
[Federal Register Volume 80, Number 202 (Tuesday, October 20, 2015)]
[Rules and Regulations]
[Pages 63422-63425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-25976]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0442; Directorate Identifier 2007-SW-24-AD; 
Amendment 39-18291; AD 2015-20-12]
RIN 2120-AA64


Airworthiness Directives; Various Sikorsky-Manufactured Transport 
and Restricted Category Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: We are superseding Airworthiness Directive (AD) 98-26-02 for 
certain Sikorsky Aircraft Corporation (Sikorsky) Model S-61A, D, E, L, 
N, NM, R, and V helicopters. AD 98-26-02 required determining whether 
the main rotor shaft (MRS) was used in repetitive external lift (REL) 
operations, performing a nondestructive inspection (NDI) for cracks, 
replacing any unairworthy MRS, and establishing retirement lives for 
each REL MRS. This new AD retains some of the requirements of AD 98-26-
02 but determines a new retirement life for each MRS, expands the 
applicability to include additional helicopters, and requires removing 
from service any MRS with oversized dowel pin bores. This AD was 
prompted by the manufacturer's reevaluation of the retirement life for 
the MRS based on torque, ground-air-ground (GAG) cycle, and fatigue 
testing. We are issuing this AD to prevent MRS structural failure, loss 
of power to the main rotor, and subsequent loss of control of the 
helicopter.

DATES: This AD is effective November 24, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 24, 
2015.

ADDRESSES: For service information identified in this AD, contact 
Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical 
Support, mailstop s581a, 6900 Main Street, Stratford, Connecticut, 
telephone (203) 383-4866, email tsslibrary@sikorsky.com, or at http://www.sikorsky.com. You may view this referenced service information at 
the FAA, Office of the Regional Counsel, 10101 Hillwood Pkwy, Room 6N-
321, Fort Worth, TX 76177.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov in Docket No. FAA-2008-0442; or in person at the 
Docket Management Facility between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The AD docket contains this AD, any 
incorporated-by-reference information, the economic evaluation, any 
comments received, and other information. The address for the Docket 
Office (phone: 800-647-5527) is Document Management Facility, U.S. 
Department of Transportation, Docket Operations, M-30, West Building 
Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 
20590.

FOR FURTHER INFORMATION CONTACT: Tracy Murphy, Aviation Safety 
Engineer, Boston Aircraft Certification Office, Engine & Propeller 
Directorate, FAA, 12 New England Executive Park, Burlington, 
Massachusetts 01803; telephone (781) 238-7172; email 
tracy.murphy@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    On April 10, 2008, we issued a notice of proposed rulemaking (NPRM) 
(73 FR 21556, April 22, 2008) proposing to amend 14 CFR part 39 by 
adding an AD for Sikorsky Aircraft Corporation Model S-61A, D, E, L, N, 
NM, R, and V; Croman Corporation Model SH-3H; Carson Helicopters, Inc., 
Model S-61L; Glacier Helicopters, Inc., Model CH-3E; Robinson Air 
Crane, Inc., Model CH-3E, CH-3C, HH-3C and HH-3E; and Siller 
Helicopters Model CH-3E and SH-3A helicopters. The NPRM proposed 
superseding AD 98-26-02 (63 FR 69177, December 16, 1998), which 
required determining whether the MRS was used in REL operations, 
performing an NDI for cracks, replacing any unairworthy MRS, and 
establishing retirement lives for each REL MRS. The NPRM proposed to 
retain some of the requirements of AD 98-26-02 but also proposed a new 
retirement life determination for each MRS, removing from service any 
MRS with oversized dowel pin bores, and expanding the applicability to 
include certain restricted category models. The NPRM was prompted by 
the manufacturer's reevaluation of the retirement life for the MRS 
based on torque, GAG cycle, and fatigue testing.

[[Page 63423]]

Those proposals were intended to prevent MRS structural failure, loss 
of power to the main rotor, and subsequent loss of control of the 
helicopter.
    On April 16, 2013, we issued a supplemental NPRM (SNPRM) (78 FR 
24363, April 25, 2013) that proposed to revise the NPRM based on 
comments received on the NPRM and a reevaluation of the relevant data. 
The SNPRM proposed retaining the proposals in the NPRM but extending 
the hours TIS required for identifying the MRS as an REL MRS to 
coincide with the NDI to prevent repeated disassembly of the shaft. The 
SNPRM also proposed to extend the time required to replace the MRS and 
revise calculations for establishing the retirement life.
    On September 19, 2014, we issued a second SNPRM (79 FR 60789, 
October 8, 2014). In addition to retaining previously-proposed 
requirements, the second SNPRM revised the Cost of Compliance section 
to reflect an increased cost for parts to replace an MRS and clarified 
some of the wording for complying with the AD.
    Since the SNPRM (79 FR 60789, October 8, 2014) was issued, the FAA 
Southwest Regional Office has relocated. We have revised the physical 
address to reflect the new address.

Comments

    We gave the public the opportunity to participate in developing 
this AD, but we did not receive any comments on the second SNPRM (79 FR 
60789, October 8, 2014).

FAA's Determination

    We have reviewed the relevant information and determined that an 
unsafe condition exists and is likely to exist or develop on other 
helicopters of these same type designs and that air safety and the 
public interest require adopting the AD requirements as proposed except 
for a minor change. Sikorsky Aircraft was inadvertently omitted as one 
of the current type certificate holders of some of the applicable model 
helicopters; we are correcting that error in this AD. This change is 
consistent with the intent of the proposals in the SNPRM (79 FR 60789, 
October 8, 2014) and will not increase the economic burden on any 
operator nor increase the scope of the AD.

Related Service Information Under 1 CFR Part 51

    Sikorsky issued Alert Service Bulletin No. 61B35-69, dated April 
19, 2004, which provides procedures for determining REL and Non-REL 
status, assigns new REL and Non-REL MRS retirement lives, and provides 
a method for marking the REL MRS. This service information is 
reasonably available because the interested parties have access to it 
through their normal course of business or by the means identified in 
the ADDRESSES section of this AD.

Other Related Service Information

    Sikorsky issued Customer Service Notice (CSN) No. 6135-10, dated 
March 18, 1987, and Service Bulletin (SB) No. 61B35-53, dated December 
2, 1981, both revised with Revision A on April 19, 2004, for Model S-
61L, N, and NM (serial number (S/N) 61454), and R series transport 
category helicopters; and S-61A, D, E, and V series restricted category 
helicopters. CSN 6135-10A specifies replacing the planetary assembly 
and MRS assembly attaching hardware with high strength hardware. CSN 
6135-10A also specifies reworking the dowel retainer to increase hole 
chamfer and related countersink diameters. SB 61B35-53A specifies 
replacing the existing planetary matching plates with new steel 
matching plates during overhaul at the operator's discretion.
    Sikorsky Aircraft Corporation also issued an All Operators Letter 
CCS-61-AOL-04-0005, dated May 18, 2004, which contains an example and 
additional information about tracking cycles and the moving average 
procedure.

Costs of Compliance

    We estimate that this AD affects 60 helicopters of U.S. Registry. 
We estimate that operators may incur the following costs in order to 
comply with this AD. It will take about 2.2 work-hours to NDI an REL 
MRS at $85 per work-hour plus a $50 consumable cost, for a total 
estimated cost of $237 per helicopter and $14,220 for the U.S. fleet. 
It will take about 2.2 work-hours to replace an MRS at $85 per work-
hour plus parts cost of $81,216, for a total estimated cost of $81,403 
per helicopter.

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 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 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) Will not affect intrastate aviation in Alaska to the extent 
that a regulatory distinction is required, 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 removing Airworthiness Directive (AD) 
98-26-02, Amendment 39-10943 (63 FR 69177, December 16, 1998), and 
adding the following new AD:

2015-20-12 Sikorsky Aircraft Corporation; Sikorsky Aircraft; Croman 
Corporation; Carson Helicopters, Inc.; Glacier Helicopters, Inc.; 
Robinson Air Crane, Inc.; and Siller Helicopters: Amendment 39-
18291; Docket No. FAA-2008-0442; Directorate Identifier 2007-SW-24-
AD.

[[Page 63424]]

(a) Applicability

    This AD applies to Model S-61A, D, E, L, N, NM (serial number 
(S/N) 61454), R, V, CH-3C, CH-3E, HH-3C, HH-3E, SH-3A, and SH-3H 
helicopters with main rotor shaft (MRS), part number S6135-20640-
001, S6135-20640-002, or S6137-23040-001, installed, certificated in 
any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as MRS structural failure, 
loss of power to the main rotor, and subsequent loss of control of 
the helicopter.

(c) Affected ADs

    This AD supersedes AD 98-26-02, Amendment 39-10943 (63 FR 69177, 
December 16, 1998).

(d) Effective Date

    This AD becomes effective November 24, 2015.

(e) 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.

(f) Required Actions

    (1) Within 10 hours time-in-service (TIS):
    (i) Create a component history card or equivalent record for 
each MRS.
    (ii) If there is no record of the hours TIS on an individual 
MRS, substitute the helicopter's hours TIS or the helicopter's 
transmission hours TIS if both the shaft and transmission were 
installed new at the same time.
    (iii) If the record of external lift cycles (lift cycles) on an 
individual MRS is incomplete, add the known number of lift cycles to 
a number calculated by multiplying the number of hours TIS of the 
individual MRS by the average lift cycles calculated according to 
the instructions in Section I of Appendix 1 of this AD or by a 
factor of 13.6, whichever is higher. An external lift cycle is 
defined as a flight cycle in which an external load is picked up, 
the helicopter is repositioned (through flight or hover), and the 
helicopter hovers and releases the load and departs or lands and 
departs.
    (iv) At the end of each day's operations, record the number of 
lift cycles performed and the hours TIS.
    (2) Within 250 hours TIS, determine whether the MRS is a 
repetitive external lift (REL) or Non-REL MRS.
    (i) Calculate the first moving average of lift cycles by 
following the instructions in Section I of Appendix 1 of this AD.
    (A) If the calculation results in 6 or more lift cycles per hour 
TIS, the MRS is an REL-MRS.
    (B) If the calculation results in less than 6 lift cycles per 
hour TIS, the MRS is a Non-REL MRS.
    (ii) If the MRS is a Non-REL MRS based on the calculation 
performed in accordance with paragraph (f)(2)(i) of this AD, 
thereafter at intervals of 50 hour TIS, recalculate the average lift 
cycles per hour TIS by following the instructions in Section II of 
Appendix 1 of this AD.
    (iii) Once an MRS is determined to be an REL MRS, you no longer 
need to perform the 250-hour TIS moving average calculation, but you 
must continue to count and record the lift cycles and number of 
hours TIS.
    (iv) If an MRS is determined to be an REL MRS, it remains an REL 
MRS for the rest of its service life and is subject to the 
retirement times for an REL MRS.
    (3) Within 1,100 hours TIS:
    (i) Conduct a Non-Destructive Inspection for a crack on each 
MRS. If there is a crack in an MRS, before further flight, replace 
it with an airworthy MRS.
    (ii) If an MRS is determined to be an REL MRS, identify it as an 
REL MRS by etching ``REL'' on the outside diameter of the MRS near 
the part S/N by following the Accomplishment Instructions, paragraph 
3.C., of Sikorsky Alert Service Bulletin No. 61B35-69, dated April 
19, 2004.
    (4) Replace each MRS with an airworthy MRS on or before reaching 
the revised retirement life as follows:
    (i) For an REL MRS that is not modified by following Sikorsky 
Customer Service Notice (CSN) No. 6135-10, dated March 18, 1987, and 
Sikorsky Service Bulletin (SB) No. 61B35-53, dated December 2, 1981 
(unmodified REL MRS), the retirement life is 30,000 lift cycles or 
1,500 hours TIS, whichever occurs first.
    (ii) For an REL MRS that is modified by following Sikorsky CSN 
No. 6135-10, dated March 18, 1987, and Sikorsky SB No. 61B35-53 
dated December 2, 1981; or Sikorsky CSN No. 6135-10A and Sikorsky SB 
No. 61B35-53A, both Revision A, and both dated April 19, 2004 
(modified REL MRS), the retirement life is 30,000 lift cycles or 
5,000 hours TIS, whichever occurs first.
    (iii) For a Non-REL MRS, the retirement life is 13,000 hours 
TIS.
    (5) Establish or revise the retirement lives of the MRS as 
indicated in paragraphs (f)(4)(i) through (f)(4)(iii) of this AD by 
recording the new or revised retirement life on the MRS component 
history card or equivalent record.
    (6) Within 50 hours TIS, remove from service any MRS with 
oversized (0.8860'' or greater diameter) dowel pin bores.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Boston Aircraft Certification Office, FAA, may 
approve AMOCs for this AD. Send your proposal to: Tracy Murphy, 
Aviation Safety Engineer, Boston Aircraft Certification Office, 
Engine & Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, Massachusetts 01803; telephone (781) 238-7172; email 
tracy.murphy@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.

(h) Additional Information

    Sikorsky Aircraft Corporation All Operators Letter CCS-61-AOL-
04-0005, dated May 18, 2004; Sikorsky Customer Service Notice (CSN) 
No. 6135-10, dated March 18, 1987; Sikorsky CSN No. 6135-10A, 
Revision A, dated April 19, 2004; Sikorsky Service Bulletin (SB) No. 
61B35-53, dated December 2, 1981; and Sikorsky SB No. 61B35-53A, 
Revision A, dated April 19, 2004, which are not incorporated by 
reference, contain additional information about the subject of this 
AD. For more information about these documents, contact Sikorsky 
Aircraft Corporation, Attn: Manager, Commercial Technical Support, 
mailstop s581a, 6900 Main Street, Stratford, Connecticut, telephone 
(203) 383-4866, email tsslibrary@sikorsky.com, or at http://www.sikorsky.com. You may review a copy of the referenced service 
information at the FAA, Office of the Regional Counsel, 10101 
Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 6320, Main Rotor 
Gearbox.

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Sikorsky Alert Service Bulletin No. 61B35-69, dated April 
19, 2004.
    (ii) Reserved.
    (3) For Sikorsky service information identified in this AD, 
contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial 
Technical Support, mailstop s581a, 6900 Main Street, Stratford, 
Connecticut, telephone (203) 383-4866, email 
tsslibrary@sikorsky.com, or at http://www.sikorsky.com.
    (4) You may view this service information at FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-
321, Fort Worth, TX 76177. For information on the availability of 
this material at the FAA, call (817) 222-5110.
    (5) You may view this service information that is incorporated 
by reference 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/cfr/ibr-locations.html.

Appendix 1 to AD 2015-20-12

Section I: The First Moving Average of External Lift Cycles (Lift 
Cycles) per Hour Time-in-Service (TIS)

    The first moving average calculation is performed on the main 
rotor shaft (MRS) assembly when the external lift component history 
card record reflects that the MRS assembly has reached its first 250 
hours TIS. To perform the calculation, divide the total number of 
lift cycles performed during the first 250 hours TIS by 250. The 
result will be the first moving average calculation of lift cycles 
per hour TIS.

[[Page 63425]]

Section II: Subsequent Moving Average of Lift Cycles per Hour TIS

    Subsequent moving average calculations are performed on the MRS 
assembly at intervals of 50 hour TIS after the first moving average 
calculation. Subtract the total number of lift cycles performed 
during the first 50-hour TIS interval used in the previous moving 
average calculation from the total number of lift cycles performed 
on the MRS assembly during the previous 300 hours TIS. Divide this 
result by 250. The result will be the next or subsequent moving 
average calculation of lift cycles per hour TIS.

Section III: Sample Calculation for Subsequent 50 Hour TIS Intervals

    Assume the total number of lift cycles for the first 50 hour TIS 
interval used in the previous moving average calculation = 450 lift 
cycles and the total number of lift cycles for the previous 300 
hours TIS = 2700 lift cycles. The subsequent moving average of lift 
cycles per hour TIS = (2700 - 450) divided by 250 = 9 lift cycles 
per hour TIS.

    Issued in Fort Worth, Texas, on October 4, 2015.
Lance T. Gant,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2015-25976 Filed 10-19-15; 8:45 am]
BILLING CODE 4910-13-P


