[Federal Register Volume 63, Number 123 (Friday, June 26, 1998)]
[Rules and Regulations]
[Pages 34796-34798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-17023]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-18-AD; Amendment 39-10632; AD 98-09-11]
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) 98-09-11 which was sent
previously to all known U.S. owners and operators of Eurocopter
Deutschland GmbH (Eurocopter) Model EC 135 helicopters by individual
letters. This AD requires, before further flight, a review of aircraft
records to determine if a tail rotor drive shaft vibration survey and
installation of a Fenestron Shaft Retrofit Kit have been accomplished;
before further flight, and thereafter at intervals not to exceed 15
hours time-in-service, 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 amendment is prompted by three reports of loose
bearings and attachment bolts, and one report of a cracked bearing
support. Excessive vibrations in the tail rotor drive shaft can loosen
attachment bolts or cause cracking in the bearing supports. This
condition, if not corrected, could result in loss of drive to the tail
rotor and subsequent loss of control of the helicopter.
DATES: Effective July 13, 1998, to all persons except those persons to
whom it was made immediately effective by priority letter AD 98-09-11,
issued on April 17, 1998, which contained the requirements of this
amendment.
Comments for inclusion in the Rules Docket must be received on or
before August 25, 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-18-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 April 17, 1998, the FAA issued priority
letter AD 98-09-11, applicable to Eurocopter Model EC 135 helicopters,
which requires, before further flight, a review of aircraft records to
determine if a tail rotor drive shaft vibration survey and installation
of a Fenestron Shaft Retrofit Kit L 535M3002 882 have been
accomplished. If a tail rotor vibration survey has not been
accomplished or if a Fenestron Shaft Retrofit Kit has not been
installed, the FAA must be contacted. Also, before further flight, and
thereafter at intervals not to exceed 15 hours time-in-service, 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 visually inspecting each bearing support for
cracks, and if a crack is found, replacing the bearing support with an
airworthy bearing support. That action was prompted by three reports of
loose bearings and attachment bolts, and one report of a cracked
bearing support. Excessive vibrations in the tail rotor drive shaft can
loosen attachment bolts or cause cracking in the bearing supports. This
condition, if not corrected, could result in loss of drive to the tail
rotor and subsequent loss of control of the helicopter.
The Luttfahrt-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 (ECD) Model
EC 135 helicopters. The LBA advises that the loosening of bolt
connections at the bearing supports may lead to a tail rotor failure
and thus to the loss of the helicopter. The LBA issued AD 1998-033/5,
dated April 6, 1998, applicable to ECD Model EC 135 helicopters.
The FAA has reviewed Eurocopter EC 135 Alert Service Bulletin No.
EC 135-53A-002, dated December 12, 1997, 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 replacement of 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 the unsafe condition described is likely to exist or develop
on other Eurocopter Model EC 135 helicopters of the same type design,
the FAA issued priority letter AD 98-09-11 to detect 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 AD requires, before
[[Page 34797]]
further flight, a review of aircraft records to determine if a tail
rotor drive shaft vibration survey and installation of a Fenestron
Shaft Retrofit Kit L 535M3002 882 have been accomplished. If a tail
rotor vibration survey has not been accomplished or if a Fenestron
Shaft Retrofit Kit has not been installed, the FAA must be contacted.
Also, before further flight, and thereafter at intervals not to exceed
15 hours time-in-service, 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 visually
inspecting each bearing support for cracks, and if a crack is found,
replacing the bearing support with an airworthy bearing support.
The short compliance time involved is required because the
previously described critical unsafe condition can adversely affect the
controllability of the helicopter. Therefore, reviewing aircraft
records, inspecting the bearing attaching lock plates, and visually
inspecting each bearing support for cracks 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 April 17, 1998 to all known U.S. owners and operators of
Eurocopter Model EC 135 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 6 helicopters of U.S. registry will be
affected by this AD, that it will take approximately .5 work hour per
helicopter to review aircraft records and 1 work hour per helicopter to
conduct the required inspections, and that the average labor rate is
$60 per work hour. Required parts will be provided at no cost by the
manufacturer. Based on these figures, the total cost impact of the AD
on U.S. operators is estimated to be $540 to review the aircraft
records and perform the inspections once on each helicopter in the U.S.
fleet.
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-18-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 98-09-11 Eurocopter Deutschland GmbH: Amendment 39-10632. Docket
No. 98-SW-18-AD.
Applicability: Model EC 135 helicopters, serial numbers 0005
through 0048, 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, review the helicopter's historical
records to determine if a tail rotor drive shaft vibration survey
and the installation of Fenestron Shaft Retrofit Kit L 535M3002 882
have been accomplished. If either action has not been accomplished,
contact the Manager, Rotorcraft Standards Staff, FAA, telephone
(817) 222-5110, fax (817) 222-5961.
[[Page 34798]]
(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.
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[GRAPHIC] [TIFF OMITTED] TR26JN98.001
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(c) Before further flight, and thereafter at intervals not to
exceed 15 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 for cracks. 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 2: 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 July 13, 1998, to all
persons except those persons to whom it was made immediately
effective by Priority Letter AD 98-09-11, issued April 17, 1998,
which contained the requirements of this amendment.
Note 3: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Federal Republic of Germany) AD 1998-033/5, dated April
6, 1998.
Issued in Fort Worth, Texas, on June 18, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-17023 Filed 6-25-98; 8:45 am]
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