Document ID: FAA-2019-0759-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Various Experimental and Restricted Category Helicopters
Posted Date: 2019-10-31T04:00Z

[Federal Register Volume 84, Number 211 (Thursday, October 31, 2019)]
[Proposed Rules]
[Pages 58341-58348]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-23686]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 84, No. 211 / Thursday, October 31, 2019 / 
Proposed Rules  

[[Page 58341]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0759; Product Identifier 2018-SW-075-AD]
RIN 2120-AA64

Airworthiness Directives; Various Experimental and Restricted 
Category Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for various helicopters operating under experimental airworthiness 
certificates and various type certificated restricted category 
helicopters. This proposed AD was prompted by multiple accidents and 
incidents involving failure of the tail boom attachment structure and 
bolts. This proposed AD would require revising the Rotorcraft Flight 
Manual (RFM) for your helicopter to incorporate pre-flight checks; 
removing paint and sealant, and cleaning; repetitive inspections of 
structural components that attach the tail boom to the fuselage; and 
depending on the outcome of the inspections, repairing or replacing 
components, or re-bonding the structure. The FAA is proposing this AD 
to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by December 
16, 2019.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For AST, Inc. service information identified in this NPRM, contact: 
AST, Inc., 34976 Kamph Drive NE, Albany, OR 97322.
    For JJASPP Engineering Services, LLC service information identified 
in this NPRM, contact: JJASPP Engineering Services, LLC, 511 Harmon 
Terrace, Arlington, TX 76010; phone: (817) 465-4495; website: 
www.jjaspp.com.
    For Northwest Rotorcraft, LLC service information identified in 
this NPRM, contact: Northwest Rotorcraft, LLC, 1000 85th Ave. SE, 
Olympia, WA 98501; phone: (360) 754-7200; website: 
www.nwhelicopters.com.
    For Richards Heavylift Helo, Inc., service information identified 
in this NPRM, contact: Richards Heavylift Helo, Inc., 1181 Osprey Nest 
Point, Orange Park, FL 32073.
    For Robinson Air Crane, Inc., service information identified in 
this NPRM, contact: Robinson Air Crane, Inc., 230 Bermuda Beach Drive, 
Ft Pierce, FL 34949; phone: (305) 302-9696.
    For Rotorcraft Development Corporation service information 
identified in this NPRM, contact: Rotorcraft Development Corporation, 
P.O. Box 430, Corvallis, MT 59828; phone: (207) 329-2518; email: 
administration@rotorcraftdevelopment.com.
    For San Joaquin Helicopters service information identified in this 
NPRM, contact: San Joaquin Helicopters, 1407 South Lexington Street, 
Delano, CA 93215; phone: (661) 725-1898; website: 
www.sjhelicopters.com.
    For Southwest Florida Aviation International, Inc. service 
information identified in this NPRM, contact: Southwest Florida 
Aviation International, Inc., 28000-A9 Airport Road, Bldg. 101, Punta 
Gorda, FL 33982-9587.
    For Tamarack Helicopters Inc. service information identified in 
this NPRM, contact: Tamarack Helicopters Inc, 2849 McIntyre Rd, 
Stevensville, MT 59870; phone: (406) 777-0144; website: 
www.tamarackhelicopters.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.

Examining the AD Docket

    You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0759; 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 NPRM, the special airworthiness information bulletins (SAIBs), the 
supplemental type certificate, the regulatory evaluation, any comments 
received, and other information. The street address for the Docket 
Operations is listed above. Comments will be available in the AD docket 
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Richard R. Thomas, Aerospace Engineer, 
Denver ACO Branch, Compliance & Airworthiness Division, FAA, 26805 East 
68th Ave., Room 214, Denver, CO 80249; phone: (303) 342-1085; fax: 
(303) 342-1088; email: richard.r.thomas@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2019-0759; 
Product Identifier 2018-SW-075-AD'' at the beginning of your comments. 
The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. The FAA will 
consider all comments received by the closing date and may amend this 
NPRM because of those comments.
    The FAA will post all comments received, without change, to http://www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Discussion

    The FAA proposes to adopt a new AD for Model EH-1H, EH-1X, HH-1H, 
HH-

[[Page 58342]]

