AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Bell Model 206B and 206L helicopters. This AD requires installing a
placard beneath the engine power dual tachometer and revising the
operating limitations section of the rotorcraft flight manual (RFM).
This AD was prompted by several incidents of third stage engine turbine
wheel failures, which were caused by excessive vibrations at certain
engine speeds during steady-state operations. These actions are
intended to alert pilots to avoid certain engine speeds during steady-
state operations, prevent failure of the third stage engine turbine,
engine power loss, and subsequent loss of control of the helicopter.

DATES: This AD is effective December 10, 2013.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of December 10,
2013.

ADDRESSES: For service information identified in this AD, contact Bell
Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel,
Quebec J7J1R4; telephone (450) 437-2862 or (800) 363-8023; fax (450)
433-0272; or at http://www.bellcustomer.com/files/. 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.

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 foreign authority's AD,
any incorporated-by-reference service information, the economic
evaluation, any comments received, and other information. The street
address for the Docket Operations Office (phone: 800-647-5527) is U.S.
Department of Transportation, Docket Operations Office, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Chinh Vuong, Aviation Safety Engineer,
Safety Management Group, Rotorcraft Directorate, FAA, 2601 Meacham
Blvd., Fort Worth, Texas 76137; telephone (817) 222-5110; email
chinh.vuong@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

On June 7, 2013, at 78 FR 34280, the Federal Register published our
notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR
part 39 by adding an AD that would apply to Bell Model 206B
helicopters, serial number (S/N) 004 through 4675, including
helicopters converted from Model 206A and Model 206L helicopters, S/N
45001 through 45153, and 46601 through 46617. The NPRM proposed to
require installing a placard on the instrument panel below the NR/N2
dual tachometer and revising the Operating Limitations section of the
Model 206B RFM and 206L RFM to limit steady-state operation between
speeds of 75% and 88%. The proposed requirements were intended to alert
pilots to avoid certain engine speeds during steady-state operations,
prevent failure of the third stage engine turbine, engine power loss,
and subsequent loss of control of the helicopter.
The NPRM was prompted by AD No. CF-2007-13R2, dated November 10,
2009, issued by Transport Canada Civil Aviation (TCCA), which is the
aviation authority for Canada. TCCA issued AD No. CF-2007-13R2 to
correct an unsafe condition for certain Model 206B (including those
converted from Model 206A) and 206L helicopters. TCCA advises of
several failures of third stage turbine wheels used in Rolls Royce 250-
C20. According to TCCA, Rolls Royce
has determined that detrimental vibrations can occur within a
particular range of turbine speeds, and may be a contributing factor to
these failures. Bell has revised the RFM and has provided a
corresponding decal to inform pilots to avoid steady-state operations
between 75% and 88% turbine speeds.
The TCCA AD requires amending the RFMs, advising pilots of the
change, and installing a decal as described in Bell Alert Service
Bulletin (ASB) No. 206-07-115, Revision C, dated February 4, 2009, for
Model 206B helicopters (ASB 206-07-115) and Bell ASB No. 206L-07-146,
Revision B, dated March 3, 2009, for Model 206L helicopters (ASB 206L-
07-146).

Comments

After our NPRM (78 FR 34280, June 7, 2013) was published, we
received comments from one commenter.

Request

Rolls-Royce Corporation requested that in addition to requiring the
placard on the instrument panel, we allow operators the option to
temporarily mark the Nr/Np gauge with colored
tape, to provide a more visual aide to the pilot for the speed
avoidance zone.
We disagree. Marking the glass surface of the gauge can create
parallax issues when viewing the avoidance ranges on the gauge,
resulting in erroneous readings.

FAA's Determination

These helicopters have been approved by the aviation authority of
Canada and are approved for operation in the United States. Pursuant to
our bilateral agreement with Canada, TCCA, its technical
representative, has notified us of the unsafe condition described in
the TCCA AD. We are issuing this AD because we evaluated all
information provided by TCCA, reviewed the relevant information,
considered the comment received, and determined the unsafe condition
exists and is likely to exist or develop on other helicopters of the
same type design and that air safety and the public interest require
adopting the AD requirements as proposed.

Differences Between This AD and the TCCA AD

The TCCA AD requires compliance within 10 calendar days, while this
AD requires compliance within 30 days.

Related Service Information

Bell has issued ASB 206-07-115 and ASB 206L-07-146, which contain
procedures for installing a placard on the instrument panel below the
main rotor RPM (Nr)/power turbine RPM (N2) dual tachometer and for
inserting the RFM changes into the flight manual.

Costs of Compliance

We estimate that this AD will affect 970 helicopters of U.S.
Registry. Based on an average labor rate of $85 per hour, we estimate
that operators will incur the following costs in order to comply with
this AD. Amending the RFM will require about 0.5 work-hour, for a cost
per helicopter of about $43 and a cost to U.S. operators of $41,710.
Installing the decal will require about 0.2 work-hour and required
parts will cost $20, for a cost per helicopter of $37 and a cost to
U.S. operators of $35,890. Based on these estimates, the total cost of
this AD is $80 per helicopter and $77,600 for the U.S. operator 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.
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 helicopters 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) 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):