[Federal Register Volume 64, Number 101 (Wednesday, May 26, 1999)]
[Rules and Regulations]
[Pages 28353-28355]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13320]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-47-AD; Amendment 39-11182; AD 99-11-11]
RIN 2120-AA64
Airworthiness Directives; Eurocopter France Model SA-365N, N1,
N2, N3, and SA-366G1 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to Eurocopter France Model SA-365N, N1 and SA-366G1
helicopters, that currently requires repetitive inspections of the main
gearbox (MGB) magnetic chip plug and oil filter if certain part number/
modification level MGB's are installed. This new action expands the
helicopter model and MGB applicability to include the SA-365N2 and N3
helicopters and all variants of the MGB. It also requires installing a
MGB planetary gear shaft (gear shaft) vibration level monitoring unit
(VLMU); inserting procedures into the Rotorcraft Flight Manual (RFM)
for a preflight vibration check using the VLMU and inserting a related
emergency procedure and limitation for an inoperative VLMU into the
RFM. This action is prompted by two occurrences of gear shaft cracks.
The actions specified by this AD are intended to detect cracks in the
MGB planetary gear shaft, which could lead to failure of the MGB and
subsequent loss of control of the helicopter.
DATES: Effective June 10, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 10, 1999.
Comments for inclusion in the Rules Docket must be received on or
before July 26, 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-47-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
The service information referenced in this AD 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
76137; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Shep Blackman, Aerospace Engineer,
Rotorcraft Standards Staff, Rotorcraft Directorate, FAA, 2601 Meacham
Blvd., Fort Worth, Texas 76137, telephone (817) 222-5296, fax (817)
222-5961.
SUPPLEMENTARY INFORMATION: The FAA issued Priority Letter AD 97-15-15
on July 18, 1997, prompted by two occurrences of MGB planetary gear
shaft cracks, AD 97-15-15 was published in the Federal Register on
February 6, 1998 (63 FR 6069). It requires that the magnetic chip plug
on any MGB that was not modified in accordance with MOD 077244 be
inspected after every flight and the MGB oil filter be inspected after
the last flight of each day or at intervals not to exceed 12 hours
time-in-service (TIS). The presence of any ferrous chips or any reports
of abnormal vibrations by the flight crew requires a MGB ground
vibration evaluation before further flight. Eurocopter France has
recently advised the FAA that the potential for planetary gear shaft
cracks exists for all MGB variants, regardless of modification level,
currently authorized for installation on FAA-certified Model SA-365/366
helicopters. The temporary installation of the VLMU enables the flight
crew to more easily and accurately assess the vibration level of the
MGB prior to each flight. The manufacturer is pursuing a redesign of
the affected MGB that will probably result in a mandatory
[[Page 28354]]
modification of the MGB and constitute a terminating action for the
requirements of this AD. It is anticipated that after the modification
is accomplished, the VLMU will no longer be required.
The Direction Generale de L'Aviation Civile (DGAC), which is the
airworthiness authority for France, has notified the FAA that an unsafe
condition may exist on Eurocopter France Model SA-365N, N1, N2, and N3,
and SA-366G1 helicopters. The DGAC advises that, based on two reports
of cracks detected on the gear shaft, an AD is necessary to mandate the
installation and the utilization of an MGB vibration level unit that
detects vibrations at the shaft rotation frequency and indicates the
potential for a crack in the gear shaft.
Eurocopter France has issued Eurocopter AS 365 Service Bulletin No.
31.00.03, applicable to Model SA-365N, N1, N2, and N3, helicopters; and
Eurocopter SA 366 Service Bulletin No. 31.01, applicable to Model SA-
366G1 helicopters, both dated June 23, 1998. These service bulletins
provide for the installation of a VLMU that enables a ground check for
vibrations amplitude at the shaft rotational frequency and provides an
indication to the pilot when the amplitude of vibration reaches a level
that could indicate the existence of a crack in the gear shaft. The
service bulletins also provide for checks of the MGB chip plug and oil
filter, and measurements of on-ground vibration levels if the VLMU
becomes inoperative. The DGAC classified these service bulletins as
mandatory and issued AD 98-324-045(A), applicable to Model 365N
helicopters, and AD 98-323-023(A), applicable to Model 366 helicopters,
both dated August 12, 1998, in order to assure the continued
airworthiness of these helicopters in France.
