Airworthiness Directives; General Electric Company CF6-80A3 Series Turbofan Engines

[Federal Register Volume 66, Number 59 (Tuesday, March 27, 2001)]
[Rules and Regulations]
[Pages 16599-16601]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-7349]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NE-35-AD; Amendment 39-12156, AD 2001-06-09]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-80A3 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to General Electric Company (GE) CF6-80A3 series 
turbofan engines, that currently requires initial and repetitive on-
wing borescope inspections of the left hand aft engine mount link 
assembly for cracks, bearing migration, and bearing race rotation, and 
if necessary, replacement with serviceable parts. This AD requires 
initial and repetitive visual inspections of both left hand and right 
hand aft engine mount link assemblies for separations, cracks, and 
bearing race migration. Cracked or separated parts will have to be 
replaced prior to further flight. If spherical bearing race migration 
is discovered, a borescope inspection for cracks is also required. If 
no cracks are discovered by the additional borescope inspection, 
assemblies would have a 75-cycle grace period for remaining in service 
before replacement. Finally, installation of improved aft engine mount 
link assemblies will constitute terminating action to the inspections 
of this AD. This amendment is prompted by a recent analysis of internal 
bearing friction and bearing migration and inspections, which revealed 
migrated spherical bearing races on two CF6-80A3 series and ten CF6-
80C2 series aft engine mount links. The actions specified by this AD 
are intended to prevent aft engine mount link failure, which can result 
in adverse redistribution of the aft engine mount loads and possible 
aft engine mount system failure.

DATES: Effective May 1, 2001. The incorporation by reference of certain 
publications listed in the regulations is approved by the Director of 
the Federal Register as of May 1, 2001.

ADDRESSES: 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 Federal Aviation Administration (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: Ann Mollica, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone 781-
238-7740, fax 781-238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 98-15-17, 
Amendment 39-10668 (63 FR 39489, July 23, 1998), which is applicable to 
GE Company CF6-80A3 series turbofan engines, was published in the 
Federal Register on July 20, 2000 (65 FR 44997). That action proposed 
to require initial and repetitive visual inspections of both left hand 
and right hand aft engine mount link assemblies for separations, 
cracks, and bearing race migration. Cracked or separated parts would 
have to be replaced prior to further flight. If spherical bearing race 
migration is discovered, a borescope inspection for cracks is also 
proposed. If no cracks are discovered by the additional borescope 
inspection, assemblies would have a 75-cycle grace period for remaining 
in service before replacement. Finally, installation of improved aft 
engine mount link assemblies would constitute terminating action to the 
inspections.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comment received.

Comments

    The sole commenter agrees with the technical intent and content of 
the proposed AD. However, the commenter

[[Page 16600]]

believes that the economic affect on his company would be considerably 
greater than that stated in the preamble to the proposed AD.
    The comment did not, however, include any analysis to support the 
conclusion that the commenter's company would incur a greater adverse 
economic affect. The elements of the economic analysis were reviewed 
with the manufacturer, GE Company. The NPRM stated that 120 worldwide 
and 59 domestic airplanes would be affected by the AD. However, that 
economic data included both CF6-80A1 and CF6-80A3 engines. Since the AD 
applies only CF6-80A3 engines, the actual numbers of engines affected 
by this AD include 108 worldwide and 59 that could be installed on 
airplanes of US registry. The economic analysis section has been 
changed accordingly. The FAA also notes that the current AD already 
requires inspection of the left hand aft mount link at intervals 
considerably shorter than this AD requires. Therefore, some of the cost 
cited in the economic analysis has already been required by the current 
AD.
    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Economic Analysis

    There are approximately 108 engines of the affected design in the 
worldwide fleet. The FAA estimates that 59 engines that could be 
installed on airplanes of US registry would be affected by this 
proposed AD, and that the cost of replacement link assemblies is 
approximately $19,473 per engine. The FAA also estimates that it would 
take approximately 2 work hours per engine to accomplish the proposed 
interim inspections, and that the average labor rate is $60 per work 
hour. Based on these figures, the total cost impact of the proposed AD 
over 3 years on US operators is estimated to be $581,533 per year.

Regulatory Impact

    This rule does not have federalism implications, as defined in 
Executive Order 13132, because it 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this rule.
    For the reasons discussed above, I certify that this action (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) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
by contacting 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 removing Amendment 39-10668 (63 FR 
39489, July 23, 1998) and by adding a new airworthiness directive, 
Amendment 39-12156, to read as follows:

2001-06-09  General Electric Company: Amendment 39-12156. Docket 98-
NE-35-AD. Supersedes AD 98-15-17, Amendment 39-10668.

    Applicability: General Electric Company (GE) CF6-80A3 series 
turbofan engines, with left hand aft engine mount link assemblies, 
part numbers (P/N's) 224-1608-501, 224-1608-503, or 224-1608-505 
installed, or right hand aft engine mount link assemblies, P/N's 
224-1609-503, 224-1609-505, or 224-1609-507 installed. These engines 
are installed on but not limited to Airbus Industrie A310-200 series 
airplanes.

