[Federal Register Volume 70, Number 120 (Thursday, June 23, 2005)]
[Rules and Regulations]
[Pages 36333-36334]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-12417]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21588; Directorate Identifier 2005-SW-24-AD; 
Amendment 39-14150; AD 2005-13-13]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
92A Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
the Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. 
This action requires replacing a certain part-numbered tail gear box 
output housing that has 600 or more hours time-in-service (TIS) with an 
airworthy part. Also, this AD revises the Airworthiness Limitations 
section of the maintenance manual by reducing the life limit of the 
tail gear box output housing. This amendment is prompted by the 
premature failure of the tail gear box output housing during fatigue 
testing by the manufacturer. The actions specified in this AD are 
intended to prevent fatigue failure of the tail gear box output 
housing, loss of tail rotor drive, and subsequent loss of control of 
the helicopter.

DATES: Effective July 8, 2005.
    Comments for inclusion in the Rules Docket must be received on or 
before August 22, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically;
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically;
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590;
     Fax: (202) 493-2251; or
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the Docket

    You may examine the docket that contains the AD, any comments, and 
other information on the Internet at http://dms.dot.gov, or in person 
at the Docket Management System (DMS) Docket Offices between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The Docket 
Office (telephone (800) 647-5227) is located on the plaza level of the 
Department of Transportation Nassif Building at the street address 
stated in the ADDRESSES section. Comments will be available in the AD 
docket shortly after the DMS receives them.

FOR FURTHER INFORMATION CONTACT: Wayne Gaulzetti, Aviation Safety 
Engineer, Boston Aircraft Certification Office, 12 New England 
Executive Park, Burlington, MA 01803, telephone (781) 238-7156, fax 
(781) 238-7170.

SUPPLEMENTARY INFORMATION: This amendment adopts a new AD for the 
Sikorsky Model S-92A helicopters. This action requires, before further 
flight, replacing tail gear box output housing, part number (P/N) 
92358-06109-043, that has 600 or more hours TIS with an airworthy gear 
box output housing with less than 600 hours TIS. Also, this AD revises 
the Airworthiness Limitations section of the maintenance manual by 
reducing the life limit of the tail gear box output housing from 4500 
hours TIS to 600 hours TIS. This amendment is prompted by the premature 
failure of the tail gear box output housing during fatigue testing by 
the manufacturer. The follow-on investigation indicated the 
manufacturing process created an oxide skin defect in the housing, 
making it necessary to reduce the life limit of the gear box housing 
from 4500 hours TIS to 600 hours TIS. The manufacturer is reviewing its 
processes on the output housing to determine methods, including a 
material change, to prevent the oxide skin defect.
    In Chapter 4 of the Sikorsky S-92 Maintenance Manual, SA S92A-AWL-
000, the tail gear box output housing is noted as a critical part. 
Further, in Note 12 to those Airworthiness Limitations and Inspection 
Requirements, the manufacturer states to remove the Tail Gear Box 
Assembly, P/N 92358-06100-043, which contains the Tail Gear Box Output 
Housing, P/N 92358-06109-043, and send it ``to a manufacturer 
authorized repair center for replacement of the time limited 
components.'' This AD does not require you to send the gear box 
assembly or output housing to a manufacturer authorized repair center 
or to the manufacturer. However, any entity removing and replacing the 
gear box assembly, output housing, or the critical parts within each of 
those components must be qualified and have approved data to perform 
that maintenance.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type design. Therefore, this AD is being issued 
to prevent fatigue failure of the tail gear box output housing, loss of 
tail rotor drive, and subsequent loss of control of the helicopter. 
This AD requires, before further flight, replacing each tail gear box 
output housing, P/N 92358-06109-043, with 600 or more hours TIS with an 
airworthy part. Also, this AD revises the Airworthiness Limitations 
section of the maintenance manual by reducing the life limit of the 
tail gear box output housing from 4500 hours TIS to 600 hours TIS.
    The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
controllability or structural integrity of the helicopter. Some 
operators may have already exceeded the 600 hours TIS. Therefore, 
replacing each tail gear box output housing that has reached 600 or 
more hours TIS with an airworthy tail gear box output housing is 
required before further flight and this AD must be issued immediately.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.
    We estimate that this AD will affect 4 helicopters of U.S. 
registry, and replacing the tail gear box output housing will take 
about 8 work hours at an average labor rate of $65 per work hour. 
Required parts will cost about $4291 per helicopter. Based on these 
figures, we estimate the total cost impact of the AD on U.S. operators 
to be $19,244.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any written data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-21588; 
Directorate Identifier 2005-SW-24-AD''

[[Page 36334]]

at the beginning of your comments. We specifically invite comments on 
the overall regulatory, economic, environmental, and energy aspects of 
the AD. We will consider all comments received by the closing date and 
may amend the AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. 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 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), or you may visit http://dms.dot.gov.

Regulatory Findings

    We have 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 above, I certify that the 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 an economic evaluation of the estimated costs to comply 
with this AD. See the DMS to examine the 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, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2005-13-13 Sikorsky Aircraft Corporation: Amendment 39-14150. Docket 
No. FAA-2005-21588; Directorate Identifier 2005-SW-24-AD.

    Applicability: Model S-92A helicopters, with a gear box output 
housing, part number (P/N) 92358-06109-043, installed, certificated 
in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue failure of the tail gear box output housing, 
loss of tail rotor drive, and subsequent loss of control of the 
helicopter, do the following:
    (a) Before further flight, replace each tail gear box output 
housing, P/N 92358-06109-043, with 600 or more hours time-in-service 
(TIS) with an airworthy tail gear box housing with less than 600 
hours TIS.

    Note: Sikorsky Maintenance Manual SA S92A-AWL-000, Airworthiness 
Limitations and Inspection Requirements, Chapter 4, dated March 3, 
2005, contains the limitation for the tail gear box output housing.

    (b) This AD revises the Airworthiness Limitations section of the 
maintenance manual by reducing the life limit of the tail gear box 
output housing from 4500 hours TIS to 600 hours TIS.
    (c) 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 Boston Aircraft Certification Office, FAA, for 
information about previously approved alternative methods of 
compliance.
    (d) This amendment becomes effective on July 8, 2005.

    Issued in Fort Worth, Texas, on June 10, 2005.
S. Frances Cox,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 05-12417 Filed 6-22-05; 8:45 am]
BILLING CODE 4910-13-P