AD 2012-22-13

We are adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters. This AD requires installing an improved throttle stop and a wider trigger on the engine control levers (ECL). This AD was prompted by a bird-strike to the windshield that resulted in unintended movement of the engine control levers from the forward position and towards the flight-idle position, which reduced power on both engines. These actions are intended to prevent unintended movement of the ECLs, resulting in main rotor speed decay and subsequent loss of control of the aircraft.

Final rule.

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

0 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]

0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):

2012-22-13 Sikorsky Aircraft Corporation: Amendment 39-17250; Docket No. FAA-2012-0340; Directorate Identifier 2011-SW-073-AD.

(a) Applicability

This AD applies to Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters, serial numbers 760506 and 760607 through 760812, certificated in any category.

(b) Unsafe Condition

This AD defines the unsafe condition as unintended movement of the engine control levers due to an external force to the windshield or canopy. This condition could result in significantly reduced engine power, unrecoverable loss of main rotor speed, and subsequent loss of control of the helicopter.

(c) Effective Date

This AD becomes effective December 20, 2012.

(d) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.

(e) Required Action

Within 6 months, replace the throttle stop and trigger assembly on each engine control lever and perform a throttle position check as specified in the Accomplishment Instructions, Sections 3.A and 3.B, of Sikorsky Alert Service Bulletin No. 76-76-6A Revision A, dated May 18, 2011.

(f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Boston Aircraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Kirk Gustafson, Aerospace Engineer, FAA, Boston Aircraft Certification Office, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA01803; telephone (781) 238-7190; email kirk.gustafson@faa.gov.
(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

(g) Subject

Joint Aircraft Service Component (JASC) Code: 7600: Engine Controls.

(h) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.
(i) Sikorsky Alert Service Bulletin No. 76-76-6A Revision A, dated May 18, 2011.
(ii) Reserved.
(3) ForSikorsky service information identified in this AD, contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone (203) 383-4866, email address tsslibrary@sikorsky.com, or at http://www.sikorsky.com.
(4) You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.
(5) You may also view this service information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion

On March 29, 2012, at 77 FR 18969, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to include an AD that would apply to Sikorsky Model S-76C helicopters with serial numbers 760506 and 760607 through 760812. That NPRM proposed to require within 6 months after the effective date of the AD, installing an improved throttle stop and a wider trigger on each ECL as specified in Sikorsky Alert Service Bulletin (ASB) No. 76- 76-6A, Revision A, dated May 18, 2011.
The proposed requirements were intended to prevent unintended in- flight movement of the ECLs from the normal ``FLY'' position towards the ``IDLE'' position, which significantly reduces engine power, resulting in an unrecoverable loss of main rotor speed and subsequent loss of control of the helicopter.

Comments

Two commenters, one anonymous and one from the National Transportation Safety Board, commented thatthey support the NPRM (77 FR 18969, March 29, 2012).

FAA's Determination

We have reviewed the relevant information and determined that an unsafe condition exists and is likely to exist or develop on other products of the same type design and that air safety and the public interest require adopting the AD requirements as proposed.

Related Service Information

We reviewed ASB 76-76-6A, which describes procedures for partially disassembling the engine control quadrant assembly, removing the existing throttle stop, and installing a new airworthy throttle stop. The ASB also describes procedures to remove the existing trigger assembly from each ECL and install a new airworthy wide trigger assembly.

Costs of Compliance

We estimate that this AD will affect 52 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD. To replace the engine control lever stop and trigger assemblies will require 2 work-hours at an average labor cost of $85 per hour. Required parts will cost about $939. Based upon these costs, we estimate a total cost of $1,109 per helicopter and a total cost of $57,668 for the entire 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 products 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;

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(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.