[Federal Register Volume 63, Number 212 (Tuesday, November 3, 1998)]
[Rules and Regulations]
[Pages 59206-59208]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-29375]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-35-AD; Amendment 39-10866; AD 98-15-25]
RIN 2120-AA64


Airworthiness Directives; Eurocopter Deutschland GmbH Model EC 
135 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) 98-15-25, which was sent 
previously to all known U.S. owners and operators of Eurocopter 
Deutschland GmbH Model EC 135 helicopters by individual letters. This 
AD supersedes AD 98-09-11, applicable to Eurocopter Deutschland GmbH 
Model EC 135 helicopters, that required, before further flight, a tail 
rotor drive shaft vibration survey and installation of a Fenestron 
Shaft Retrofit Kit; inspecting the tail rotor drive shaft bearing 
(bearing) attaching lock plates for bent-open tabs, and broken or 
missing slippage marks; and visually inspecting each bearing support 
for cracks. This AD requires the same actions as the superseded AD, 
however it changes the required compliance time for the repetitive 
inspections. This amendment is prompted by reports of loose bearings 
and attachment bolts. This condition, if not corrected, could result in 
loose bearing attachment bolts, or cracked bearing supports, which 
could result in loss of drive to the tail rotor and subsequent loss of 
control of the helicopter.

DATES: Effective November 18, 1998, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 98-15-
25, issued on July 17, 1998, which contained the requirements of this 
amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before January 4, 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-35-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr. Scott Horn, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham 
Blvd., Fort Worth, Texas 76137, telephone (817) 222-5125, fax (817) 
222-5961.

SUPPLEMENTARY INFORMATION: On July 17, 1998, the FAA issued priority 
letter AD 98-15-25, applicable to Eurocopter Deutschland GmbH Model EC 
135 helicopters, which requires, before further flight, a tail rotor 
drive shaft vibration survey and installation of a Fenestron Shaft 
Retrofit Kit L 535M3002 882; before further flight, and thereafter at 
intervals not to exceed 15 hours time-in-service (TIS), inspecting the 
bearing attaching lock plates for bent-open tabs, and broken or missing 
slippage marks; and before further flight, and thereafter at intervals 
not to exceed 3 hours TIS, visually inspecting each bearing support for 
cracks. That action was prompted by several reports of loose tail rotor 
drive shaft bearings and attachment bolts. This condition, if not 
corrected, could result in loose bearing attachment bolts, or cracked 
bearing supports, which could result in loss of drive to the tail rotor 
and subsequent loss of control of the helicopter.
    The FAA previously issued AD 98-09-11 on June 18, 1998 (63 FR 
34796, June 26, 1998). AD 98-09-11 contained the same requirements as 
this AD except that this AD requires the repetitive visual inspection 
of each bearing support to be conducted at intervals not to exceed 3 
hours TIS instead of the previous 15 hours TIS.
    Since the issuance of AD 98-09-11, it has been determined that 
cracks can form in additional areas outside the bend radius of the 
bearing support, and that the cracks can form and propagate to failure 
within the previously-required 15 hours TIS inspection interval.
    The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority 
for the Federal Republic of Germany, recently notified the FAA that an 
unsafe condition may exist on Eurocopter Deutschland GmbH Model EC 135 
helicopters. The LBA advises that loosening of bolt connections at 
bearing supports may lead to a tail rotor failure and loss of the 
helicopter. The LBA issued AD 1998-033/6, dated July 9, 1998, 
applicable to ECD Model EC 135 helicopters.
    The FAA has reviewed Eurocopter EC 135 Alert Service Bulletin No. 
EC 135-53A-002, Revision 1, dated July 7, 1998, which describes 
procedures for visually inspecting the bearing supports, and Eurocopter 
EC 135 Alert Service Bulletin No. EC 135-53A-005, Revision 1, dated 
April 6, 1998, which describes procedures for measuring vibrations on 
the tail rotor drive shaft and replacing roller bearing attaching 
hardware at bearing locations.
    This helicopter model is manufactured in the Federal Republic of 
Germany and is type certificated for operation in the United States 
under the provision 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 operations in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Eurocopter Deutschland GmbH Model EC 135 
helicopters of the same type design, this AD requires, before further 
flight, a tail rotor drive shaft vibration survey and installation of a 
Fenestron Shaft Retrofit Kit L 535M3002 882. Also, before further 
flight, and thereafter at intervals not to exceed 15 hours TIS, the AD 
requires inspecting the bearing attaching lock plates at each bearing 
support for bent-open tabs, and inspecting for broken or missing 
slippage marks. If a bearing attaching lock plate tab is bent open, or 
if a slippage mark is broken or missing, the FAA must be notified. 
Finally, the AD requires, before further flight, and thereafter at 
intervals not to exceed 3 hours TIS, inspecting the bearing supports 
for cracks in the areas shown in the attached Figure 1, from the bend 
radius to the attaching screws and rivets connecting the bearing 
supports to the tailboom. Use of a 6-power or higher magnifying glass 
and a bright light are required for this inspection. If a crack is 
found, the cracked bearing support is to be replaced with an airworthy 
bearing support.
    The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
structural integrity and controllability of the aircraft. Therefore, 
the installation and an inspection are required before further flight, 
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 July 17, 1998 to all known U.S. owners and operators of 
Eurocopter Deutschland GmbH Model EC 135 helicopters. These conditions 
still exist, and the AD is hereby

