[Federal Register Volume 63, Number 62 (Wednesday, April 1, 1998)]
[Proposed Rules]
[Pages 15790-15791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8469]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-10-AD]
Airworthiness Directives; Bell Helicopter Textron Canada Model
407 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) that is applicable to Bell Helicopter Textron Canada
(BHTC) Model 407 helicopters. This proposal would require shimming the
tail rotor drive system bearing supports (bearing supports). This
proposal is prompted by reports of cracked bearing hangar support arms
in the area of the fillet radius. The actions specified by the proposed
AD are intended to prevent failure of the bearing supports, which could
result in excessive tail rotor drive system vibration, loss of tail
rotor drive, and subsequent loss of control of the helicopter.
DATES: Comments must be received on or before May 1, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-10-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Bell Helicopter Textron Canada, 12,800 Rue de l'Avenir,
Mirabel, Quebec JON1LO, telephone (800) 463-3036, fax (514) 433-0272.
This information may be examined at the FAA, Office of the Regional
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas.
FOR FURTHER INFORMATION CONTACT: Mr. Jurgen Priester, Aerospace
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office,
2601 Meacham Blvd., Fort Worth, Texas 76137, (817) 222-5159, fax (817)
222-5960.
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. 98-SW-10-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. 98-SW-10-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
Discussion
Transport Canada, which is the airworthiness authority for Canada,
recently notified the FAA that an unsafe condition may exist on BHTC
Model 407 helicopters. Transport Canada advises that there have been
some occurrences of a gap between the bearing support and the bearing
hanger on the tailboom. They further advise that this situation, if not
corrected, could lead to serious vibration of the tail rotor drive
shaft, and eventually, to total disintegration of the shaft.
BHTC has issued Bell Helicopter Textron Alert Service Bulletin No.
407-97-7, dated February 27, 1997, which specifies a procedure for
shimming
[[Page 15791]]
between the bearing supports and the bearing hangers on the tailboom.
Transport Canada classified this service bulletin as mandatory and
issued AD No. CF-97-08, dated May 30, 1997, in order to assure the
continued airworthiness of these helicopters in Canada.
This helicopter model is manufactured in Canada and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, Transport Canada has kept the FAA
informed of the situation described above. The FAA has examined the
findings of Transport Canada, reviewed all available information, and
determined that AD action is necessary for products of this type design
that are certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to
exist or develop on other BHTC Model 407 helicopters of the same type
design registered in the United States, the proposed AD would require
shimming the bearing supports within the next 25 hours time-in-service.
The actions would be required to be accomplished in accordance with the
service bulletin described previously.
The FAA estimates that 160 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 4 work
hours per helicopter to accomplish the shimming of the bearing support,
and that the average labor rate is $60 per work hour. Required parts
would cost approximately $30 per helicopter. Based on these figures,
the total cost impact of the proposed AD on U.S. operators is estimated
to be $43,200.
The regulations proposed herein would not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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:
Bell Helicopter Textron Canada: Docket No. 98-SW-10-AD.
Applicability: Model 407 helicopters, serial numbers 53000,
53002 through 53065, 53067, and 53069 through 53075, certificated in
any category.
Note 1: This AD applies to each helicopter identified in the
preceding applicability provision, regardless of whether it has been
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 use the authority
provided in paragraph (b) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition, or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any helicopter from the applicability of this AD.
Compliance: Required within 25 hours time-in-service, unless
accomplished previously.
To prevent failure of the bearing supports, which could result
in excessive tail rotor drive system vibration, loss of tail rotor
drive, and subsequent loss of control of the helicopter, accomplish
the following:
(a) Shim the tail rotor drive system bearing supports in
accordance with the Accomplishment Instructions contained in Bell
Helicopter Textron Alert Service Bulletin No. 407-97-7, dated
February 27, 1997.
(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,
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.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from Rotorcraft Certification.
(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.
Note 3: The subject of this AD is addressed in Transport Canada
(Canada) AD No. CF-97-08, dated May 30, 1997.
Issued in Fort Worth, Texas, on March 24, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-8469 Filed 3-31-98; 8:45 am]
BILLING CODE 4910-13-P
