
[Federal Register: October 26, 2011 (Volume 76, Number 207)]
[Proposed Rules]               
[Page 66209-66211]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26oc11-20]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1113; Directorate Identifier 2009-SW-53-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. This proposal would 
require inspecting each tail rotor blade (blade) for mislocated 
aluminum wire mesh in the blade skin. This proposal is prompted by the 
discovery that blades were manufactured with aluminum wire mesh 
mislocated, leaving portions of the graphite torque tube (spar) region 
unprotected from a lightning strike. This condition can exist in both 
the upper and lower blade skin airfoils. The actions specified by this 
proposed AD are intended to detect mislocated blade wire mesh and to 
prevent spar delamination, loss of the blade tip cap during a lightning 
strike, blade

[[Page 66210]]

imbalance, loss of a blade, and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before December 27, 2011.

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: Nicholas Faust, Aviation Safety 
Engineer, Boston Aircraft Certification Office, 12 New England 
Executive Park, Burlington, MA 01803, telephone (781) 238-7763, 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-2011-1113, 
Directorate Identifier 2009-SW-53-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 (65 FR 19477-78).

Examining the Docket

    You may examine the docket that contains the proposed 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) 647-5527) 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. This proposal would require inspecting each blade for 
mislocated aluminum wire mesh in the blade skin. This proposal is 
prompted by the discovery that blades were manufactured with aluminum 
wire mesh mislocated, leaving portions of the graphite torque tube 
(spar) region unprotected from a lightning strike. This condition can 
exist on both the upper and lower blade skin airfoils. The actions 
specified by this proposed AD are intended to detect mislocated blade 
wire mesh to prevent spar delamination and loss of the blade tip cap 
during a lightning strike leading to blade imbalance, loss of a blade, 
and subsequent loss of control of the helicopter.
    We have reviewed Sikorsky Special Service Instructions SSI No. 92-
021A, dated October 21, 2009 (SSI), which specifies inspecting the 
blade for mislocated blade wire mesh. Two options are identified in the 
SSI. One option is to conduct an eddy current inspection and the other 
option is to conduct a visual inspection after sanding to determine if 
there is mislocated wire mesh.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type design. Therefore, the proposed AD would 
require inspecting each blade to determine if the wire mesh is 
mislocated and replacing the blade with an airworthy blade if the wire 
mesh is mislocated. The actions would be required to be done by 
following the service information described previously.
    We estimate that this proposed AD would affect 44 helicopters of 
U.S. registry. There are 486 suspect blades worldwide, and we assume 29 
percent (141) of those blades may be on helicopters of U.S. registry. 
We estimate that inspecting a blade for mislocated wire mesh would take 
about 4 work hours per blade, assuming all operators opt to do the 
blade sanding inspection rather than the eddy current inspection, at an 
average labor rate of $85 per work hour. Required parts would cost 
about $13,000 for each blade repaired by the manufacturer or $180,000 
for each new blade. The total cost of the proposed AD for U.S. 
operators would be $3,215,940, assuming 51 blades are found with 
mislocated wire mesh, and assuming 36 of those blades are replaced with 
blades repaired by the manufacturer and 15 blades are replaced with new 
blades.

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);
    3. Will not affect intrastate aviation in Alaska to the extent that 
it justifies making a regulatory distinction; 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.
    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, methods, and procedures

[[Page 66211]]

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-2011-1113; Directorate 
Identifier 2009-SW-53-AD.

    Applicability: Model S-92A helicopters, tail rotor blade 
assembly (blade), part numbers (P/N) 92170-11000-044, -045, and -
046, with a serial number with a prefix of ``A111'' and a number 
equal to or less than ``-00585,'' installed, certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect mislocated blade wire mesh and to prevent spar 
delamination, loss of the blade tip cap during a lightning strike, 
blade imbalance, loss of a blade, and subsequent loss of control of 
the helicopter, do the following:
    (a) Within 60 days, inspect the upper and lower airfoils of each 
tail rotor blade to determine if the wire mesh is mislocated.
    (1) Inspect by using either an eddy current inspection in 
accordance with paragraphs B.(1)(a) through B.(1)(o) or using the 
hand-sanding method and visually inspecting in accordance with 
paragraphs B.(2)(a) through B.(2)(d) of Sikorsky Special Service 
Instructions SSI No. 92-021A, Revision A, dated October 21, 2009, 
except you are not required to contact or report nonconforming 
blades to the manufacturer. If you sand and visually inspect and 
confirm the correct location of the wire mesh, touch-up and repaint 
the sanded area.
    (2) If there is a blade with a mislocated wire mesh, before 
further flight, replace the blade with an airworthy blade.
    (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, FAA, 
Attn: Nicholas Faust, Aviation Safety Engineer, Boston Aircraft 
Certification Office, 12 New England Executive Park, Burlington, MA 
01803, telephone (781) 238-7763, fax (781) 238-7170, for information 
about previously approved alternative methods of compliance.
    (c) The Joint Aircraft System/Component (JASC) Code is 6410, 
Tail Rotor Blades.

    Issued in Fort Worth, Texas, on October 7, 2011.
Lance T. Gant,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2011-27669 Filed 10-25-11; 8:45 am]
BILLING CODE 4910-13-P

