[Federal Register Volume 65, Number 36 (Wednesday, February 23, 2000)]
[Proposed Rules]
[Pages 8892-8894]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-4263]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 65, No. 36 / Wednesday, February 23, 2000 / 
Proposed Rules  

[[Page 8892]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-45-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Models CF6-
80C2A1/A2/A3/A5/A5F/A8/D1F Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to General Electric Company (GE) 
Models CF6-80C2A1/A2/A3/A5/A5F/A8/D1F turbofan engines. This proposal 
would require initial and repetitive visual inspections of left hand 
and right hand aft engine mount link assemblies for separations, cracks 
and spherical bearing race migration. Cracked or separated parts must 
be replaced prior to further flight. If spherical bearing race 
migration is discovered, an additional borescope inspection for cracks 
is also proposed. If no cracks are discovered in the additional 
borescope inspection, assemblies have a 75-cycle grace period for 
remaining in service before replacement. Finally, installation of 
improved aft engine mount link assemblies constitutes terminating 
action to the inspections of this AD. This proposal is prompted by a 
report of a fractured left-hand aft engine mount link discovered during 
a scheduled removal of an engine of similar design. The actions 
specified by the proposed 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: Comments must be received by April 24, 2000.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 99-NE-45-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299. Comments may also be sent via the Internet 
using the following address: ``[email protected]''. Comments sent 
via the Internet must contain the docket number in the subject line. 
Comments may be inspected at this location between 8 a.m. and 4:30 
p.m., Monday through Friday, except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from General Electric Company via Lockheed Martin Technology 
Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, 
telephone 513-672-8400, fax 513-672-8422. This information may be 
examined at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA.

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:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal 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 99-NE-45-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-NE-45-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    In September 1997, the Federal Aviation Administration (FAA) 
received a report of a fractured General Electric Company (GE) CF6-80A3 
series aft engine mount link found during a scheduled engine removal on 
an Airbus Industrie A310 series aircraft. Recent inspections revealed 
migrated spherical bearing races on two CF6-80A3 series and ten CF6-
80C2 series aft engine mount links. Aft engine mount link spherical 
bearing race migration adversely affects link fatigue life. This 
condition, if not corrected, could result in aft engine mount link 
failure, which can result in adverse redistribution of the aft engine 
mount loads and possible aft engine mount system failure.

Service Information

    The FAA has reviewed and approved the technical contents of GE CF6-
80C2 Alert Service Bulletin (ASB) 72-A0989, dated January 19, 2000, 
that describes the aft engine mount link replacement. The FAA has also 
reviewed and approved the technical contents of GE CF6-80C2 ASB 72-
A0964, Revision 2, dated January 24, 2000, that describes procedures 
for visual inspections of existing left hand and right hand aft engine 
mount link assemblies for separations, cracks, and spherical bearing 
race migration, and provides rejection criteria.

Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would

[[Page 8893]]

require initial and repetitive visual inspections of left hand and 
right hand aft engine mount link assemblies for separations, cracks, 
and spherical bearing race migration. If spherical bearing race 
migration is discovered, a borescope inspection for cracks is also 
proposed. Aft engine mount link assemblies found cracked or separated 
must be replaced with serviceable parts prior to further flight. Aft 
engine mount link assemblies discovered with spherical bearing race 
migration may remain in service for another 75 cycles-in-service (CIS) 
following borescope inspection prior to replacement with serviceable 
parts. Finally, this AD would require the replacement of left hand and 
right hand aft engine mount link assemblies with improved design 
assemblies at the next engine shop visit, or prior to accumulating 
29,000 engine cycles since new (CSN), whichever occurs first. Replacing 
the assemblies would constitute terminating action to the repetitive 
inspections. These actions would be required to be accomplished in 
accordance with the ASBs described previously.

Economic Analysis

    There are approximately 975 engines of the affected design in the 
worldwide fleet. The FAA estimates that 323 engines installed on 
aircraft of US registry would be affected by this proposed AD. The cost 
to replace link assemblies is approximately $7,000. The FAA estimates 
that it would take approximately 0.5 work hours per engine to 
accomplish each of an average of two interim inspections prior to next 
engine shop visit and that the average labor rate is $60 per work hour. 
Based on these figures, the total cost impact of the proposed AD on US 
operators is estimated to be $2,280,380.

Regulatory Impact

    The regulations proposed herein 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. Therefore, it 
is determined that this proposed rule does not have federalism 
implications under Executive Order (EO) No.13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under EO No. 
12866; (2) is not a ``significant rule'' under the DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if 
promulgated, 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 copy of the draft regulatory 
evaluation prepared for this action 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, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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:

General Electric Company: Docket No. 99-NE-45-AD.

    Applicability: General Electric Company (GE) Models CF6-80C2A1/
A2/A3/A5/A5F/A8/D1F turbofan engines, with left hand aft engine 
mount link assemblies, part numbers (P/Ns) 9348M79G01 or 9348M79G02 
installed, or right hand aft engine mount link assemblies, P/Ns 
9348M84G01 or 9348M84G02 installed. These engines are installed on 
but not limited to Airbus Industrie A300 and A310 series, and 
McDonnell Douglas MD-11 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 (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

     Within 400 cycles-in-service (CIS) after the effective 
date of this AD, if not previously inspected using GE CF6-80C2 Alert 
Service Bulletin (ASB) 72-A0964, Revision 2, dated January 24, 2000, 
Revision 1, dated November 12, 1999, or Original, dated April 16, 
1999, or

Previously Inspected

     Within 400 cycles-since-last-inspection (CSLI), if 
previously inspected using GE CF6-80C2 Alert Service Bulletin (ASB) 
72-A0964, Revision 2, dated January 24, 2000, Revision 1, dated 
Month Day, Year, or Original, dated Month Day, Year, GE CF6-80C2 ASB 
72-A0964, Revision 2, dated January 24, 2000.
    (1) Visually inspect for:
     Separations,
     Cracks, and
     Spherical bearing race migration.
    (2) Inspect in accordance with the Accomplishment Instructions 
of GE CF6-80C2 ASB 72-A0964, Revision 2, dated January 24, 2000.

Cracked or Separated Parts

    (3) 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

    (4) If an aft engine mount link assembly is found with spherical 
bearing race migration, but no cracks or separations, prior to 
further flight, either

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 paragraph (3)(I) of the Accomplishment Instructions 
of GE CF6-80C2 ASB 72-A0964, Revision 2, dated January 24, 2000.

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.

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)(4)(ii) of 
this AD:

[[Page 8894]]

     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 paragraph 3(I)(1)(d) or 3(I)(2)(d) of 
GE CF6-80C2 ASB 72-A0964, Revision 2, dated January 24, 2000, as 
applicable, only if visual inspection of the removed link shows no 
cracks or separations.

    Note 2: Link attaching hardware include 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 CF6-80C2 ASB 72-A0989, dated January 19, 2000.

Left Hand Aft Engine Mount Link Assemblies

    (2) Replace left-hand aft engine mount link assemblies, P/Ns 
9348M79G01 or 9348M79G02, with improved left-hand aft engine mount 
link assemblies, P/N 1846M23G01.

Right Hand Aft Engine Mount Link Assemblies

    (3) Replace right hand aft engine mount link assemblies, P/Ns 
9348M84G01 or 9348M84G02, with improved right hand aft engine mount 
link assemblies, P/N 9348M84G03.

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.

Ferry Flights

    (e) Special flight permits may be issued in accordance with 
Secs. 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.


    Issued in Burlington, Massachusetts, on February 15, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-4263 Filed 2-22-00; 8:45 am]
BILLING CODE 4910-13-U