DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-1183; Project Identifier 2019-SW-008-AD; Amendment
39-21565; AD 2021-11-03]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Airbus Helicopters Model EC 155B, EC155B1, SA-365N, SA-365N1,
AS-365N2, and AS 365 N3 helicopters, as identified in a European
Aviation Safety Agency (now European Union Aviation Safety Agency)
(EASA) AD. This AD was prompted by a report of an in-flight loss of
engine and main gearbox (MGB) cowlings. This AD requires inspecting the
MGB fixed cowling front fitting (MGB front fitting), and depending on
findings, corrective action. This AD also requires a new modification,
which is a terminating action for the inspection, as specified in an
EASA AD, which is incorporated by reference. The FAA is issuing this AD
to address the unsafe condition on these products.
DATES: This AD is effective July 15, 2021.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of July 15,
ADDRESSES: For EASA material incorporated by reference (IBR) in
AD, contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany;
telephone +49 221 8999 000; email ADs@easa.europa.eu; internet
www.easa.europa.eu. You may find this material on the EASA website at
https://ad.easa.europa.eu. For Airbus Helicopters service information,
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 this material 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. It is also available in the
AD docket on the internet at https://www.regulations.gov by searching
for and locating Docket No. FAA-2020-1183.
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-
1183; 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 final rule, any comments received, and other information. The
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: Blaine Williams, Aerospace Engineer,
Los Angeles ACO Branch, Compliance & Airworthiness Division, 3960
Paramount Blvd., Lakewood, California 90712; telephone (562) 627-5371;
EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2019-0008, dated January 22, 2019
(EASA AD 2019-0008) to correct an unsafe condition for certain Airbus
Helicopters (AH), formerly Eurocopter, Eurocopter France, Aerospatiale,
Model EC 155 B, EC 155 B1, SA 365 N, SA 365 N1, AS 365 N2, and AS 365
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Model EC 155 B,
EC155B1, SA-365N, SA-365N1, AS-365N2, and AS 365 N3 helicopters. The
NPRM published in the Federal Register on March 5, 2021 (86 FR 12862).
The NPRM was prompted by reports of an in-flight loss of engine and MGB
cowlings. Subsequent investigations revealed that the MGB cowling
attachment fittings failed because of mounting stress in the MGB front
fitting and air intake bulkhead. The NPRM proposed to require
inspecting and if necessary, replacing the MGB front fitting. The NPRM
also proposed to require modifying the MGB front fitting, as specified
in an EASA AD.
The FAA is issuing this AD to address failure of an MGB front
fitting and subsequent detachment of the MGB or engine cowlings. See
EASA AD 2019-0008 for additional background information.
Discussion of Final Airworthiness Directive
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed.
Related Service Information Under 1 CFR Part 51
EASA AD 2019-0008 requires inspecting the MGB front fittings within
110 flight hours after April 14, 2017 (the effective date of EASA AD
2017-0055, dated March 31, 2017). If there is a discrepancy, the EASA
AD requires applicable corrective action(s) before next flight. EASA AD
2019-0008 also requires modification of the MGB fixed cowling
attachments within 660 flight hours or 23 months, whichever occurs
first, after the effective date described in EASA AD 2019-0008.
Accomplishing the modification constitutes a terminating action for the
The FAA also reviewed Airbus Helicopters Alert Service Bulletin ASB
No. AS365-53.00.62 and ASB No. EC155-53A038, each Revision 0 and dated
December 20, 2018 (ASB AS365-53.00.62 and ASB EC155-53A038). ASB AS365-
53.00.62 applies to Model AS365-series helicopters. ASB EC155-53A038
applies to Model EC155-series helicopters. This service information
specifies replacing the front bracket, inspecting for stress of the MGB
fixed cowlings on the radiator bulkhead, and installing an additional
This material 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.
Costs of Compliance
The FAA estimates that this AD affects 19 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates that operators may incur the following
costs in order to comply with this AD.
Inspecting the MGB front fittings takes about 2 work-hours for an
estimated cost of $170 per helicopter and $3,230 for the U.S. fleet. If
required, replacing an MGB front fitting takes about 2 work-hours and
parts cost about $590 for an estimated total cost of $760 per fitting.
Other repairs will take up to 8 work-hours (excluding drying time) and
parts will cost a minimal amount for an estimated cost of up to $680
Modifying the MGB fixed cowling attachments takes about 5 work-
hours and parts cost about $630 for an estimated cost of $1,055 per
helicopter and $20,045 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 products identified in this rulemaking action.
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
(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
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 adding the following new airworthiness