1N, UH-1D, UH-1M, UH-1N, and UH-1V helicopters operating under 
experimental airworthiness certificates; and for restricted category 
type certificated Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B without STC 
No. SR00026DE installed, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P 
helicopters. The FAA plans to publish separate rulemaking to address 
Model UH-1B with STC No. SR00026DE installed.
    The type certificate holders for the restricted category models are 
Arrow Falcon Exporters Inc.; AST, Inc.; Bell Helicopter Textron, Inc.; 
California Department of Forestry; West Coast Fabrications; Global 
Helicopter Technology, Inc.; Hagglund Helicopters, LLC; International 
Helicopters, Inc.; JJASPP Engineering Services, LLC; JTBAM, Inc.; 
Northwest Rotorcraft, LLC; Red Tail Flying Services, LLC; Richards 
Heavylift Helo, Inc.; Robinson Air Crane, Inc.; Rotorcraft Development 
Corporation; San Joaquin Helicopters; Smith Helicopters; Southwest 
Florida Aviation International, Inc.; and Tamarack Helicopters, Inc.
    This proposed AD would require revising the RFM for your helicopter 
to incorporate pre-flight checks; removing paint and sealant, and 
cleaning structural components that attach the tail boom to the 
fuselage; repetitive inspections of the cleaned structural components; 
repairing scratches, nicks, gouges, tears, and corrosion within 
allowable limits; replacing structural components with non-repairable 
damage, cracks, buckling, or distortion; replacing loose or missing 
rivets; re-bonding structures with dis-bonds; and removing loose bolts 
and self-locking nuts from service and replacing them with new bolts 
and new self-locking nuts.
    This proposed AD was prompted by a series of accidents and 
incidents involving failure of the tail boom attachment structure on 
several restricted category military surplus helicopters. This 
condition, if not addressed, could result in separation of the tail 
boom from the helicopter, and subsequent loss of control of the 
helicopter.
    In January 1982, a tail boom separated from a UH-1B helicopter 
engaged in logging operations, resulting in a fatal accident. The 
National Transportation Safety Board's (NTSB) final report identified 
structural fatigue and inadequate maintenance as probable causes. In 
September 2013, a tail boom separated from another UH-1B helicopter 
engaged in logging operations, resulting in another fatal accident. The 
NTSB's final report for that accident identified the cause as fatigue 
failure of the upper two tail boom attach points. Contributing to this 
accident was poor maintenance throughout the helicopter's operational 
life. In addition to these accidents, the FAA is aware of three forced 
landings due to tail boom attachment structure failures, one in May 
2014 on a UH-1H helicopter, one in August 2016 on a UH-1H helicopter, 
and one in August 2018 on a UH-1F helicopter. The helicopter involved 
in the May 2014 forced landing was engaged in construction operations. 
The operations the helicopter was engaged in during the August 2016 
forced landing are unknown. The helicopter involved in the August 2018 
forced landing was engaged in firefighting operations.
    In the first fatal accident and two of the forced landings, a loud 
pop or bang was heard in the rear of the aircraft at the moment of 
failure. In the second fatal accident, the pilot indicated before the 
flight that the helicopter felt like it ``shuffled'' during 
translational lift. Four of the five incidents involved a failure of 
the upper left hand tail boom attachment structure. In three cases it 
was the attach fitting on the tail boom side. In one case it was the 
longeron on the tail boom side. The upper left hand tail boom attach 
point is the most heavily loaded of the four attach points.
    The FAA issued Special Airworthiness Information Bulletin SW-18-29 
(SAIB SW-18-29) on October 1, 2018 to alert owners and operators of 
Restricted Category Bell Model HH-1K, UH-1A, UH-1B, UH-1E, UH-1F, UH-
1H, UH-1L, UH-1P, TH-1F, and TH-1L helicopters of failure of the tail 
boom attachment structure.
    SAIB SW-18-29 recommends adhering to the helicopter's Instructions 
for Continued Airworthiness which includes a repetitive 100 hour time-
in-service (TIS) inspection of the tail boom attachment structure on 
both sides of the four attachment points. SAIB SW-18-29 also specifies 
the following supplemental recommendations: Keeping the fittings on 
both sides of all four attachment points, the cap angles running 
forward from the fuselage side fitting, and the longerons running aft 
from the tail boom side fitting, clean and free of paint and any non-
faying sealant; and inspecting for cracks in the attachment structure 
with a borescope since the tail boom side structure is difficult to 
access. On the fuselage side, SAIB SW-18-29 recommends paying 
particular attention to the most forward fitting fasteners, the cap 
angle and the cap angle rivets just forward of the fitting as failures 
in these areas are more common. On the tail boom side, SAIB SW-18-29 
recommends paying particular attention to the most aft fitting 
fasteners as failures in this area are more common. SAIB SW-18-29 also 
advises that smoking rivets are an indicator of attachment point 
issues. For helicopters that perform heavy lift operations, SAIB SW-18-
29 recommends performing a repetitive 20 hours TIS inspection of both 
the fuselage and tail boom upper left-hand (LH) attach fittings, 
fuselage side cap angle, and tail boom side longeron. Lastly, for all 
affected helicopters, if a loud noise (typically a ``pop'' or ``bang'') 
is heard in the rear of the aircraft during flight, SAIB SW-18-29 
recommends minimizing hovering, slow flight, and pedal turns; reducing 
power when possible to avoid left pedal input; jettisoning external 
loads (if present) as soon as possible; and landing the aircraft as 
soon as possible. If an external load must be landed, SAIB SW-18-29 
recommends performing a forward descent until the load touches down.
    Based on input from a repair station, the FAA revised SAIB SW-18-29 
to SAIB SW-18-29R1, dated February 19, 2019 (SAIB SW-18-29R1), to alert 
all owners and operators of clarified paint and sealant removal 
procedures and simplify the wording of recommendations to provide 
clarity. In particular, it was necessary to correct the emphasized 
inspection areas. The fuselage side fitting emphasis was revised to 
focus on the fitting section through the rivets closest to the attach 
bolt (the aft fitting fasteners) rather than through the most forward 
fitting fasteners. The tail boom side fitting emphasis was revised to 
focus on the fitting section through the rivets closest to the attach 
bolt (the forward fitting fasteners) rather than through the most aft 
fitting fasteners.

