Document ID: FAA-2021-0189-0009
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Various Restricted Category Helicopters
Posted Date: 2022-01-21T05:00Z

[Federal Register Volume 87, Number 14 (Friday, January 21, 2022)]
[Rules and Regulations]
[Pages 3176-3182]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-00991]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0189; Project Identifier AD-2020-00645-R; 
Amendment 39-21875; AD 2021-26-16]
RIN 2120-AA64

Airworthiness Directives; Various Restricted Category Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain type certificated Model UH-1H restricted category helicopters. 
This AD was prompted by multiple reports of failure of the main 
driveshaft. This AD requires establishing a limit to replace certain 
main driveshafts, and a one-time and repetitive inspections of the main 
driveshafts. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective February 25, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of February 25, 
2022.

ADDRESSES: For service information identified in this final rule, 
contact U.S. Army Materiel Command Logistics Data Analysis Center 
(USAMC LDAC), ATTN: Equipment Publication Control Officers (EPCOs), 
Building 3305, Redeye Road, Redstone Arsenal, AL 35898-7466; telephone 
(256) 955-7716 or 1-866-211-3367; email 
[email protected]; or at https://enterprise.armyerp.army.mil.
    You may also contact the following as applicable:
    Arrow Falcon Exporters Inc., 2081 S Wildcat Way, Porterville, CA 
93257; telephone (559) 781-8604; fax (559) 781-9271; email 
[email protected].
    Global Helicopter Technology, Inc., P.O. Box 180681, Arlington, 
Texas 76096; telephone (817) 557-3391; email [email protected].
    Hagglund Helicopters, LLC, 5101 NW A Avenue, Pendleton, OR 97801; 
telephone (800) 882-3554 or (541) 276-3554; fax (541) 276-1597.
    JASPP Engineering Services, LLC., 511 Harmon Terrace, Arlington, TX 
76010; telephone (817) 465-4495; or at www.jjaspp.com.
    Northwest Rotorcraft, LLC, 1000 85th Ave. SE, Olympia, WA 98501; 
telephone (360) 754-7200; or at www.nwhelicopters.com.
    Overseas Aircraft Support, Inc., P.O. Box 898, Lakeside, AZ 85929; 
telephone (928) 368-6965; fax (928) 368-6962.
    Richards Heavylift Helo, Inc., 1181 Osprey Nest Point, Orange Park, 
FL 32073; (904) 472-1481; email [email protected].
    Rotorcraft Development Corporation, P.O. Box 430, Corvallis, MT 
59828; telephone (207) 329-2518; email 
[email protected].
    Southwest Florida Aviation International, Inc., 28000-A9 Airport 
Road, Bldg. 101, Punta Gorda, FL 33982-9587; telephone (941) 637-1161; 
fax (941) 637-6264; email [email protected].
    Tamarack Helicopters, Inc., 2849 McIntyre Rd., Stevensville, MT 
59870; telephone (406) 777-0144; or at www.tamarackhelicopters.com.
    You may view the 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. Service information that is 
incorporated by reference is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0189.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0189; 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: Ameet Shrotriya, Aerospace Engineer, 
Delegation Oversight Section, DSCO Branch, Compliance & Airworthiness 
Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 
(817) 222-5525; 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 restricted category 
Model UH-1H helicopters with KAflex main driveshaft part number (P/N) 
SKCP2180-1, SKCP2281-1,

[[Page 3177]]

SKCP2281-1R, or SKCP2281-103 installed. The NPRM published in the 
Federal Register on March 26, 2021 (86 FR 16126). The NPRM was prompted 
by multiple reports of failure of a main driveshaft. In the NPRM, the 
FAA proposed to require establishing a life limit for those part-
numbered main driveshafts, removing and inspecting the main driveshaft, 
inspecting the alignment of the main driveshaft installation, and 
repetitive inspections of the main driveshaft. As an optional 
terminating action, the NPRM proposed to allow the installation of a 
certain part-numbered main driveshaft not affected by this unsafe 
condition. This condition, if not addressed, could result in loss of 
engine power to the transmission and subsequent loss of control of the 
helicopter.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from seven commenters. The commenters 
were Kamatics Corporation; Northwest Helicopters, LLC; Salmon River 
Helicopters; and four individuals. The following presents the comments 
received on the NPRM and the FAA's response to each comment.

