
[Federal Register Volume 78, Number 141 (Tuesday, July 23, 2013)]
[Proposed Rules]
[Pages 44045-44048]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-17629]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0636; Directorate Identifier 2012-SW-065-AD]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation 
(Sikorsky) Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
Sikorsky Model S-70, S-70A, and S-70C helicopters. This proposed AD 
would establish a new life limit based

[[Page 44046]]

on a prorated formula for certain identified components (parts) 
installed on Model S-70, S-70A, and S-70C helicopters after being 
previously installed on certain military model helicopters. This 
proposed AD is prompted by the discovery that certain parts have been 
interchanged between military helicopter models with different life 
limits and the possibility that these same parts can be interchanged 
with civilian models with different life limits. The proposed actions 
are intended to establish a pro-rated in service life limit for each 
identified part to prevent fatigue failure of a part and subsequent 
loss of control of the helicopter.

DATES: We must receive comments on this proposed AD by September 23, 
2013.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 proposed AD, the economic 
evaluation, any comments received, and other information. The street 
address for the Docket Operations Office (telephone 800-647-5527) is in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Michael Davison, Flight Test Engineer, 
Boston Aircraft Certification Office, Engine & Propeller Directorate, 
12 New England Executive Park, Burlington, Massachusetts 01803; 
telephone (781) 238-7156; email michael.davison@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to participate in this rulemaking by submitting 
written comments, data, or views. We also invite comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    We will file in the docket all comments that we receive, as well as 
a report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    We propose to adopt a new AD for Sikorsky Model S-70, S-70A and S-
70C helicopters. Certain parts on Model S-70, S-70A, and S-70C 
helicopters are common to military Model UH-60M and SH-60B/F 
helicopters. These parts have identical part numbers. However, the part 
life limits may be different on the military models and are often lower 
due to higher usage and flight load spectrum. This proposed AD is 
prompted by the discovery that personnel at a military depot had 
installed military Model UH-60M parts on military Model UH-60A/L 
helicopters. Because the civilian Model S-70 series helicopters are 
derived from the military Model UH-60, it is possible that parts 
previously installed on military aircraft with a lower life limit could 
inadvertently be later installed on civil aircraft. This proposed AD 
would require establishing a pro-rated life limit for each affected 
part to account for the heavier usage when previously installed on the 
Model UH-60M or SH-60B/F. The proposed actions are intended to 
establish appropriate remaining in-service lives to identified parts to 
prevent fatigue failure of a part and subsequent loss of control of the 
helicopter.

FAA's Determination

    We are proposing this AD because we evaluated all known relevant 
information and determined that an unsafe condition exists and is 
likely to exist or develop on other helicopters of this same type 
design.

Proposed AD Requirements

    This proposed AD would require, within 25 hours time-in-service, 
inserting the component life prorating formula into the airworthiness 
limitation section of the maintenance manual or instructions for 
continued airworthiness, calculating the new life limit for each part 
by applying the formula, and establishing life limits for certain parts 
without applying the formula. Furthermore, the proposed AD would 
require updating the component log or equivalent record with the new 
in-service life limit. This proposed AD would also require replacing 
each part that has reached or exceeded its new life limit with an 
airworthy part. Lastly, this proposed AD would prohibit installing any 
applicable part on a Model S-70, S-70A, or S-70C helicopter if the 
number of hours is unknown and would prohibit installing certain parts 
on a Model S-70, S-70A, or S-70C helicopter if they have been 
previously installed on a Model UH-60M helicopter.

Costs of Compliance

    We estimate that this proposed AD would affect 9 helicopters of 
U.S. Registry.
    We estimate that the cost to insert the pages into the TM would be 
negligible.

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

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on

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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, I certify this 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 an economic evaluation of the estimated costs to comply 
with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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):

Sikorsky Aircraft Corporation (Sikorsky): Docket No. FAA-2013-0636; 
Directorate Identifier 2012-SW-065-AD.

(a) Applicability

    This AD applies to Model S-70, S-70A, and S-70C helicopters, 
certificated in any category, with the following parts installed:
    (1) Spindle and liner assembly, part number (P/N) 38023-10374-
041;
    (2) Main Rotor Hub, P/N 70070-10046-055 and -056;
    (3) Main Rotor Spindle nut, P/N 70102-08105-102;
    (4) Main Rotor Control Horn, P/N 70102-08111-047;
    (5) Main Rotor Hub, P/N 70103-08112-041 and -047;
    (6) Rotating Swashplate, P/N 70104-08001-044 and -045;
    (7) Main rotor Shaft Extension, P/N 70351-08186-043;
    (8) Main Rotor Gear Box Housing, P/N 70351-38110-043, -044, and 
-045;
    (9) Main Rotor Shaft, P/N 70351-38131-042;
    (10) Output Bevel Gear and Shaft, P/N 70358-06620-101 and -102;
    (11) Left Tie Rod Assembly, P/N 70400-08115-043, -045, -046, and 
-047;
    (12) Forward Bellcrank Support Assembly, P/N 70400-08162-042;
    (13) Lateral Servo Bellcrank, P/N 70400-08166-041; or
    (14) Tail rotor Servo Assembly, P/N 70410-06520-044 through -
046.