    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 (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 aft engine mount link failure, which can result in 
adverse redistribution of the aft engine mount loads and possible 
aft engine mount system failure, accomplish the following:

Initial Inspection

    (a) Inspect aft engine mount link assemblies as follows:

Not Previously Inspected

    (1) Within 400 cycles-in-service (CIS) after the effective date 
of this AD, if not previously inspected using Rohr Alert Service 
Bulletin (ASB) CF6-80A3-NAC-A71-061, Revision 1, dated February 22, 
2000, or Rohr Alert Service Bulletin (ASB) CF6-80A3-NAC-A71-061, 
dated April 16, 1999; or

Previously Inspected

    (2) Within 400 cycles-since-last-inspection (CSLI), if 
previously inspected using Rohr ASB CF6-80A3-NAC-A71-061, Revision 
1, dated February 22, 2000, or Rohr ASB CF6-80A3-NAC-A71-061, dated 
April 16, 1999.
    (3) Visually inspect for: separations, cracks, and spherical 
bearing race migration.
    (4) Inspect in accordance with the Accomplishment Instructions 
of Rohr ASB CF6-80A3-NAC-A71-061, Revision 1, dated February 22, 
2000.

Cracked or Separated Parts

    (5) If a crack or separation is discovered, prior to further 
flight, remove the cracked or separated aft engine mount link 
assembly and the attaching hardware from service, and replace with 
serviceable parts.

Removal of Aft Engine Mount Link Assemblies With Spherical Bearing Race 
Migration

    (6) If an aft engine mount link assembly is found with spherical 
bearing race migration, but no cracks or separations, prior to 
further flight, do either of the following:

Removal

    (i) Remove the aft engine mount link assembly and the attaching 
hardware from service and replace with serviceable parts; or

Additional Borescope Inspection of Aft Engine Mount Link Assemblies 
with Spherical Bearing Race Migration

    (ii) Perform an additional borescope inspection for cracks in 
accordance with paragraphs (2)(D)(5) and (2)(G)(5) of the 
Accomplishment Instructions of Rohr ASB CF6-80A3-NAC-A71-061, 
Revision 1, dated February 22, 2000, and perform the following:

After Additional Borescope Inspection, If Parts Are Cracked

    (A) If a crack indication is discovered, prior to further 
flight, remove the cracked aft engine mount link assembly and the 
attaching hardware from service, and replace with serviceable parts.

[[Page 16601]]

After Additional Borescope Inspection, If Parts Are Not Cracked (Grace 
Period)

    (B) If crack indications are not discovered, within 75 CIS after 
the inspection performed in accordance with paragraph (a)(6)(ii) of 
this AD, remove the aft engine mount link assembly from service, and 
replace with serviceable parts.

Attaching Hardware

    (iii) Attaching hardware may be returned to service after 
inspection in accordance with paragraphs 2(D)(6)(a) or 2(G)(6)(a) of 
Rohr ASB CF6-80A3-NAC-A71-061, Revision 1, dated February 22, 2000, 
only if inspection of the removed link shows no cracks or 
separations.

    Note 2: Link attaching hardware includes the nuts, bolts and 
washers that secure the link.

Repetitive Inspections

    (b) Thereafter, perform the actions required by paragraph (a) 
and associated subparagraphs at intervals not to exceed 400 CSLI.

Replacement With Improved Link Assemblies

    (c) Replace aft engine mount link assemblies with improved aft 
engine mount link assemblies at the next engine shop visit (ESV), or 
prior to accumulating 29,000 engine cycles since new (CSN), 
whichever occurs first.
    (1) Replace in accordance with the Accomplishment Instructions 
of Rohr ASB CF6-80A3-NAC-A71-064, dated April 4, 2000.

Left Hand Aft Engine Mount Link Assemblies

    (2) Replace left hand aft engine mount link assemblies, P/N's 
224-1608-501, 224-1608-503, or 224-1608-505, with improved left hand 
aft engine mount link assemblies, P/N's 224-1608-507 or 224-1608-
509.

Right Hand Aft Engine Mount Link Assemblies

    (3) Replace right hand aft engine mount link assemblies, P/N's 
224-1609-503, 224-1609-505, or 224-1609-507, with improved right 
hand aft engine mount link assemblies, P/N's 224-1609-509 or 224-
1609-511.

Terminating Action

    (4) Installation of improved aft engine mount link assemblies in 
accordance with paragraph (c) and its subparagraphs constitutes 
terminating action to the inspections required by paragraphs (a) and 
(b) of this AD.

Alternate Methods of Compliance

    (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, Engine 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 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

Special Flight Permits

    (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 aircraft to a location where 
the inspection requirements of this AD can be accomplished.

Incorporation by Reference

    (f) The FAA has reviewed and approved the technical content of 
the listed Rohr Alert Service Bulletins ASBs. The actions required 
by this AD shall be done in accordance with the following Rohr ASBs:

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             Document No.                    Pages                Revision                       Date
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ASB CF6-80A3-NAC-A71-061..............      1-11        Revision 1.................  Feb. 22, 2000.
  Total pages: 11
ASB CF6-80A3-NAC-A71-064..............       1-8        Original...................  April 4, 2000.
  Total pages: 8
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The incorporations by reference were 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 
01803-5299; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (g) This amendment becomes effective on May 1, 2001.

    Issued in Burlington, Massachusetts, on March 19, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-7349 Filed 3-26-01; 8:45 am]
BILLING CODE 4910-13-P

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