[Federal Register Volume 64, Number 173 (Wednesday, September 8, 1999)]
[Proposed Rules]
[Pages 48721-48723]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23254]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-24-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-80C2 
Series 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) CF6-
80C2 series turbofan engines. This proposal would 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. This proposal 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 the proposed 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.


[[Page 48722]]


DATES: Comments must be received by November 8, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-24-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ane-
adcomment@faa.gov''. 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 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 FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA.

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:

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-24-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-24-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) received reports of 21 
incidents of fuel leaks on General Electric Company (GE) CF6-80C2 
series engines at the fuel tube flanges at either the tube connecting 
the Main Engine Control (MEC) or Hydromechanical Unit (HMU) to the fuel 
flowmeter or the tube connecting the fuel flowmeter to the Integrated 
Drive Generator (IDG) cooler. Five of the incidents resulted in in-
flight engine shutdowns, with the majority directly attributable to 
incorrect flange seating of one of the fuel tube flanges. One of these 
events resulted in an engine fire on a Boeing 747-400 aircraft. This 
engine fire was caused by fuel leaking due to improper fuel tube flange 
seating at the inlet mating flange end of the tube connecting with the 
IDG cooler. The improper fuel tube flange seating condition, if not 
corrected, could result in high-pressure fuel leaks, which could result 
in an engine fire and damage to the airplane.
    The FAA has reviewed and approved the technical contents of GE 
Alert Service Bulletin (ASB) No. 73-A224, Revision 2, July 9, 1997, 
that describes procedures for replacing the fuel flowmeter to IDG 
cooler fuel tube with an improved tube; and ASB No. 73-A0231, Revision 
1, May 3, 1999, that describes procedures for replacing the MEC or HMU 
to fuel flowmeter fuel tubes with improved tubes.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same type design, the proposed 
AD would require replacement of the fuel flowmeter to IDG cooler fuel 
tubes and MEC or HMU to fuel flowmeter fuel tubes with improved tubes. 
The improved design fuel tube prevents hang-up of the flange on the 
tube, thus allowing proper flange seating. The replacement would be 
required at the next time the tubes are disconnected, or the next shop 
visit after the effective date of this AD, whichever occurs first. The 
actions are required to be accomplished in accordance with the ASBs 
described previously.
    There are approximately 2,693 engines of the affected design in the 
worldwide fleet. The FAA estimates that 581 engines installed on 
airplanes of US registry would be affected by this proposed AD, that it 
would take approximately 0.5 work hours per engine to accomplish the 
proposed actions, and that the average labor rate is $60 per work hour. 
Of the 581 engines, some have already complied with the ASBs. Required 
parts for complying with ASB 73-A224 would cost approximately $659 per 
engine for the remaining 35 domestic engines. To comply with ASB 73-
A0231, required parts would cost $2,858 per engine for the remaining 
204 domestic Full Authority Digital Engine Control (FADEC) engines, and 
$1,229 per engine for the remaining 204 domestic Power Management 
Control (PMC) engines. Based on these figures, the total cost impact of 
the proposed AD on U.S. operators is estimated to be $856,813.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (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) 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:

[[Page 48723]]

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-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 (c) 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:
    (a) At the next time the tubes are disconnected 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, as follows:
    (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.
    (2) Replace 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 for engines with Power 
Management Controls, or Hydromechanical Unit (HMU) to fuel flowmeter 
fuel tubes, P/Ns 1383M12G01 and 1374M30G01 with serviceable parts, 
in accordance with paragraph 3B for engines with Full Authority 
Digital Electronic Controls, in accordance with GE ASB No. 73-A0231, 
Revision 1, 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.

    (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.
    (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 request 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.

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

    Issued in Burlington, Massachusetts, on August 30, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-23254 Filed 9-7-99; 8:45 am]
BILLING CODE 4910-13-U