Request Regarding the FAA's Justification of the Unsafe Condition

    Salmon River Helicopters and two individual commenters requested 
information about the driveshaft failures and one individual commenter 
asked if the issue is unsafe.
    The FAA utilized the FAA's Service Difficulty Reporting System 
(SDRS) database,\1\ the National Transportation Safety Board (NTSB) 
database,2 3 manufacturer reports of failures, and other 
sources to identify seven failures. The seven failures are: 891 Total 
hours time-in-service (TIS) of the main driveshaft, 1997, source: NTSB 
Accident Number SEA97LA126; time in service not identified, 2005, 
source: FAA Service Difficult Report Unique Control #2005FA0000785; 
3341 total hours TIS of the main driveshaft, 2007, source: 
Manufacturer; 2432 total hours TIS of the main driveshaft, 2010, 
source: Manufacturer; 7598.6 total hours TIS since last inspection, 
2015, source NTSB Accident Number WPR15LA178; 4353 total hours TIS of 
the main driveshaft, 2016, source: Manufacturer; and time in service 
not identified, 2020, source: Australian Transport Safety Bureau. Based 
on recent review of collected data, which factored in the usage of the 
main driveshafts, the FAA has determined that an unsafe condition 
exists.
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    \1\ https://av-info.faa.gov/sdrx/Query.aspx.
    \2\ To search for NTSB cases in 2008 and previous, go to: 
https://www.ntsb.gov/Pages/AviationQuery.aspx.
    \3\ To search for NTSB cases after 2008, go to: https://data.ntsb.gov/carol-main-public/query-builder.
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Requests Pertaining to the Applicability

    An individual commenter asked for information about main driveshaft 
P/Ns SKCP2180-1 and SKCP2281-1R.
    Main driveshaft P/Ns SKCP2180-1 and SKCP2281-1R are older P/Ns that 
currently have approval for installation in the domestic fleet and 
could be in service. Those two P/Ns are included in this AD due to 
design similarity and the determination that they are affected by the 
unsafe condition in this AD.
    An individual commenter stated that National Stock Number (NSN) 
615-01-072-5670 is used for both main driveshaft P/N CP2281-103, which 
is affected by this AD, and main driveshaft P/N SKCP3303-1, which is 
not affected by this AD. The commenter asked how main driveshaft P/N 
CP2281-103 is affected by this AD and not main driveshaft P/N SKCP3303-
1 when, according to the NSN, they are built to the same standard.
    An NSN is an identification label assigned to an item or a group of 
similar items, not limited to aircraft parts, and is used for 
procurement purposes in the Department of Defense (DOD) inventory. An 
NSN provides a common nomenclature of function, not a standard, and is 
used in a catalog system that is cross-compatible within multiple 
agencies under DOD. A P/N is assigned by the manufacturer. The 
applicability of this AD is narrowed down to any P/Ns that have an 
unsafe condition. Main driveshaft P/N SKCP3303-1 is an alternative 
part, and the FAA does not have information indicating that it is 
affected by the unsafe condition in this AD.

Requests Regarding Overhauling a Main Driveshaft

    Northwest Helicopters, LLC, and an individual commenter asked if 
the 5,000 total hours TIS removal is a retirement life limit or an 
overhaul life limit. The individual commenter requested that if it is 
an overhaul life limit, the AD state that KAflex main driveshaft P/N 
SKCP2281-103 can be overhauled in accordance with the US Army, Depot 
Maintenance Work Requirement (DMWR) 55-1615-278.
    The FAA partially agrees. The FAA agrees that a main driveshaft 
could be overhauled. Accordingly, the requirements proposed in 
paragraphs (g)(1) and (2) of the NPRM to remove the main driveshaft 
from service have been changed to replace the main driveshaft in this 
final rule. Additionally, clarification that the main driveshaft may be 
overhauled has been added to each instance to replace the main 
driveshaft in the Required Actions paragraph. The overhaul must be 
accomplished by following FAA-approved procedures. U.S. Army Aviation 
and Missile Command, DMWR for Main Drive Shaft DMWR 55-1615-278, 
Original Issuance, dated September 30, 2009 (DMWR 55-1615-278), 
specifies procedures that are not FAA-approved. The FAA disagrees with 
requiring DMWR 55-1615-278 to accomplish an overhaul as it requires 
specialized tooling to which owners/operators may not have access. 
Operators may, however, under the provisions of paragraph (h) of this 
AD, request approval of an alternative method of compliance (AMOC) to 
use DMWR 55-1615-278.
    Kamatics Corporation stated that an older main driveshaft can be 
rebuilt or upgraded into main driveshaft P/N SKCP3303-1 at a lower cost 
than installing a new main driveshaft and requested the FAA add this 
alternative cost information.
    The FAA agrees that some main driveshafts could be overhauled into 
main driveshaft P/N SKCP3303-1 and has updated the Costs of Compliance 
section accordingly.

