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[Federal Register: April 22, 2010 (Volume 75, Number 77)]
[Proposed Rules]               
[Page 20933-20935]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22ap10-13]                         

[[Page 20933]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0427; Directorate Identifier 2008-SW-72-AD]
RIN 2120-AA64

 
Airworthiness Directives; Arrow Falcon Exporters, Inc. 
(previously Utah State University); California Department of Forestry; 
Firefly Aviation Helicopter Services (previously Erickson Air-Crane 
Co.); Garlick Helicopters, Inc.; Global Helicopter Technology, Inc.; 
Hagglund Helicopters, LLC (previously Western International Aviation, 
Inc.); International Helicopters, Inc.; Precision Helicopters, LLC; 
Robinson Air Crane, Inc.; San Joaquin Helicopters (previously Hawkins 
and Powers Aviation, Inc.); S.M.&T. Aircraft (previously US 
Helicopters, Inc., UNC Helicopter, Inc., Southern Aero Corporation, and 
Wilco Aviation); Smith Helicopters; Southern Helicopter, Inc.; 
Southwest Florida Aviation International, Inc. (previously Jamie R. 
Hill and Southwest Florida Aviation); Tamarack Helicopters, Inc. 
(previously Ranger Helicopter Services, Inc.); US Helicopter, Inc. 
(previously UNC Helicopter, Inc.); West Coast Fabrication; and Williams 
Helicopter Corporation (previously Scott Paper Co.) Model AH-1G, AH-1S, 
HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-
1P Helicopters; and Southwest Florida Aviation Model UH-1B (SW204 and 
SW204HP) and UH-1H (SW205) Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes superseding an existing airworthiness 
directive (AD) for Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-
1F, UH-1H, UH-1L, and UH-1P helicopters; and Southwest Florida Aviation 
Model SW204, SW204HP, SW205, and SW205A-1 helicopters, manufactured by 
Bell Helicopter Textron, Inc. (BHTI) for the Armed Forces of the United 
States. That AD currently requires updating the product identification, 
extending the application of the AD to other helicopter models, 
continuing the existing retirement time for certain main rotor tension-
torsion (TT) straps, and adding the TT strap part numbers to the 
applicability. This action proposes to require removing certain serial-
numbered TT straps from service, reduce the retirement life for other 
TT straps, and establish a retirement life in terms of calendar time in 
addition to hours time-in-service (TIS) for certain other affected TT 
straps. This action would also add two model helicopters to the 
applicability of the AD. This proposal is prompted by fatigue cracking 
in certain TT straps that have stainless steel filament windings and a 
determination that corrosion damage, which is related to calendar time, 
necessitates a calendar time retirement life for certain TT straps in 
addition to the retirement life based on hours TIS. This proposal is 
also prompted by fatigue cracking in other TT straps with encased thin 
stainless steel plates. These proposals are based on the service 
history of helicopters that are the same or similar in type design to 
the helicopters to which this AD would apply. The actions specified by 
the proposed AD are intended to prevent failure of a TT strap, loss of 
a main rotor blade, and subsequent loss of control of the helicopter.

DATES: Comments must be received on or before June 21, 2010.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     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.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aviation Safety 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 
2601 Meacham Blvd., Fort Worth, Texas 76193, telephone (817) 222-5170, 
fax (817) 222-5783.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA- 2010-
0427, Directorate Identifier 2008-SW-72-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed rulemaking. Using the 
search function of our docket Web site, you can find and read the 
comments to any of our dockets, including the name of the individual 
who sent or signed the comment. You may review the DOT's complete 
Privacy Act Statement in the Federal Register published on April 11, 
2000 (65 FR 19477-78).

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located in Room W12-140 on the ground floor of the West Building at the 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

Discussion

    On July 31, 1980, we issued AD 80-17-09, Amendment 39-3876 (45 FR 
54014, August 14, 1980), Docket No. 80-ASW-25. That AD required 
replacing certain TT straps on or before attaining 1,200 hours TIS or 
24 months, whichever occurs first, for the BHTI Model 204B, 205A-1, 
212, 214B, 214B-1, and the Model UH-1 series military surplus 
helicopters. That action was prompted by an offshore accident of a BHTI 
Model 212 helicopter in which a TT strap reportedly failed in flight 
after 2,140 hours TIS with resulting loss of the main rotor blade. The 
requirements of that AD were intended to prevent failure of a TT strap, 
loss of a main rotor blade, and subsequent loss of control of the 
helicopter.
    On September 18, 2002, we issued AD 2002-20-01, Amendment 39-12895 
(67 FR 61771, October 2, 2002), Docket No. 2001-SW-41-AD, for the 
restricted category Model HH-1K, SW204, SW204HP, SW205, SW205A-1, TH-
1F,

