
[Federal Register Volume 76, Number 106 (Thursday, June 2, 2011)]
[Rules and Regulations]
[Pages 31796-31798]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-13531]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0548; Directorate Identifier 2011-SW-025-AD; 
Amendment 39-16710; AD 2011-12-03]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
Sikorsky Model S-92A helicopters. This AD requires a nondestructive 
inspection (NDI), eddy current or fluorescent penetrant inspection 
(FPI), of each main gearbox (MGB) upper housing assembly rib on the 
left, right, and forward MGB mounting foot at specified intervals based 
on the MGB upper housing assembly hours time-in-service (TIS). If there 
is a crack, this AD requires replacing the MGB upper housing assembly 
with an airworthy MGB upper housing assembly. This AD is prompted by a 
report of a crack found on the MGB upper housing assembly left mounting 
foot forward rib that cannot be detected visually. We are issuing this 
AD to prevent loss of the MGB and subsequent loss of control of the 
helicopter.

DATES: This AD is effective June 17, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of June 17, 
2011.
    We must receive comments on this AD by August 1, 2011.

ADDRESSES: You may send comments by any of the following methods:
     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, West Building Ground Floor, Room W12-140, 1200 New Jersey 
Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, 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.
    For service information identified in this AD, contact 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 AD Docket

    You may examine the AD docket 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 AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone: 800-647-5527) is in the 
ADDRESSES

[[Page 31797]]

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, Michael.Schwetz@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We are adopting a new AD for the Sikorsky Model S-92A helicopters. 
This AD requires an NDI, eddy current or FPI, of each MGB upper housing 
assembly rib on the left, right, and forward MGB mounting foot for a 
crack because it cannot be detected visually. This AD is prompted by a 
report of a crack found on the MGB upper housing assembly left mounting 
foot forward rib during removal of an MGB that had reached its life 
limit of 1,000 hours TIS. The MGB mounting foot has a history of two 
types of cracks. The visual inspection for these two types of cracks is 
required in AD 2010-24-04 (75 FR 70812, November 19, 2010). The 
discovery of a third type of crack on the left mounting foot forward 
rib may not be reliably detected by visual inspection. This condition, 
if not detected and corrected, could result in loss of the MGB, and 
subsequent loss of control of the helicopter.

Relevant Service Information

    We reviewed Sikorsky Alert Service Bulletin No. 92-63-025A, 
Revision A, dated May 12, 2011 (ASB). The ASB specifies a one-time NDI 
of the MGB assembly at the mounting foot ribs for cracks.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other helicopters of the same type 
design.

AD Requirements

    This AD requires, at specified intervals based on the MGB upper 
housing assembly hours TIS, eddy current or FPI inspecting the left, 
right, and forward MGB upper housing mounting foot ribs for a crack. If 
there is a crack, the AD requires replacing the MGB upper housing 
assembly with an airworthy MGB upper housing assembly. This AD requires 
accomplishing the actions by following the specified portions in the 
ASB.

Differences Between the AD and the Service Information

    We refer to ``flight hours'' as ``hours TIS.'' This AD requires the 
inspection to be done by an ASNT Level 2 or equivalent inspector and 
this AD requires recurring inspections.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because of 
the short compliance time required to NDI certain MGB upper housing 
assembly mounting foot ribs for a crack. Therefore, we find that notice 
and opportunity for prior public comment are impracticable and that 
good cause exists for making this amendment effective in less than 30 
days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2011-0548 and 
Directorate Identifier 2011-SW-025-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because 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 about this AD.

Costs of Compliance

    We estimate that this AD affects 29 helicopters of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated costs
----------------------------------------------------------------------------------------------------------------
                                                                               Cost per          Cost on U.S.
             Action                   Labor cost          Parts cost          helicopter           operators
----------------------------------------------------------------------------------------------------------------
NDI of each left, right, and      29 helicopters x    $286,000 for a MGB  $4,760 to do 16     $428,800, assuming
 forward MGB mounting foot rib.    3.5 work-hours      upper housing.      NDI inspections     1 replacement of
                                   per inspection x                        per year.           the MGB upper
                                   16 inspections                                              housing assembly.
                                   per year x $85
                                   per work-hour =
                                   $138,040.
                                  1 x 56 work-hours
                                   x $85 per work-
                                   hour = $4,760, to
                                   replace 1 MGB.
----------------------------------------------------------------------------------------------------------------

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.

