[Federal Register Volume 65, Number 58 (Friday, March 24, 2000)]
[Proposed Rules]
[Pages 15882-15883]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-7339]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-01-AD]


Airworthiness Directives; Bell Helicopter Textron Inc.-
Manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-
1H, UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, 
SW205, and SW205A-1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) applicable to Bell Helicopter Textron Inc. (BHTI)-
manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-
1H, UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, 
SW205, and SW205A-1 helicopters. This AD would require removing and 
replacing certain main rotor mast (mast) assemblies. This proposal is 
prompted by the crash of a BHTI-manufactured Model UH-1B due to failure 
of a thin-wall mast installed on the helicopter. The actions specified 
by the proposed AD are intended to prevent fatigue failure of the mast 
and subsequent loss of control of the helicopter.

DATES: Comments must be received on or before May 8, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2000-SW-01-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort 
Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-5783.

SUPPLEMENTARY INFORMATION:  

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 2000-SW-01-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2000-SW-01-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137.

Discussion

    This document proposes the adoption of a new airworthiness 
directive (AD) for BHTI-manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, 
UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida 
Aviation SW204, SW204HP, SW205, and SW205A-1 helicopters. This AD would 
require removing any mast assembly, part number (P/N) 204-011-450-001 
or -005, and replacing it with an airworthy mast assembly. This 
proposal is prompted by the crash of a BHTI-manufactured Model UH-1B 
due to failure of a thin-wall mast assembly, P/N 204-011-450-001, as 
the result of undetected fatigue cracking in the stabilizer bar damper 
spline. Metallurgical examination of the failed part by the National 
Transportation Safety Board (NTSB) Materials Laboratory revealed 
fatigue features on the crack faces adjacent to the upper groove on the 
stabilizer bar damper splice. Several other cracks were noted in the 
same area during visual examination. The mast was reported to have 
accumulated 4006 hours time-in-service. As a result of the accident 
investigation, the NTSB recommended among other things that the FAA 
issue an AD requiring that ``thin-walled'' rotor masts be replaced with 
``thick-walled'' rotor masts. The FAA agrees with this recommendation. 
This condition, if not corrected, could result in fatigue failure of 
the mast and subsequent loss of control of the helicopter.
    The FAA has reviewed Garlick Helicopters, Inc. Service Bulletin 
UH1-97-06, dated September 26, 1997, which describes procedures for 
removing all mast tubes, P/N 204-011-450-001, from service for 
Garlick's type-certificated Model HH-1K, TH-1F, TH-1L, UH-1B, UH-1E, 
UH-1F, UH-1H, UH-1L, and UH-1P helicopters. The service bulletin also 
establishes a maximum torque event cycle count of 300,000 for the P/N 
204-011-450 (all other dashes) mast tube.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-
1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida Aviation 
SW204, SW204HP, SW205, and SW205A-1 helicopters of the same type 
designs, the proposed AD would require removing any mast assembly, P/N 
204-011-450-001 or -005, from service and replacing it with an 
airworthy mast assembly.
    The FAA estimates that 75 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 10 work 
hours per helicopter to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Replacing a mast assembly 
would cost approximately

[[Page 15883]]

$8,862. Based on these figures, the total cost impact of the proposed 
AD on U.S. operators is estimated to be $709,650 to replace all the 
masts in the fleet.
    The regulations proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

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 adding a new airworthiness directive 
to read as follows:

    Firefly Aviation Helicopter Services (Previously Erickson Air 
Crane Co.); Garlick Helicopters, Inc.; Hawkins and Powers Aviation, 
Inc.; International Helicopters, Inc.; Tamarack Helicopters, Inc. 
(Previously Ranger Helicopter Services, Inc.); Robinson Air Crane, 
Inc.; Williams Helicopter Corporation (Previously Scott Paper Co.); 
Smith Helicopters; Southern Helicopter, Inc.; Southwest Florida 
Aviation; Utah State University; Western International Aviation, 
Inc.; and U.S. Helicopter, Inc.; Docket No. 2000-SW-01-AD.
    Applicability: Bell Helicopter Textron Inc.-manufactured Model 
HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and 
UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, and 
SW205A-1 helicopters with a main rotor mast (mast) assembly, part 
number (P/N) 205-011-450-001 or -005, installed, certificated in any 
category.

    Note 1: This AD applies to each helicopter identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For helicopters that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required within 25 hours time-in-service (TIS), 
unless accomplished previously.
    To prevent fatigue failure of the mast and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Remove any mast assembly, part number (P/N) 204-011-450-001 
or -005, from service. Replace with an airworthy mast assembly. 
Neither P/N 204-011-450-001 nor 204-011-450-005 are eligible for 
installation on any affected helicopter.
    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Rotorcraft Certification Office, 
Rotorcraft Directorate, FAA. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Rotorcraft Certification 
Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Certification Office.

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the helicopter to a location where 
the requirements of this AD can be accomplished.

    Issued in Fort Worth, Texas, on March 17, 2000.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-7339 Filed 3-23-00; 8:45 am]
BILLING CODE 4910-13-P