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

ACTION: Final rule; request for comments.

SUMMARY: We are adopting a new airworthiness directive (AD) that
supersedes an existing Emergency Airworthiness Directive (EAD) for
certain Eurocopter Deutschland GmbH (ECD) Model EC135 helicopters. The
existing EAD, which was previously sent to all known U.S. owners and
operators of ECD Model EC135 helicopters and not made generally
effective by publication in the Federal Register, currently requires
inspecting the ring frame between the rear structure tube (tailboom)
and the tail rotor fenestron housing (fenestron housing) for a crack
before the first flight of each day and replacing any cracked ring
frame with an airworthy ring frame. Since we issued that EAD, we have
determined that a pre-flight pilot check in conjunction with a
recurring 25-hour inspection is sufficient for determining the
airworthiness of the ring frame. Additionally, ECD has developed a
modification that is terminating action for the requirements of that
EAD. This superseding AD revises the inspection requirements of the EAD
to allow an owner/operator to perform the pre-flight pilot check, adds
a recurring inspection of the ring frame, and allows for installation
of a ring frame reinforcement as an optional terminating action for the
AD requirements. The actions are intended to detect a crack in the ring
frame which could result in loss of the fenestron structure and
subsequent loss of control of the helicopter.

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
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: Sharon Miles, Aerospace Engineer, FAA,
Rotorcraft Directorate, Regulations and Policy Group, 2601 Meacham
Blvd., Fort Worth, Texas 76137; phone (817) 222-5110; email:
sharon.y.miles@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

The European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Union, has issued EASA EAD
No.: 2008-0190-E, dated October 13, 2008 (EAD 2008-0190-E), to correct
an unsafe condition for EC135 and EC635 model helicopters. EASA advises
that, during a recent pre-flight check on an EC 135 helicopter, a crack
was detected on the ring frame that connects the tail rotor fenestron
housing to the rear structure tube (tailboom). EASA states that this
condition, if not corrected, could lead to crack propagation remaining
undetected, possibly resulting in loss of the fenestron structure and
loss of control of the helicopter. EAD 2008-0190-E requires
accomplishing a pilot pre-flight check of the rear structure tube for
cracks before each first flight of the day; amending the flight manual
to reflect the pilot pre-flight check; within 25 flight hours, having
the rear structure tube inspected for cracks by a mechanic; and, if any
cracks are detected contacting ECD for approved corrective actions.
On October 16, 2008, we issued EAD No. 2008-22-51 (EAD 2008-22-51)
for the ECD Model EC135 helicopter. That EAD requires, before further
flight and thereafter before the first flight of each day, visually
inspecting the ring frame between the tailboom and fenestron housing
for a crack, and replacing the ring frame with an airworthy ring frame
if there is a crack. That EAD resulted from two reports of cracks on
the ring frame connecting the tail rotor fenestron housing to the
tailboom. The first crack was discovered in Germany and is discussed in
EAD 2008-0190-E. The second crack, which was 9 inches long, was
discovered in the U.S. and was in the same area as the first reported
crack. We issued EAD 2008-22-51 to detect a crack in the ring frame,
which could result in loss of the fenestron structure and subsequent
loss of control of the helicopter.

Actions Since Existing EAD Was Issued

Since we issued EAD 2008-22-51, EASA issued AD No.: 2009-0065,
dated March 13, 2009 (AD 2009-0065), which supersedes EAD 2008-0190-E.
AD 2009-0065 retains the requirements of EAD 2008-0190-E, expands the
applicability to EC 135 helicopters manufactured in Spain, and adds a
repetitive 100-hour inspection of the rear fuselage structure area for
cracks.
EASA next issued AD No.: 2009-0065R1, dated September 8, 2009 (AD
2009-0065R1), which revises AD 2009-0065. EASA advises that ECD has
developed a modification (reinforcement) of the aft ring frame,
including a part number (P/N) change, for both production and in-
service application. Consequently, AD 2009-0065R1 retains the
inspection requirements of AD 2009-0065 but limits its applicability to
helicopters without the reinforced aft ring frame installed, and allows
installation of the reinforced aft ring frame as an optional
terminating action for the repetitive checks and inspections.
EASA then issued AD No.: 2010-0254, dated December 20, 2010 (AD
2010-0254), which supersedes AD 2009-0065R1. AD 2010-0254 retains the
repetitive inspection requirements of AD 2009-0065R1, but reduces the
interval of the visual inspection from 100 hours to 25 hours and
requires installation of the reinforced aft ring frame within 12 months
as terminating action for the repetitive checks and inspections.
Since we issued EAD 2008-22-51, we have determined that a pre-
flight pilot check in conjunction with a recurring 25-hour inspection
is sufficient for determining the airworthiness of the ring frame.
Therefore, we are issuing this AD to revise the inspection
requirements, as well as allow for the optional terminating action
developed by ECD.