Regulatory Findings

    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

[[Page 31798]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Does not warrant making distinction for intrastate aviation in 
Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

    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 adding the following new airworthiness 
directive (AD):

2011-12-03 Sikorsky Aircraft Corporation (Sikorsky): Amendment 39-
16710; Docket No. FAA-2011-0548; Directorate Identifier 2011-SW-025-
AD.

Effective Date

    (a) This AD is effective June 17, 2011.

Affected ADs

    (b) None.

Applicability

    (c) Model S-92A helicopters with main gearbox (MGB) upper 
housing assembly, part number (P/N) 92351-15110-042, -043, -044, -
045, or -046, installed, certificated in any category.

Unsafe Condition

    (d) This AD is prompted by a report of a crack found on the MGB 
left mounting foot forward rib that may not be found during a visual 
inspection. We are issuing this AD to prevent loss of a MGB and 
subsequent loss of control of the helicopter.

Compliance

    (e) For each MGB upper housing assembly with 700 or more hours 
time-in-service (TIS), within 30 hours TIS, unless already done, or 
for each MGB upper housing assembly with more than 500 hours TIS but 
less than 700 hours TIS, within 50 hours TIS, unless already done, 
and for all helicopters thereafter at intervals not to exceed 50 
hours TIS:
    (1) Clean and Eddy Current inspect the forward, left, and right 
MGB mounting foot ribs for a crack by following the Accomplishment 
Instructions, paragraphs 3.C. through 3.D.(2)(d), of Sikorsky Alert 
Service Bulletin No. 92-63-025A, Revision A, dated May 12, 2011 
(ASB); or
    (2) Clean and fluorescent penetrant inspect (FPI) the MGB 
mounting foot ribs for a crack by following the Accomplishment 
Instructions, paragraphs 3.E.(1) through 3.E.(5), of the ASB.
    (3) An inspector qualified to ASNT Level II or equivalent is 
required to perform the nondestructive inspection (NDI), by Eddy 
Current or FPI, of the left, right, and forward MGB mounting foot 
ribs for a crack.
    (f) If there is a crack, before further flight, replace the MGB 
upper housing assembly with an airworthy MGB upper housing assembly.

    Note: Sikorsky has developed a Phase III MGB upper housing 
assembly, P/N 92351-15310-041, is not subject to the 
``Applicability'' of this AD.

Alternative Methods of Compliance (AMOCs)

    (g)(1) The Manager, Boston Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested, using 
the procedures found in 14 CFR 39.19. In accordance with 14 CFR 
39.19, send your request to your principal inspector or local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the ACO, send it to the attention of the 
person identified in the Additional Information section of this AD.
    (2) Before using any approved AMOC, we request that you notify 
your appropriate principal inspector, or lacking a principal 
inspector, the manager of the local flight standards district 
office/certificate holding district office.

Additional Information

    (h) For more information about this AD, 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, E-mail Michael.Schwetz@faa.gov.

Material Incorporated by Reference

    (i)(1) Inspect the MGB upper housing assembly mounting foot ribs 
for a crack by following the specified portions of Sikorsky Alert 
Service Bulletin No. 92-63-025A, Revision A, dated May 12, 2011. The 
Director of the Federal Register approved the incorporation by 
reference of the service information.
    (2) For service information identified in this AD, contact 
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.
    (3) 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 an 
NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Subject

    (j) The Joint Aircraft System Component (JASC)/Air Transport 
Association (ATA) of America Code is 6320 Main Gearbox.

    Issued in Fort Worth, Texas on May 24, 2011.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2011-13531 Filed 6-1-11; 8:45 am]
BILLING CODE 4910-13-P


