Document ID: FAA-2010-0490-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corp. Model S-70A and S-70C Helicopters
Posted Date: 2010-05-13T04:00Z

[Federal Register Volume 75, Number 92 (Thursday, May 13, 2010)]
[Proposed Rules]
[Pages 26888-26889]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-11423]

 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 75, No. 92 / Thursday, May 13, 2010 / 
Proposed Rules  

[[Page 26888]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0490; Directorate Identifier 2010-SW-037-AD]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation 
(Sikorsky) Model S-70A and S-70C Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for the Sikorsky Model S-70A and S-70C helicopters. This proposal 
would require an ultrasonic test (UT) inspection of the tail gearbox 
output bevel gear (gear) for a crack. If you find a crack, replacing 
the gear with an airworthy gear before further flight would be 
required. This proposal is prompted by three gear cracking incidents, 
one of which resulted in the tail rotor separating from the helicopter. 
The actions specified by this proposed AD are intended to detect a 
crack in the gear to prevent a tail rotor separating, loss of tail 
rotor control, and subsequent loss of control of the helicopter.

DATES: Comments must be received on or before July 12, 2010.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    You may get the service information identified in this proposed AD 
from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical 
Support, mailstop s581a, 6900 Main Street, Stratford, CT, telephone 
(203) 383-4866, e-mail address tsslibrary@sikorsky.com, or at http://www.sikorsky.com.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Terry Fahr, Aviation Safety Engineer, 
Boston Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803, telephone (781) 238-7155, fax (781) 238-7170.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA-2010-0490, 
Directorate Identifier 2010-SW-037-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed rulemaking. Using the 
search function of our docket web site, you can find and read the 
comments to any of our dockets, including the name of the individual 
who sent or signed the comment. You may review the DOT's complete 
Privacy Act Statement in the Federal Register published on April 11, 
2000 (65 FR 19477-78).

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located in Room W12-140 on the ground floor of the West Building at the 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

Discussion

    This document proposes adopting a new AD for the Sikorsky Model S-
70A and S-70C helicopters. This proposal would require a UT inspection 
of the gear for a crack. If you find a crack, replacing the gear with 
an airworthy gear would be required before further flight. This 
proposal is prompted by three gear crack incidents, one of which 
resulted in the tail rotor separating from the helicopter. The tail 
gearbox on the helicopter where the tail rotor separated from the 
helicopter experienced a fracture of the output shaft spline that 
drives the tail rotor blades. An investigation into the cause of the 
cracks is ongoing. The unsafe condition described previously, if not 
corrected, could result in a tail rotor separating, loss of tail rotor 
control, and subsequent loss of control of the helicopter.
    We have reviewed Sikorsky Alert Service Bulletin No. 70-06-28A, 
Revision A, dated May 21, 2009 (ASB), which refers to procedures for a 
UT inspection of the gear in accordance with Special Service 
Instructions (SSI) No. 70-121A or latest revision.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type design. Therefore, the proposed AD would 
require a UT inspection of the gear, part number 70358-06620, for a 
crack. If you find a crack, the AD requires replacing the gear with an 
airworthy gear before further flight. The actions would be required to 
be to be done by following the SSI described previously.
    We estimate that this proposed AD would affect 5 helicopters of 
U.S. registry, and the proposed actions would take about 4 work hours 
per helicopter at an average labor rate of $85 per work hour. Required 
parts would cost about $20,000 for each gear. Based on these figures, 
we estimate the total cost impact of the proposed AD on U.S. operators 
to be $101,700, assuming the gear is replaced on the entire fleet.

[[Page 26889]]

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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 above, I certify that the 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); and
    3. 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 a draft economic evaluation of the estimated costs to 
comply with this proposed AD. See the AD docket to examine the draft 
economic evaluation.

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

Sikorsky Aircraft Corp.: Docket No. FAA-2010-0490; Directorate 
Identifier 2010-SW-037-AD.

Applicability

    Model S-70A and S-70C helicopters, tail gearbox output bevel 
gear (gear), part number 70358-06620, certificated in any category.

Compliance

    Required as indicated.
    To prevent a tail rotor separating, loss of tail rotor control, 
and subsequent loss of control of the helicopter, do the following:
    (a) Within 500 hours time-in-service (TIS), unless accomplished 
previously, and thereafter at intervals not to exceed 500 hours TIS, 
remove the tail rotor servo control and pitch beam shaft, and using 
a Level II Ultrasonic Testing Technician or equivalent, ultransonic 
inspect the gear for a crack. Ultrasonic inspect the gear by 
following paragraphs A.(5)a. through A(5)n., Note 7, Special Service 
Instructions (SSI) No. 70-121A, Revision A, dated May 21, 2009. If 
you find a crack, before further flight, replace the gear with an 
airworthy gear.
    (b) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Manager, Boston Aircraft Certification Office, FAA, 
ATTN: Terry Fahr, Aviation Safety Engineer, Boston Aircraft 
Certification Office, 12 New England Executive Park, Burlington, MA 
01803, telephone (781) 238-7155, fax (781) 238-7170, for information 
about previously approved alternative methods of compliance.
    (c) The Joint Aircraft System/Component (JASC) Code is: 6520: 
Tail rotor gearbox.

    Issued in Fort Worth, Texas, on May 3, 2010.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-11423 Filed 5-12-10; 8:45 am]
BILLING CODE 4910-13-P