Published 2021-03-12 · Federal Register document 2021-05146
Airworthiness Directives; Airbus Helicopters Deutschland GmbH (Type Certificate Previously Held by Eurocopter Deutschland GmbH) Helicopters
Publication summary
The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model BO-105A, BO-105C, BO-105S, 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 a report of a loss of electrical ground between the starter-generator and the generator voltage regulator (regulator). This AD requires inspecting the starter-generator electrical ground connection, retrofitting the starter-generator wire harness, and depending on model, revising the existing Rotorcraft Flight Manual (RFM) for your helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Why this record is shown
Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.
- Source revision
- federal_register_ad_metadata_2021-9c919420683447c6
- Source row
- results[74]
- Raw source SHA-256
- 9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5
Final-rule publication
Recorded publication clauses
- AD identifier printed in this edition
- 2021-05-07
- Effective date printed in this edition
- 2021-04-16
Read 10 complete recorded clauses
Effective Date
(a) Effective Date
This airworthiness directive (AD) is effective April 16, 2021.
Exact source excerpt. Text positions 12822–12910, end exclusive, in the original decoded publication. SHA-256: a106c1165886f3823bb319ae0b72bf2489c05fb2a16b0d2d1e39451f95981792
Affected ADs
(b) Affected ADs
None.
Exact source excerpt. Text positions 12910–12939, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0
Applicability wording · Applicability
(c) Applicability
This AD applies to the following Airbus Helicopters Deutschland
GmbH (Type Certificate previously held by Eurocopter Deutschland
GmbH) helicopters, certificated in any category:
(1) Model BO-105A, BO-105C, and BO-105S helicopters with a
voltage regulator part number (P/N) 51565-000, 51565-000R, or 51509-
002R installed; and
(2) 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.
Exact source excerpt. Text positions 12939–13423, end exclusive, in the original decoded publication. SHA-256: 8156dac174b9e882fe761ebb96bb0cbd1b35d8eed2ea78b5d5ada31073d9735c
Subject
(d) Subject
Joint Aircraft Service Component (JASC) Code: 2497, Electrical
Power System Wiring.
Exact source excerpt. Text positions 13423–13526, end exclusive, in the original decoded publication. SHA-256: 8bb0e6cebc1b93e8fac6308d031b87ce8f807a397cf6a62d648ae377058b2b9c
Unsafe Condition
(e) Unsafe Condition
This AD was prompted by a report of a loss of electrical ground
between the starter-
[[Page 13977]]
generator and the generator voltage regulator (regulator). The FAA
is issuing this AD to address loss of electrical ground between the
starter-generator and the regulator. This condition could result in
an overvoltage of electrical power, damage to electronic equipment,
and subsequent loss of control of the helicopter.
Exact source excerpt. Text positions 13526–13981, end exclusive, in the original decoded publication. SHA-256: 5686c195e289a63c520e06309747fb793f673666b918962a15db51c518dd3474
Compliance
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
Exact source excerpt. Text positions 13981–14083, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3
Required Actions
(g) Required Actions
(1) Within 50 hours time-in-service (TIS):
(i) Visually inspect the wire terminal of wire P55F16N/P56F16N
for Model BO-105A, BO-105C, and BO-105S helicopters and wire
1PA53B20/2PA53B20 for 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 on Terminal E of each starter-generator for a crack, a
kink, fraying, looseness, missing material, and corrosion. If there
is a crack, a kink, fraying, looseness, missing material, or any
corrosion, before further flight, replace the wire terminal.
(ii) Measure the resistance between each starter-generator and
its regulator in accordance with the Accomplishment Instructions,
paragraph 2.A.2.3. of Eurocopter Alert Service Bulletin ASB BO105-
90-103, Revision 4, dated June 21, 2010, or paragraphs 2.A.2.3. and
2.A.2.5. of Eurocopter Alert Service Bulletin ASB-MBB-BK117-90-118,
Revision 2, dated May 4, 2009, as applicable to your model
helicopter. If the resistance is more than 500 milliohms, before
further flight, replace the wire terminal.
(2) Within 150 hours TIS:
(i) Install a wire harness from each generator voltage regulator
as follows.
(A) For Model BO-105A, BO-105C, and BO-105S helicopters: Wire
harness P/N 105-90081.
(B) For Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4,
MBB-BK 117 B-1, and MBB-BK 117 B-2 helicopters: Wire harness P/N
117-901941.
(C) For Model MBB-BK 117 C-1 helicopters: Wire harness P/N 117-
901961.
