AD Amdt-39-10990

[Federal Register Volume 64, Number 7 (Tuesday, January 12, 1999)]
[Rules and Regulations]
[Pages 1715-1716]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 99-615]



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Federal Register / Vol. 64, No. 7 / Tuesday, January 12, 1999 / Rules 
and Regulations

[[Page 1715]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-43-AD; Amendment 39-10990; AD 98-19-13]


Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) 
Model 407 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting Airworthiness Directive (AD) 98-19-13, which was sent 
previously to all known U.S. owners and operators of BHTC Model 407 
helicopters by individual letters. This AD requires, on or before the 
accumulation of 50 hours total time-in-service (TIS) on the engine-to-
transmission driveshaft (driveshaft), replacing the driveshaft with an 
airworthy driveshaft. This amendment is prompted by analysis and test 
data which revealed that the life limit of the driveshaft is less than 
that which is stated in the applicable maintenance manual. The actions 
specified by this AD are intended to prevent failure of the driveshaft, 
loss of engine drive to the rotor system, damage to critical structural 
components, and subsequent loss of control of the helicopter.

DATES: Effective January 27, 1999. To all persons except those persons 
to whom it was made immediately effective by priority letter AD 98-19-
13, issued on September 2, 1998, which contained the requirements of 
this amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before March 15, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-43-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr. Jurgen Priester, Aerospace 
Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 
2601 Meacham Blvd., Fort Worth, Texas, 76137, telephone (817) 222-5159, 
fax (817) 222-5783.

SUPPLEMENTARY INFORMATION: On September 2, 1998, the FAA issued 
priority letter AD 98-19-13, applicable to BHTC Model 407 helicopters, 
which requires, on or before the accumulation of 50 hours total TIS on 
the driveshaft, replacing the driveshaft with an airworthy driveshaft. 
That action was prompted by analysis and test data that revealed that 
the life limit of the driveshaft is less than that which is stated in 
the applicable maintenance manual. The published life limit has been 
2,500 hours TIS; however, new data indicate the life limit should be 
approximately 50 hours TIS. This condition, if not corrected, could 
result in failure of the driveshaft, loss of engine drive to the rotor 
system, damage to critical structural components, and subsequent loss 
of control of the helicopter.
    The FAA has reviewed Bell Helicopter Textron Alert Service Bulletin 
No. 407-98-19, dated June 19, 1998, which describes procedures for 
replacing the driveshaft, part number (P/N) 206-340-300-103, with 
driveshaft, P/N 206-340-300-105, which has a longer service life.
    Since the unsafe condition described is likely to exist or develop 
on other BHTC Model 407 helicopters of the same type design, the FAA 
issued priority letter AD 98-19-13 to prevent failure of the 
driveshaft, loss of engine drive to the rotor system, damage to 
critical structural components, and subsequent loss of control of the 
helicopter. The AD requires, on or before the accumulation of 50 hours 
total TIS on the driveshaft, replacing the driveshaft, P/N 206-340-300-
103, with an airworthy driveshaft, P/N 206-340-300-105. The short 
compliance time involved is required because the previously described 
critical unsafe condition can adversely affect the controllability of 
the helicopter. Therefore, replacing the driveshaft is required within 
50 hours, and this AD must be issued immediately.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on September 2, 1998, to all known U.S. owners and operators of 
BHTC Model 407 helicopters. These conditions still exist, and the AD is 
hereby published in the Federal Register as an amendment to section 
39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it 
effective to all persons.
    The FAA estimates that 146 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 5 work hours per 
helicopter to accomplish the required actions, and that the average 
labor rate is $60 per work hour. Required parts will cost approximately 
$24,500 per helicopter. Based on these figures, the total cost impact 
of the AD on U.S. operators is estimated to be $3,620,800.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by

[[Page 1716]]

interested persons. A report that summarizes each FAA-public contact 
concerned with the substance of this AD will be filed in the Rules 
Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 98-SW-43-AD.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from 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.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

AD 98-19-13 Bell Helicopter Textron Canada: Amendment 39-10990. 
Docket No. 98-SW-43-AD.

    Applicability: Model 407 helicopters, with engine-to-
transmission driveshaft (driveshaft), part number (P/N) 206-340-300-
103, 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 
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 (c) 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 prior to or upon accumulating 50 hours 
total time-in-service (TIS) on driveshaft, P/N 206-340-300-103.
    To prevent failure of the driveshaft, which could result in loss 
of engine drive to the rotor system, damage to critical structural 
components, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Remove driveshaft, P/N 206-340-300-103, and replace it with 
an airworthy driveshaft, P/N 206-340-300-105. Driveshaft, P/N 206-
340-300-103, must not be installed on any helicopter.

    Note 2: Bell Helicopter Textron Alert Service Bulletin No. 407-
98-19, dated June 19, 1998, pertains to the subject of this AD. 
Removed driveshaft, P/N 206-340-300-103, should be destroyed.

    (b) This AD revises the Airworthiness Limitations section of the 
maintenance manual by establishing a retirement life of 5,000 hours 
TIS for driveshaft, P/N 206-340-300-105. A component record card or 
equivalent record for this P/N must also be established.
    (c) 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, 
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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Certification Office.

    (d) Special flight permits will not be issued.
    (e) This amendment becomes effective on January 27, 1999. To all 
persons except those persons to whom it was made immediately 
effective by Priority Letter AD 98-19-13, issued September 2, 1998, 
which contained the requirements of this amendment.

    Note 4: The subject of this AD is addressed in Transport Canada 
(Canada) AD CF-98-25, August 25, 1998.

    Issued in Fort Worth, Texas, on January 5, 1999.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-615 Filed 1-11-99; 8:45 am]
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