[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: ``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