AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule; request for comments.

SUMMARY: We are adopting a new airworthiness directive (AD) for AHD
Model EC135P1, P2, P2+, T1, T2, and T2+ helicopters. This AD requires
repetitive visual inspections of the ring frame X9227 for a crack and,
if there is a crack, replacing the ring frame before further flight.
This AD is prompted by a fatigue crack in the ring frame. These actions
are intended to detect a crack in the ring frame and prevent loss of
the tail rotor and subsequent loss of control of the helicopter.

DATES: This AD becomes effective July 30, 2014.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of July 30, 2014.
We must receive comments on this AD by September 15, 2014.

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 European Aviation Safety
Agency (EASA) AD, the economic evaluation, any incorporated by
reference service information, 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 Airbus
Helicopters, Inc., 2701 N. Forum Drive, Grand Prairie, TX 75052;
telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at
http://www.airbushelicopters.com/techpub.
You may review the referenced 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: Matt Fuller, Senior Aviation Safety
Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 2601
Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5110; email
matthew.fuller@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

We are adopting a new AD for AHD Model EC135P1, P2, P2+, T1, T2,
and T2+ helicopters with certain mounting ring frames installed. This
AD requires repetitive visual inspections of the ring frame X9227 for a
crack and, if there is a crack, replacing the ring frame with an
airworthy part before further flight. These actions are intended to
detect a crack in the ring frame and prevent loss of tail rotor and
subsequent loss of control of the helicopter.
This AD was prompted by AD No. 2013-0289-E, dated December 6, 2013,
issued by EASA, which is the Technical Agent for the Member States of
the European Union, to correct an unsafe condition for AHD Model
EC135P1, EC135P2, EC135P2+, EC135T1, EC135T2, EC135T2+, EC635P2+,
EC635T1, and EC635T2+ helicopters equipped with mounting ring frame
X9227, part number (P/N) L535H2120301, P/N L535H2120303, or P/N
L535H2120304 without frame reinforcement. EASA advises that ring frames
X9227 with frame reinforcement P/N L535H2100201 are not affected by its
AD. EASA advises that the fuselage tail boom structure of the EC135/
EC635 type design is connected to the tail rotor ``fenestron'' housing
by means of a ring frame attached by two rivet rows each. EASA states
that during a recent post flight check, the pilot detected a crack that
ran along three rivets across the ring frame. According to EASA, this
condition if not corrected would gradually reduce the structural
integrity of the tail boom fenestron attachment, potentially resulting
in detachment of the fenestron and loss of the helicopter. To address
this condition, EASA AD No. 2013-0289-E requires repetitive visual
inspections of the ring frame X9227.

FAA's Determination

These helicopters have been approved by the aviation authority of
Germany and are approved for operation in the United States. Pursuant
to our bilateral agreement with Germany, EASA, its 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 exists
and is likely to exist or develop on other helicopters of these same
type designs.

Related Service Information

Eurocopter issued Safety Information Notice No. 2636-S-53, dated
October 10, 2013, alerting operators that during a post-flight check a
pilot discovered a crack at the rear ring frame between the rear
structure tube and the fenestron box. The Notice reminds operators to
conduct the dedicated visual ring frame check according to the flight
manual's pre-flight check so any cracked ring frames will be
immediately discovered.
Eurocopter also issued Alert Service Bulletin ASB EC 135-53A-029,
Revision 0, dated November 19, 2013 (ASB). The ASB specifies, every 50
flight hours, visually inspecting ring frame X9227 for a crack in
addition to the visual pre-flight check of the ring frame. The ASB
states that a crack within the ring frame and between the rivet heads
is not permissible, and if detected in this area, AHD must be contacted
before further flight.

AD Requirements

This AD requires, on or before reaching 100 hours TIS, or within 50
hours TIS for helicopters with more than 100 hours TIS, and thereafter
at intervals not to exceed 50 hours TIS, using a 10X or higher power
magnifying glass and a light, visually inspecting the ring frame X9227
for a crack between the rivets. If a crack is found, this AD requires,
before further flight, replacing the ring frame X9227 with an airworthy
part.

Differences Between This AD and the EASA AD

The EASA AD applies to EC635P2+, EC635T1, and EC635T2+ helicopters,
and this AD does not because those helicopters are non-FAA type
certificated. The EASA AD requires contacting the manufacturer if a
crack is found in the ring frame. This AD requires replacing the ring
frame if a crack is found.

Costs of Compliance

We estimate that this AD will affect 275 helicopters of U.S.
Registry.
We estimate that operators may incur the following costs in order
to comply with this AD. Labor costs are estimated at $85 per work hour.
We estimate 0.2 work hour to do the inspection for a total estimated
cost of $17 per helicopter and $4,675 for the U.S. fleet per inspection
cycle. Replacing a ring frame will require 5 work hours and $18,500 for
parts for a total cost of $18,925 per helicopter.

FAA's Justification and Determination of the Effective Date

Providing an opportunity for public comments before 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 before
adopting this rule because the required corrective actions in a
structural critical area must be done within 50 hours TIS, a very short
time period based on the average flight-hour utilization rate for air
ambulance and law enforcement operations of these helicopters.
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 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 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 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
directive (AD):