(ii) For Model 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, revise the existing
Rotorcraft Flight Manual (RFM) for your helicopter to include the
information in Section 3 Emergency and Malfunction Procedures of the
following temporary revisions, as applicable to your helicopter:
Eurocopter Flight Manual BK117 A-3 Temporary Revision 9, Eurocopter
Flight Manual BK117 A-4 Temporary Revision 5, Eurocopter Flight
Manual BK117 B-1 Temporary Revision 6, Eurocopter Flight Manual BK
117 B-2 Temporary Revision 1, or Eurocopter Flight Manual BK 117 C-1
Temporary Revision 2, all dated September 22, 2006. Using a later
RFM revision with information identical to that contained in the
temporary revision specified for your helicopter is acceptable for
compliance with the requirement of this paragraph.
(iii) For Model MBB-BK 117 A-1 helicopters, revise Section 3
Emergency and Malfunction Procedures of the existing RFM for your
helicopter to include the information in Figures 1 through 3 to
paragraph (g)(2)(iii) of this AD.
BILLING CODE 4910-13-P
[[Page 13978]]
[GRAPHIC] [TIFF OMITTED] TR12MR21.007
[[Page 13979]]
[GRAPHIC] [TIFF OMITTED] TR12MR21.008
[[Page 13980]]
[GRAPHIC] [TIFF OMITTED] TR12MR21.009
[[Page 13981]]
[GRAPHIC] [TIFF OMITTED] TR12MR21.010
BILLING CODE 4910-13-C
[[Page 13982]]
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Alternative Methods of Compliance (AMOCs)
(h) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Strategic Policy Rotorcraft Section, FAA, has
the authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the manager of the certification office, send it to the
attention of the person identified in paragraph (i)(1) of this AD.
Information may be emailed to: [email protected] or
[email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
Exact source excerpt. Text positions 16993–17801, end exclusive, in the original decoded publication. SHA-256: f038160d34c3a1a74e6f8d9d906b1fa75bd02adec8ce50f9297177a9a409210a
Related Information
(i) Related Information
(1) For more information about this AD, contact Ronnea L. Derby,
Aerospace Engineer, Denver ACO Branch, FAA, 26805 East 68th Ave.,
Room 214, Denver, CO 80249; telephone 303-342-1093; email
[email protected].
(2) The subject of this AD is addressed in European Aviation
Safety Agency (now European Union Aviation Safety Agency) (EASA) AD
2015-0098, dated June 2, 2015, and EASA AD 2015-0220, dated November
9, 2015. You may view the EASA ADs on the internet at https://www.regulations.gov in Docket No. FAA-2015-4497.
(3) The following documents, which are not incorporated by
reference, contain additional information about the subject of this
AD: Eurocopter Alert Service Bulletin ASB-BO 105-80-118, Revision 1,
dated November 29, 1995; Eurocopter Information Notice 2370-I-24,
Revision 0, dated November 15, 2011; Eurocopter Service Bulletin SB-
BO105-80-119, dated November 7, 1994; and Eurocopter Service
Bulletin SB BO105-90-104, Revision 1, dated June 21, 2010.
(4) Service information identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (j)(3) and (4) of this AD.
Exact source excerpt. Text positions 17801–18989, end exclusive, in the original decoded publication. SHA-256: b453554da1e05c29b064f21db74599d3be0c4515062fa720c9d8c293d6dd8140
Material Incorporated by Reference
(j) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless this AD specifies otherwise.
(i) Eurocopter Alert Service Bulletin ASB-MBB-BK117-90-118,
Revision 2, dated May 4, 2009.
(ii) Eurocopter Alert Service Bulletin ASB BO105-90-103,
Revision 4, dated June 21, 2010.
(iii) Eurocopter Flight Manual BK117 A-3 Temporary Revision 9,
dated September 22, 2006.
(iv) Eurocopter Flight Manual BK117 A-4 Temporary Revision 5,
dated September 22, 2006.
(v) Eurocopter Flight Manual BK117 B-1 Temporary Revision 6,
dated September 22, 2006.
(vi) Eurocopter Flight Manual BK 117 B-2 Temporary Revision 1,
dated September 22, 2006.
(vii) Eurocopter Flight Manual BK 117 C-1 Temporary Revision 2,
dated September 22, 2006.
(3) For Eurocopter service information identified in this AD,
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.
(4) 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.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.
Exact source excerpt. Text positions 18989–20843, end exclusive, in the original decoded publication. SHA-256: 1bd1e42c65ea75764727523eeb03ff7a519d8f302c209f801ee12fd123f237ce
No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.
Find all recorded historical references to AD 2021-05-07 · 0 printed reference observations in this pinned collection.