[[Page 20934]]

TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters 
to require updating the product identification, extending the 
applicability to other helicopter models, continuing the existing 
retirement time for certain TT straps, and adding the TT strap part 
numbers to the applicability. That action was prompted by the need to 
expand the applicability to additional restricted category helicopters 
and to add two part numbers to the applicability. The requirements of 
that AD are intended to prevent failure of a TT strap, loss of a main 
rotor blade, and subsequent loss of control of the helicopter. AD 2002-
20-01 contains the requirements from AD 80-17-09 for the Model UH-1 
series military surplus helicopters.
    Since issuing AD 2002-20-01, we have determined that an unsafe 
condition exists if TT straps, BHTI part number (P/N) 204-012-112-5 or 
Bendix Energy Controls Co. (Bendix) P/N 2601399, with a serial number 
(S/N) of 41623 through 54362, or BHTI P/N 204-012-112-7 or Bendix P/N 
2601400, with a S/N of 11415 or higher, are allowed to remain in 
service. These TT straps have stainless steel filament windings encased 
in a urethane cover and were manufactured using Caytur 21 as the 
urethane-curing accelerator. Caytur 21 contains chlorides which are 
retained in the urethane cover after cure resulting in corrosion 
problems with the encased steel wires. Those part-numbered TT straps 
made outside the affected S/N ranges were manufactured using a MOCA 
curing agent and do not pose the same aggravated corrosion problem.
    An unsafe condition also exists if TT straps, P/N 204-011-113-1 or 
204-012-112-1, are used beyond a certain number of hours TIS due to the 
possibility of fatigue cracks occurring in either the encased thin 
stainless steel plates or filament windings, respectively. These 
particular TT straps are of older designs and a reduced life in hours 
TIS is needed to preclude a fatigue failure. TT straps, P/N 204-011-
113-1, have the encased stack of thin steel stainless plates. TT 
straps, P/N 204-012-112-1, have encased filament windings with a lower 
strength, smaller diameter wire and a different urethane coating which 
is more susceptible to react with the wire material than the other TT 
straps of the same design. Service history has shown that the 
retirement life for both TT straps, P/N 204-011-113-1 or 204-012-112-1, 
needs to be reduced.
    We have also determined that an unsafe condition exists if certain 
other TT straps with encased stainless steel filament windings are 
allowed to remain in service beyond a specified calendar time or beyond 
a specified number of hours TIS. The calendar time retirement life is 
needed to prevent failure caused by corrosion. The hours TIS retirement 
life is needed to prevent a fatigue failure in the filament windings. 
In addition, a need exists to clarify the TT strap manufacturer, 
acknowledge the current Type Certificate owners, and add the model AH-
1G and AH-1S helicopters to the applicability.
    The previously described unsafe conditions are likely to exist or 
develop on other helicopters of the same type designs. Therefore, the 
proposed AD would supersede AD 2002-20-01 and require removing certain 
serial-numbered TT straps from service, replacing certain TT straps at 
specified intervals, revising the Airworthiness Limitations section of 
the maintenance manual or the Instructions for Continued Airworthiness 
(ICAs) by establishing new or maintaining current retirement lives for 
certain TT straps, and recording the life limit of the TT straps on the 
component history cards or equivalent records.
    These proposed actions are based on the service history of certain 
TT straps manufactured with stainless steel filament windings or thin 
stainless steel plates encased in a urethane coating. TT strap failures 
have occurred in both types of TT straps. Some of the failures were 
attributed to undetected moisture penetration through the urethane 
coating which led to corrosion pitting in the stainless steel wires and 
subsequent fatigue failure of the TT strap. Other failures were 
attributed to fatigue cracking in the stainless steel plates or 
filament windings which led to a fatigue failure of the TT strap. A 
fatigue failure of the TT strap during flight will result in a loss of 
main rotor blade and subsequent loss of control of the helicopter.
    We estimate that 716 helicopters of U.S. registry would be affected 
by this proposed AD, that it would take approximately 8 work hours per 
helicopter to replace a set of TT straps (2 TT straps), and that the 
average labor rate is $85 per work hour. Required parts would cost 
approximately $12,500 for 2 TT straps. Based on these figures, the 
total cost impact of the proposed AD on U.S. operators is estimated to 
be $329,500, assuming that 25 TT strap sets (50 TT straps) would be 
replaced.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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 the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this proposed AD. See the AD docket to examine the draft economic 
evaluation.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    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]

    2. Section 39.13 is amended by removing Amendment 39-12895 (67 FR

[[Page 20935]]

61771, October 2, 2002), and by adding a new airworthiness directive 
(AD), to read as follows:

