DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2018-0740; Product Identifier 2016-SW-045-AD; Amendment
39-19631; AD 2019-08-10]
Airworthiness Directives; Bell Helicopter Textron Canada Limited
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: We are adopting a new airworthiness directive (AD) for
Helicopter Textron Canada Limited (Bell) Model 206A, 206B, 206L, 206L-
1, 206L-3, 206L-4, and 407 helicopters. This AD requires inspecting and
cleaning the oil supply restrictor (restrictor) to the freewheel
assembly. This AD was prompted by reports of a blocked oil line
restrictor in the freewheel lubrication system. The actions of this AD
are intended to address an unsafe condition on these products.
DATES: This AD is effective June 24, 2019.
ADDRESSES: For service information identified in this final rule,
contact Bell Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir,
Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or (800) 363-8023; fax
(450) 433-0272; or at http://www.bellcustomer.com/files/. You may
review the 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 http://www.regulations.
gov by searching for and locating Docket No. FAA-2018-
0740; 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 Transport Canada AD, the economic evaluation, any comments
received, and other information. The street address for Docket
Operations (phone: 800-647-5527) 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: David Hatfield, Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110;
On August 21, 2018, at 83 FR 42232, the Federal Register published
our notice of proposed rulemaking (NPRM), which proposed to amend 14
CFR part 39 by adding an AD that would apply to Bell Model 206A, 206B,
206L, 206L-1, 206L-3, 206L-4, and 407 helicopters. The NPRM proposed to
require inspecting and cleaning the freewheel oil supply system, and if
there is blockage in the restrictor, disassembling and inspecting the
freewheel assembly for condition and wear. Additionally, for Model
206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters, the NPRM
proposed to require replacing the reducer with a filter, part number
50-075-1. The proposed requirements were intended to detect blockage in
the restrictor, which could cause failure of the freewheel assembly,
failure of the main rotor mast, and subsequent loss of control of the
The NPRM was prompted by Transport Canada AD No. CF-2016-13, dated
May 2, 2016 (AD No. CF-2016-13), issued by Transport Canada, which is
the aviation authority for Canada, to correct an unsafe condition for
Bell Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, and 407
helicopters. Transport Canada advises that they have received two
reports of torsional overload failure of the main rotor mast caused by
a blocked restrictor in the freewheel lubrication system. Transport
Canada states the restrictor may become contaminated during
maintenance, causing blockage. Transport Canada further states that a
blocked restrictor could cause the freewheel assembly to malfunction
and result in failure of the main rotor mast and loss of control of the
Additionally, the Canadian AD advises that although certain later
versions of these helicopters are equipped with a filter in the
freewheel lubrication system that is designed to trap contaminants and
prevent blockage of the restrictor, installation of the filter does not
guarantee the restrictor will remain free of contaminants. According to
Transport Canada, one occurrence of restrictor blockage resulted from
contaminants being introduced downstream from the filter, which
subsequently caused failure of the freewheel assembly. For these
reasons, AD No. CF-2016-13 requires inspecting and cleaning the
restrictors and filters, and depending on helicopter model, replacing
the reducer with a filter. Additionally, AD No. CF-2016-13 requires a
repetitive on-condition cleaning and inspection of the freewheel oil
The NPRM stated the incorrect date of May 16, 2016, for AD No. CF-
2016-13. The correct issue date is May 2, 2016. We have corrected the
date throughout this Final Rule.
In addition, the ``Costs of Compliance'' section in the preamble of
the NPRM incorrectly provides the estimated cost ``per inspection
cycle.'' However, the inspection and cleaning requirements are one-time
requirements. ``Per inspection cycle'' has been removed in this section
of the Final Rule. In this regard, we have added a section titled
``Differences Between this AD and the Transport Canada AD'' to this
Final Rule to advise that the Transport Canada AD contains repetitive
requirements and this AD does not.
We gave the public the opportunity to participate in developing
this AD, but we did not receive any comments on the NPRM.
These helicopters have been approved by the aviation authority of
Canada and are approved for operation in the United States. Pursuant to
our bilateral agreement with Canada, Transport Canada, its technical
representative, has notified us of the unsafe condition described in
its AD. We are issuing this AD because we evaluated all of the
information provided by Transport Canada and determined 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 Transport Canada AD
The Transport Canada AD includes a repetitive on-condition cleaning
and inspection of the freewheel oil supply system any time the
freewheel oil supply system is opened upstream of the restrictor. This
AD does not require this type of repetitive on-condition cleaning and
inspection because it could be difficult to track.
Related Service Information
Bell has issued Alert Service Bulletin (ASB) 206-14-132 for Model
206A/B and TH-67 helicopters; ASB 206L-14-174 for Model 206L, 206L-1,
206L-3, and 206L-4 helicopters; and ASB 407-14-106 for Model 407
helicopters. Each ASB is Revision A and dated February 9, 2016. This
service information specifies removing, cleaning, inspecting, and
reinstalling certain freewheel assembly components. ASB 206-14-132 and
ASB 206L-14-174 also contain procedures for replacing the reducer with
a filter if not already installed.
Costs of Compliance
We estimate that this AD affects 2,227 helicopters of U.S.
Registry. We estimate that operators may incur the following costs in
order to comply with this AD.
At an average labor rate of $85 per work-hour, inspecting and
cleaning the freewheel oil supply system requires about 1 work-hour,
for a cost per helicopter of $85 and $189,295 for the U.S. fleet.
If required, inspecting the freewheel assembly requires about 1
work-hour, for a cost per helicopter of $85.
If required, replacing a restrictor with a filter requires about 1
work-hour and required parts cost $125, for a cost per helicopter of
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 helicopters identified in this
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) 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, 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.
We prepared an economic evaluation of the estimated costs to comply
with this AD and placed it in the AD docket.
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 adding the following new airworthiness