Request Regarding Determining the Total Hours TIS of the Main 
Driveshaft

    Kamatics Corporation stated that service hours for most of the 
fielded main driveshafts is often not known and an individual commenter 
asked what to do if the proof of time since new on the main drive shaft 
is not recorded in any aircraft logs.
    The FAA recognizes that this situation could exist. In light of 
this, the FAA has determined to require using the helicopter's total 
hours TIS if the total hours TIS of the main driveshaft cannot be 
determined.

Request To Restrict Accomplishment of Certain AD Requirements

    Kamatics Corporation requested the AD require that any main 
driveshaft teardown be accomplished by an FAA-approved facility. 
Kamatics Corporation stated that inspection for wear within critical 
bolt joints requires a teardown. Kamatics Corporation stated that UH-1H 
Technical Manual paragraph 6-24.5 of Change 13 states ``do not attempt 
to loosen or tighten any hardware (with respect to the drive shaft).''
    The FAA disagrees. While the owner/operator may choose to have the 
actions

[[Page 3178]]

required by this AD accomplished at an approved repair station, a 
mechanic that meets the requirements of 14 CFR part 65 subpart D is 
adequate to accomplish the actions required by this AD. Pertaining to 
paragraph 6-24.5 of the UH-1H Technical Manual, this AD does not 
require accomplishing the procedures specified in paragraph 6-24.5 of 
Headquarters, Department of the Army, Aviation Unit and Intermediate 
Maintenance Instructions Army Model UH-1H/V/EH-1H/X Helicopters, 
Technical Manual TM 55-1520-210-23-1, Change No. 42, dated April 14, 
2003 (TM 55-1520-210-23-1 Change 42).

Requests Pertaining to Certain Service Information

    An individual commenter requested the FAA revise the AD so actions 
that are required by following certain procedures in TM 55-1520-210-23-
1 Change 42, would be required using Headquarters, Department of the 
Army, Aviation Unit and Intermediate Maintenance Instructions Army 
Model UH-1H/V/EH-1H/X Helicopters, Technical Manual TM 55-1520-210-23-
1, Change No. 47, dated September 20, 2005 (TM 55-1520-210-23-1 Change 
47), instead because TM 55-1520-210-23-1 Change 47 is the current 
change.
    The FAA agrees to allow TM 55-1520-210-23-1 Change 47 as an option.
    An individual commenter requested the FAA revise the AD to 
reference U.S. Army DMWR 55-1615-278 because this service information 
provides inspection and repair criteria for (main) driveshaft P/N 
SKCP2281-103 once it has been removed from the helicopter.
    The FAA agrees. The FAA has reviewed this service information and 
added it to the Other Related Service Information section.

Request To Require Removal of Certain Part-Numbered Main Driveshafts 
From Service

    Kamatics Corporation requested the FAA revise the AD to require 
removal of main driveshaft P/Ns SKCP2180-1, SKCP 2281-1, and SKCP2281-
1R from service. According to Kamatics Corporation, those P/Ns were 
removed from service by the U.S. Army due to flex frame bolted joint 
deterioration.
    The FAA disagrees because no data has been provided to substantiate 
the commenter's request.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, 
including updating the contact information for the U.S. Army, 
clarifying the specific portions of TM 55-1520-210-23-1 Change 42 that 
are required to accomplish this Final rule, and the changes described 
previously, this AD is adopted as proposed in the NPRM. None of the 
changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed ``Figure 4-9. Engine Air Inlet Filter 
Installation'' on page 4-16; page 4-17; ``Figure 6-7. Transmission 
Positioning for Driveshaft Alignment'' on page 6-2; ``Figure 6-8. Tool 
Application--Use of Alignment Tool Set (T47)'' on page 6-3; and pages 
6-21 through 6-24, of TM 55-1520-210-23-1 Change 42. This service 
information contains main driveshaft assembly figures and specifies 
procedures for the main driveshaft disassembly, and inspecting and 
correction of its alignment.
    The FAA also reviewed ``Figure 4-9. Engine Air Inlet Filter 
Installation'' on page 4-16; page 4-17; ``Figure 6-7. Transmission 
Positioning for Driveshaft Alignment'' on page 6-2; ``Figure 6-8. Tool 
Application--Use of Alignment Tool Set (T47)'' on page 6-3; pages 6-21 
through 6-24; and ``Figure 6-12.2. Main Driveshaft Installation & 
Removal Tool'' and ``Figure 6-12.3. Work Aid Tool Installed on Main 
Driveshaft'' on page 6-27, of TM 55-1520-210-23-1 Change 47. This 
service information specifies the same procedures as TM 55-1520-210-23-
1 Change 42 with various updates throughout.
    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 ADDRESSES.

Other Related Service Information

    The FAA reviewed DMWR 55-1615-278, for main driveshaft P/N 
SKCP2281-103, which specifies maintenance, overhaul, repair, assembly, 
and balance procedures.

Costs of Compliance

    The FAA estimates that this AD affects 384 helicopters of U.S. 
registry. Labor rates are estimated at $85 per work-hour. Based on 
these numbers, the FAA estimates that operators may incur the following 
costs in order to comply with this AD.
    Determining the total hours TIS of the main driveshaft takes about 
0.5 work-hour for an estimated cost of about $43 per helicopter and 
$16,512 for the U.S. fleet. Removing and inspecting the main driveshaft 
takes about 4 work-hours for an estimated cost of $340 per helicopter 
and $130,560 for the U.S. fleet. Inspecting the installed main 
driveshaft takes about 1 work-hour for an estimated cost of about $85 
per helicopter and $32,640 for the U.S. fleet, per inspection cycle. 
Inspecting the alignment of the main driveshaft installation takes 
about 2 work-hours for an estimated cost of $170 per helicopter and 
$65,280 for the U.S. fleet. If required, adjusting the alignment takes 
about 0.5 work-hour for an estimated cost of $43 per instance. 
Replacing a main driveshaft takes about 1 work-hour and parts cost 
about $54,000, for an estimated cost of $54,085 per replacement. 
Alternatively, overhauling a main driveshaft takes about 1 work-hour 
for removal and reinstallation and parts cost about $38,000, for an 
estimated cost of $38,085 per overhaul.

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

[[Page 3179]]

    (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:

2021-26-16 Various Restricted Category Helicopters: Amendment 39-
21875; Docket No. FAA-2021-0189; Project Identifier AD-2020-00645-R.

(a) Effective Date

    This airworthiness directive (AD) is effective February 25, 
2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to restricted category Model UH-1H helicopters; 
current type certificate holders include but are not limited to 
Arrow Falcon Exporters Inc.; Global Helicopter Technology, Inc.; 
Hagglund Helicopters, LLC; JJASPP Engineering Services, LLC.; 
Northwest Rotorcraft, LLC; Overseas Aircraft Support, Inc.; Richards 
Heavylift Helo, Inc.; Rotorcraft Development Corporation; Southwest 
Florida Aviation International, Inc.; and Tamarack Helicopters, 
Inc., with KAflex main driveshaft part number (P/N) SKCP2180-1, 
SKCP2281-1, SKCP2281-1R, or SKCP2281-103 installed.
    Note 1 to paragraph (c): Helicopters with an SW205 designation 
are Southwest Florida Aviation International, Inc., Model UH-1H 
helicopters.

(d) Subject

    Joint Aircraft System Component (JASC) Code: 6310, Engine/
Transmission Coupling.

