Document ID: FAA-2010-1136-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Sikorsky Aircraft Corp. Model S-92A Helicopters
Posted Date: 2010-11-19T05:00Z

[Federal Register Volume 75, Number 223 (Friday, November 19, 2010)]
[Rules and Regulations]
[Pages 70812-70814]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-29201]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-1136; Directorate Identifier 2010-SW-069-AD; 
Amendment 39-16522; AD 2010-24-04]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD) for Sikorsky Model S-92A helicopters that currently requires 
cleaning and inspecting each main gearbox (MGB) assembly mounting foot 
pad and rib for a crack and corrosion. If you do not find a crack, the 
AD requires applying a corrosion preventive compound. If you find a 
crack, the AD requires replacing the MGB before further flight. If you 
find corrosion, bubbled paint, or paint discoloration, the AD requires 
you to repair the MGB before further flight. This amendment retains the 
current requirements and expands the applicability to include another 
part-numbered MGB assembly and MGB housing. This amendment is prompted 
by the need to expand the applicability to include another MGB assembly 
and MGB housing that is prone to the same cracks and corrosion as the 
MGB listed in the current AD. The actions specified by this AD are 
intended to prevent the loss of the MGB and subsequent loss of control 
of the helicopter.

DATES: Effective December 6, 2010.
    The incorporation by reference of certain publications listed in 
the regulations was approved previously by the Director of the Federal 
Register as of February 19, 2010 (75 FR 5684, February 4, 2010).
    We must receive comments on this AD by January 18, 2011.

ADDRESSES: Use one of the following addresses to comment on this 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 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.
    Examining the Docket: You may examine the docket that contains the 
AD, any comments, and other information 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 Docket Operations office (telephone (800) 647-

[[Page 70813]]

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.

FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aviation Safety 
Engineer, Boston Aircraft Certification Office, 12 New England 
Executive Park, Burlington, MA 01803, telephone (781) 238-7761, fax 
(781) 238-7170.

SUPPLEMENTARY INFORMATION: On December 18, 2009, we issued AD 2009-23-
51, Amendment 39-16190 (75 FR 5684, February 4, 2010), to require 
cleaning and inspecting each MGB assembly mounting foot pad and rib for 
a crack and corrosion. If you do not find a crack, the AD requires 
applying a corrosion preventive compound. If you find a crack, the AD 
requires replacing the MGB before further flight. If you find 
corrosion, bubbled paint, or paint discoloration, the AD requires you 
to repair the MGB before further flight. That action was prompted by 
reports of cracks in the MGB mounting foot pads and foot ribs. That 
condition, if not corrected, could result in loss of the MGB and 
subsequent loss of control of the helicopter.
    Since issuing that AD, we have determined the need to expand the 
applicability to include another MGB assembly and MBG housing, which 
introduced a six-stud attachment for the oil filter bowl and more edge 
distance on the right and left foot pads. This new housing 
configuration is added to the applicability of this AD because it is 
prone to the same cracks as the MGB listed in the current AD. The 
manufacturer is still investigating the root cause of these cracks. 
Contributing factors may include corrosion and the bushing press fit in 
the mounting foot bolt hole. The actions specified in this AD are 
interim actions until the root cause of the cracking is determined. 
After that determination, we anticipate further rulemaking.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Sikorsky S-92A helicopters of the same type 
design, this AD supersedes AD 2009-23-51 to retain the same 
requirements and to expand the applicability to include the MGB 
assembly, part number (P/N) 92351-15000-044, with a MGB housing, P/N 
92351-15110-046. This AD is being issued to prevent the loss of the MGB 
and subsequent loss of control of the helicopter. This AD requires an 
initial and at 10-hour time-in-service (TIS) intervals, cleaning and 
inspecting each MGB assembly mounting foot pad and rib for a crack and 
corrosion. If you do not find a crack, this AD requires applying a 
corrosion preventive compound. If you find a crack, this AD requires 
replacing the MGB before further flight. If you find corrosion, bubbled 
paint, or paint discoloration, this AD requires you to repair the MGB 
before further flight.
    The short compliance time is required because the previously 
described critical unsafe condition can adversely affect the structural 
integrity and controllability of the helicopter. Therefore, because of 
the short compliance time, 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 this AD will affect 44 helicopters of U.S. registry, 
and inspecting the MGB assembly mounting foot pads and foot ribs for 
corrosion or a crack will take about:
     2 work hours to do the visual inspection, assuming 2200 
(50 inspections X 44 helicopters) inspections per year for commercial 
and part 91 operators; and
     24 work hours to remove and replace an MGB.

