DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0912; Product Identifier 2015-SW-071-AD; Amendment
39-21492; AD 2021-07-15]
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is superseding Airworthiness Directive (AD) 82-20-05
for Societe Nationale Industrielle Aerospatiale (now Airbus
Helicopters) Model AS-350 and AS-355 series helicopters. AD 82-20-05
required inspecting and establishing a life limit for the tail rotor
(TR) drive shaft bearing (bearing). This new AD requires replacing
certain part-numbered TR bearings with one part-numbered bearing and
repetitively inspecting one part-numbered bearing. This AD was prompted
by inconsistencies that have been identified between inspections and
maintenance actions required by ADs and inspections and maintenance
actions specified in the applicable maintenance manual. The actions of
this AD are intended to address an unsafe condition on these products.
DATES: This AD is effective May 7, 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
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.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov
in Docket No. FAA-2020-0912; 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 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: Bang Nguyen, Aerospace Engineer,
Structures Certification Section, Fort Worth ACO Branch, FAA, 10101
Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to remove AD 82-20-05, Amendment 39-4466 (47 FR 43018,
September 30, 1982) (AD 82-20-05), and add a new AD. AD 82-20-05
applied to Societe Nationale Industrielle Aerospatiale (now Airbus
Helicopters) Model AS-350 and AS-355 series helicopters. The NPRM
published in the Federal Register on October 14, 2020 (85 FR 64995) and
proposed to apply to Airbus Helicopters Model AS350B, AS350B1, AS350B2,
AS350B3, AS350BA, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1,
AS355F2, AS355N, and AS355NP helicopters with a bearing part number (P/N)
593404, 6007-2RS1MT47CA, P9107NPP7, 83A851BC3, or 83A851B-1C3, or
manufacturer part number (MP/N) 704A33-651-010, 704A33-651-111, 704A33-
651-143, or 704A33-651-181 installed. The NPRM proposed to require,
within 100 hours time-in-service (TIS), and thereafter at intervals not
to exceed 165 hours TIS, for helicopters with certain part-numbered
bearings installed, inspecting each bearing holder damper bushing for
wear, a crack, tears, and play between each bushing and support plate;
each bearing holder for a crack, fretting, and corrosion around the
attachment holes; and each rubber sleeve for rotation, crazing, play
between the inner races and the rubber sleeve, and lack of integrity of
the elastomer. Depending on the inspection results, the NRPM proposed
to require removing certain parts from service. The NPRM also proposed
to require making a mark with white paint on the rubber sleeves and on
the shaft within 100 hours TIS. For helicopters with bearing P/N 6007-
2RS1MT47CA, P9107NPP7, 83A851BC3, or 83A851B-1C3, or MP/N
704A33-651-010, 704A33-651-111, or
704A33-651-143 installed, the NPRM proposed to require removing those
part numbered bearings from service and installing bearing P/N 593404
or MP/N 704A33-651-181. The NPRM also proposed to prohibit installing
certain bearings on any helicopter.
The NPRM was prompted by EASA AD 2015-0195, dated September 23,
2015 (EASA AD 2015-0195), 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 B, BA, BB, B1, B2, B3,
and D, and AS 355 E, F, F1, F2, N, and NP helicopters with certain part
numbered bearings installed. EASA advises that after inconsistencies
were identified between inspections and maintenance actions required by
French Civil Aviation Authority ADs and EASA ADs, Airbus Helicopters
issued service information to specify replacing four different part
numbered bearings with one bearing P/N 593404 (also listed as MP/N
704A33-651-181) and to provide inspection procedures for the new
bearing. Accordingly, EASA AD 2015-0195 retains the inspections for the
older design bearings, requires replacing the bearings with the new
bearings, and requires repetitive inspections for the new bearings.
After the NPRM was published, the FAA received comments from two
Both commenters stated that the recurring 165 hour TIS inspections
for TR bearing P/N 593404 and MP/N 704A33-651-181 are already captured
in the FAA-approved manufacturer Airworthiness Limitations Schedule
(ALS) as a 150 hour recurring inspection, and should not be part of
this AD. One of the commenters added that the AD's recurring inspection
would create a double sign-off and more paperwork.
The FAA disagrees. Operators may not have to follow the version of
the ALS referred to by the commenters because operators might be
following an older or newer version depending on the delivery date of
the helicopter. Additionally, the repetitive inspections required by
this AD must be accomplished at intervals not to exceed 165 hours TIS;
if operators accomplish these inspections every 150 hours TIS as stated
in the ALS, they are meeting the AD's required compliance time.
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 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 these same type designs and that air safety and the
public interest require adopting the AD requirements as proposed.
Differences Between This AD and the EASA AD
The EASA AD requires replacing the older design bearings within 10
months, while this AD requires replacing the bearings within 100 hours
TIS instead. The EASA AD applies to Model AS350BB helicopters, whereas
this AD does not as this model helicopter is not FAA type-certificated.
Finally, this AD applies to Model AS350C and AS350D1 helicopters as
they have the same bearings installed, and the EASA AD does not.
Related Service Information
The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB)
No. AS355-01.00.57, Revision 2, dated January 19, 2016, for Model AS355
helicopters, and ASB AS350-01.00.70, Revision 1, dated September 21,
2015, for Model AS350 helicopters. This service information describes
procedures for inspecting bearing P/N 593404 and MP/N 704A33-651-181
for position, condition, and wear. This service information also
advises customers that older designed bearings are not fit for flight,
and specifies replacing the older designed bearings with new bearing P/
N 593404 or MP/N 704A33-651-181. This service information also
references procedures for repetitively inspecting the newer bearings.
Costs of Compliance
The FAA estimates that this AD will affect 915 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.
For Model AS350 B, BA, B1, B2, B3, and C helicopters, inspecting
the bearings takes about 2.5 work hours, for an estimated cost of $213
per helicopter per inspection cycle. Replacing each bearing with a
single part numbered bearing takes about 2.5 work hours and parts cost
about $1,225, for an estimated cost of $1,438 per helicopter.
For Model AS350 D, D1, and AS355-series helicopters, inspecting the
bearings takes about 3 work hours, for an estimated cost of $255 per
helicopter per inspection cycle. Replacing each bearing with a single
part numbered bearing takes about 3 work hours and parts cost about
$1,470, for an estimated cost of $1,725 per helicopter.
Making a mark with white paint on the rubber sleeves and shaft
takes a minimal amount of time and has a nominal parts cost.
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.
The FAA has 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) 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
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:
a. Removing Airworthiness Directive (AD) 82-20-05, Amendment 39-4466
(47 FR 43018, September 30, 1982); and
b. Adding the following new AD: