Published 2021-05-27 · Federal Register document 2021-11081
Airworthiness Directives; Carson Helicopters, Inc.; Croman Corporation; Sikorsky Aircraft Corporation; and Siller Helicopters
Publication summary
The FAA is adopting a new airworthiness directive (AD) for all Carson Helicopters, Inc., Model S-61L and SH-3H helicopters; Croman Corporation Model SH-3H helicopters; Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and S-61V helicopters; and Siller Helicopters Model CH-3E and SH-3A helicopters. This AD was prompted by an accident. This AD requires tracking hours time-in-service (TIS) and external lift cycles (lift cycles) for certain main gearbox left and right input freewheel unit (IFWU) assemblies. This AD also requires determining the type of IFWU assembly installed and depending on the results, calculating the moving average, repetitive inspections, recording certain information, replacing parts, and marking parts. The FAA is issuing this AD to address the unsafe condition on these products.
Why this record is shown
Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.
- Source revision
- federal_register_ad_metadata_2021-9c919420683447c6
- Source row
- results[169]
- Raw source SHA-256
- 9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5
Final-rule publication
Recorded publication clauses
- AD identifier printed in this edition
- 2021-10-16
- Effective date printed in this edition
- 2021-07-01
Read 13 complete recorded clauses
Effective Date
(a) Effective Date
This airworthiness directive (AD) is effective July 1, 2021.
Exact source excerpt. Text positions 11665–11751, end exclusive, in the original decoded publication. SHA-256: 565eabf7ab92e024f327b31a3d429931b0ce50d2a3301ece9dbee45b5a679def
Affected ADs
(b) Affected ADs
None.
Exact source excerpt. Text positions 11751–11780, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0
Applicability wording · Applicability
(c) Applicability
This AD applies to all helicopters identified in paragraphs
(c)(1) through (6) of this AD, certificated in any category
including restricted.
(1) Carson Helicopters, Inc., Model S-61L helicopters.
(2) Carson Helicopters, Inc., Model SH-3H helicopters.
(3) Croman Corporation Model SH-3H helicopters.
(4) Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and
S-61V helicopters.
(5) Siller Helicopters Model CH-3E helicopters.
(6) Siller Helicopters Model SH-3A helicopters.
Exact source excerpt. Text positions 11780–12311, end exclusive, in the original decoded publication. SHA-256: c0a7f0f94e7f0f8847d737966c59715b004de887e2f456b5a917e3db33cdcea2
Subject
(d) Subject
Joint Aircraft System Component (JASC) Code 6310, Engine/
Transmission Coupling.
Exact source excerpt. Text positions 12311–12410, end exclusive, in the original decoded publication. SHA-256: 79b90b3c6a4e6cc0eeb14bbd6a68b623ce43cf49cdec3033c0d18ba9e4e6c008
Unsafe Condition
(e) Unsafe Condition
This AD was prompted by an accident in which the left and right
input freewheel unit (IFWU) assembly on a helicopter slipped or
disengaged, resulting in both engines overspeeding, engine
shutdowns, and loss of engine power to the transmissions. The FAA is
issuing this AD to address slipping of the main gearbox IFWU
assembly, loss of engine power, and subsequent loss of control of
the helicopter.
Exact source excerpt. Text positions 12410–12842, end exclusive, in the original decoded publication. SHA-256: c192cb2f570bd4d87ceee1a785e9be947b5ad2c9923025c5ac5c85aee261e74a
Compliance
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
Exact source excerpt. Text positions 12842–12944, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3
Creation of History Card or Equivalent and Daily Actions
(g) Creation of History Card or Equivalent and Daily Actions
Within 10 hours time-in-service (TIS) after the effective date
of this AD, do the actions specified in paragraphs (g)(1) and (2) of
this AD.
(1) Create an external lift component history card or equivalent
record for each IFWU assembly, part number (P/N) 61074-35000-041
through 61074-35000-063 inclusive.
(2) Count and, at the end of each day's operations, record the
number of external lift cycles (lift cycles) performed and the hours
TIS for each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive. A ``lift cycle'' is defined as the lifting of an
external load and subsequent release of the load. Record the lift
cycles and hours TIS on the external lift component history card or
equivalent record.
Exact source excerpt. Text positions 12944–13752, end exclusive, in the original decoded publication. SHA-256: cedd00ff1624bcf4658ae0f3e64a0bbb615496c9684eee6019ddc0f109cc68c9
Determination of IFWU Assembly Type and Calculations
(h) Determination of IFWU Assembly Type and Calculations
(1) Upon reaching 250 hours TIS after the effective date of this
AD on each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive, determine whether the IFWU assembly is a repetitive
external lift (REL) or non-REL IFWU assembly by using a 250-hour TIS
moving average. 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.
(i) If the calculation specified in paragraph (h)(1) of this AD
results in more than 6 lift cycles per hour TIS, the IFWU assembly
is an REL IFWU assembly.
(ii) If the calculation specified in paragraph (h)(1) of this AD
results in 6 or less lift cycles per hour TIS, the IFWU assembly is
a Non-REL IFWU assembly.
(2) For each IFWU assembly determined to be a Non-REL IFWU
assembly based on the first calculation of the 250-hour TIS moving
average for lift cycles specified in paragraph (h)(1) of this AD:
Within 50 hours TIS after the determination, and thereafter at
intervals of 50 hours TIS, recalculate the average lift cycles per
hour TIS to determine whether the IFWU assembly is an REL or non-REL
IFWU assembly. To perform the 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 IFWU 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.
(i) If any calculation specified in paragraph (h)(2) of this AD
results in more than 6 lift
[[Page 28476]]
cycles per hour TIS, the IFWU assembly is an REL IFWU assembly.
(ii) If any calculation specified in paragraph (h)(2) of this AD
results in 6 or less lift cycles per hour TIS, the IFWU assembly is
a Non-REL IFWU assembly.
Note 1 to paragraph (h)(2): Sikorsky Aircraft Corporation All
Operators Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004,
provides an example and additional information about tracking cycles
and the moving average procedure.
Note 2 to paragraph (h)(2): The following is a 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 = 2,700 lift
cycles. The subsequent moving average of lift cycles per hour TIS =
(2,700-450) divided by 250 = 9 lift cycles per hour TIS.
(3) Once an IFWU assembly is determined to be an REL IFWU
assembly, it remains an REL IFWU assembly for the rest of its
service life and is subject to the inspection for REL IFWU
assemblies required by paragraph (i) of this AD.
(4) Once an IFWU assembly is determined to be an REL IFWU
assembly, you no longer need to perform the 250-hour TIS moving
average calculation required by paragraph (h)(2) of this AD, but you
must continue to count and record the lift cycles as required by
paragraph (g)(2) of this AD.
Exact source excerpt. Text positions 13752–17014, end exclusive, in the original decoded publication. SHA-256: a52a69061be2f7ac8d85e94b67483838df09c4c9ae7964ae5cbd4252d9309e24
Repetitive Inspections of REL IFWU Assemblies and Replacement
(i) Repetitive Inspections of REL IFWU Assemblies and Replacement
For each REL IFWU assembly, as determined by paragraph (h)(1) or
(2) of this AD:
(1) Within 500 hours TIS or 7,500 lift cycles, whichever occurs
first since the assembly was determined to be a REL IFWU assembly,
and thereafter at intervals not to exceed 500 hours TIS or 7,500
lift cycles, whichever occurs first, inspect for wear, surface
distress, and endplay by following paragraphs B.(1) through B.(6) of
the Accomplishment Instructions of Sikorsky Aircraft Corporation
Alert Service Bulletin 61B35-67B, Revision B, dated August 11, 2003.
Record all the information specified in Figures 1 through 3 of the
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B,
Revision B, dated August 11, 2003. You may record this information
on any suitable maintenance record, or you may use the Sikorsky
evaluation forms provided in Sikorsky Aircraft Corporation Alert
Service Bulletin 61B35-67B, Revision B, dated August 11, 2003. This
AD does not require you to contact Sikorsky or provide information
to Sikorsky.
(2) If during any inspection required by paragraph (i)(1) of
this AD, any IFWU assembly part is found whose average wear, wear
marks, surface distress, or endplay exceeds the limits specified in
paragraphs B.(1) through B.(6) of the Accomplishment Instructions of
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B,
Revision B, dated August 11, 2003, before further flight, replace
the affected part with an airworthy IFWU assembly part.
Note 3 to paragraph (i)(2): Sikorsky Aircraft S-61L/N Overhaul
Manual, SA4045-83, Revision 20, dated August 15, 2003, as revised by
Temporary Revisions 65-193, -194, -195, and -196, contains the
overhaul procedures for the IFWU assembly.
Exact source excerpt. Text positions 17014–18829, end exclusive, in the original decoded publication. SHA-256: ebeeff4ca390c0fdf7be94a477bd8b2d5270ef0656e5b6d5b04aff3367ec5d49
Part Marking
(j) Part Marking
For each REL IFWU assembly, as determined by paragraph (h)(1) or
(2) of this AD: Before further flight after the assembly was
determined to be an REL IFWU assembly, permanently mark IFWU
camshafts, P/N 61350-24052, 61350-24072, S6135-20611, S6135-20614
and S6137-23075, and IFWU gear housings, P/N 61350-24051, 61350-
24068, S6135-20695, and S6137-23057, with the letters ``REL''. Mark
the camshafts by applying etching ink on the surface of the part
that is 0.5-inch square with the depth of the letters not to exceed
0.001 inch. Before further flight and after etching, neutralize the
etched surface and oil to prevent corrosion.
Exact source excerpt. Text positions 18829–19492, end exclusive, in the original decoded publication. SHA-256: 6836136714bd2b9783fcf93d87895971e27f815f8e29775f2fe18eca15960097
Alternative Methods of Compliance (AMOCs)
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation Branch, 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 International Validation Branch, send
it to the attention of the person identified in paragraph (l)(1) of
this AD. Information may be emailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
Exact source excerpt. Text positions 19492–20285, end exclusive, in the original decoded publication. SHA-256: f58faf8a1f3baf543b874c7e4c8ea0353fd22f70efe93ff61ed3a34b6cf95dcf
Related Information
(l) Related Information
(1) For more information about this AD, contact Isabel Saltzman,
Aviation Safety Engineer, Boston ACO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803; telephone 781-238-7649; email
[email protected].
(2) Service information identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (m)(3) and (4) of this AD.
Exact source excerpt. Text positions 20285–20697, end exclusive, in the original decoded publication. SHA-256: fe0f5bd7db0d75754a3c495da3fbf6e261562a677d080744e3e61c22a3a9cc23
Material Incorporated by Reference
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) 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 Aircraft Corporation Alert Service Bulletin 61B35-
67B, Revision B, dated August 11, 2003.
(ii) [Reserved]
(3) For service information identified in this AD, contact your
local Sikorsky Field Representative or Sikorsky's Service
Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road,
Trumbull, CT 06611; telephone 1-800-Winged-S; email
[email protected]. Operators may also log on to
the Sikorsky 360 website at https://www.sikorsky360.com.
(4) You may view this service information at the 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, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.
Exact source excerpt. Text positions 20697–22103, end exclusive, in the original decoded publication. SHA-256: 61f2095b8870ff151f28feb2d3303432b08fbc28bbcb50c8853d7e81489cb2f3
No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.
Find all recorded historical references to AD 2021-10-16 · 0 printed reference observations in this pinned collection.
These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.
Why these observations are shown
They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.
Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: f6e6e3fe14a7395d1ea7f4c4c99af3b7891a17420b1744cba11b8f76172df859. Source manifest: 22550a4832ce219b71cfbe32a5ffc7658c8d4a0703d7977aef0a02c3e3513f41.
Official source · 2021-05-27
Publication text
This is the complete recorded text of this dated publication.
Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.
Read the complete official publication text
[Federal Register Volume 86, Number 101 (Thursday, May 27, 2021)]
[Rules and Regulations]
[Pages 28473-28476]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-11081]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-26107; Project Identifier 2004-SW-30-AD; Amendment
39-21549; AD 2021-10-16]
RIN 2120-AA64
Airworthiness Directives; Carson Helicopters, Inc.; Croman
Corporation; Sikorsky Aircraft Corporation; and Siller Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Carson Helicopters, Inc., Model S-61L and SH-3H helicopters; Croman
Corporation Model SH-3H helicopters; Sikorsky Aircraft Corporation
Model S-61A, S-61D, S-61E, and S-61V helicopters; and Siller
Helicopters Model CH-3E and SH-3A helicopters. This AD was prompted by
an accident. This AD requires tracking hours time-in-service (TIS) and
external lift cycles (lift cycles) for certain main gearbox left and
right input freewheel unit (IFWU) assemblies. This AD also requires
determining the type of IFWU assembly installed and depending on the
results, calculating the moving average, repetitive inspections,
recording certain information, replacing parts, and marking parts. The
FAA is issuing this AD to address the unsafe condition on these
products.
DATES: This AD is effective July 1, 2021.
[[Page 28474]]
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of July 1,
2021.
ADDRESSES: For service information identified in this final rule,
contact your local Sikorsky Field Representative or Sikorsky's Service
Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road,
Trumbull, CT 06611; telephone 1-800-Winged-S; email
[email protected]. Operators may also log on to the
Sikorsky 360 website at https://www.sikorsky360.com. You may view this
service information at the 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. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2006-
26107.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2006-26107; or in person at
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket contains this final rule, any
comments received, and other information. The address for Docket
Operations is 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: Isabel Saltzman, Aviation Safety
Engineer, Boston ACO Branch, FAA, 1200 District Avenue, Burlington, MA
01803; telephone 781-238-7649; email [email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all Sikorsky Aircraft
Corporation Model S-61 A, D, E, and V helicopters; Croman Corporation
Model SH-3H helicopters, Carson Helicopters, Inc. Model S-61L
helicopters; and Siller Helicopters Model CH-3E and SH-3A helicopters.
The NPRM published in the Federal Register on October 30, 2006 (71 FR
63272). The NPRM was prompted by an accident in which the left and
right IFWU assembly on a helicopter slipped or disengaged resulting in
both engines overspeeding, engine shutdowns, and loss of engine power
to the transmissions. In the NPRM, the FAA proposed to require creating
a component history card or equivalent record and recording the hours
TIS and the lift cycles for each affected main gearbox left and right
IFWU assembly. The NPRM also proposed to require determining if the
IFWU assembly is a repetitive external lift (REL) or non-REL IFWU
assembly. The determination includes calculating a moving average of
lift cycles per hour TIS at specified intervals on each IFWU assembly.
For REL IFWU assemblies, the NPRM proposed to require repetitive
inspections, which include visual and dimensional inspections, of the
IFWU assembly for wear, surface distress, and endplay, recording
certain information, and replacing affected parts with an airworthy
part. In addition, the NPRM proposed to require permanently marking the
REL IFWU camshafts and gear housings with the letters ``REL'' on the
surface of these parts.
The FAA issued a supplemental notice of proposed rulemaking (SNPRM)
to amend 14 CFR part 39 by adding an AD that would apply to all Carson
Helicopters, Inc., Model S-61L and SH-3H helicopters; Croman
Corporation Model SH-3H helicopters; Sikorsky Aircraft Corporation
Model S-61A, S-61D, S-61E, and S-61V helicopters; and Siller
Helicopters Model CH-3E and SH-3A helicopters. The SNPRM published in
the Federal Register on March 15, 2021 (86 FR 14285). The SNPRM was
prompted by a determination that additional camshaft and gear housing
part numbers need to be marked and the applicability and certain
compliance times need clarification. The SNPRM proposed to require the
same actions specified in the NPRM. The SNPRM also proposed to mark
additional camshaft and gear housing part numbers. Additionally, the
SNPRM clarified the applicability and certain compliance times. The FAA
is issuing this AD to address the unsafe condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from one commenter. The commenter was
Croman Corp. The commenter supported the SNPRM without change.
Conclusion
The FAA reviewed the relevant data, considered the comments
received, and determined that air safety requires adopting the AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, this
AD is adopted as proposed in the SNPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Sikorsky Aircraft Corporation Alert Service
Bulletin 61B35-67B, Revision B, dated August 11, 2003. This service
information specifies, among other actions, procedures for inspections,
which includes visual and dimensional inspections, of the IFWU assembly
for wear, surface distress, and endplay, and for recording certain
information. 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.
Other Related Service Information
The FAA also reviewed Sikorsky Aircraft Corporation All Operators
Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004. This service
information provides an example and additional information about
tracking cycles and the moving average procedure.
The FAA also reviewed Sikorsky Aircraft S-61L/N Overhaul Manual,
SA4045-83, Revision 20, dated August 15, 2003, as revised by Temporary
Revisions 65-193, -194, -195, and -196, which contains the overhaul
procedures for the IFWU assembly.
Differences Between This AD and the Service Information
The effectivity of Sikorsky Aircraft Corporation Alert Service
Bulletin 61B35-67B, Revision B, dated August 11, 2003, includes Model
S-61 L, N, NM, and R helicopters. However, for those helicopters, the
unsafe condition is addressed in AD 2007-01-05, Amendment 39-14876 (72
FR 1139, January 10, 2007). Therefore, those helicopters are not
included in the applicability of this AD.
