DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0921; Project Identifier AD-2020-00323-R;
Amendment 39-21303; AD 2020-22-07]
Airworthiness Directives; Bell Textron Inc. (Type Certificate
Previously Held by Bell Helicopter Textron Inc.) Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Bell Textron Inc. (Type Certificate previously held by Bell Helicopter
Textron Inc.) Model 412, 412CF, and 412EP helicopters. This AD requires
revising the existing Rotorcraft Flight Manual (RFM) for your
helicopter. This AD was prompted by an accident and multiple reports of
a cracked main gearbox (MGB) support case. The FAA is issuing this AD
to address the unsafe condition on these products.
DATES: This AD is effective November 18, 2020.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 18,
The FAA must receive comments on this AD by December 18, 2020.
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
instructions for submitting comments.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
For service information identified in this final rule, contact Bell
Textron, Inc., P.O. Box 482, Fort Worth, TX 76101; telephone 817-280-
3391; fax 817-280-6466; or at https://www.bellcustomer.com. 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. It is also available on the internet at
https://www.regulations.gov by searching for and locating Docket No.
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-
0921; 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 service information that is incorporated by
reference, any comments received, and other information. The street
address for the Docket Operations is listed above. Comments will be
available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Kuethe Harmon, Safety Management
Program Manager, DSCO Branch, Compliance & Airworthiness Division, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222- 5198;
The FAA is adopting a new AD for Bell Textron Inc. Model 412,
412CF, and 412EP helicopters. This AD was prompted by an accident on a
Model 412EP helicopter and multiple reports of a cracked MGB support
case. Initial investigations showed that excessive pylon pitch
vibrations likely caused overload that resulted in these failures, and
investigations are ongoing to determine the root cause of these
vibrations. However, field experience and flight test data indicate
that excessive degradation of the transmission mounts and friction
dampers could cause the sudden increase in one-per-rev vertical
vibration, and minimum collective and cyclic controls friction not
meeting the maintenance manual specifications may also be a
This condition, if not addressed, could result in structural
failure of the MGB support case and subsequent reduced control of the
helicopter. To address this unsafe condition, this AD requires revising
Section 2, Normal Procedures, under both ``BEFORE TAKEOFF'' and ``IN-
FLIGHT OPERATION(S)'' of the existing RFM for your helicopter.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Section 2--Normal Procedures, of Bell 412 BHT-412-
FM-1 RFM, Revision 26; Bell 412 BHT-412-FM-2 RFM, Revision 13; Bell 412
BHT-412-FM-3 RFM, Revision 20; Bell 412EP BHT-412-FM-4 RFM, Revision
37; Bell 412EPI BHT-412-FM-5 RFM, Revision 9; and Subaru Bell 412EPX
BHT-412-FM-6 RFM, Revision 5, each dated August 19, 2020. These RFM
revisions add a caution under ``BEFORE TAKEOFF'' and ``IN-FLIGHT
OPERATION(S)'' to the existing RFM for your helicopter.
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 Bell Operation Safety Notice 412-18-43, dated
December 19, 2018 (OSN), which notified Model 412 and 412EP helicopter
owners and operators of reports regarding rapid buildup of one-per-rev
vertical vibration associated with a large steady state forward cyclic
displacement in combination with collective input while at 100/103
percent revolutions per minute (RPM) with any part of the skid gear in
contact with the ground. The OSN also noted that this vibration mode
can be encountered on all Bell Model 412 helicopters equipped with any
type of landing gear. Finally, the OSN reminded operators that, should
this vibration mode be experienced, the amount of forward cyclic input
shall immediately be reduced and, if necessary, the collective and
rotor RPM shall also be reduced to exit the vibration mode described.
The FAA is issuing this AD after evaluating all of the relevant
information and determining the unsafe condition described previously
is likely to exist or develop in other helicopters of these same type
This AD requires, before further flight, revising Section 2, Normal
Procedures, under both ``BEFORE TAKEOFF'' and ``IN-FLIGHT
OPERATION(S)'' of the existing RFM for your helicopter to add a caution
about what to do if a sudden increase in one-per-rev vertical
vibrations occurs with large steady state forward cycle displacements
in combination with collective input while at a certain RPM % is
encountered while any part of the skids is touching the ground. The
caution varies depending on your helicopter model and serial number.
Revising the existing RFM for your helicopter may be performed by
the owner/operator (pilot) holding at least a private pilot
certificate. This authorization is an exception to the FAA's standard
maintenance regulations. The pilot must record compliance with this AD
in the aircraft maintenance records in accordance with 14 CFR
43.9(a)(1) through (4) and 14 CFR 91.417(a)(2)(v). The record must be
maintained as required by 14 CFR 91.417, 121.380, or 135.439.
The FAA considers this AD interim action. If final action is later
identified, the FAA might consider further rulemaking then.
FAA's Justification and Determination of the Effective Date
Section 553(b)(3)(B) of the Administrative Procedure Act (5 U.S.C.)
authorizes agencies to dispense with notice and comment procedures for
rules when the agency, for ``good cause'' finds that those procedures
are ``impracticable, unnecessary, or contrary to the public interest.''
Under this section, an agency, upon finding good cause, may issue a
final rule without seeking comment prior to the rulemaking.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies waiving notice and comment prior to adoption of this rule
because the required corrective action must be completed before further
flight. Therefore, notice and opportunity for prior public comment are
impracticable and contrary to public interest pursuant to 5 U.S.C.
553(b)(3)(B). In addition, for the reasons stated above, the FAA finds
that good cause exists pursuant to 5 U.S.C. 553(d) for making this
amendment effective in less than one month.
This AD is a final rule that involves requirements affecting flight
safety, and the FAA did not provide you with notice and an opportunity
to provide your comments prior to it becoming effective. However, 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 AD, 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 them 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 rulemaking during the comment period. The FAA
will consider all the comments received and may conduct additional
rulemaking based on those comments.
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 (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this final rule 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 final rule, 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 final rule. Submissions containing CBI
should be sent to Kuethe Harmon, Safety Management Program Manager,
DSCO Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood
Pkwy., Fort Worth, TX 76177; telephone 817-222- 5198; email
firstname.lastname@example.org. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because FAA has determined
that it has good cause to adopt this rule without notice and comment,
RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 96 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 412 and 412EP helicopters, revising the existing RFM for
your helicopter takes about 0.5 work-hour for an estimated cost of $43
per helicopter and $4,128 for the U.S. fleet.
For Model 412CF helicopters, there are no costs of compliance
associated with this AD because there are no helicopters with this type
certificate on the U.S. Registry.
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
Order 12866, and
(2) Will not affect intrastate aviation in Alaska.
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