Related Service Information

    The FAA reviewed portions of the following related service 
information:
     Garlick Helicopters Inc. Instructions for Continued 
Airworthiness Report No. GH-H13WE-CA1H, UH-1H Helicopters, Revision 4, 
dated August 9, 2012, available from Rotorcraft Development 
Corporation. This report contains a Component Overhaul Schedule, an 
Airworthiness Limitation Schedule, and a Continued Airworthiness 
Documents Section that lists Army Technical Manuals required for 
servicing, maintaining, inspecting, repairing, and overhauling the 
helicopter, its engine, rotors, and appliances, and for special purpose 
modifications.

[[Page 58343]]

     Garlick Helicopters Inc. Instructions for Continued 
Airworthiness Report No. GH-H5NM-CA1, UH-1E, UH-1L, TH-1L and HH-1K 
Helicopters, Revision Original, dated October 22, 2002, available from 
Rotorcraft Development Corporation. This report contains a Component 
Overhaul Schedule, an Airworthiness Limitation Schedule, and a 
Continued Airworthiness Documents Section that lists Army Technical 
Manuals required for servicing, maintaining, inspecting, repairing, and 
overhauling the helicopter, its engine, rotors, appliances, and for 
special purpose modifications.
     Headquarters, Department of the Army, Aviation Unit and 
Intermediate Maintenance Instructions Model UH-1H/V/EH-1H/X 
Helicopters, Technical Manual TM 55-1520-210-23-1, Change 42, dated 
April 14, 2003, available from JJASPP Engineering Services, LLC, 
Richards Heavylift Helo, Inc., and San Joaquin Helicopters. This 
service information contains: Tail boom hoisting/handling instructions; 
hard landing, tail rotor blade strike, and sudden stoppage due to 
compressor stall tail boom inspection requirements; tail boom removal 
and installation instructions including attachment bolt installation 
and tightening instructions, tail boom attachment fitting inspection 
instructions, tail boom and fuselage attachment fitting bolt hole wear 
limits, allowable tail boom attachment fitting damage and corrosion 
repair instructions; loose attachment fitting fastener inspection and 
replacement instructions; tail boom attachment fitting replacement 
instructions; classification of damage as negligible, repairable or 
requiring replacement for tail boom structure including rivets, 
fasteners, tail boom attachment fittings, stringers, and longerons; 
tail boom structural material specifications; allowable area for damage 
repair of tail boom attachment fittings; longeron damage limits and 
repair criteria; and stringer repair instructions.
     Headquarters, Department of the Army, Aviation Unit and 
Intermediate Maintenance Instructions Army Model UH-1H/V/EH-1H/X, 
Technical Manual TM 55-1520-210-23-3, Change 8, dated June 14, 1996, 
available from JJASPP Engineering Services, LLC, Richards Heavylift 
Helo, Inc., and San Joaquin Helicopters. This service information 
contains: A Maintenance Allocation Chart which assigns tail boom 
maintenance functions to three levels, (1) high-frequency field tasks 
requiring general knowledge to maintain the helicopter in an airworthy 
condition or return the helicopter to an airworthy condition, (2) low-
frequency field tasks requiring specialized knowledge to return the 
helicopter to an airworthy condition, and (3) helicopter or component 
maintenance tasks which cannot be performed in the field; and 
instructions for field manufacture of part number (P/N) 204-030-800-
443, Tail Boom Assembly Cover, and P/N 205-031-801-53, Tail Boom Cover.
     Headquarters, Department of the Army, Aviation Unit 
Maintenance (AVUM) and Aviation Intermediate Maintenance (AVIM) Manual 
for General Aircraft Maintenance (General Maintenance and Practices), 
Volume 1, Technical Manual TM 1-1500-204-23-1, Change 5, dated May 31, 
2006, available from Richards Heavylift Helo, Inc. This service 
information contains general maintenance practice information.
     Headquarters, Department of the Army, AVUM and AVIM Manual 
for General Aircraft Maintenance (Hardware and Consumable Materials) 
