DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-1180; Project Identifier MCAI-2021-00794-R]
Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for all Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-3
helicopters. This proposed AD was prompted by reports of a main rotor
(M/R) blade lead-lag damper in a tilted position. This proposed AD
would require inspecting the Flex Control Unit (FCU), and corrective
actions if necessary, as well as rework and re-identification of the
bearing pin, as specified in a European Union Aviation Safety Agency
(EASA) AD, which is proposed for incorporation by reference (IBR). The
FAA is proposing this AD to address the unsafe condition on these
DATES: The FAA must receive comments on this proposed AD by February
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
for submitting comments.
Fax: (202) 493-2251.
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: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For EASA material that is proposed for IBR in this AD, contact the
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221
8999 000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu. You
may find the EASA material on the EASA website at https://ad.easa.europa.eu.
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. This material is also
available at https://www.regulations.gov by searching for and locating
Docket No. FAA-2021-1180.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-1180; 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 NPRM, the EASA AD,
any comments received, and other information. The street address for
Docket Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Andrea Jimenez, Aerospace Engineer,
COS Program Management Section, Operational Safety Branch, Compliance
Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY
11590; telephone (516) 228-7330; email firstname.lastname@example.org.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2021-1180; Project Identifier
MCAI-2021-00794-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
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 post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
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 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
Andrea Jimenez, Aerospace Engineer, COS Program Management Section,
Operational Safety Branch, Compliance & Airworthiness Division, FAA,
1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone (516) 228-
7330; email email@example.com. Any commentary that the FAA
receives that is not specifically designated as CBI will be placed in
the public docket for this rulemaking.
EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD 2021-0160, dated July 5, 2021 (EASA
AD 2021-0160), to correct an unsafe condition for Airbus Helicopters
Deutschland GmbH (AHD), formerly Eurocopter Deutschland GmbH, Model
MBB-BK117 D-3 helicopters, all serial numbers, including Model MBB-
BK117 D-2 helicopters that have been converted into Model MBB-BK117 D-3
helicopters through Airbus Helicopters Service Bulletin MBB-BK117 D-2-
This proposed AD was prompted by reports of an M/R blade lead-lag
damper in a tilted position. EASA advises that subsequent investigation
results determined that the tolerances stack-up may lead to an
insufficient clamping on the bearing pin. The FAA is proposing this AD
to address this unsafe condition, which if not detected and corrected,
could result in an unbalance of the M/R system, excessive vibration,
and reduced control of the helicopter. See EASA AD 2021-0160 for
additional background information.
Related Service Information Under 1 CFR Part 51
EASA AD 2021-0160 requires a one-time inspection of the affected
FCU and depending on findings, accomplishment of applicable corrective
actions. EASA AD 2021-0160 also requires after the initial FCU
inspection, re-working and re-identifying each affected part by marking
the part with a letter ``M.'' EASA AD 2021-0160 prohibits installing an
affected FCU or affected part on any helicopter.
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.
Other Related Service Information
The FAA reviewed Airbus Helicopters Alert Service Bulletin ASB MBB-
BK117 D-3-62A-002, dated June 29, 2021, which specifies procedures for
a one-time inspection of the FCU and re-work of the bearing pin
installed on the support assembly.
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 about the
unsafe condition described in its AD. The FAA is proposing this AD
after evaluating all known relevant information and determining that
the unsafe condition described previously is likely to exist or develop
on other helicopters of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in EASA AD 2021-0160, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this proposed AD.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has been
coordinating this process with manufacturers and CAAs. As a result, the
FAA proposes to incorporate EASA AD 2021-0160 by reference in the FAA
final rule. This proposed AD would, therefore, require compliance with
EASA AD 2021-0160 in its entirety through that incorporation, except
for any differences identified as exceptions in the regulatory text of
this proposed AD. Using common terms that are the same as the heading
of a particular section in EASA AD 2021-0160 does not mean that
operators need comply only with that section. For example, where the AD
requirement refers to ``all required actions and compliance times,''
compliance with this AD requirement is not limited to the section
titled ``Required Action(s) and Compliance Time(s)'' in EASA AD 2021-
0160. Service information referenced in EASA AD 2021-0160 for
compliance will be available at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-1180 after the FAA final
rule is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 41 helicopters of U.S. Registry. Labor rates are estimated at
$85 per work-hour. Based on these numbers, the FAA estimates the
following costs to comply with this proposed AD.
Inspecting each FCU, including inspecting each rotor hub-shaft,
hexagonal screw, nut, damper assembly, bearing pin, support assembly,
spherical bearing, and integrated bearing sleeve, would take about 3
work-hours for an estimated cost of $255 per FCU inspection and $10,455
for the U.S. fleet per FCU inspection.
Reworking and re-identifying the bearing pin would take about 0.5
work-hour for an estimated cost of $43 per helicopter and $1,763 for
the U.S. fleet per bearing pin.
The FAA has received no definitive data on which to base the cost
estimates for the on-condition repairs specified in this proposed AD.
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 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 above, I certify this proposed
(1) Is not a ``significant regulatory action'' under Executive
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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
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
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