DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0967; Product Identifier 2018-SW-013-AD]
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for Airbus Helicopters Deutschland GmbH Model MBB-BK117 A-1, MBB-BK117
A-3, MBB-BK117 A-4, MBB-BK117 B-1, MBB-BK117 B-2, MBB-BK117 C-1, and
MBB-BK117 C-2 helicopters. This proposed AD would require inspecting
the tail gearbox (TGB) bellcrank attachment arm (arm) for a crack. This
proposed AD was prompted by a report of a cracked TGB arm. The actions
of this proposed AD are intended to address an unsafe condition on
DATES: The FAA must receive comments on this proposed AD by December
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow
online instructions for sending your comments electronically.
Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.
Hand Delivery: Deliver to the "Mail" address between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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-2020-0967;
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 proposed 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 listed
above. Comments will be available in the AD docket shortly after
For service information identified in this proposed 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 https://
www.airbus.com/helicopters/services/technical-support.html. You may
view the referenced service information at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321,
Fort Worth, TX 76177.
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; email
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-2020-0967; Product Identifier
2018-SW-013-AD" 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 proposal.
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 David
Hatfield, Aviation Safety Engineer, Safety Management Section,
Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone 817-222-5110; 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.
EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD No. 2018-0046, dated February 19,
2018, to correct an unsafe condition for Airbus Helicopters Deutschland
GmbH (AHD) (formerly Eurocopter Deutschland GmbH, Eurocopter
Hubschrauber GmbH, Messerschmitt-B[ouml]lkow-Blohm GmbH), Airbus
Helicopters Inc. (formerly American Eurocopter LLC) Model MBB-BK117 A-
1, MBB-BK117 A-3, MBB-BK117 A-4, MBB-BK117 B-1, MBB-BK117 B-2, MBB-
BK117 C-1, and MBB-BK117 C-2 helicopters. The EASA AD advises that a
crack was detected on a Model MBB-BK117 A-4 TGB arm and that this
condition, if not corrected, could result in disconnection of the arm
from the TGB and possible loss of control of the helicopter. To address
this unsafe condition, the EASA AD requires an inspection of the TGB
arm for a crack and for surface anomalies.
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 an
unsafe condition is likely to exist or develop on other products of the
same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Airbus Helicopters Alert Service Bulletin (ASB)
MBB-BK117 C-2-65A-008 for Model MBB-BK117 C-2 helicopters and ASB MBB-
BK117-30A-120 for Model MBB-BK117 A-1, MBB-BK117 A-3, MBB-BK117 A-4,
MBB-BK117 B-1, MBB-BK117 B-2, and MBB-BK117 C-1 helicopters, each
Revision 0 and dated January 31, 2018. The service information contains
procedures for inspecting the TGB arm for a crack and surface
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.
Proposed AD Requirements
This proposed AD would require the following:
Within 100 hours time-in-service, removing the surface
coating from the TGB bellcrank attachment arm and using a 5X or higher
power magnifying glass, dye-penetrant inspecting the TGB arm for a
crack and for any dent, nick, and scratch.
If there is a crack, before further flight, replacing the TGB.
If there is a dent, nick, or scratch, before further
flight, removing the surface material up to 0.2 mm using 80-grit
abrasive paper and repeating the dye penetrant inspection. If there is
a crack or if the damage cannot be removed, before further flight,
replacing the TGB.
If there is no crack and no dent, nick, or scratch, before
further flight, finishing the surface with 600-grit or finer abrasive
Differences Between This Proposed AD and the EASA AD
The EASA AD requires operators to contact Airbus Helicopters if
there is a crack or if there is damage that cannot be repaired by
removing surface material. This proposed AD would require replacing the
Costs of Compliance
The FAA estimates that this proposed AD would affect 177
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 proposed AD.
Removing the surface protection and inspecting the TGB arm for a
crack would take about 2 work-hours and the cost of materials would be
minimal, for an estimated cost of $170 per helicopter and $30,090 for
the U.S. fleet.
If required, reworking the TGB arm would take about 1 work-hour and
the cost of materials would be minimal, for an estimated cost of $85
per helicopter. Replacing a TGB with a cracked arm would take about 4.5
work-hours and cost about $69,000 for required parts, for an estimated
cost of $69,383 per helicopter.
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, I certify this proposed regulation:
1. Is not a "significant regulatory action" under Executive Order
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
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