Volume 6, Technical Manual TM 1-1500-204-23-6, Change 4, dated August 
20, 2004, available from Richards Heavylift Helo, Inc. This service 
information contains general information pertaining to the use and 
identification of hardware and materials, specifically bolts, nuts, 
rivets, clamps, fittings, plate nuts, torque values, lockwire 
techniques, cotter pins, safety pins, and Hi-Shear rivets.
     Headquarters, Department of the Army, AVUM and AVIM Manual 
for General Aircraft Maintenance (Nondestructive Testing and Flaw 
Detection Procedures and Practices) Volume 7, Technical Manual TM 1-
1500-204-23-7, Change 1, dated December 30, 1993, available from 
Richards Heavylift Helo, Inc. This service information contains general 
information pertaining to nondestructive testing and flaws, and 
nondestructive inspection procedures and practices, particularly 
magnetic particle inspections, radiography, ultrasonic inspections, and 
electromagnetic inspections.
     Headquarters, Department of the Army, AVUM and AVIM Manual 
for General Aircraft Maintenance (Sheet Metal Shop Practices) Volume 
10, Technical Manual TM 1-1500-204-23-10, Change 3, dated August 20, 
2004, available from Richards Heavylift Helo, Inc. This service 
information contains general information pertaining to the repair of 
aircraft structures, structural metals, forming of replacement 
structure, rivets and riveting techniques, airframe sheet metal repair, 
and sandwich construction repair.
     Headquarters, Department of the Army, AVUM and AVIM Manual 
Nondestructive Inspection Procedures for UH-1 Helicopter Series, 
Technical Manual TM 1-1520-256-23, dated November 30, 1996, available 
from Richards Heavylift Helo, Inc. This service information contains 
instructions for accomplishing an eddy current inspection of the 
fuselage structure, tail boom and fuselage tail boom attachment 
fittings, and tail boom longerons.
     Headquarters, Department of the Army, Operator's Manual 
Army Model UH-1B Helicopter, Technical Manual TM 55-1520-219-10, Change 
20, dated May 16, 1983, available from Richards Heavylift Helo, Inc., 
and Rotorcraft Development Corporation. This manual contains operating 
instructions and procedures for the UH-1B helicopter. It includes a 
brief description of the tail boom structure.
     Headquarters, Department of the Army, Operator's Manual 
Army Model UH-1H/V Helicopters, Technical Manual TM 55-1520-210-10, 
Change 20, dated June 23, 2005, available from Northwest Rotorcraft, 
LLC, Richards Heavylift Helo, Inc., and Rotorcraft Development 
Corporation. This manual contains operating instructions and procedures 
for the UH-1H/V helicopter. It includes a brief description of the tail 
boom structure and a pre-flight check of the tail boom attachment 
bolts.
     Headquarters, Department of the Army, Organizational 
Maintenance Manual Army Model UH-1B Helicopter, Technical Manual TM 55-
1520-219-20, Change 28, dated August 2, 1982, available from Richards 
Heavylift Helo, Inc., Rotorcraft Development Corporation, and Southwest 
Florida Aviation International, Inc. This manual provides various 
maintenance instructions for flight line maintenance crews, including 
special inspections of the tail boom attachment structure. Following 
hard landings, tail rotor blade strikes, or compressor stalls, 
maintenance crews are required to inspect the area where the tail boom 
attaches to the forward fuselage section, specifically the attachment 
fittings, longerons and cap angles, for cracks, distortion, and loose 
rivets, and the attachment bolts for torque.
     Headquarters, Department of the Army, Preparation for 
Shipment of UH-1/EH-1 Helicopters, Technical Manual TM 55-1520-242-S, 
Change 5, dated June 30, 1993, available from JJASPP Engineering 
Services, LLC. This service information contains instructions to coat 
attachment points and hardware with corrosion preventive when tail boom 
is removed for transport.
     Headquarters, Department of the Army, Rotorcraft 
Development

[[Page 58344]]

Corporation, UH-1B Aircraft Preventive Maintenance Services, Technical 
Manual TM 55-1520-219-PMS, Change 7, dated August 9, 1976, available 
from Rotorcraft Development Corporation. This service information 
contains requirements: To inspect the tail boom attaching bolts for 
security and the fittings for cracks daily and every 25, 50, 75, and 
100 flight hours; and to inspect the tail boom interior structure and 
longerons for damage, cracks, and corrosion every 100 flight hours.
     Headquarters, Department of the Army, UH-1B DS and GS 
Maintenance Manual, Technical Manual TM 55-1520-219-34, Change 9, dated 
June 5, 1972, available from Richards Heavylift Helo, Inc., Rotorcraft 
Development Corporation, and Southwest Florida Aviation International, 
Inc. This service information contains: Instructions to remove and 
install the tail boom; attachment bolt exposed thread limits; 
attachment bolt tightening instructions with instructions for 
manufacturing a special torque wrench extension; allowable tail boom 
attachment fitting hole diameters; damage classifications for tail boom 
skin, stringers and longerons as negligible, reparable by patching, 
reparable by insertion, or damage necessitating replacement; and 
instructions for field manufacture of P/N 204-030-800-443, Tail Boom 
Assembly Cover.
     Headquarters, Department of the Army, UH-1H/V and EH-1H/X 
Aircraft Phased Maintenance Checklist, Technical Manual TM 55-1520-210-
PM, Changes 22, dated May 8, 2002, available from Northwest Rotorcraft, 
LLC. This service information contains phased inspection requirements 
for the tail boom interior and fuselage heater compartment to check for 
damage, cracks, and corrosion.
     Headquarters, Department of the Army, UH-1H/V and EH-1H/X 
Aircraft Preventative Maintenance Daily Inspection Checklist, Technical 
Manual TM 55-1520-210-PMD, Preventive Maintenance Daily Inspection 
Checklist UH-1H/V and EH-1H/X Helicopters, Change 11, dated April 11, 
2003, available from JJASPP Engineering Services, LLC, and Northwest 
Rotorcraft, LLC. This service information contains preventative daily 
maintenance instructions to be accomplished prior to the first flight 
of the day to inspect for loose or missing rivets, the tail boom 
attachment bolts for security, and tail boom attachment fittings and 
longerons up to 12 inches from the fittings for cracks.
     JJASPP Engineering Services Instructions for Continued 
Airworthiness for Restricted Category UH-1H Rotorcraft Report No. 
JJASPP-ICA-12-005, Revision IR, approved February 6, 2013, available 
from JJASPP Engineering Services, LLC. This report contains a Component 
Overhaul Schedule, an Airworthiness Limitation Schedule, and a 
Continued Airworthiness Documents section that list documents and 
reports required for servicing, maintaining, inspecting, repairing, and 
overhauling the rotorcraft, its engine, rotors, and appliances.
     Northwest Rotorcraft, LLC, UH-1H Instructions for 
Continued Airworthiness Report No. PH-106, Revision 7, approved March 
15, 2012, available from Northwest Rotorcraft, LLC. This report 
contains a Component Overhaul Schedule, an Airworthiness Limitation 
Schedule, and a Continued Airworthiness Documents Section, which lists 
Army Technical Manuals required for servicing, maintaining, inspecting, 
repairing, and overhauling the helicopter, its engine, rotors, and 
appliances, and for special purpose modifications.
     Rotorcraft Development Corporation Instructions for 
Continued Airworthiness Report No. GH-H3NM-CA1, UH-1B Helicopters, 
Revision 1, dated December 6, 2012, available from Rotorcraft 
Development Corporation. This report contains a Component Overhaul 
Schedule, an Airworthiness Limitation Schedule, and a Continued 
Airworthiness Documents Section that lists Army Technical Manuals 
required for servicing, maintaining, inspecting, repairing, and 
overhauling the helicopter, its engine, rotors, and appliances, and for 
special purpose modifications.
     Tamarack Helicopters, Inc., Instructions for Continued 
Airworthiness Report No. ICA-1, UH-1F, UH-1P AND TH-1F Helicopters, 
Revision 6, dated March 14, 2016, available from Tamarack Helicopters, 
Inc. This report contains a Component Overhaul Schedule, an 
Airworthiness Limitation Schedule, and a list of Air Force Technical 
Orders required for servicing, maintaining, inspecting, repairing, and 
overhauling the helicopter, its engine, rotors, and appliances.
     Tamarack Helicopters, Inc., UH-1H Instructions for 
Continued Airworthiness Report No. TAM-102, Revision Original, dated 
July 23, 2009, available from Tamarack Helicopter, Inc. This report 
contains a Component Overhaul Schedule, an Airworthiness Limitations 
Schedule and a Continued Airworthiness Documents section, which lists 
documents and reports required for servicing, maintaining, inspecting, 
repairing, and overhauling the helicopter, its engine, rotors, 
appliances and special purpose modifications.
     U.S. Army Aviation and Missile Command Depot Maintenance 
Work Requirement DMWR 55-1560-222, All H-1Series Tailboom Structural 
Assemblies, Change 6, dated June 18, 2002, available from JJASPP 
Engineering Services, LLC. This service information contains 
descriptions of the tail boom structure and guidance explaining tail 
boom attachment fitting structural loads; tail boom differences between 
helicopter models; required depot level modifications; tail boom 
structure isometric figures identifying the structural components; 
instructions to inspect the tail boom longerons for dents, cracks, 
holes, tears, corrosion, and distortion; longeron repair limits and 
repair instructions; instructions to inspect attachment fittings for 
cracks and hole elongation; attachment fitting repair limits and repair 
instructions; tail boom attachment fitting deburr before bonding to 
longeron instructions; and a requirement to dye penetrant the tail boom 
attachment fittings.
     U.S. Army Aviation and Troop Command Aircraft Depot 
Maintenance Work Requirement DMWR 55-1520-210, UH-1H/UH-1V Helicopters, 
Change 11, dated August 31, 1994, available from Northwest Rotorcraft, 
LLC, and Southwest Florida Aviation International, Inc. This higher-
level document directs maintenance personnel to DMWR 55-1560-222 for 
detail depot maintenance instructions. It also contains information 
regarding differences between the two models, instructions for cleaning 
and corrosion control, longeron and stringer allowable damage and 
repair; requirements to check tail boom for alignment; general aircraft 
repair procedures; guidance explaining tail boom attachment fitting 
structural loads; and guidance regarding primary vs. secondary tail 
boom structure.