These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.
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They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.
Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: ebe21cc83e6eaa092bf73965a18da677314fd03e18b35c451d3e7312e96d85f8. Source manifest: f457d3d18a8c0a03f75e73cbb1d3e0a5513cf7d5491a241c430eb27c18957e9f.
Official source · 2021-03-12
Publication text
This is the complete recorded text of this dated publication.
Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.
Read the complete official publication text
[Federal Register Volume 86, Number 47 (Friday, March 12, 2021)]
[Rules and Regulations]
[Pages 13975-13982]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05146]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2015-4497; Project Identifier 2016-SW-011-AD; Amendment
39-21450; AD 2021-05-07]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(Type Certificate Previously Held by Eurocopter Deutschland GmbH)
Helicopters
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model BO-105A,
BO-105C, BO-105S, 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 a report of a loss of electrical ground between the
starter-generator and the generator voltage regulator (regulator). This
AD requires inspecting the starter-generator electrical ground
connection, retrofitting the starter-generator wire harness, and
depending on model, revising the existing Rotorcraft Flight Manual
(RFM) for your helicopter. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective April 16, 2021.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of April 16,
2021.
ADDRESSES: For Eurocopter service information identified in this final
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 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.
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-2015-
4497; 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 comments received, and other information. The
street 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: Ronnea L. Derby, Aerospace Engineer,
Denver ACO Branch, FAA, 26805 East 68th Ave., Room 214, Denver, CO
80249; telephone 303-342-1093; email [email protected].
SUPPLEMENTARY INFORMATION:
Discussion
The European Aviation Safety Agency (now European Union Aviation
Safety Agency) (EASA), which is the Technical Agent for the Member
States of the European Union, has issued EASA AD 2015-0098, dated June
2, 2015 (EASA AD 2015-0098), and EASA AD 2015-0220, dated November 9,
2015 (EASA AD 2015-0220) (also referred to as the Mandatory Continuing
Airworthiness Information, or the MCAI), to correct an unsafe condition
for all Airbus Helicopters 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;
and Airbus Helicopters Model BO105 A, BO105 C, BO105 D and BO105 S
helicopters with certain part-numbered voltage regulators.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Airbus
Helicopters Model BO-105A, BO-105C, and BO-105S helicopters; and all
Airbus Helicopters 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. The
NPRM published in the Federal Register on July 16, 2020 (85 FR 43153).
The NPRM was prompted by a report of a loss of electrical ground
between the starter-generator and the regulator. The NPRM proposed to
require inspecting the starter-generator electrical ground connection,
retrofitting the starter-generator wire harness, and depending on
model, revising the existing RFM for your helicopter.
The FAA is issuing this AD to address the loss of electrical ground
between the starter-generator and the regulator. This condition could
result in an overvoltage of electrical power, damage to electronic
equipment, and subsequent loss of control of the helicopter.
Comments
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.
Conclusion
The FAA reviewed the relevant data and determined that air safety
and the public interest require adopting this final rule as proposed,
except for minor editorial changes. The FAA has determined that these
minor changes:
<bullet> Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
<bullet> Do not add any additional burden upon the public than was
already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
Eurocopter (now Airbus Helicopters) issued Alert Service Bulletin
ASB-MBB-BK117-90-118, Revision 2, dated May 4, 2009, for certain Model
MBB-BK117 helicopters and Alert Service Bulletin ASB BO105-90-103,
Revision 4, dated June 21, 2010, for certain Model BO105 helicopters.
This service information specifies a visual inspection for damage,
corrosion, and cracks and measuring the resistance of the left-hand and
right-hand electrical ground connections between each starter-generator
and the regulator. If there is damage or suspected damage, or if the
resistance is out of tolerance, this service information specifies
replacing the wire terminal. This service information also specifies
performing the visual inspection and resistance measurement each time
the starter generator is removed or the wiring is disconnected until a
retrofit ground connection is installed. These documents are distinct
since they apply to different models.
Eurocopter also issued Eurocopter Flight Manual BK117 A-3 Temporary
Revision 9, Eurocopter Flight Manual BK117 A-4 Temporary Revision 5,
Eurocopter Flight Manual BK117 B-1 Temporary Revision 6, Eurocopter
Flight Manual BK 117 B-2 Temporary Revision 1, and Eurocopter Flight
Manual BK 117 C-1 Temporary Revision 2, all dated September 22, 2006,
to provide updated procedures in the event of a generator failure.
These
[[Page 13976]]
documents are distinct since they apply to different models.
