11,404 for a total cost of $16,164 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.
    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 products identified in this rulemaking action.

[[Page 47927]]

Regulatory Findings

    The FAA 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. 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.

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

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 (AD):

Airbus Helicopters: Docket No. FAA-2017-1036; Product Identifier 
2018-SW-015-AD.

(a) Applicability

    This AD applies to Airbus Helicopters Model AS-365N2, AS 365 N3, 
SA-365N, and SA-365N1 helicopters, certified in any category, with 
at least one Type X or Y planet gear assembly with a serial number 
(S/N) listed in Appendices 4.A. through 4.B of Airbus Helicopters 
Alert Service Bulletin (ASB) No. AS365-05.00.78, Revision 3, dated 
March 2, 2018 (ASB AS-365-05.00.78) installed on the main gearbox 
(MGB).

(b) Unsafe Condition

    This AD defines the unsafe condition as failure of an MGB planet 
gear assembly. This condition could result in failure of the MGB and 
subsequent loss of helicopter control.

(c) Comments Due Date

    The FAA must receive comments by September 21, 2020.

(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

    (1) For helicopters with at least one Type X planet gear 
assembly with an S/N listed in Appendix 4.A. of ASB AS-365-05.00.78 
installed, before further flight, replace the MGB or as an 
alternative to replacing an affected MGB, replace the epicyclic 
reduction gear module Post Modification (MOD) 0763C52 in the 
affected MGB in accordance with paragraph 3.B.2 of the 
Accomplishment Instructions of Airbus Helicopters Service Bulletin 
SB No. AS365-63.00.21, Revision 3, dated July 26, 2018 (SB AS365-
63.00.21), except you are not required to contact Airbus 
Helicopters.
    (2) For helicopters without any Type X planet gear assembly 
installed but with at least one Type Y planet gear assembly with an 
S/N listed in Appendix 4.B. of ASB AS-365-05.0078 installed, within 
300 hours time-in-service (TIS), or before any gear accumulates 
1,300 hours TIS since new, whichever occurs first, replace the MGB 
or as an alternative to replacing the MGB, replace the epicyclic 
reduction gear module MOD 0763C52 in the affected MGB in accordance 
with paragraphs 3.B.2. of the Accomplishment Instructions of SB 
AS365-63.00.21, except you are not required to contact Airbus 
Helicopters.
    (3) After the effective date of this AD, do not install an MGB 
with a Type X or Type Y gear assembly with an S/N listed in Appendix 
4.A. or 4.B. of ASB AS-365-05.0078 installed, on any helicopter.
    (4) For all helicopters, within 10 hours TIS and thereafter 
before the first flight of the day or at intervals not to exceed 10 
hours TIS, whichever occurs first, inspect the lower MGB magnetic 
plugs for particles.
    (i) If there are particles that consist of any scale, flake, or 
splinter, or particles other than cotter pin fragments, pieces of 
lock wire, swarf, abrasion, or miscellaneous non-metallic waste and 
the planet gear assembly has logged less than 50 hours TIS since 
new, inspect the MGB plugs for particles before further flight and 
inspect the oil filter for particles within 5 hours TIS. Thereafter, 
for 25 hours TIS, continue to inspect the MGB plugs for particles 
before each flight, inspect the oil filter for particles at 
intervals not to exceed 5 hours TIS, and perform the actions 
required by paragraphs (e)(4)(ii)(A) through (B) of this AD.
    (ii) If there are particles that consist of any scale, flake, or 
splinter, or particles other than cotter pin fragments, pieces of 
lock wire, swarf, abrasion, or miscellaneous non-metallic waste and 
the planet gear assembly has logged more than 50 hours TIS since 
new, inspect the cumulative surface area of the particles collected 
from both the magnetic plug and the oil filter, since last MGB 
overhaul or since new if no overhaul has been performed.
    (A) If the total surface area of the particles is less than 3 
mm\2\, examine the particles with largest surface area (S), longest 
particle length (L) and thickest particles (e).
    (1) If largest surface area (S) of a particle is less than 1 
mm\2\, the L is less than 1.5 mm, and the e is less than 0.2 mm, 
inspect the MGB plugs for particles before further flight and 
inspect the oil filter for particles within 5 hours TIS. Thereafter, 
for 25 hours TIS, continue to inspect the MGB plugs for particles 
before each flight, inspect the oil filter for particles at 
intervals not to exceed 5 hours TIS, and perform the actions 
required by paragraphs (e)(4)(ii)(A) through (B) of this AD.
    (2) If largest particle size (S) is greater than 1 mm\2\, the L 
is greater than 1.5 mm, or the e is greater than 0.2 mm, perform a 
metallurgical analysis for any 16NCD13 particles using a method in 
accordance with FAA-approved procedures.
    (3) If there are any 16NCD13 particles, replace the MGB with an 
airworthy MGB.
    (4) If there are no 16NCD13 particles, inspect the MGB plugs for 
particles before further flight and inspect the oil filter for 
particles within 5 hours TIS. Thereafter, for 25 hours TIS, continue 
to inspect the MGB plugs for particles before each flight, inspect 
the oil filter for particles at intervals not to exceed 5 hours TIS, 
and perform the actions required by paragraphs (e)(4)(ii)(A) through 
(B) of this AD.
    (B) If the total surface area of collected particles is greater 
than or equal to 3 mm\2\, before further flight, perform a 
metallurgical analysis for any 6NCD13 particles using a method in 
accordance with FAA-approved procedures.
    (1) If there are any 16NCD13 particles, before further flight, 
replace the MGB with an airworthy MGB.
    (2) If there are no 16NCD13 particles, inspect the MGB plugs for 
particles before further flight and inspect the oil filter for 
particles within 5 hours TIS. Thereafter, for 25 hours TIS, continue 
to inspect the MGB plugs for particles before each flight, inspect 
the oil filter for particles at intervals not to exceed 5 hours TIS, 
and perform the actions required by paragraphs (e)(4)(ii)(A) through 
(B) of this AD.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Rotorcraft Standards Branch, FAA, may approve 
AMOCs for this AD. Send your proposal to: Rao Edupuganti, Aviation 
Safety Engineer, Regulations and Policy Section, Rotorcraft 
Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; 
telephone 817-222-5110; email 9-ASW-FTW-AMOC-Requests@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, the FAA suggests 
that you notify your principal inspector, or lacking a principal 
inspector, the manager of the local flight standards district office 
or certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    The subject of this AD is addressed in European Aviation Safety 
Agency (now European Union Aviation Safety Agency) (EASA) AD 2017-
0116R2, dated March 2, 2018. You may view the EASA AD on the

[[Page 47928]]

internet at https://www.regulations.gov in the AD Docket.

 (h) Subject

    Joint Aircraft Service Component (JASC) Code: 6300, Main Rotor 
Drive System.

    Issued on August 3, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-17271 Filed 8-6-20; 8:45 am]
BILLING CODE 4910-13-P