FAA's Determination

    The FAA is proposing this AD because the FAA evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of these 
same type designs.

Proposed AD Requirements

    This proposed AD would require revising the RFM for your helicopter 
to add before each flight and before first flight of the day pre-flight 
checks; removing excess paint and sealant from, and cleaning certain 
tail boom

[[Page 58345]]

attachment structures; repetitive inspections for scratches, nicks, 
gouges, tears, corrosion, cracks, bond separation, loose, missing, and 
smoking rivets, buckling, distortion, number of attachment bolt exposed 
threads, and attachment bolt movement.
    This proposed AD would require repairing scratches, nicks, gouges, 
tears, and corrosion within allowable limits. This proposed AD would 
require removing from service components with scratches, nicks, gouges, 
tears, and corrosion that exceed allowable limits, removing from 
service components with any cracks, buckling, or distortion, and 
removing from service loose, missing, or smoking rivets. This proposed 
AD would also require re-bonding any structure with dis-bonds, and 
removing loose bolts and self-locking nuts from service, and replacing 
them with new bolts and new self-locking nuts.

Differences Between This Proposed AD, the SAIB, and the Service 
Information

    This proposed AD differs from SAIB SW-18-29R1 by expanding the 
applicability to add various model helicopters operating under 
experimental airworthiness certificates due to design similarity. This 
proposed AD also updates part name nomenclature from SAIB SW-18-29R1 by 
using ``attachment bolt'' and ``attachment fitting'' instead of 
``attach bolt'' and ``attach fitting.''
    This proposed AD would require daily checks be performed with a 
flashlight and 25 hour and 100 hour TIS inspections be performed with a 
bright light and borescope. The service information does not specify 
any items to assist with the required checks or inspections. The 
proposed AD would require pushing on the tail boom while making certain 
inspections. The service information does not. On the fuselage side, 
this proposed AD would require paying particular attention to the 
attachment fitting section near the rivets closest to the attachment 
bolt, and the cap angle rivets next to the fitting. On the tail boom 
side, this proposed AD would require paying particular attention to the 
attachment fitting section near the rivets closest to the attachment 
bolt. The service information does not single out these sections. This 
proposed AD would require replacing any cracked components, while the 
service information allows stop drilling of certain cracks. This 
proposed AD would require removing any loose attachment bolts and their 
self-locking nuts from service and replacing them with new bolts and 
new self-locking nuts. The service information does not require 
replacement of any loose attachment bolts.

Costs of Compliance

    The FAA estimates that this proposed AD would affect 504 
helicopters of U.S. registry. Labor costs are estimated at $85 per 
work-hour. Based on these numbers, the FAA estimates the following 
costs to comply with this proposed AD.
    Revising the RFM for your helicopter would take about 0.5 work-
hour, for an estimated cost of $43 per helicopter and $21,672 for the 
U.S. fleet. The pre-flight check before each flight would take about 
0.25 work-hour, for an estimated cost of $21 per helicopter per check 
and $10,584 for the U.S. fleet per check. The pre-flight check before 
first flight of the day would take about 0.5 work-hour, for an 
estimated cost of $43 per helicopter per check and $21,672 for the U.S. 
fleet per check.
    Removing excess paint and sealant, and cleaning all eight tail boom 
attachment fittings would take about 5 work-hours and a nominal 
materials cost, for an estimated cost of $425 per helicopter per 
instance and $214,200 for the U.S. fleet per instance.
    Inspecting all four tail boom attachments for scratches, nicks, 
gouges, tears, corrosion, cracks, bond separation, loose, missing or 
smoking rivets, buckling, distortion, attachment bolt exposed thread, 
and attachment bolt movement would take about 4 work-hours, for an 
estimated cost of $340 per helicopter per inspection and $171,360 for 
the U.S. fleet per inspection.
    Inspecting only the upper left hand tail boom attachment for 
scratches, nicks, gouges, tears, corrosion, cracks, bond separation, 
loose, missing or smoking rivets, buckling, distortion, attachment bolt 
exposed threads, and attachment bolt movement would take about 0.5 
work-hour, for an estimated cost of $43 per helicopter per inspection.
    The FAA cannot estimate the costs to do any allowable repair based 
on the results of the inspections and the FAA has no way of determining 
the number of aircraft that might need repair.
    The FAA estimates the following costs to do any necessary 
replacements based on the results of the inspections. The FAA has no 
way of determining the number of aircraft that might need these 
replacements.
     Replacing a tail boom attachment fitting would take about 
33 work-hours and parts would cost about $1,500 for an estimated cost 
of $4,305.
     Replacing a tail boom longeron bond assembly (attachment 
fitting, longeron, and doubler) would take about 42 work-hours and 
parts would cost about $7,000 (rebuilt) or $21,270 (new) for an 
estimated cost of $10,570 (rebuilt) or $24,840 (new parts).
     Replacing a fuselage attachment fitting would take about 
45 work-hours and parts would cost about $1,838 for an estimated cost 
of $5,663.
     Replacing a fuselage cap angle would take about 42 work-
hours and parts would cost about $1,827 for an estimated cost of 
$5,397.
     Replacing an attachment bolt and self-locking nut would 
take about 1 work-hour and parts would cost about $313 for an estimated 
cost of $398.