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
Eurocopter (now Airbus Helicopters) issued Service Bulletin SB
BO105-90-104, Revision 1, dated June 21, 2010, for certain Model BO105
helicopters. This service information specifies procedures for
installing a retrofit ground connection of the starter-generator.
Eurocopter issued Alert Service Bulletin ASB-BO 105-80-118,
Revision 1, dated November 29, 1995, and Service Bulletin SB-BO105-80-
119, dated November 7, 1994, both for certain Model BO105 helicopters.
This service information specifies retrofitting certain helicopters
with voltage regulators that incorporate overvoltage protection by
modifying the main relay box, modifying the overhead panel, and
performing a functional test.
Eurocopter issued Information Notice 2370-I-24, Revision 0, dated
November 15, 2011, for certain Model BO105 helicopters to provide
notice that a modified starter-generator may only be installed on
helicopters that have also been modified. This service information
states that combining modified with non-modified can cause overvoltage
in the electrical system during the first ground run following engine
replacement and subsequent damage to electronic equipment. This service
information also recommends retrofitting all helicopters approved to
only fly under visual flight rules.
Differences Between This AD and the EASA ADs
The EASA ADs require visually inspecting the wire terminals for
damage, corrosion, and cracks. This AD requires visually inspecting for
a crack, a kink, fraying, looseness, missing material, and corrosion.
The EASA ADs require repeating the visual inspection and resistance
measurement each time a starter-generator is removed or the wiring is
disconnected from a starter-generator. This AD does not because such a
compliance time would be difficult to enforce.
EASA AD 2015-0220 requires additional actions for Model BO-105
helicopters with a serial number up to 0160 than for helicopters with a
serial number 0161 and larger. This AD requires the same actions for
all Model BO-105 helicopters regardless of serial number.
EASA AD 2015-0220 allows credit for complying with Eurocopter Alert
Service Bulletin ASB BO105-90-103, Revision 2 or Revision 3, whereas
this AD does not.
Costs of Compliance
The FAA estimates that this AD affects 40 Model BO-105 helicopters
and 44 Model MBB-BK 117 helicopters of U.S. Registry. The FAA estimates
that operators may incur the following costs in order to comply with
this AD using an estimated labor cost of $85 per work-hour.
Performing a visual inspection and resistance measurement of the
electrical ground connection takes about 2 work-hours for an estimated
cost of $170 per helicopter and $14,280 for the U.S. fleet per
inspection and measurement.
Performing the retrofit of the wiring harness takes about 10 work-
hours. Required parts for a Model BO-105 helicopter cost $2,509 for an
estimated replacement cost of $3,359 per helicopter and $134,360 for
the U.S. fleet. Required parts for a Model MBB-BK 117 helicopter cost
$1,730 for an estimated replacement cost of $2,580 per helicopter and
$113,520 for the U.S. fleet. Revising the existing RFM for Model MBB-BK
117 helicopters takes about 0.5 work-hour, for an estimated cost of $43
per helicopter and $1,892 for the U.S. fleet.
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.
Regulatory Findings
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,
(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
reference, Safety.
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
0
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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2021-05-07 Airbus Helicopters Deutschland GmbH (Type Certificate
Previously Held by Eurocopter Deutschland GmbH): Amendment 39-21450;
Docket No. FAA-2015-4497; Project Identifier 2016-SW-011-AD.
(a) Effective Date
This airworthiness directive (AD) is effective April 16, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to the following Airbus Helicopters Deutschland
GmbH (Type Certificate previously held by Eurocopter Deutschland
GmbH) helicopters, certificated in any category:
(1) Model BO-105A, BO-105C, and BO-105S helicopters with a
voltage regulator part number (P/N) 51565-000, 51565-000R, or 51509-
002R installed; and
(2) 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.
(d) Subject
Joint Aircraft Service Component (JASC) Code: 2497, Electrical
Power System Wiring.
(e) Unsafe Condition
This AD was prompted by a report of a loss of electrical ground
between the starter-
[[Page 13977]]
generator and the generator voltage regulator (regulator). The FAA
is issuing this AD to address loss of electrical ground between the
starter-generator and the regulator. This condition could result in
an overvoltage of electrical power, damage to electronic equipment,
and subsequent loss of control of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Within 50 hours time-in-service (TIS):
(i) Visually inspect the wire terminal of wire P55F16N/P56F16N
for Model BO-105A, BO-105C, and BO-105S helicopters and wire
1PA53B20/2PA53B20 for 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 on Terminal E of each starter-generator for a crack, a
kink, fraying, looseness, missing material, and corrosion. If there
is a crack, a kink, fraying, looseness, missing material, or any
corrosion, before further flight, replace the wire terminal.