The average labor rate is $85 per work hour and required parts will 
cost about $590,000 per helicopter. Based on these figures, we estimate 
the total cost impact of the AD on U.S. operators to be $26,423,760 
assuming all 44 helicopters will require an MGB replacement.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and an opportunity for 
public comment. We invite you to send any written relevant data, views, 
or arguments regarding this AD. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2010-1136; 
Directorate Identifier 2010-SW-069-AD'' 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://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive concerning this AD. Using the search function of the 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).

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 AD docket 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, Incorporation by 
reference, Safety.

[[Page 70814]]

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The FAA amends Sec.  39.13 by removing Airworthiness Directive (AD) 
2009-23-51, Amendment 39-16190 (75 FR 5684, dated February 4, 2010), 
and by adding a new AD to read as follows:

2010-24-04 Sikorsky Aircraft Corporation: Amendment 39-16522; Docket 
No. FAA-2010-1136; Directorate Identifier 2010-SW-069-AD. Supersedes 
AD 2009-23-51; Amendment 39-16190; Docket No. FAA-2010-0066; 
Directorate Identifier 2009-SW-52-AD.

    Applicability: Model S-92A helicopters, with main gearbox (MGB) 
assembly, part number (P/N) 92351-15000-042, -043, or -044, with MGB 
housing, P/N 92351-15110-042, -043, -044, -045, or -046, installed, 
certificated in any category.
    Compliance: Required as indicated.
    To prevent loss of an MGB and subsequent loss of control of the 
helicopter, do the following:
    (a) Within 10 hours time-in-service (TIS), unless accomplished 
previously, and thereafter at intervals not to exceed 10 hours TIS, 
clean and inspect each MGB assembly mounting foot pad and rib for a 
crack and corrosion in the area depicted in Figure 1 and as shown in 
the examples in Figures 2, 3, and 4 of Sikorsky Alert Service 
Bulletin No. 92-63-020, dated September 11, 2009 (ASB). If no crack 
is found, apply the corrosion preventive compound to each foot pad 
and rib area.

    Note 1:  When conducting a visual inspection, use a bright, non-
LED light.
    (1) If you find a crack, replace the MGB before further flight.
    (2) If you find corrosion, bubbled paint, or paint 
discoloration, before further flight, repair the affected area.

    Note 2:  Even though MGB assembly, P/N 92351-15000-044, with MGB 
housing, P/N 92351-15110-046, is not included in the ASB, following 
the Accomplishment Instructions in the ASB accomplishes the intent 
of this AD.

    (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: 
Michael Schwetz, Aviation Safety Engineer, 12 New England Executive 
Park, Burlington, MA 01803, telephone (781) 238-7761, 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.
    (d) Do the inspections by following the specified portions of 
Sikorsky Alert Service Bulletin No. 92-63-020, dated September 11, 
2009. The Director of the Federal Register approved this 
incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51 
as of February 19, 2010 (75 FR 5684, February 4, 2010). Copies may 
be obtained 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. Copies may 
be inspected at the FAA, Office of the Regional Counsel, Southwest 
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas, or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
    (e) This amendment becomes effective on December 6, 2010.

    Issued in Fort Worth, Texas, on November 9, 2010.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-29201 Filed 11-18-10; 8:45 am]
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