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B,
Revision B, dated August 11, 2003, specifies contacting Sikorsky and
providing information to Sikorsky. This AD does not require you to
contact Sikorsky or provide information to Sikorsky.
Costs of Compliance
The FAA estimates that this AD affects 55 helicopters of U.S.
registry. The FAA estimates the following costs to comply with this AD:
[[Page 28475]]
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Creating history card; Up to 8 work- Up to $1,975....... Up to $2,655....... Up to $146,025.
determining type of IFWU hours x $85 per
assembly; inspecting IFWU hour = $680.
assemblies; recording
information; replacing parts;
and marking certain parts.
----------------------------------------------------------------------------------------------------------------
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.
The FAA is 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 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) Will not affect intrastate aviation in Alaska, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
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:
2021-10-16 Carson Helicopters, Inc.; Croman Corporation; Sikorsky
Aircraft Corporation; and Siller Helicopters: Amendment 39-21549;
Docket No. FAA-2006-26107; Project Identifier 2004-SW-30-AD.
(a) Effective Date
This airworthiness directive (AD) is effective July 1, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all helicopters identified in paragraphs
(c)(1) through (6) of this AD, certificated in any category
including restricted.
(1) Carson Helicopters, Inc., Model S-61L helicopters.
(2) Carson Helicopters, Inc., Model SH-3H helicopters.
(3) Croman Corporation Model SH-3H helicopters.
(4) Sikorsky Aircraft Corporation Model S-61A, S-61D, S-61E, and
S-61V helicopters.
(5) Siller Helicopters Model CH-3E helicopters.
(6) Siller Helicopters Model SH-3A helicopters.
(d) Subject
Joint Aircraft System Component (JASC) Code 6310, Engine/
Transmission Coupling.
(e) Unsafe Condition
This AD was prompted by an accident in which the left and right
input freewheel unit (IFWU) assembly on a helicopter slipped or
disengaged, resulting in both engines overspeeding, engine
shutdowns, and loss of engine power to the transmissions. The FAA is
issuing this AD to address slipping of the main gearbox IFWU
assembly, loss of engine power, and subsequent loss of control of
the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Creation of History Card or Equivalent and Daily Actions
Within 10 hours time-in-service (TIS) after the effective date
of this AD, do the actions specified in paragraphs (g)(1) and (2) of
this AD.
(1) Create an external lift component history card or equivalent
record for each IFWU assembly, part number (P/N) 61074-35000-041
through 61074-35000-063 inclusive.
(2) Count and, at the end of each day's operations, record the
number of external lift cycles (lift cycles) performed and the hours
TIS for each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive. A ``lift cycle'' is defined as the lifting of an
external load and subsequent release of the load. Record the lift
cycles and hours TIS on the external lift component history card or
equivalent record.
(h) Determination of IFWU Assembly Type and Calculations
(1) Upon reaching 250 hours TIS after the effective date of this
AD on each IFWU assembly, P/N 61074-35000-041 through 61074-35000-
063 inclusive, determine whether the IFWU assembly is a repetitive
external lift (REL) or non-REL IFWU assembly by using a 250-hour TIS
moving average. 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.
(i) If the calculation specified in paragraph (h)(1) of this AD
results in more than 6 lift cycles per hour TIS, the IFWU assembly
is an REL IFWU assembly.
(ii) If the calculation specified in paragraph (h)(1) of this AD
results in 6 or less lift cycles per hour TIS, the IFWU assembly is
a Non-REL IFWU assembly.
(2) For each IFWU assembly determined to be a Non-REL IFWU
assembly based on the first calculation of the 250-hour TIS moving
average for lift cycles specified in paragraph (h)(1) of this AD:
Within 50 hours TIS after the determination, and thereafter at
intervals of 50 hours TIS, recalculate the average lift cycles per
hour TIS to determine whether the IFWU assembly is an REL or non-REL
IFWU assembly. To perform the 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 IFWU 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.
(i) If any calculation specified in paragraph (h)(2) of this AD
results in more than 6 lift
[[Page 28476]]
cycles per hour TIS, the IFWU assembly is an REL IFWU assembly.
(ii) If any calculation specified in paragraph (h)(2) of this AD
results in 6 or less lift cycles per hour TIS, the IFWU assembly is
a Non-REL IFWU assembly.
Note 1 to paragraph (h)(2): Sikorsky Aircraft Corporation All
Operators Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004,
provides an example and additional information about tracking cycles
and the moving average procedure.
Note 2 to paragraph (h)(2): The following is a 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 = 2,700 lift
cycles. The subsequent moving average of lift cycles per hour TIS =
(2,700-450) divided by 250 = 9 lift cycles per hour TIS.
(3) Once an IFWU assembly is determined to be an REL IFWU
assembly, it remains an REL IFWU assembly for the rest of its
service life and is subject to the inspection for REL IFWU
assemblies required by paragraph (i) of this AD.
(4) Once an IFWU assembly is determined to be an REL IFWU
assembly, you no longer need to perform the 250-hour TIS moving
average calculation required by paragraph (h)(2) of this AD, but you
must continue to count and record the lift cycles as required by
paragraph (g)(2) of this AD.
(i) Repetitive Inspections of REL IFWU Assemblies and Replacement
For each REL IFWU assembly, as determined by paragraph (h)(1) or
(2) of this AD:
(1) Within 500 hours TIS or 7,500 lift cycles, whichever occurs
first since the assembly was determined to be a REL IFWU assembly,
and thereafter at intervals not to exceed 500 hours TIS or 7,500
lift cycles, whichever occurs first, inspect for wear, surface
distress, and endplay by following paragraphs B.(1) through B.(6) of
the Accomplishment Instructions of Sikorsky Aircraft Corporation
Alert Service Bulletin 61B35-67B, Revision B, dated August 11, 2003.
Record all the information specified in Figures 1 through 3 of the
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B,
Revision B, dated August 11, 2003. You may record this information
on any suitable maintenance record, or you may use the Sikorsky
evaluation forms provided in Sikorsky Aircraft Corporation Alert
Service Bulletin 61B35-67B, Revision B, dated August 11, 2003. This
AD does not require you to contact Sikorsky or provide information
to Sikorsky.
(2) If during any inspection required by paragraph (i)(1) of
this AD, any IFWU assembly part is found whose average wear, wear
marks, surface distress, or endplay exceeds the limits specified in
paragraphs B.(1) through B.(6) of the Accomplishment Instructions of
Sikorsky Aircraft Corporation Alert Service Bulletin 61B35-67B,
Revision B, dated August 11, 2003, before further flight, replace
the affected part with an airworthy IFWU assembly part.
Note 3 to paragraph (i)(2): Sikorsky Aircraft S-61L/N Overhaul
Manual, SA4045-83, Revision 20, dated August 15, 2003, as revised by
Temporary Revisions 65-193, -194, -195, and -196, contains the
overhaul procedures for the IFWU assembly.
(j) Part Marking
For each REL IFWU assembly, as determined by paragraph (h)(1) or
(2) of this AD: Before further flight after the assembly was
determined to be an REL IFWU assembly, permanently mark IFWU
camshafts, P/N 61350-24052, 61350-24072, S6135-20611, S6135-20614
and S6137-23075, and IFWU gear housings, P/N 61350-24051, 61350-
24068, S6135-20695, and S6137-23057, with the letters ``REL''. Mark
the camshafts by applying etching ink on the surface of the part
that is 0.5-inch square with the depth of the letters not to exceed
0.001 inch. Before further flight and after etching, neutralize the
etched surface and oil to prevent corrosion.
(k) Alternative Methods of Compliance (AMOCs)
(1) The Manager, International Validation Branch, 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 International Validation Branch, send
it to the attention of the person identified in paragraph (l)(1) of
this AD. Information may be emailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the local flight standards district office/certificate holding
district office.
(l) Related Information
(1) For more information about this AD, contact Isabel Saltzman,
Aviation Safety Engineer, Boston ACO Branch, FAA, 1200 District
Avenue, Burlington, MA 01803; telephone 781-238-7649; email
[email protected].
(2) Service information identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (m)(3) and (4) of this AD.
(m) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) 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 Aircraft Corporation Alert Service Bulletin 61B35-
67B, Revision B, dated August 11, 2003.
(ii) [Reserved]
(3) For service information identified in this AD, contact your
local Sikorsky Field Representative or Sikorsky's Service
Engineering Group at Sikorsky Aircraft Corporation, 124 Quarry Road,
Trumbull, CT 06611; telephone 1-800-Winged-S; email
[email protected]. Operators may also log on to
the Sikorsky 360 website at https://www.sikorsky360.com.
(4) You may view this service information at the 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, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued on May 4, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-11081 Filed 5-26-21; 8:45 am]
BILLING CODE 4910-13-P
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