[Federal Register Volume 63, Number 141 (Thursday, July 23, 1998)]
[Rules and Regulations]
[Pages 39489-39491]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19485]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-35-AD; Amendment 39-10668; AD 98-15-17]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-80A3
Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to General Electric Company CF6-80A3 series turbofan
engines. This action requires initial and repetitive on-wing borescope
inspections of the left hand aft mount link assembly for cracks,
bearing migration, and bearing race rotation, and, if necessary,
replacement with serviceable parts. This amendment is prompted by a
report of a fractured left hand aft mount link discovered during a
scheduled engine removal. The actions specified in this AD are intended
to prevent left hand aft mount link failure, which can result in
adverse redistribution of the aft mount loads and possible aft mount
system failure.
DATES: Effective August 7, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 7, 1998.
Comments for inclusion in the Rules Docket must be received on or
before September 21, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 98-ANE-35-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``engineprop@faa.dot.gov''. Comments sent via the Internet must contain
the docket number in the subject line.
The service information referenced in this AD may be obtained from
Rohr, Inc., 850 Lagoon Dr., Chula Vista, CA 91910-2098; telephone (619-
691-3102), fax (619-498-7215). This information may be examined at the
FAA, New England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: William S. Ricci, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7742, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA)
has received a report of a fractured left hand aft mount link
discovered during a scheduled engine removal of a General Electric
Company (GE) CF6-80A3 series turbofan engine. Failure analysis revealed
a fatigue type fracture with no metallurgical anomalies and no
geometric discrepancies in the area of the crack origin. Over the
course of the investigation of the cracked left hand aft mount link
assembly and the review of other link assemblies returned from service,
two conditions were noted that individually could be considered benign
but when combined could result in higher stress levels and the reduced
fatigue capability of link assemblies. The first condition is the
incorrect orientation of the entry slots of the spherical bearing
assembly and the second condition is high friction between the bearing
and the race resulting from contamination between faying bearing
surfaces. This condition, if not corrected, could result in left hand
aft mount link failure, which can result in adverse redistribution of
the aft mount loads and possible aft mount system failure.
On May 20, 1998, the Direction Generale de L'Aviation Civile
(DGAC), the airworthiness authority of France, issued AD 98-205-260(B),
applicable to Airbus A310 aircraft, addressing this unsafe condition by
requiring initial and repetitive on-wing borescope inspections of the
left hand aft mount link assembly for cracks, bearing
[[Page 39490]]
migration, and bearing race rotation, and, if necessary, replacement
with serviceable parts. On June 3, 1998, the Transport Airplane
Directorate (TAD) of the FAA issued AD 98-12-24, also applicable to
Airbus A310 aircraft, requiring a one-time on-wing borescope inspection
for cracks and bearing migration. The Engine and Propeller Directorate
has consulted with the DGAC and the TAD and has determined that it is
necessary to issue this AD applicable to GE CF6-80A3 series engines
mandating repetitive borescope inspections in order to assure the
continued airworthiness of the aft mount links.
The FAA has reviewed and approved the technical contents of Rohr
Alert Service Bulletin (ASB) No. CF6-80A3-NAC-A71-060, dated January
30, 1998, that describes procedures for borescope inspections of the
left hand aft mount link for cracks, bearing migration, and bearing
race rotation.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design, this AD is
being issued to prevent left hand aft mount link failure. This AD
requires initial and repetitive on-wing borescope inspections of the
left hand aft mount link assembly for cracks, bearing migration, and
bearing race rotation, and, if necessary, replacement with serviceable
parts. The investigation is ongoing, and further rulemaking may be
necessary that may require additional piece-part inspections or the
installation of a modified left hand aft mount link assembly that would
terminate the repetitive inspections required by this AD. The actions
are required to be accomplished in accordance with the ASB described
previously.
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.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-ANE-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 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 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 the following new
airworthiness directive:
98-15-17 General Electric Company: Amendment 39-10668. Docket 98-
ANE-35-AD.
Applicability: General Electric Company (GE) CF6-80A3 series
turbofan engines, installed on but not limited to Airbus A310 series
aircraft.
Note 1: This airworthiness directive (AD) applies to each engine
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 engines 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 (b) 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 left hand aft mount link failure, accomplish the
following:
(a) Perform initial and repetitive borescope on-wing inspections
of the left hand aft mount link assembly for cracks, bearing
migration, and bearing race rotation exceeding the limits specified
in Rohr Alert Service Bulletin (ASB) No. CF6-80A3-NAC-A71-060, dated
January 30, 1998, and, if necessary, replace with serviceable parts,
as follows:
(1) Initially inspect within 50 cycles in service (CIS) after
the effective date of this AD.
(2) Thereafter, reinspect at intervals not to exceed 175 CIS
since last inspection.
(3) Prior to further flight, remove from service any left hand
aft mount link discovered with cracks, bearing migration, or bearing
race rotation, exceeding the limits specified in Rohr ASB No. CF6-
80A3-NAC-A71-060, dated January 30, 1998, and replace with
serviceable parts.
(b) 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, Engine
[[Page 39491]]
Certification Office. Operators shall submit their requests through
an appropriate FAA Principal Maintenance Inspector, who may add
comments and then send it to the Manager, Engine Certification
Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(c) 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 aircraft to a location where
the requirements of this AD can be accomplished.
(d) The actions required by this AD shall be done in accordance
with the following Rohr ASB:
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Document No. Pages Date
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CF6-80A3-NAC-A71-060............. 1-10 January 30, 1998.
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Total pages: 10.
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 Rohr, Inc., 850 Lagoon Dr.,
Chula Vista, CA 91910-2098; telephone (619-691-3102), fax (619-498-
7215). Copies may be inspected at the FAA, New England Region,
Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on August 7, 1998.
Issued in Burlington, Massachusetts, on July 15, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 98-19485 Filed 7-22-98; 8:45 am]
BILLING CODE 4910-13-U
