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[Federal Register: January 27, 2010 (Volume 75, Number 17)]
[Proposed Rules]               
[Page 4308-4310]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27ja10-25]                         

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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.

[[Page 4309]]

     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 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

[[Page 4310]]

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 Corporation: Docket No. FAA-2010-0060; Directorate 
Identifier 2010-SW-06-AD.

    Applicability: Model S-92A helicopters, with main gearbox (MGB) 
filter bowl assembly, part number (P/N) 92351-15802-101, installed, 
certificated in any category.
    Compliance: Required as indicated, unless done previously.
    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, do the following:
    (a) Within 60 days:
    (1) Remove the MGB filter bowl assembly by following the 
Accomplishment Instructions, paragraphs 3.A.(1) through 3.A.(5), of 
Sikorsky Alert Service Bulletin No. 92-63-022A, dated December 18, 
2009 (ASB).
    (2) Remove the primary filter element, P/N 70351-38801-102, from 
the MGB lube system filter and visually inspect it for damage as 
depicted in Figures 1, 2, and 3 of the ASB. If the primary filter 
element has ``wavy'' pleats, internal buckling, or indented dimples, 
before further flight, replace it with an airworthy filter element.
    (3) Visually inspect the secondary filter element, P/N 70351-
38801-103, for damage as depicted in Figures 4 and 5 of the ASB. If 
the secondary filter element has ``wavy'' pleats or an elongated 
cup, before further flight, replace it with an airworthy filter 
element.
    (4) Replace the MGB lube system filter assembly mounting studs:
    (i) Remove the studs by following the Accomplishment 
Instructions, paragraphs 3.B.(1) through 3.B.(4) of the ASB. 
Visually inspect the tapped holes for any damage to the threads. 
Serrations on the entire counter bore (360 degrees) are acceptable. 
Serrations in the housing must be intact, and mating serrations on 
the lock ring must line up with serrations on the housing. Visually 
inspect the housing to determine that the housing threads are free 
from damage and corrosion. Visually inspect housing lockring 
counterbore to determine if the housing is airworthy.
    (ii) If you find damage or corrosion to the housing threads, the 
housing, or the lockring counterbore, stop work and 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.
    (iii) If you do not find damage to the housing threads, the 
housing, or the lockring counterbore that requires repair, replace 
the mounting studs by following the Accomplishment Instructions, 
paragraphs 3.B.(7) through 3.B.(15) of the ASB.
    (5) Install an airworthy, two-piece MGB filter bowl assembly 
modification kit, P/N 92070-35005-011, as depicted in Figures 8 and 
9 of the ASB and by following the Accomplishment Instructions, 
paragraphs 3.C.(1) through 3.C.(20), of the ASB.
    (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, ATTN: 
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, for information about previously approved 
alternative methods of compliance.
    (c) The Joint Aircraft System/Component (JASC) Code is 6320: 
Main Rotor Gearbox.

    Issued in Fort Worth, Texas, on January 20, 2010.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-1521 Filed 1-26-10; 8:45 am]
BILLING CODE 4910-13-P
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