DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
14 CFR Part 39
[Docket No. FAA-2010-0060; Directorate Identifier 2010-SW-06-AD] RIN 2120
-AA64
AIRWORTHINESS DIRECTIVES; Sikorsky Aircraft Corporation (Sikorsky) Model
S-92A 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-92A helicopters. The AD would require
replacing the main gearbox (MGB) filter bowl assembly with a two-piece MGB
filter bowl assembly and replacing the existing mounting studs. The AD
would also require inspecting the MGB lube system filters, the housing,
the housing threads, and the lockring counterbore and repairing or
replacing them as necessary. This proposed AD is prompted by tests
indicating that an existing MGB filter bowl assembly can fail under
certain loading conditions including those associated with a damaged MGB
filter or mounting stud resulting from high frequency maintenance tasks.
Testing of the improved MGB filter bowl assembly demonstrates a
significant increase in strength and durability over the existing filter
bowl. The actions specified by this proposed AD are intended to prevent
failure of the MGB filter bowl assembly due to failure of the mounting
studs or the filter bowl, loss of oil from the MGB, failure of the MGB,
and subsequent loss of control of the helicopter.
DATES: Comments must be received on or before March 29, 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.
FOR FURTHER INFORMATION CONTACT: Kirk Gustafson, Aviation Safety Engineer,
Boston Aircraft Certification Office, Engine and Propeller Directorate,
FAA, 12 New England Executive Park, Burlington, MA 01803, telephone (781)
238-7190, 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-2010-0060, Directorate
Identifier 2010-SW-06-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.
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-92A
helicopters. The AD would require replacing the MGB filter bowl assembly
with a two-piece MGB filter bowl assembly and replacing the existing
mounting studs. The AD would also require inspecting the MGB lube system
filters, the housing, the housing threads, and the lockring counterbore
and repairing and replacing them as necessary. This proposed AD is
prompted by tests indicating the existing MGB filter bowl assembly can
fail under certain loading conditions including those associated with a
damaged MGB filter or mounting stud resulting from high frequency
maintenance tasks that can lead to complete loss of oil from the MGB.
Testing of the improved MGB filter bowl assembly demonstrates a reduced
susceptibility to damage of MGB filter bowl assembly during routine
maintenance. This proposed AD is intended to prevent failure of the MGB
filter bowl assembly due to failure of the mounting studs or the filter
bowl, loss of oil from the MGB, failure of the MGB, and subsequent loss of
control of the helicopter.
We have reviewed Sikorsky Alert Service Bulletin No. 92-63-022A, dated
December 18, 2009 (ASB), which describes procedures for replacing the
existing MGB filter bowl assembly with a new, two-piece filter bowl
assembly. The ASB also describes procedures for replacing the existing
studs with new studs.
This unsafe condition is likely to exist or develop on other helicopters
of the same type design. Therefore, the proposed AD would require the
following within 60 days.
Removing the MGB filter bowl assembly and the MGB lube system filter.
Removing the primary filter element, part number (P/N) 70351-38801-102,
and visually inspecting it for damage. If the primary filter element has
"wavy" pleats, internal buckling, or indented dimples, before further
flight, replacing it with an airworthy filter element.
Visually inspecting the secondary filter element, P/N 70351-38801-103, for
damage. If the secondary filter element has "wavy" pleats or an elongated
cup, before further flight, replacing it with an airworthy filter element.
Replacing the MGB lube system filter assembly mounting studs by removing
the studs and visually inspecting the tapped holes for any damage to the
threads, visually inspecting the housing to determine that the housing
threads are free from damage and corrosion, and visually inspecting
housing lockring counterbore to determine if the housing is airworthy.
If you find damage or corrosion to the housing threads, the housing, or
the lockring counterbore, stopping work and contacting the FAA.
If you do not find damage to the housing threads, the housing, or the
lockring counterbore that requires repair, replacing the mounting studs.
Installing an airworthy, two-piece MGB filter bowl assembly modification
kit, P/N 92070-35005-011.
The AD would require that specified portions of the ASB be followed.
We estimate that this proposed AD would affect 22 helicopters of U.S.
registry. We also estimate that it would take about 6 hours to inspect the
existing filter bowl assembly and replace the MGB lube system filters, the
mounting studs, and to install an improved filter bowl assembly at an
average labor rate of $80 per work hour. Required parts would cost about
$3,257 per helicopter. Based on these figures, the total cost impact of
the proposed AD on U.S. operators would be $82,214.
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 Proc-
edures (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, meth-
ods, 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 prod-
ucts 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: