[Federal Register Volume 65, Number 67 (Thursday, April 6, 2000)]
[Proposed Rules]
[Pages 18010-18014]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8520]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-74-AD]


Airworthiness Directives; Eurocopter Deutschland GmbH Model EC 
135 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to Eurocopter Deutschland GmbH 
(ECD) Model EC-135 helicopters. The existing AD requires conducting a 
tail rotor drive shaft vibration survey (survey), installing a 
Fenestron Shaft Retrofit Kit, inspecting each tail rotor drive shaft 
bearing (bearing) attaching lock plate for bent-open tabs and broken or 
missing slippage marks, and visually inspecting each bearing support 
for cracks. This action would require conducting the survey and 
installing the Fenestron Shaft Retrofit Kit. This AD would also require 
installing double bearing supports and struts, revising the required 
compliance time for the repetitive inspections of the bearing attach 
hardware and supports, and removing the requirement to contact the FAA 
if a lock plate tab is bent open or if slippage marks are broken or 
missing. This proposal is prompted by continued reports of misaligned 
or cracked bearing supports and loose bearing attachment bolts. The 
actions specified by the proposed AD are intended to prevent loss of 
drive to the tail rotor and subsequent loss of control of the 
helicopter.

DATES: Comments must be received on or before June 5, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 98-SW-74-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. Comments may be inspected at this location 
between 9 am and 3 pm, Monday through Friday, except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from American Eurocopter Corporation, 2701 Forum Drive, Grand 
Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-
3527. 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: Shep Blackman, Aviation Safety 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort 
Worth,

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Texas 76137, telephone (817) 222-5296, fax (817) 222-5961.

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-74-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-74-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    On October 27, 1998, the FAA issued AD 98-15-25, Amendment 39-10866 
(63 FR 59206, November 3, 1998), requiring the following:
     Before further flight, conduct a survey and install a 
Fenestron Shaft Retrofit Kit L 535M3002 882.
     Before further flight and thereafter at intervals not to 
exceed 15 hours time-in-service (TIS), inspect the bearing attaching 
lock plate for bent-open tabs and broken or missing slippage marks. If 
found, the FAA must be notified.
     Before further flight and thereafter at intervals not to 
exceed 3 hours TIS, using a 6-power or higher magnifying glass and a 
bright light, visually inspect the bearing supports for cracks.
    That action was prompted by reports of loose bearings and 
attachment bolts. The actions of that AD were intended to prevent loss 
of drive to the tail rotor and subsequent loss of control of the 
helicopter.
    Since the issuance of AD 98-15-25, additional reports of 
misaligned, cracked, or corroded bearing supports, and loose bearing 
attachment bolts have been received. The original bearing supports have 
been redesigned to enable more precise alignment with the tail rotor 
driveshaft and have been strengthened to prevent cracking. In addition, 
they are now fabricated of corrosion-resistant material. Struts have 
been added to the tail boom to improve airframe vibration 
characteristics and further minimize bearing support cracking.
    The Luftfahrt-Bundesamt (LBA), the airworthiness authority for the 
Federal Republic of Germany, notified the FAA that an unsafe condition 
may exist on ECD Model EC 135 helicopters. The LBA advises that 
misaligned, corroded, or cracked bearing supports and loose bearing 
attachment bolts may lead to a tail rotor failure and subsequent loss 
of the helicopter.
    Since those cited in AD 98-15-25, ECD has issued the following 
Alert Service Bulletins (ASB's):
     EC 135-53A-004, dated August 14, 1998, to specify 
replacing the current single bearing supports with double bearing 
supports made of corrosion-resistant material and to provide 
instructions for aligning these double bearing supports with the drive 
shaft axis for improved tail rotor drive shaft support.
     EC 135-53A-005, Revision 3, dated September 2, 1998, to 
extend the time interval for compliance with the repetitive bearing 
attach hardware inspection and to identify the required tail rotor 
driveshaft vibration measurement procedure.
     EC 135-53A-002, Revision 2, dated September 2, 1998, to 
extend the time interval for compliance with the repetitive bearing 
support crack inspection contingent on accomplishing Alert Service 
Bulletin EC 135-53A-004.
    The LBA classified these ASB's as mandatory and issued AD's 1998-
033/7 and 1998-389, both dated September 14, 1998, to ensure the 
continued airworthiness of these helicopters in the Federal Republic of 
Germany.
    This helicopter model is manufactured in the Federal Republic of 
Germany 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, the LBA 
has kept the FAA informed of the situation described above. The FAA has 
examined the findings of the LBA, 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 ECD Model EC 135 helicopters of the same type 
design, the proposed AD would supersede AD 98-15-25. The proposed AD 
would require the following:
     Conducting a vibration survey and installing the Fenestron 
Shaft Retrofit Kit L535M3002 882;
     Installing double bearing supports and struts;
     Replacing bearing attach hardware if necessary; and
     Increasing the repetitive inspection interval for the 
bearing supports and attach hardware to 50 hours TIS.
    The FAA estimates that 16 helicopters of U.S. registry would be 
affected by this proposed AD. The 50-hour inspection would take 
approximately 2 work hours to complete. The average labor rate is $60 
per work hour. ECD has stated in its ASB's that the baseline vibration 
measurements and initial installation of all new parts are provided at 
no charge to the owner/operator. Assuming the helicopters are operated 
900 hours TIS per year, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $34,560.
    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

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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 removing Amendment 39-10866; AD 98-
15-25, Docket No. 98-SW-35-AD, and by adding a new airworthiness 
directive (AD), to read as follows:

Eurocopter Deutschland GmbH: Docket No. 98-SW-74-AD. Supersedes AD 
98-15-25, Amendment 39-10866, Docket No. 98-SW-35-AD.

    Applicability: Model EC 135 helicopters, 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 (d) 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 as indicated, unless accomplished 
previously.

    To prevent loss of drive to the tail rotor and subsequent loss 
of control of the helicopter, accomplish the following:
    (a) Before further flight, conduct a tail rotor drive shaft 
vibration survey and install a Fenestron Shaft Retrofit Kit 
L535M3002 882 in accordance with Eurocopter Deutschland GmbH Alert 
Service Bulletin (ASB) EC 135-53A-005, Revision 3, dated September 
2, 1998.
    (b) Before further flight, install double bearing supports for 
the tail rotor driveshaft and tail boom struts in accordance with 
ASB EC 135-53A-004, dated August 14, 1998.


    Note 2: ASB EC 135-53A-002, Revision 2, dated September 2, 1998, 
pertains to the subject of this AD.

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    (c) Before further flight and thereafter at intervals not to 
exceed 50 hours time-in-service, perform the following:
    (1) Clean each tail rotor drive shaft bearing support. Using a 
6-power or higher magnifying glass and a bright light, visually 
inspect the attach lugs of the bearing supports B and C (shown in 
Figure 1) for cracks, particularly in the area extending from the 
bend radius to the attaching screws and rivets connecting the 
bearing supports to the tail boom. Before further flight, replace 
each cracked bearing support with an airworthy bearing support.
    (2) Inspect each bearing attach hardware lock plate for bent-
open tabs and slippage marks for attach hardware looseness or 
rotation. Before further flight, replace any loose bearing attach 
hardware (including lock plates found bent or open due to bolt 
rotation) with airworthy hardware.
    (d) 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, Regulations Group, 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, Regulations Group.


    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Regulations Group.


    (e) 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 4: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Federal Republic of Germany) AD's 1998-033/7 and 1998-
389, both dated September 14, 1998.



    Issued in Fort Worth, Texas, on March 29, 2000.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-8520 Filed 4-5-00; 8:45 am]
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