[Federal Register Volume 65, Number 40 (Tuesday, February 29, 2000)]
[Rules and Regulations]
[Pages 10698-10700]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-4433]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-24-AD; Amendment 39-11597; AD 2000-04-14]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-80C2 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to General Electric Company (GE) CF6-80C2 series turbofan 
engines, that requires replacement of the fuel tube connecting the 
flowmeter to the Integrated Drive Generator (IDG) and the fuel tube(s) 
connecting the Main Engine Control (MEC) or Hydromechanical (HMU) to 
the flowmeter with improved fuel tubes. This amendment is prompted by 
reports of fuel leaking in the core cowl cavity under high pressure 
that can be ignited by the hot engine case temperatures. The actions 
specified by this AD are intended to prevent high-pressure fuel leaks 
caused by improper seating of fuel tube flanges, which could result in 
an engine fire and damage to the airplane.

DATES: Effective May 1, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 1, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from General Electric Aircraft Engines, c/o Commercial 
Technical Publications, 1 Neumann Way, Room 230, Cincinnati, OH 45215-
1988; telephone 513-552-2005, fax 513-552-2816. 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: Ian Dargin, Aerospace Engineer, 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone 781-238-
7178, fax 781-238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to General Electric Company (GE) CF6-
80C2 series turbofan engines was published in the Federal Register on 
September 8, 1999 (64 FR 48721). That action proposed to require 
replacement of the fuel tube connecting the flowmeter to the Integrated 
Drive Generator (IDG) and the fuel tube(s) connecting the Main Engine 
Control (MEC) or Hydromechanical (HMU) to the flowmeter with improved 
fuel tubes. That action was prompted by reports of fuel leaking in the 
core cowl cavity under high pressure that can be ignited by the hot 
engine case temperatures. That condition, if not corrected, could 
result in high-pressure fuel leaks caused by improper seating of fuel 
tube flanges, which could result in an engine fire and damage to the 
airplane.

Comments Received

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Compliance Time for Fuel Tube Replacement

    Four commenters state that the compliance time should be the next 
shop visit only, not at the next time the fuel tubes are disconnected 
for on-wing maintenance.
    One commenter believes that requiring compliance the next time the 
fuel tubes are disconnected for on-wing maintenance would call for 
stocking parts in many locations and would prevent possible non-
compliance of this AD should an unscheduled on-wing maintenance 
activity occur.
    One commenter believes that line maintenance personnel would 
require a system that tells them which fuel tubes need to be replaced 
and therefore performing the proposed requirements at a shop visit 
would be preferable.
    Two commenters believe that tracking the accomplishment of this AD 
would be a burden and proposes that replacement of the fuel tubes after 
a fixed number of hours or at the next shop visit would be preferable.

FAA Response

    The FAA does not concur. While parts availability and tracking of 
on wing maintenance can be a burden, the risk associated with any 
additional maintenance action only increases the chance of improper 
installation and a high-pressure fuel leak unless these old fuel tubes 
are replaced with the new design fuel tubes at the first opportunity. 
The new design fuel tubes will prevent hang-up of the flange on the 
fuel tube, allowing proper seating and preventing fuel leaks. Although 
there may be situations where a fuel tube is unavailable, the 
commenters provide no additional data or information that would support 
their changes that still show an acceptable mitigation of risk of a 
fuel tube leak and fire.
    One commenter provided useful information as to which fuel tubes 
the line maintenance personnel should replace for on wing maintenance. 
The FAA requires only those fuel tubes that are disconnected to be 
replaced during on-wing maintenance and has added a clarifying 
statement to this final rule.
    Similarly, one commenter provided a definition of ``disconnected'' 
and the FAA has added a clarifying statement to this final rule to 
indicate that disconnecting at ``either end'' triggers this AD for on 
wing maintenance.

[[Page 10699]]

Recommendation for On-Wing Maintenance or Attaching a Label to the 
Fuel Tubes

    One commenter suggests recommending fuel tube replacement rather 
than mandating it. The commenter also suggests attaching a label to the 
fuel tube. The commenter is concerned that in the event of unplanned 
maintenance trouble shooting, the AD may not be complied with. The FAA 
does not concur. Although the idea of a label might be useful, the FAA 
does not believe that the use of labels should be mandated. AD 
compliance should be managed under the individual operator's 
maintenance system. Furthermore, the FAA believes that it is necessary 
to have the fuel tube replacement accomplished at the earlier of on-
wing maintenance or a shop visit, and that making the on-wing 
maintenance only a recommendation would not achieve the desired level 
of safety. The FAA has determined that continued use of the old fuel 
tubes constitutes an unacceptable risk and that this AD is necessary to 
achieve a substantial mitigation of that risk through the mandated 
replacement of the old fuel tubes with fuel tubes of an improved 
design. As previously stated, any additional maintenance action only 
increases the chance of improper installation and a high-pressure fuel 
leak unless these old fuel tubes are replaced with the new design fuel 
tubes at the first opportunity.

