DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-4497; Product Identifier 2016-SW-011-AD]
RIN 2120-AA64

Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(Type Certificate Previously Held by Eurocopter Deutschland GmbH)
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt 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
proposed AD would require inspecting the starter-generator electrical
ground connection, retrofitting the starter-generator wire harness, and
depending on model, revising the Rotorcraft Flight Manual (RFM) for
your helicopter. This proposed AD was prompted by a report of a loss of
electrical ground between the starter-generator and the generator
voltage regulator (regulator). The proposed actions are intended to
correct an unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by September
14, 2020.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: 202-493-2251.

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-2015-4497;
or in person at the Docket Operations Office 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) ADs, any comments
received, and other information. The street address for the Docket
Operations Office is listed above. Comments will be available in the AD
docket shortly after receipt.

For Airbus Helicopters and Eurocopter 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: George Schwab, Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110;
email george.schwab@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

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 proposal, 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 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 proposed rulemaking. Before acting on this
proposal, the FAA will consider all comments received on or before the
closing date for comments. The FAA will consider comments filed after
the comment period has closed if it is possible to do so without
incurring expense or delay. The FAA may change this proposal in light
of the comments received.

Confidential Business Information

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 George Schwab, Aviation Safety Engineer, Safety
Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood
Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email
george.schwab@faa.gov. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.

Discussion

EASA, which is the Technical Agent for the Member States of the
European Union, has issued EASA AD No. 2015-0098, dated June 2, 2015,
and EASA AD No. 2015-0220, dated November 9, 2015 (EASA AD 2015-0220),
to correct an unsafe condition for Airbus Helicopters (previously
Eurocopter Deutschland GmbH) 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, respectively. EASA advises
of a report of damaged electronic equipment caused by an in-flight
overvoltage in the electrical power system of a Model MBB-BK117
helicopter. Due to design similarity, a similar occurrence could affect
Model BO105 helicopters. According to EASA, the overvoltage was caused
by an interruption of the electrical ground between the starter
generator and the regulator due to a break in a wire terminal attached
at Terminal E. EASA further advises that use of an outdated RFM
revision for Model MBB-BK117 helicopters could lead to the use of
incorrect emergency procedures in the event of an overvoltage.

For these reasons, the EASA ADs require recurring inspections of
the wire terminals and measurements of the resistance between the
starter generator and the regulator, as well as modifying the ground
reference line and, for Model MBB-BK117 helicopters, revising the RFM.

FAA's Determination

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 of the
unsafe condition described in its ADs. 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 designs.

Related Service Information Under 1 CFR Part 51

Eurocopter (now Airbus Helicopters) issued Alert Service Bulletin
(ASB) No. ASB-MBB-BK117-90-118, Revision 2, dated May 4, 2009, for
certain Model MBB-BK117 helicopters and ASB No. 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.

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.

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)
No. 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 for
certain Model BO105 helicopters.

Eurocopter issued ASB No. ASB-BO 105-80-118, Revision 1, dated
November 29, 1995, and SB No. 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 No. 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.

Proposed AD Requirements

This proposed AD would require, within 50 hours time-in-service
(TIS), visually inspecting the electrical ground connection of each
starter-generator and measuring the resistance between each starter-
generator and its regulator. Depending on these outcomes, this proposed
AD would require replacing the wire terminal. Within 150 hours TIS,
this proposed AD would require installing a wire harness retrofit.

For Model MBB-BK 117 helicopters, this proposed AD would also
require revising the RFM for your helicopter.

Differences Between This Proposed AD and the EASA ADs

The EASA ADs require visually inspecting the wire terminals for
damage, corrosion, and cracks. This proposed AD would require 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 proposed AD would 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 proposed AD would require the same
actions for all Model BO-105 helicopters regardless of serial number.

EASA AD 2015-0220 allows credit for complying with Eurocopter ASB
No. ASB BO105-90-103, Revision 2 or Revision 3, whereas this proposed
AD would not.

Costs of Compliance

The FAA estimates that this proposed 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 proposed AD using an estimated labor cost of $85 per
work-hour.

Performing a visual inspection and resistance measurement of the
electrical ground connection would take 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 would take about 10
work-hours. Required parts for a Model BO-105 helicopter would 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 would cost $1,730 for an estimated replacement cost of
$2,580 per helicopter and $113,520 for the U.S. fleet. Revising the RFM
for Model MBB-BK 117 helicopters would take 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

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
12866,

2. Will not affect intrastate aviation in Alaska to the extent that
it justifies making a regulatory distinction, 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.

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
directive (AD):