(e) Unsafe Condition

    This AD was prompted by multiple reports of failure of the main 
driveshaft. The unsafe condition, if not addressed, could result in 
loss of engine power to the transmission and subsequent loss of 
control of the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Before further flight after the effective date of this AD, 
determine the total hours time-in-service (TIS) of the main 
driveshaft. If the total hours TIS of the main driveshaft cannot be 
determined, use the helicopter's total hours TIS as the total hours 
TIS of the main driveshaft for the action required by this 
paragraph.
    (i) If the main driveshaft has accumulated less than 5,000 total 
hours TIS, before exceeding 5,000 total hours TIS, replace the main 
driveshaft. The main driveshaft may be overhauled in accordance with 
FAA-approved procedures to accomplish the replacement required by 
this paragraph.
    Note 2 to paragraph (g)(1)(i): This note applies to paragraphs 
(g)(1)(i) and (ii), (g)(2), and (g)(3)(i) through (iv) of this AD. 
U.S. Army Aviation and Missile Command, Depot Maintenance Work 
Requirement for Main Drive Shaft DMWR 55-1615-278, Original 
Issuance, dated September 30, 2009, specifies procedures that are 
not FAA-approved.
    (ii) If the main driveshaft has accumulated 5,000 or more total 
hours TIS, before further flight, replace the main driveshaft. The 
main drive shaft may be overhauled in accordance with FAA-approved 
procedures to accomplish the replacement required by this paragraph.
    (2) Thereafter following paragraph (g)(1) of this AD, replace 
the main driveshaft before accumulating 5,000 total hours TIS. The 
main drive shaft may be overhauled in accordance with FAA-approved 
procedures to accomplish the replacement required by this paragraph.
    (3) Within 25 hours TIS after the effective date of this AD, 
remove main driveshaft P/N SKCP2180-1, SKCP2281-1, SKCP2281-1R, or 
SKCP2281-103 by following ``6-24.3. Removal--Main Driveshaft P/N 
SKCP2281-103'' on page 6-24, including ``4-24. Removal--Air Inlet 
Filters'' on page 4-17 and ``Figure 4-9. Engine Air Inlet Filter 
Installation'' on page 4-16, of Headquarters, Department of the 
Army, Aviation Unit and Intermediate Maintenance Instructions Army 
Model UH-1H/V/EH-1H/X Helicopters, Technical Manual TM 55-1520-210-
23-1, Change No. 42, dated April 14, 2003 (TM 55-1520-210-23-1 C 
42), except where instructed to ``refer to figure 6-12.2'' in TM 55-
1520-210-23-1 C 42, refer to Figure 1 to the introductory text of 
paragraph (g)(3) of this AD, and where instructed to ``see figure 6-
12.3'' in TM 55-1520-210-23-1 C 42, see Figure 2 to the introductory 
text of paragraph (g)(3) of this AD, and:
    Note 3 to the introductory text of paragraph (g)(3): Figures 6-
12.2 and 6-12.3 are missing from TM 55-1520-210-23-1 C 42.

[[Page 3180]]

[GRAPHIC] [TIFF OMITTED] TR21JA22.000

[GRAPHIC] [TIFF OMITTED] TR21JA22.001

    (i) Inspect for any broken, loose, or missing hardware. If there 
is broken or loose hardware, before further flight, remove the main 
driveshaft from service. If there is missing hardware, before 
further flight, replace the main driveshaft. The main drive shaft 
may be overhauled in accordance with FAA-approved procedures to 
accomplish the replacement required by this paragraph.
    (ii) Visually inspect each flex frame and mount bolt torque 
stripe (red or yellow) for movement. If there is any torque stripe 
movement, before further flight, replace the main driveshaft. The 
main drive shaft may be overhauled in accordance with FAA-approved 
procedures to accomplish the replacement required by this paragraph.
    (iii) Visually inspect each joint for fretting corrosion, which 
may be indicated by red metallic particles. If there is any grease, 
oil, or dirt covering a joint, clean the area and visually inspect 
again. If there is any fretting corrosion, before further flight, 
replace the main driveshaft. The main drive shaft may be overhauled 
in accordance with FAA-approved procedures to accomplish the 
replacement required by this paragraph.
    (iv) Inspect the main driveshaft for mechanical damage, 
corrosion, an edge dent, and nick as shown in Figure 3 to paragraph 
(g)(3)(iv) of this AD. For the purposes of this inspection, 
mechanical damage may be indicated by a crack, scratch, or wear; and 
corrosion may be indicated by corrosion or pitting. If there is a 
scratch, wear, corrosion, pitting, an edge dent, or a nick within 
allowable limits, before further flight, repair the main driveshaft 
in accordance with FAA-approved procedures. If there is a crack, or 
a scratch, wear, corrosion, pitting, an edge dent, or a nick that 
exceeds allowable limits,

[[Page 3181]]

before further flight, replace the main driveshaft. The main drive 
shaft may be overhauled in accordance with FAA-approved procedures 
to accomplish the replacement required by this paragraph.
[GRAPHIC] [TIFF OMITTED] TR21JA22.002

[[Page 3182]]

