AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

SUMMARY: We are superseding an existing airworthiness directive (AD)
for all Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 C-2
helicopters. That AD currently requires revising the ``Emergency and
Malfunction Procedures'' and ``Performance Data'' sections of the
Rotorcraft Flight Manual (RFM) by inserting three temporary pages into
the RFM to alert pilots to monitor the power display when a generator
is deactivated and provides procedures to prevent failure of the
remaining generator. Before we issued that AD, the manufacturer
developed a procedure to modify the two ``After Junction Boxes'' by
removing a diode from each box, which provides terminating action for
our AD requirements. These actions are intended to require implementing
this terminating action to prevent an electrical power system failure
and subsequent loss of control of the helicopter and revising the RFM
accordingly, by removing the temporary pages inserted to comply with
the superseded AD.

DATES: This AD becomes effective July 10, 2012.
The Director of the Federal Register approved the incorporation by
reference of certain documents listed in this AD as of July 10, 2012.
We must receive comments on this AD by August 24, 2012.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to http://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 http://www.regulations.gov 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 AD, the economic
evaluation, any comments received and other information. The street
address for the Docket Operations Office (telephone 800-647-5527) is in
the ADDRESSES section. Comments will be available in the AD docket
shortly after receipt.
For service information identified in this AD, contact American
Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 75052,
telephone (972) 641-0000 or (800) 232-0323, fax (972) 641-3775, or at
http://www.eurocopter.com/techpub. You may review a copy of the service
information at the FAA, Office of the Regional Counsel, Southwest
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: George Schwab, Aviation Safety
Engineer, FAA, Rotorcraft Directorate, Safety Management Group, 2601
Meacham Blvd., Fort Worth, TX 76137, telephone (817) 222-5110, email:
george.schwab@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and we did not provide you with notice and an opportunity to
provide your comments prior to it becoming effective. However, we
invite you to participate in this rulemaking by submitting written
comments, data, or views. We also invite comments relating to the
economic, environmental, energy, or federalism impacts that resulted
from adopting this AD. The most helpful comments reference a specific
portion of the AD, 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 them only one time. We will file in the docket all comments that we
receive, as well as a report summarizing each substantive public contact with
FAA personnel concerning this rulemaking during the comment period. We will
consider all the comments we receive and may conduct additional rulemaking
based on those comments.

Discussion

On September 29, 2011, we issued AD 2011-21-13 (76 FR 68299,
November 4, 2011), for all ECD model MBB-BK 117 C-2 helicopters. Our AD
2011-21-13 was based on European Aviation Safety Agency (EASA)
Emergency AD No. 2010-0268-E, dated December 21, 2010 (EAD 2010-0268-
E), requiring the introduction of additional RFM procedures to monitor
the electrical power display generator amperes (GEN AMPS) on the
Vehicle and Engine Multifunction Display (VEMD) during switching of the
generator. EASA advised that some ECD MBB-BK117 C-2 helicopters
detected an excessive current flow when one generator was deactivated.
This situation, if not detected and corrected, could lead to failure of
the generator, likely resulting in loss of electrical power and
inducing loss of systems that are necessary for safe flight. To address
this unsafe condition, AD 2011-21-13 requires revising the ``Emergency
and Malfunction Procedures'' and the ``Performance Data'' sections of
the RFM by inserting three temporary pages from ECD Alert Service
Bulletin (ASB) No. ASB MBB BK117 C-2-24A-008, dated December 20, 2010
(MBB BK117 C-2-24A-008). Those pages require operators to insert pages
into the RFM, which provide that pilots visually monitor the power
display GEN AMPS on the VEMD for too high of a current when a generator
is shut down, such as during the ENGINE POWER CHECK. These revised RFM
provisions provide for switching off the two main electrical buses on
the overhead panel to prevent the operating generator from being
damaged when the other generator is shut down. We issued AD 2011-21-13
to prevent failure of a generator, which could result in loss of
electrical power, loss of systems necessary for flight safety, and
subsequent loss of control of the helicopter.

Actions Since Existing AD Was Issued

Before we issued AD 2011-21-13 (76 FR 68299, November 4, 2011),
EASA, which is the Technical Agent for the Member States of the
European Union, issued EASA AD No. 2011-0162, dated August 30, 2011 (AD
2011-0162). In AD 2011-0162, EASA states that ECD has developed a
modification to prevent the possibility of too high current flow when a
generator is deactivated, and updated the RFM procedures accordingly.
This EASA AD requires the RFM changes introduced by EAD 2010-0268-E to
be removed. The EASA AD also requires modification of the Generator
Relay left-hand and right-hand After Junction Boxes by removing diodes,
CR10007 and CR10008, respectively, on ECD MBB-BK117 C-2 helicopters,
serial numbers 9004 through 9500. Through this AD action, the FAA is
requiring this same modification to the After Junction Boxes in
helicopters registered in the United States and removal of the same
pages from the RFM that were introduced by AD 2011-21-13.

FAA's Determination

These helicopters have been approved by the aviation authority of
the Federal Republic of Germany (FRG) and are approved for operation in
the United States. Pursuant to our bilateral agreement with the FRG,
EASA, their technical representative, has notified us of the unsafe
condition described in the EASA AD. We are issuing this AD because we
evaluated all information provided by EASA and determined the unsafe
condition is likely to exist or develop on other helicopters of the
same type design.

Related Service Information

We reviewed ECD ASB MBB BK117 C-2-24A-008, Revision 1, dated August
29, 2011. The ASB describes procedures for removing two diodes on the
generator relays in the After Junction Boxes. EASA classified this ASB
as mandatory and issued AD 2011-0162 to ensure the continued
airworthiness of these helicopters.

AD Requirements

This AD requires, within 30 days, removing temporary pages from the
RFM that were inserted for AD 2011-21-13. This AD also requires
modifying Generator Relay left-hand and right-hand After Junction Boxes
by removing diodes, CR10007 and CR10008.

Differences Between This AD and the EASA AD

The EASA AD requires compliance by September 6, 2011; the FAA
requires compliance within 30 days from the effective date of the AD.

Costs of Compliance

We estimate that this AD affects 232 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to
comply with this AD. Removing the diodes from the after junction boxes
will require 2 work hours at an average labor cost of $85 per hour and
incorporating the changes into the RFM will require .5 work hour for a
total cost per operator of $213 and a cost to the entire U.S. fleet of
$49,416.

FAA's Justification and Determination of the Effective Date

Providing an opportunity for public comments prior to adopting
these AD requirements would delay implementing the safety actions
needed to correct this known unsafe condition. Therefore, we find that
the risk to the flying public justifies waiving notice and comment
prior to the adoption of this rule because the required corrective
actions must be accomplished within 30 days.
Since an unsafe condition exists that requires the immediate
adoption of this AD, we determined that notice and opportunity for
public comment before issuing this AD are impracticable and contrary to
the public interest and that good cause exists for making this
amendment effective in less than 30 days.

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.
We are 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

We determined that 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, I certify that this AD:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979);
3. Will not affect intrastate aviation in Alaska to the extent that
it justifies making a regulatory distinction; and
4. 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.
We prepared an economic evaluation of the estimated costs to comply
with this AD and placed it in the AD docket.

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 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 removing Amendment 39-16836 (76 FR
68299, November 4, 2011), and adding the following new airworthiness
directive (AD):