 (b) Unsafe Condition

    This AD defines the unsafe condition as a critical part 
remaining in service beyond its life limit due to previously being 
installed on a different helicopter model with higher usage and 
flight loads. This condition could result in fatigue failure of a 
critical part and subsequent loss of control of the helicopter.

(c) Comments Due Date

    We must receive comments by September 23, 2013.

 (d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Within 25 hours time-in-service (TIS):
    (i) Insert into the airworthiness limitation section of the 
maintenance manual or instructions for continued airworthiness the 
component life prorating formula in Section 1.1.3 of Sikorsky 
Technical Manual TM 1-70-23AW-2, Change 3, dated April 15, 2012.
    (ii) Using the service life limits in Table 1 to paragraph (e) 
of this AD, apply the component life prorating formula and calculate 
the new life limit for each specified part. If the number of hours 
of a part is unknown, that part cannot be installed on a Sikorsky 
Model S-70, S-70A, or S-70C helicopter. Do not calculate a new life 
limit for the part where the Model SH-60 life limit is higher than 
the life limit on Models S-70, S-70A, and S-70C.

                                            Table 1 to Paragraph (e)
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                                                                  S-70, S-70A, S-
                  P/N                       Part description        70C Service   UH-60M Service     SH-60B/F
                                                                       life            life        Service life
----------------------------------------------------------------------------------------------------------------
38023-10374-041.......................  Spindle and Liner                  8,000           6,400          10,000
                                         Assembly.
70070-10046-055 and -056..............  Main Rotor Hub..........           5,100           3,100         N/A \1\
70102-08105-102.......................  Main Rotor Spindle Nut..           8,000           6,400          10,000
70102-08111-047.......................  Main Rotor Control Horn.    20,000/1,300          10,000         N/A \1\
                                                                   \2\/2,500 \2\
70103-08112-041 and -047..............  Main Rotor Hub..........           5,100           3,100         N/A \1\
70104[dash]08001[dash]044[dash]045....  Rotating Swashplate.....          11,000           4,600           9,600
70351-08186-043.......................  Main Rotor Shaft                  14,000           4,900          16,000
                                         Extension.
70351-38110-043, -044, and -045.......  Main Rotor Gear Box               11,000           4,000           9,000
                                         Housing.
70351-38131-042.......................  Main Rotor Shaft........          17,000           5,200          19,000
70358-06620-101 and -102..............  Output Bevel Gear and              5,000           1,800         N/A \1\
                                         Shaft.
70400-08115-043, -045, -046, and        Left Tie Rod Assembly...          14,000           4,600           6,300
 [dash]047.
70400-08162-042.......................  Forward Bellcrank           14,000/2,500           5,600           7,600
                                         Support Assembly.                   \3\
70400-08166-041.......................  Lateral Servo Bellcrank.          20,000          11,000          14,000
70410-06520-044 through -046..........  Tail Rotor Servo                  15,000          11,000         N/A \1\
                                         Assembly.
----------------------------------------------------------------------------------------------------------------
\1\ There is no service life limit listed because the parts on Model SH-60B/F have a different P/N than the
  parts on Models S-70, S-70A, and S-70C.
\2\ For serial number (S/N) 32479930 through 324791859, with CAGE code 60078, the life limit is 1,300 hours TIS.
For S/N A241-07543 through A241-07594, A241[dash]07706 through A241-07755, A241[dash]07768 through A241-07771,
  A241-07800 through A241-07831, R241-00101 through R241-00355, R241-00701 through R241[dash]00966, and R241-
  01001 through R241[dash]01166, the life limit is 2,500 hours TIS.
\3\ For S/N A-367-00001 through A367-00035, with CAGE code 78286, the life limit is 2,500 hours TIS.


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    (iii) Record the newly-established life limit of each part on 
the part's component log card or equivalent record.
    (2) After establishing the new life limit, replace each part 
that has reached or exceeded its new life limit with an airworthy 
part before further flight.
    (3) Do not install the following parts on a Model S-70, S-70A, 
or S-70C helicopter if they have been previously installed on a 
Model UH-60M helicopter:
    (i) Bolt, self retaining, P/N 70103-08801-102;
    (ii) Bifilar, P/N 70107-08400-046; (iii) Aft Bellcrank, P/N 
70400-08102-045;
    (iv) Aft Walking Beam Assembly, P/N 70400-08104-048; or
    (v) Close Tolerance Bolt, P/N 70400-26802-102 and -103.

(f) Alternative Methods of Compliance (AMOC)

    (1) The Manager, Boston Aircraft Certification Office, FAA, may 
approve AMOCs for this AD. Send your proposal to: Michael Davison, 
Flight Test Engineer, Boston Aircraft Certification Office, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, 
Massachusetts 01803; telephone (781) 238-7156; email 
michael.davison@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Subject

    Joint Aircraft Service Component (JASC) Code: 6220 Main Rotor 
Hub, 6230 Main Rotor Mast/Swashplate, 6320 Main Rotor Gearbox, 6310 
Engine/Transmission Coupling, 6510 Tail Rotor Drive Shaft.

    Issued in Fort Worth, Texas, on July 11, 2013.
Kim Smith,
Directorate Manager, Rotorcraft Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-17629 Filed 7-22-13; 8:45 am]
BILLING CODE 4910-13-P