These helicopter models are manufactured in France and are type
certificated for operation in the United States under the provisions of
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the
applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the DGAC has kept the FAA informed
of the situation described above. The FAA has examined the findings of
the DGAC, 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 Eurocopter France SA-365N, N1, N2, and N3,
and SA-366G1 helicopters of the same type design registered in the
United States, this AD is being issued to detect cracks in the MGB
planetary gear shaft, which could lead to failure of the MGB and
subsequent loss of control of the helicopter. This AD requires
installing a MGB VLMU to enable a preflight MGB vibration check,
revising the RFM normal, emergency and limitations sections, and if the
VLMU becomes inoperative, inspecting the MGB magnetic plug after every
flight and the oil filter each day in which flights are conducted (not
to exceed 12 hours time-in-service between inspections). The actions
are required to be accomplished in accordance with the applicable
service bulletins described previously. If metallic particles are found
on the magnetic plug or oil filter, drive system ground vibration
measurements must be conducted. The short compliance time involved is
required because the previously described critical unsafe condition can
adversely affect the structural integrity of the helicopter. Therefore,
the actions are required within 25 hours time-in-service and this AD
must be issued immediately.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
The FAA estimates that 26 helicopters will be affected by this AD,
that it will take approximately 10 work hours to install the VLMU, and
that the average labor rate is $60 per work hour. The manufacturer has
stated that required parts are available at no cost. Based on these
figures, the total cost impact of the AD on U.S. operators is estimated
to be $15,600.
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-47-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, Incorporation by
reference, 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
[[Page 28355]]
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 99-11-11 Eurocopter France: Amendment 39-11182. Docket No. 98-
SW-47-AD. Supersedes AD 97-15-15, Amendment 39-10313, Docket No. 97-
SW-23-AD.
Applicability: Model SA-365N, N1, N2, and N3 helicopters, serial
numbers up to and including 6538, and SA-366G1 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 detect cracks in the main gearbox (MGB) planetary gear shaft
(shaft), which could lead to failure of the MGB and subsequent loss
of control of the helicopter, accomplish the following:
(a) Within 25 hours time-in-service, install a MGB shaft
vibration level monitoring unit (VLMU), in accordance with paragraph
B. of the Accomplishment Instructions of either Eurocopter AS 365
Service Bulletin No. 31.00.03, applicable to Model SA-365N, N1, N2,
and N3 helicopters; or Eurocopter SA 366 Service Bulletin No. 31.01,
applicable to Model SA-366G1 helicopters, both dated June 23, 1998
(SB's).
(b) Before further flight, accomplish the following:
(1) Insert paragraphs 2D1), 2D2), and 2D3) of the SB's into the
applicable Rotorcraft Flight Manual post-start normal procedures
section.
(2) Insert the following statement in the Emergency Procedures
section of the applicable Rotorcraft Flight Manual: ``If vertical
vibrations at approximately 4/rev frequency are detected, reduce
power, land as soon as practicable, and perform a VLMU vibration
level check.''
(3) Insert the following statement into the Limitations section
of the applicable Rotorcraft Flight Manual: ``If the VLMU becomes
inoperative, it must be returned to service within 30 calendar days
or the helicopter must be grounded until such repairs are made.''
(c) If the VLMU becomes inoperative, inspect the MGB magnetic
plug; it must be inspected before every flight and inspect the MGB
oil filter each day in which flights are conducted or at intervals
not to exceed 12 hours time-in-service, whichever occurs first. When
metallic particles are found on either the magnetic plug or the oil
filter element, conduct drive system ground vibration measurements
before further flight.
(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,
Rotorcraft Directorate, FAA. Operators shall submit their requests
through a 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 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.
(f) The actions shall be done in accordance with the Eurocopter
AS 365 Service Bulletin No. 31.00.03, or Eurocopter SA 366 Service
Bulletin No. 31.01, both dated June 23, 1998, as applicable. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from American Eurocopter Corporation,
2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972)
641-3460, fax (972) 641-3527. Copies may be inspected at the FAA,
Office of the Regional Counsel, Southwest Region, 2601 Meacham
Blvd., Room 663, Fort Worth, Texas 76137; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
(g) This amendment becomes effective on June 10, 1999.
Note 3: The subject of this AD is addressed in Direction
Generale de L'Aviation Civile (France) AD 98-324-045(A), applicable
to Model SA-365N helicopters, and AD 98-323-023(A), applicable to
Model SA-366 helicopters, both dated August 12, 1998.
Issued in Fort Worth, Texas, on May 18, 1999.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-13320 Filed 5-25-99; 8:45 am]
BILLING CODE 4910-13-U