[[Page 59207]]

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 only difference between the priority letter AD and 
this published version of this AD is that a NOTE 2 is added to this AD 
to inform the reader that the procedures and limits for the vibration 
survey are contained in Eurocopter Deutschland document D/TA 13/98, 
Revision 01. This note is informational only and is not a substantive 
change.
    The FAA estimates that 6 helicopters of U.S. registry will be 
affected by this AD. The 15 hours TIS inspection will take 
approximately 0.5 work hours and the 3 hours TIS inspection will take 
approximately 1.5 work hours. The average labor rate is $60 per work 
hour. The manufacturer has represented that they will accomplish this 
vibration survey and the installation of the Fenestron Shaft Retrofit 
kit at no cost to the owners/operators. Assuming the helicopters are 
operated 900 hours TIS per year, the total cost impact of the AD on 
U.S. operators for one year is estimated to be $172,800.

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 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-35-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 removing Amendment 39-10632 (63 FR 
34796, June 26, 1998) and by adding a new airworthiness directive to 
read as follows:

98-15-25  Eurocopter Deutschland: Amendment 39-10866. Docket No. 98-
SW-35-AD. Supersedes AD 98-09-11, Amendment 39-10632, Docket No. 98-
SW-18-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 
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 (d) 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 as indicated, unless accomplished 
previously.
    To detect loose tail rotor drive shaft bearing (bearing) 
attachment bolts, or cracked bearing supports, which could result in 
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 L 
535M3002 882.

    Note 2: Procedures and limits for the vibration survey are 
provided in Eurocopter Deutschland document D/TA 13/98 Revision 01.

    (b) Before further flight, and thereafter at intervals not to 
exceed 15 hours time-in-service (TIS), at each bearing support:
    (1) Inspect each bearing attaching lock plate that was installed 
with the Fenestron Shaft Retrofit Kit L 535M3002 882 for bent-open 
tabs.
    (2) Inspect for broken or missing slippage marks that may 
indicate looseness or rotation of attaching hardware.
    (3) If a lock plate tab is bent open on bearing supports A, B, 
or C (shown in Figure 1), or if slippage marks are broken or 
missing, contact the Manager, Rotorcraft Standards Staff, FAA, 
telephone (817) 222-5110, fax (817) 222-5961.

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[GRAPHIC] [TIFF OMITTED] TR03NO98.028



    (c) 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 bearing supports B and C as shown in 
Figure 1, from the bend radius to the attaching screws and rivets 
connecting the bearing supports to the tailboom. If a crack is 
found, replace the bearing support with an airworthy bearing 
support.
    (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, Rotorcraft Standards Staff, 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 Standards Staff.

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

    (e) Special flight permits will not be issued.
    (f) This amendment becomes effective on November 18, 1998, to 
all persons except those persons to whom it was made immediately 
effective by Priority Letter AD 98-15-25, issued July 17, 1998, 
which contained the requirements of this amendment.

    Note 4: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Federal Republic of Germany) AD 1998-033/6, dated July 9, 
1988.

    Issued in Fort Worth, Texas, on October 27, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-29375 Filed 11-2-98; 8:45 am]
BILLING CODE 4910-13-P