[Federal Register Volume 65, Number 191 (Monday, October 2, 2000)]
[Proposed Rules]
[Pages 58681-58682]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-25154]



[[Page 58681]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-SW-16-AD
RIN 2120-AA64


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
204B Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for Bell Helicopter Textron, Inc. (BHTI) Model 204B helicopters. 
The AD would require replacing any main rotor mast assembly (mast), 
part number (P/N) 204-011-450-001, within 25 hours time-in-service 
(TIS). This proposal is prompted by the crash of a restricted category 
Model UH-1B helicopter due to failure of a mast, P/N 204-011-450-001. 
The same mast P/N is used on the Model 204B helicopters. The actions 
specified by the proposed AD are intended to prevent failure of the 
mast and subsequent loss of control of the helicopter.

DATES: Comments must be received on or before December 1, 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-16-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: <a href="/cdn-cgi/l/email-protection#447d69253733692520272b2929212a3037042225256a232b32"><span class="__cf_email__" data-cfemail="182135796b6f35797c7b7775757d766c6b587e7979367f776e">[email protected]</span></a>. 
Comments may be inspected at the Office of the Regional Counsel between 
9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aviation Safety 
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 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 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 mailed 
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-16-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-16-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137.

Discussion

    This document proposes adopting a new AD for BHTI Model 204B 
helicopters. The AD would require replacing any mast, P/N 204-011-450-
001, within 25 hours time-in-service (TIS). This proposal is prompted 
by the crash of a restricted category Model UH-1B helicopter due to 
failure of a mast, P/N 204-011-450-001, as a result of an undetected 
fatigue crack in the stabilizer bar damper spline. Metallurgical 
examination of the failed part by the National Transportation Safety 
Board (NTSB) Materials Laboratory revealed fatigue cracking adjacent to 
the upper groove on the stabilizer bar damper spline. Several other 
cracks were noted in the same area during visual examination. The mast 
was reported to have accumulated 4006 hours TIS. The accident 
investigation also revealed that the U. S. Army removed the masts, P/N 
204-011-450-001 and -005, from service in July 1984.
    The FAA issued AD 2000-15-21 on August 1, 2000 (65 FR 48605, August 
9, 2000), requiring removal of the mast, P/N 204-011-450-001 and -005, 
from service on former U.S. military restricted category helicopters. 
Because the same P/N mast is used on the Bell Model 204B helicopters, 
this AD proposes to remove the mast, P/N 204-011-450-001, from service 
on these model helicopters as well. The actions specified by the 
proposed AD are intended to prevent failure of the mast. This 
condition, if not corrected, could result in loss of control of the 
helicopter.
    We have identified an unsafe condition that is likely to exist or 
develop on other BHTI Model helicopters of the same type design. The 
proposed AD would require replacing any mast, P/N 204-011-450-001, 
which would no longer be eligible for installation on any helicopter.
    We estimate that 15 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. Required parts would cost 
approximately $8,862 per helicopter. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$141,930.
    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:

[[Page 58682]]

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:

Bell Helicopter Textron, Inc.: Docket No. 2000-SW-16-AD.

    Applicability: Model 204B helicopters with main rotor mast 
assembly, part number (P/N) 204-011-450-001, 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, unless 
accomplished previously.
    To prevent failure of the main rotor mast assembly (mast) and 
subsequent loss of control of the helicopter, accomplish the 
following:
    (a) Remove any mast, P/N 204-011-450-001, from service and 
replace it with an airworthy mast. Accomplishing the requirement of 
this paragraph constitutes terminating action for the requirements 
of this AD. P/N 204-011-450-001 is not eligible for installation on 
any 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 September 25, 2000.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-25154 Filed 9-29-00; 8:45 am]
BILLING CODE 4910-13-P


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