    (4) Before installing the main driveshaft following paragraph 
(g)(3) of this AD, and with the engine adapter installed in the end 
of the engine output shaft, inspect the alignment of the main 
driveshaft installation between the transmission input drive quill 
coupling and the engine output shaft adapter by following ``6-24. 
Alignment--Main Driveshaft,'' paragraphs c. through g. on pages 6-21 
through 6-23, including ``Figure 6-7. Transmission Positioning for 
Driveshaft Alignment'' on page 6-2 (Figure 6-7), and ``Figure 6-8. 
Tool Application--Use of Alignment Tool Set (T47)'' on page 6-3 
(Figure 6-8), of TM 55-1520-210-23-1 C 42. If there is misalignment, 
before further flight, adjust the alignment by following ``6-24. 
Alignment--Main Driveshaft,'' paragraphs h. through j. on page 6-23, 
including Figure 6-7 and Figure 6-8, of TM 55-1520-210-23-1 C 42.
    (5) Within 300 hours TIS after the effective date of this AD, 
and thereafter within intervals not to exceed 300 hours TIS, with 
the main driveshaft installed, accomplish the actions in paragraphs 
(g)(3)(i) through (iv) of this AD.
    (6) As an optional terminating action for the requirements of 
this AD, you may install KAflex main driveshaft P/N SKCP3303-1.
    (7) As an option to accomplishing the actions by following the 
specified portions in TM 55-1520-210-23-1 C 42 in paragraphs (g)(3) 
and (4) of this AD, you may accomplish the actions by following 
those specified portions in Headquarters, Department of the Army, 
Aviation Unit and Intermediate Maintenance Instructions Army Model 
UH-1H/V/EH-1H/X Helicopters, Technical Manual TM 55-1520-210-23-1, 
Change No. 47, dated September 20, 2005 (TM 55-1520-210-23-1 C 47), 
and disregard exceptions to refer to Figure 1 and see Figure 2 to 
the introductory text of paragraph (g)(3) of this AD, instead refer 
to ``Figure 6-12.2. Main Driveshaft Installation & Removal Tool'' 
and see ``Figure 6-12.3. Work Aid Tool Installed on Main 
Driveshaft,'' on page 6-27 of TM 55-1520-210-23-1 C 47 as instructed 
in TM 55-1520-210-23-1 C 47.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, DSCO 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 
certification office, send it to the attention of the person 
identified in paragraph (i) 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.

(i) Related Information

    For more information about this AD, contact Ameet Shrotriya, 
Aerospace Engineer, Delegation Oversight Section, DSCO Branch, 
Compliance & Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort 
Worth, TX 76177; telephone (817) 222-5525; email 
[email protected].

(j) 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) Headquarters, Department of the Army, Aviation Unit and 
Intermediate Maintenance Instructions Army Model UH-1H/V/EH-1H/X 
Helicopters, Technical Manual TM 55-1520-210-23-1, Change No. 42, 
dated April 14, 2003:
    (A) ``Figure 4-9. Engine Air Inlet Filter Installation,'' page 
4-16;
    (B) Page 4-17;
    (C) ``Figure 6-7. Transmission Positioning for Driveshaft 
Alignment,'' page 6-2;
    (D) ``Figure 6-8. Tool Application--Use of Alignment Tool Set 
(T47),'' page 6-3; and
    (E) Pages 6-21 through 6-24.
    (ii) Headquarters, Department of the Army, Aviation Unit and 
Intermediate Maintenance Instructions Army Model UH-1H/V/EH-1H/X 
Helicopters, Technical Manual TM 55-1520-210-23-1, Change No. 47, 
dated September 20, 2005:
    (A) ``Figure 4-9. Engine Air Inlet Filter Installation,'' page 
4-16;
    (B) Page 4-17;
    (C) ``Figure 6-7. Transmission Positioning for Driveshaft 
Alignment,'' page 6-2;
    (D) ``Figure 6-8. Tool Application--Use of Alignment Tool Set 
(T47),'' page 6-3;
    (E) Pages 6-21 through 6-24; and
    (F) ``Figure 6-12.2. Main Driveshaft Installation & Removal 
Tool'' and ``Figure 6-12.3. Work Aid Tool Installed on Main 
Driveshaft,'' page 6-27.
    (3) For service information identified in this AD, contact U.S. 
Army Materiel Command Logistics Data Analysis Center (USAMC LDAC), 
ATTN: Equipment Publication Control Officers (EPCOs), Building 3305, 
Redeye Road, Redstone Arsenal, AL 35898-7466; telephone (256) 955-
7716 or 1-866-211-3367; email 
[email protected]; or at https://enterprise.armyerp.army.mil.
    (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, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on December 10, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-00991 Filed 1-20-22; 8:45 am]
BILLING CODE 4910-13-P