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 proposing 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

    The FAA 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 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 proposed 
regulation:
    (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.

[[Page 58346]]

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):

Various Experimental and Restricted Category Helicopters: Docket No. 
FAA-2019-0759; Product Identifier 2018-SW-075-AD.

(a) Comments Due Date

    The FAA must receive comments by December 16, 2019.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the following helicopters, certificated in 
any category, including experimental and restricted:
    (1) Model EH-1H, EH-1X, HH-1H, HH-1N, UH-1D, UH-1M, UH-1N, and 
UH-1V helicopters;
    (2) Rotorcraft Development Corporation Model HH-1K helicopters;
    (3) Robinson Air Crane, Inc.; Rotorcraft Development 
Corporation; and Tamarack Helicopters, Inc., Model TH-1F 
helicopters;
    (4) Bell Helicopter Textron, Inc.; JTBAM, Inc.; and Rotorcraft 
Development Corporation, Model TH-1L helicopters;
    (5) Richards Heavylift Helo, Inc., Model UH-1A helicopters;
    (6) International Helicopters, Inc.; JTBAM, Inc.; Red Tail 
Flying Services, LLC; Richards Heavylift Helo, Inc.; Rotorcraft 
Development Corporation; San Joaquin Helicopters; and Southwest 
Florida Aviation International, Inc., Model UH-1B helicopters 
without Supplemental Type Certificate (STC) No. SR00026DE installed;
    (7) Bell Helicopter Textron, Inc.; West Coast Fabrications; 
JTBAM, Inc.; Rotorcraft Development Corporation; and Smith 
Helicopters, Model UH-1E helicopters;
    (8) AST, Inc.; California Department of Forestry; Robinson Air 
Crane, Inc.; Rotorcraft Development Corporation; and Tamarack 
Helicopters, Inc., Model UH-1F helicopters;
    (9) Arrow Falcon Exporters Inc.; Global Helicopter Technology, 
Inc.; Hagglund Helicopters, LLC; JJASPP Engineering Services, LLC; 
JTBAM, Inc.; Northwest Rotorcraft, LLC; Richards Heavylift Helo, 
Inc.; Rotorcraft Development Corporation; Southwest Florida Aviation 
International, Inc.; and Tamarack Helicopters, Inc., Model UH-1H 
helicopters;
    (10) Bell Helicopter Textron, Inc.; JTBAM, Inc.; and Rotorcraft 
Development Corporation, Model UH-1L helicopters; and
    (11) Robinson Air Crane, Inc.; and Rotorcraft Development 
Corporation, Model UH-1P helicopters.

(d) Subject

    Joint Aircraft System Component (JASC): 5302, Rotorcraft Tail 
Boom.

(e) Unsafe Condition

    This AD was prompted by multiple accidents and incidents 
involving failure of the tail boom attachment structure and bolts. 
The FAA is issuing this AD to address fatigue cracking of tail boom 
attachment fittings, cap angles, longerons, and bolts. The unsafe 
condition, if not addressed, could result in separation of the tail 
boom from the helicopter 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, revise the limitations section of the 
Rotorcraft Flight Manual (RFM) for your helicopter by adding the 
information in Figure 1 to paragraph (g)(1) of this AD or by 
inserting a copy of this AD. This action may be done by the owner/
operator (pilot) holding at least a private pilot certificate and 
must be entered into the aircraft records showing compliance with 
this AD by following 14 CFR 43.9 (a)(1) through (4) and 14 CFR 
91.417(a)(2)(v). The record must be maintained as required by 14 CFR 
91.417, 121.380, or 135.439.
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[[Page 58347]]

