DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0196; Project Identifier 2018-SW-021-AD; Amendment
39-21571; AD 2021-11-09]
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
Airbus Helicopters Deutschland GmbH Model MBB-BK 117 A-1, MBB-BK 117 A-
3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1
helicopters. This AD was prompted by an analysis of the main rotor (M/
R) blade loop area. This AD requires repetitive inspections of certain
M/R blade thimble areas and corrective actions if necessary, as
specified in a European Aviation Safety Agency (now European Union
Aviation Safety Agency) (EASA) AD, which is incorporated by reference
(IBR). The FAA is issuing this AD to address the unsafe condition on
DATES: This AD is effective July 12, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of July 12,
ADDRESSES: For EASA material in this AD, contact EASA, Konrad-Adenauer-
Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email
ADs@easa.europa.eu; internet www.easa.europa.eu. You may find this
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. It is also available on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-
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-2021-
0196; 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, the EASA AD, any comments received, and other
information. The 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: Kathleen Arrigotti, Aerospace
Engineer, Large Aircraft Section, International Validation Branch, FAA,
2200 South 216th St., Des Moines, WA; telephone (206) 231-3218; email
EASA, which is the Technical Agent for the Member States of the
European Community, has issued EASA AD 2018-0061, dated March 20, 2018
(EASA AD 2018-0061), 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, and MBB-BK117 C-1 helicopters, all serial numbers.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to Airbus Helicopters
Deutschland GmbH Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4,
MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters with an
``affected `angle 0' parts'' or ``affected `angle 1' parts'' installed,
as identified in EASA AD 2018-0061. The NPRM published in the Federal
Register on March 26, 2021 (86 FR 16121). The NPRM was prompted by new
test results from an analysis of the M/R blade loop area, which
revealed that certain M/R blade thimbles require reduced inspection
intervals. The NPRM proposed to require repetitive inspections of
certain M/R blade thimble areas and corrective actions if necessary, as
specified in EASA AD 2018-0061. The FAA is issuing this AD to address
composite failure of the M/R blades, resulting in loss of control of
the helicopter. See EASA AD 2018-0061 for additional background
The FAA gave the public the opportunity to participate in
developing this final rule. The FAA received no comments on the NPRM or
on the determination of the cost to the public.
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed.
Related Service Information Under 1 CFR Part 51
EASA AD 2018-0061 specifies compliance intervals to repetitively
inspect certain M/R blades, with a blade sweep angle of 1 degree, for
cracks and resin chippings in the area of the greater thimble radius
and corrective actions, if there is a crack or anomaly. EASA AD 2018-
0061 also specifies compliance intervals to repetitively inspect
certain M/R blades, with a blade sweep angle of 0 degrees, for cracks
and bulging in the teflon foil in the area of the greater thimble
radius and corrective actions, if there is a crack or bulge. Corrective
actions include dispatching the M/R blades to an authorized repair
station, as required.
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.
Differences Between This AD and the EASA AD
EASA AD 2018-0061 applies to 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, whereas this AD applies to Model MBB-BK 117 A-1, MBB-BK
117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117
C-1 helicopters with certain M/R blades installed instead. The service
information required by EASA AD 2018-0061 requires accomplishment of
certain corrective action by ``ECD'' or an authorized service or repair
station, whereas this AD requires performing the corrective action in
accordance with FAA-approved procedures instead. EASA AD 2018-0061
requires revising the Aircraft Maintenance Program (AMP), whereas this
AD does not. EASA AD 2018-0061 allows a tolerance to compliance times,
whereas this AD does not.
Costs of Compliance
The FAA estimates that this AD affects 216 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.
Inspecting an M/R blade thimble area takes about 1 work-hour for an
estimated cost of about $85 per M/R blade thimble, per inspection
Repairing or replacing an M/R blade takes up to about 20 work-hours
and parts cost up to about $23,100 for an estimated cost of up to
$24,800 per blade.
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 this AD:
(1) Is not a ``significant regulatory action'' under Executive
(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 adding the following new airworthiness