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, 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 these same type
designs.

Related Service Information

We reviewed ECD Emergency Alert Service Bulletin (ASB) EC135-53A-
022, Revision 02, dated November 30, 2010 (ASB EC135-53A-022). ASB
EC135-53A-022 describes procedures for a pilot check of the ring frame
during the preflight check. ASB EC135-53A-022 additionally prescribes a
recurring inspection of the ring frame every 25 flight hours and
accomplishment of ECD Service Bulletin EC135-53-023, as corrected
November 13, 2009 (SB EC135-53-023), which describes procedures to
attach a frame reinforcement to the ring frame. The correction
coversheet attached to SB EC135-53-023 is dated November 13, 2009; it
describes the correction on page 6 of the service bulletin. All pages
of the corrected service bulletin show the original issue date of
August 19, 2009; the date has been underlined on page 6 of the
corrected service bulletin. Accomplishment of SB EC135-53-023
constitutes terminating action for the visual inspection requirements
of ASB EC135-53A-022.

AD Requirements

This AD supersedes EAD 2008-22-51 and requires the following:
Before further flight, and thereafter at each preflight
check, performing a visual check of the ring frame which connects the
tail rotor Fenestron housing to the tailboom for a crack. An owner/
operator (pilot) may perform this check because it involves only a
visual check for a crack in the ring frame and can be performed equally
well by a pilot or a mechanic.
Within 25 hours time-in-service (TIS), and every 25 hours
TIS thereafter, removing the tail rotor drive shaft paneling and
inspecting the ring frame for a crack.
As an optional terminating action for the requirements of
this AD, installing a frame reinforcement to the ring frame and re-
identifying the ring frame by following specified portions of the
manufacturer's service bulletin.

Differences Between This AD and the EASA AD

This AD differs from the EASA AD as follows:
The EASA AD requires amendment of the Flight Manual with a
page from ASB EC135-53A-022. Following issuance of the EASA AD, a
revision has been published for the Flight Manuals and the amended
pages are no longer issued with ASB EC135-53A-022. Therefore, this AD
does not require this.
The EASA AD requires modification of the aft ring frame
within 12 months as terminating action; this AD provides it as an
optional terminating action.
The EASA AD applies to the Model EC 635 helicopter, and
this AD does not include this model because it does not have an FAA-
issued type certificate.
The EASA AD includes a ``tolerance'' range for
accomplishment of the pilot check and visual inspections. This AD does
not allow this.

Interim Action

We consider this AD interim action. We are currently considering
requiring the installation of the ECD-developed ring frame modification
as terminating action for the repetitive inspection requirements of
this AD. However, the planned compliance time for the installation of
the modification would allow enough time to provide notice and
opportunity for prior public comment on the merits of the modification.

Costs of Compliance

We estimate that this AD will affect 226 helicopters of U.S.
Registry. We estimate that operators may incur the following costs in
order to comply with this AD. Inspecting the ring frame requires .5
work-hour at an average labor rate of $85 per hour, for a cost per
inspection cycle of $42.50 per helicopter, and a cost to the fleet of
$9,605. Replacing a cracked ring frame will require about 8 work hours
at an average labor rate of $85 per hour, and a parts cost of $7,425,
for a total cost per helicopter of $8,105. Modifying and re-identifying
the ring frame requires 17 work-hours and a parts cost of $1,320, for a
total cost per helicopter of $2,765 and the cost to the fleet is
$624,890.
According to the manufacturer, they will cover all parts costs for
a cracked ring frame, thereby reducing the cost impact on affected
persons. However, as we do not control such coverage by the
manufacturer, we have included all costs in our cost estimate.

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 some of the required checks
and inspections must be accomplished before further flight.
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):