(ii) Measure the resistance between each starter-generator and
its regulator in accordance with the Accomplishment Instructions,
paragraph 2.A.2.3. of Eurocopter Alert Service Bulletin ASB BO105-
90-103, Revision 4, dated June 21, 2010, or paragraphs 2.A.2.3. and
2.A.2.5. of Eurocopter Alert Service Bulletin ASB-MBB-BK117-90-118,
Revision 2, dated May 4, 2009, as applicable to your model
helicopter. If the resistance is more than 500 milliohms, before
further flight, replace the wire terminal.
(2) Within 150 hours TIS:
(i) Install a wire harness from each generator voltage regulator
as follows.
(A) For Model BO-105A, BO-105C, and BO-105S helicopters: Wire
harness P/N 105-90081.
(B) For Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4,
MBB-BK 117 B-1, and MBB-BK 117 B-2 helicopters: Wire harness P/N
117-901941.
(C) For Model MBB-BK 117 C-1 helicopters: Wire harness P/N 117-
901961.
(ii) For Model 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, revise the existing
Rotorcraft Flight Manual (RFM) for your helicopter to include the
information in Section 3 Emergency and Malfunction Procedures of the
following temporary revisions, as applicable to your helicopter:
Eurocopter Flight Manual BK117 A-3 Temporary Revision 9, Eurocopter
Flight Manual BK117 A-4 Temporary Revision 5, Eurocopter Flight
Manual BK117 B-1 Temporary Revision 6, Eurocopter Flight Manual BK
117 B-2 Temporary Revision 1, or Eurocopter Flight Manual BK 117 C-1
Temporary Revision 2, all dated September 22, 2006. Using a later
RFM revision with information identical to that contained in the
temporary revision specified for your helicopter is acceptable for
compliance with the requirement of this paragraph.
(iii) For Model MBB-BK 117 A-1 helicopters, revise Section 3
Emergency and Malfunction Procedures of the existing RFM for your
helicopter to include the information in Figures 1 through 3 to
paragraph (g)(2)(iii) of this AD.
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(h) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Strategic Policy Rotorcraft Section, FAA, has
the authority to approve AMOCs for this AD, if requested using the
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19,
send your request to your principal inspector or local Flight
Standards District Office, as appropriate. If sending information
directly to the manager of the certification office, send it to the
attention of the person identified in paragraph (i)(1) of this AD.
Information may be emailed to: [email protected] or
[email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(i) Related Information
(1) For more information about this AD, contact Ronnea L. Derby,
Aerospace Engineer, Denver ACO Branch, FAA, 26805 East 68th Ave.,
Room 214, Denver, CO 80249; telephone 303-342-1093; email
[email protected].
(2) The subject of this AD is addressed in European Aviation
Safety Agency (now European Union Aviation Safety Agency) (EASA) AD
2015-0098, dated June 2, 2015, and EASA AD 2015-0220, dated November
9, 2015. You may view the EASA ADs on the internet at https://www.regulations.gov in Docket No. FAA-2015-4497.
(3) The following documents, which are not incorporated by
reference, contain additional information about the subject of this
AD: Eurocopter Alert Service Bulletin ASB-BO 105-80-118, Revision 1,
dated November 29, 1995; Eurocopter Information Notice 2370-I-24,
Revision 0, dated November 15, 2011; Eurocopter Service Bulletin SB-
BO105-80-119, dated November 7, 1994; and Eurocopter Service
Bulletin SB BO105-90-104, Revision 1, dated June 21, 2010.
(4) Service information identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (j)(3) and (4) of this AD.
(j) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless this AD specifies otherwise.
(i) Eurocopter Alert Service Bulletin ASB-MBB-BK117-90-118,
Revision 2, dated May 4, 2009.
(ii) Eurocopter Alert Service Bulletin ASB BO105-90-103,
Revision 4, dated June 21, 2010.
(iii) Eurocopter Flight Manual BK117 A-3 Temporary Revision 9,
dated September 22, 2006.
(iv) Eurocopter Flight Manual BK117 A-4 Temporary Revision 5,
dated September 22, 2006.
(v) Eurocopter Flight Manual BK117 B-1 Temporary Revision 6,
dated September 22, 2006.
(vi) Eurocopter Flight Manual BK 117 B-2 Temporary Revision 1,
dated September 22, 2006.
(vii) Eurocopter Flight Manual BK 117 C-1 Temporary Revision 2,
dated September 22, 2006.
(3) For Eurocopter service information identified in this AD,
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.
(4) 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.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued on February 19, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-05146 Filed 3-11-21; 8:45 am]
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