Hard Time or Calendar Date Removal

    One commenter states that the proposal should mandate fuel tube 
replacement at a hard time or calendar date, and that the fuel tube 
replacement would best be accomplished at a shop visit. The commenter 
states that line maintenance actions would be more difficult to record 
than during a shop visit. The commenter also suggests that a trial 
period would be necessary to review the procedure. The FAA does not 
concur. While replacement on a fixed date would accomplish the required 
objective, replacement of fuel tubes, it would also result in requiring 
operators to disconnect tubes that have been on-wing and have not had 
an indication of a leak. Initiating action on a system that is 
functioning properly may result in potentially more risk and is 
therefore not desirable. The FAA believes that any training that may be 
necessary should be controlled by the operator under its individual 
maintenance system.

Concurrence

    One commenter concurs with the rule as proposed.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously.

Economic Analysis

    There are approximately 2,693 engines of the affected design in the 
worldwide fleet. The FAA estimates that 581 engines installed on 
airplanes of U.S. registry will be affected by this proposed AD, that 
it will take approximately 0.5 work hours per engine to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
Of the 581 engines, some have already complied with the GE Alert 
Service Bulletins (ASBs). There is no cost impact to the domestic fleet 
for parts complying with ASB 73-A224 since all domestic engines are now 
in compliance. To comply with ASB 73-A0231, required parts would cost 
$2,858 per engine for the remaining 128 domestic FADEC engines, and 
$1,229 per engine for the remaining 138 domestic Power Management 
Control (PMC) engines. Based on these figures, the total cost impact of 
the AD on US operators is estimated to be $535,426.

Regulatory Impact

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order (EO) No. 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under EO No. 12866; (2) is not 
a ``significant rule'' under 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 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:

2000-04-14  General Electric Company: Amendment 39-11597. Docket 99-
NE-24-AD.

    Applicability: General Electric Company (GE) CF6-80C2 A1/ A2/ 
A3/ A5/ A8/ A5F/ B1/ B2/ B4/ B6/ B1F/ B2F/ B4F/ B6F/ B7F/ D1F 
turbofan engines, installed on but not limited to Airbus Industrie 
A300-600/ 600R series and A310-200Adv/ 300 series, and Boeing 747-
200/ 300/ 400 series and 767-200ER/ 300/ 300ER/ 400ER and McDonnell 
Douglas MD-11 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 improper fuel tube flange seating, resulting in high 
pressure fuel leaks, which could result in an engine fire and damage 
to the airplane, accomplish the following:

Replacement

    (a) At the next time the fuel tubes are disconnected at either 
end for on-wing maintenance, or the next shop visit after the 
effective date of this AD, whichever occurs first, replace the old 
configuration fuel tubes with the improved tubes. For on-wing 
maintenance, replace only the fuel tube(s) that have been 
disconnected. Perform the actions as follows:

[[Page 10700]]

    (1) Replace the fuel flowmeter to Integrated Drive Generator 
(IDG) cooler fuel tube, part number (P/N) 1321M42G01, with a 
serviceable part in accordance with paragraph 2 of GE Alert Service 
Bulletin (ASB) No. 73-A224, Revision 2, July 9, 1997, and perform a 
leak check after accomplishing the replacement.

Power Management Controls

    (2) For engines with Power Management Controls, replace the Main 
Engine Control (MEC) to fuel flowmeter fuel tube, P/N 1334M88G01, 
and bolts, P/N MS9557-12, with serviceable parts, in accordance with 
paragraph 3A of GE ASB 73-A0231, Revision 1, dated May 3, 1999 and 
perform a leak check after accomplishing the replacement.

Full Authority Digital Electronic Controls

    (3) For engines with Full Authority Digital Electronic Controls 
replace the Hydromechanical Unit (HMU) to fuel flowmeter fuel tubes, 
P/Ns 1383M12G01 and 1374M30G01 with serviceable parts, in accordance 
with paragraph 3B of GE ASB 73-A0231, Revision 1, dated May 3, 1999 
and perform a leak check after accomplishing the replacement.

    Note 2: Information on performing the leak check can be found in 
the Aircraft Maintenance Manual, 71-00-00.

Definitions

    (b) For the purpose of this AD, a shop visit is defined as any 
time an engine is removed from service and returned to the shop for 
any maintenance.
    (c) For the purpose of this AD, a serviceable part is defined as 
any part other than tube, P/N 1321M42G01, for the fuel flowmeter to 
IDG cooler; tube; P/N 1334M88G01, and bolt, P/N MS9557-12, for the 
MEC to fuel flowmeter tube; and tubes, P/Ns 1383M12G01 and 
1374M30G01, for the HMU to fuel flowmeter fuel tubes.

Alternative 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 
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.

Incorporation by Reference

    (f) The actions required by this AD shall be done in accordance 
with the following GE ASBs: 73-A224, Revision 2, July 9, 1997, and 
73-A0231, Revision 1, May 3, 1999. 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 
General Electric Aircraft Engines, c/o Commercial Technical 
Publications, 1 Neumann Way, Room 230, Cincinnati, OH 45215-1988; 
telephone 513-552-2005, fax 513-552-2816. 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.
    (g) This amendment becomes effective on May 1, 2000.

    Issued in Burlington, Massachusetts, on February 17, 2000.
Ronald A. Vavruska,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-4433 Filed 2-28-00; 8:45 am]
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