[GRAPHIC] [TIFF OMITTED] TP31OC19.000

BILLING CODE 4910-13-C
    (2) Within 25 hours time in service (TIS):
    (i) Open the oil cooler/baggage compartment door on the right 
hand side of the helicopter to gain access to the interior of the 
tail boom.
    (ii) Remove paint and stray sealant and clean the eight 
attachment fittings (four on the tail boom side and four on the 
fuselage side). Remove paint and stray sealant and clean the four 
cap angles, forward of the fuselage fittings, for at least 12 inches 
from

[[Page 58348]]

the end of the fittings. Remove paint and stray sealant and clean 
the four longerons, aft of the tail boom fittings, for at least 12 
inches from the end of the fittings. It is only necessary to remove 
the topcoat. Primer may be left in place and edge and fillet sealant 
may be left in place. If any primer or edge or fillet sealant is 
removed, before further flight, reapply the removed primer and 
sealant.
    Note 1 to paragraph (g)(2)(ii) of this AD: On some models, the 
baggage compartment floor and net must be removed to gain access to 
the lower fuselage attachment fittings and cap angles.
    (iii) With an additional person pushing on the tail boom at the 
third vertical rivet line aft of the trailing edge of the elevator 
with both hands and gradually applying and relieving pressure using 
body weight a minimum of three times in each of the following 
directions: Inboard pushing from the left; inboard pushing from the 
right; and upward pushing from the bottom; and using a bright light 
and borescope, inspect each of the four tail boom attachment 
structures for cracks, bond separation, and loose rivets. On the 
fuselage side, inspect the fittings and the cap angles running 
forward from the fittings, paying particular attention to the 
fitting sections near the rivets closest to the attachment bolts and 
the cap angle rivets next to the fittings. On the tail boom side, 
inspect the fittings and the longerons running aft from the 
fittings, paying particular attention to the fitting sections near 
the rivets closest to the attachment bolts. Without pushing on the 
tail boom, and using a bright light and borescope, inspect each of 
the four tail boom attachment structures for scratches, nicks, 
gouges, tears, corrosion, buckling, and distortion, and for loose, 
missing, and smoking rivets. If there are any scratches, nicks, 
gouges, tears, or corrosion within allowable limits, before further 
flight, repair the affected components. If there are any scratches, 
nicks, gouges, tears, or corrosion that exceed allowable limits, or 
any cracks, buckling or distortion, or loose, missing, or smoking 
rivets, before further flight, remove the affected components from 
service. If there is any bond separation, before further flight, re-
bond the affected components.
    Note 2 to paragraph (g)(2)(iii) of this AD: It is not required 
to push on the tail boom on helicopters with 39-inch extended 
landing gear installed per STC SR01742NY while checking for cracks, 
bond separation, and loose rivets.
    (iv) Inspect each of the four tail boom attachment bolts for 
exposed threads. If there is less than one full thread or more than 
three threads exposed, before further flight, remove the bolt and 
self-locking nut from service and replace with a new bolt and new 
self-locking nut.
    (v) Inspect each of the four tail boom attachment bolts for 
movement by either applying the required installation torque in the 
tightening direction only, or by inspecting for torque stripe 
misalignment if present and attempting to rotate the bolt by hand. 
If a bolt is under-torqued, a torque stripe is misaligned, or a bolt 
moves, before further flight, remove the bolt and self-locking nut 
from service and replace with a new bolt and new self-locking nut.
    (vi) After the first flight following any bolt replacement as 
required by paragraph (g)(iv) or (v) of this AD, retighten any 
replaced bolt by applying torque in the tightening direction only 
and then apply a torque stripe on the bolt head.
    (3) At intervals not to exceed 25 hours TIS, perform the actions 
required by paragraph (g)(2)(i) through (vi) of this AD, except you 
are only required to perform the actions on the upper left hand tail 
boom attachment structure and bolt.
    (4) At intervals not to exceed 100 hours TIS, perform the 
actions required by paragraph (g)(2)(i) through (vi) of this AD at 
all four tail boom attachment locations.

(h) Special Flight Permit

    Special flight permits are prohibited.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Denver ACO 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 your proposal to: Richard 
R. Thomas, Aerospace Engineer, Denver ACO Branch, Compliance & 
Airworthiness Division, FAA, 26805 East 68th Ave., Room 214, Denver, 
CO 80249; phone: (303) 342-1085; fax: (303) 342-1088; email: 
richard.r.thomas@faa.gov and 2910046d4c475f4c5b0468405b4a5b484f5d046a4c5b5d694f4848074e465f.
    (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.

(j) Related Information

    For more information about this AD, contact Richard R. Thomas, 
Aerospace Engineer, Denver ACO Branch, Compliance & Airworthiness 
Division, FAA, 26805 East 68th Ave., Room 214, Denver, CO 80249; 
phone: (303) 342-1085; fax: (303) 342-1088; email: 
richard.r.thomas@faa.gov.

    Issued in Fort Worth, Texas, on October 23, 2019.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2019-23686 Filed 10-30-19; 8:45 am]
 BILLING CODE 4910-13-P