Arrow Falcon Exporters, Inc. (previously Utah State University); 
California Department of Forestry; Firefly Aviation Helicopter 
Services (previously Erickson Air-Crane Co.); Garlick Helicopters, 
Inc.; Global Helicopter Technology, Inc.; Hagglund Helicopters, LLC 
(previously Western International Aviation, Inc.); International 
Helicopters, Inc.; Precision Helicopters, LLC; Robinson Air Crane, 
Inc.; San Joaquin Helicopters (previously Hawkins and Powers 
Aviation, Inc.); S.M.&T. Aircraft (previously US Helicopters, Inc., 
UNC Helicopter, Inc., Southern Aero Corporation, and Wilco 
Aviation); Smith Helicopters; Southern Helicopter, Inc.; Southwest 
Florida Aviation International, Inc. (previously Jamie R. Hill and 
Southwest Florida Aviation); Tamarack Helicopters, Inc. (previously 
Ranger Helicopter Services, Inc.); US Helicopter, Inc. (previously 
UNC Helicopter, Inc.); West Coast Fabrication; and Williams 
Helicopter Corporation (previously Scott Paper Co.) Model AH-1G, AH-
1S, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, 
and UH-1P Helicopters; and Southwest Florida Aviation Model UH-1B 
(SW204 and SW204HP) and UH-1H (SW205) Helicopters: Docket No. FAA-
2010-0427; Directorate Identifier 2008-SW-72-AD. Supersedes AD 2002-
20-01, Amendment 39-12895, Docket No. 2001-SW-41-AD.

    Applicability: Model AH-1G, AH-1S, HH-1K, TH-1F, TH-1L, UH-1A, 
UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters, with Bell 
Helicopter Textron, Inc. (BHTI) main rotor tension-torsion (TT) 
strap, part number (P/N) 204-011-113-1, 204-012-112-1. 204-012-112-
5, 204-012-112-7, 204-012-122-1, 204-012-122-5, 204-310-101-101, or 
Bendix Energy Controls Co. (Bendix) P/N 2601139, 2601399, 2601400, 
or 2606650, installed, certificated in any category.
    Compliance: Within 25 hours time-in-service (TIS), or one month, 
whichever occurs first, unless accomplished previously.
    To prevent failure of a TT strap, loss of a main rotor blade, 
and subsequent loss of control of the helicopter, accomplish the 
following:
    (a) Remove any TT strap, P/N 204-012-112-5 or 2601399, with a 
serial number (S/N) of 41623 through 54362, or P/N 204-012-112-7 or 
2601400, with a S/N of 11415 or higher, and replace it with an 
airworthy TT strap. Any TT strap required to be removed in 
accordance with this paragraph is unairworthy and is not eligible 
for reinstallation on any helicopter.
    (b) Remove any TT strap P/N that has been in service for the 
length of time or longer than the retirement life listed in Table 1 
of this AD and replace it with an airworthy TT strap.

                                 Table 1
------------------------------------------------------------------------
                  P/N                            Retirement life
------------------------------------------------------------------------
204-011-113-1..........................  200 hours TIS.
204-012-112-1..........................  1,000 hours TIS.
204-012-112-5 or 2601399, S/N 1 through  1,200 hours TIS or 24 months
 41622.                                   since the initial installation
                                          on any helicopter, whichever
                                          occurs first.
204-012-112-5 or 2601399, S/N 54363 and  ...............................
 higher
204-012-112-7 or 2601400, S/N 1 through  ...............................
 11414
204-012-122-1                            ...............................
204-012-122-5                            ...............................
204-310-101-101                          ...............................
2601139                                  ...............................
2606650                                  ...............................
------------------------------------------------------------------------

    (c) Revise the Airworthiness Limitations section of the 
maintenance manual or the Instructions for Continued Airworthiness 
(ICAs) by establishing or maintaining the current retirement life 
for each TT strap listed in Table 1 of this AD by marking pen and 
ink changes or inserting a copy of this AD into the maintenance 
manual or ICAs.
    (d) Record the life limit for each TT strap listed in Table 1 of 
this AD on the component history cards or equivalent record.
    (e) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Manager, Rotorcraft Directorate, Rotorcraft 
Certification Office, FAA, ATTN: Michael Kohner, Aviation Safety 
Engineer, 2601 Meacham Blvd., Fort Worth, Texas 76193, telephone 
(817) 222-5170, fax (817) 222-5783, for information about previously 
approved alternative methods of compliance.
    (f) Special flight permits will not be issued.

    Issued in Fort Worth, Texas, on April 14, 2010.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2010-9293 Filed 4-21-10; 8:45 am]
BILLING CODE 4910-13-P
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