Document ID: FAA-2012-0340-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corp. Helicopters
Posted Date: 2012-03-29T04:00Z

[Federal Register Volume 77, Number 61 (Thursday, March 29, 2012)]
[Proposed Rules]
[Pages 18969-18970]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-7541]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0340; Directorate Identifier 2011-SW-073-AD]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76C 
helicopters. This proposed AD is 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.

DATES: We must receive comments on this proposed AD by May 29, 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 proposed 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 proposed 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.
    You may review copies 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: Kirk Gustafson, Aerospace Engineer, 
FAA, Boston Aircraft Certification Office, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
telephone (781) 238-7190; email kirk.gustafson@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    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 might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, 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 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 proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    We are proposing this AD as the result of an accident investigation 
which concluded that a bird-strike to the upper portion of the 
windshield caused significant forces to be transferred into the 
overhead engine control quadrant assembly. This caused both ECLs to 
move aft from the normal ``FLY'' position toward the ``IDLE'' position. 
Unintended in-flight movement of the ECLs from the ``FLY'' position 
significantly reduced engine power, and resulted in an unrecoverable 
loss of main rotor speed and loss of control of the aircraft. A 
subsequent National Transportation Safety Board (NTSB) investigation 
resulted in a recommendation to modify the design of the engine control 
quadrant to protect against unintended movement of the ECLs from 
external force to the windshield or canopy. Sikorsky then issued Alert 
Service Bulletin (ASB) No. 76-76-6A, Revision A, dated May 18, 2011 
(ASB 76-76-6A) which describes procedures to modify the engine control 
quadrant assembly with an improved throttle stop and a wider trigger 
assembly.

FAA's Determination

    We are proposing this AD because we evaluated all known relevant 
information and determined that an unsafe condition exists and is 
likely to exist or develop on other products of the same type design.

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.

[[Page 18970]]

Proposed AD Requirements

    This proposed AD would require, for S-76C model helicopters with 
serial numbers 760506 and 760607 through 760812, within 6 months after 
the effective date of the proposed AD, installing an improved throttle 
stop and a wider trigger on each ECL as specified in the ASB.

Differences Between This Proposed AD and the Service Information

    The Sikorsky ASB requires installation of the modifications on or 
before March 7, 2012. The proposed AD requires installation within 6 
months after the effective date of the AD.

Costs of Compliance

    We estimate that this proposed AD would 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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
    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 proposed 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.

The Proposed 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 adding the following new 
Airworthiness Directive (AD):

Sikorsky Aircraft Corporation: 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) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless accomplished 
previously.

(d) 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.

(e) Alternative Methods of Compliance (AMOC)

    (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, MA 01803; telephone (781) 238-7190; email 
kirk.gustafson@faa.gov.
    (2) For operations conducted under a Part 119 operating 
certificate or under 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.

(f) Subject

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

    Issued in Fort Worth, Texas, on March 20, 2012.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2012-7541 Filed 3-28-12; 8:45 am]
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