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

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-ANE-02; Amendment 39-9034; AD 94-20-06]

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 a repetitive oil quantity check after engine

start-up but prior to taxi, and installation of a flame arrestor plug

support (FAPS) in the aft end of the center vent tube as a terminating

action to the repetitive oil quantity checks. This amendment is

prompted by three reports of uncontained engine failure due to

separation of the fan mid shaft. The actions specified by this AD are

intended to prevent an uncontained engine failure and inflight engine

shutdown due to fuel contamination of the oil system.

DATES: Effective December 27, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 27, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from General Electric Aircraft Engines, CF6 Distribution

Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 45246. This

information may be examined at the Federal Aviation Administration

(FAA), New England Region, Office of the Assistant Chief 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: Glorianne Messemer, Aerospace

Engineer, Engine Certification Office, FAA, Engine and Propeller

Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;

telephone (617) 238-7132, fax (617) 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

May 2, 1994 (59 FR 22565). That action proposed to require a repetitive

oil quantity check after engine start-up but prior to taxi, and

installation of a flame arrestor plug support (FAPS) in the aft end of

the center vent tube (CVT) as a terminating action to the repetitive

oil quantity checks. The installation would be accomplished in

accordance with GE CF6-80C2 Service Bulletin (SB) No. 72-648, Revision

1, dated January 11, 1993, and GE CF6-80C2 SB No. 72-095, Revision 2,

dated January 11, 1993.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter supports the rule as proposed.

One commenter (the engine manufacturer) states that in the Summary

and Discussion sections the word ``and'' should be replaced with

``but'' to read ``* * * require a repetitive oil quantity check after

engine start up but prior to taxi.'' The commenter adds that the word

``and'' may cause some confusion and lead an operator to believe there

may be two checks. The FAA concurs and has revised this final rule

accordingly.

The commenter further states that in the Discussion section and

paragraphs (a) and (b) of the compliance section the phrase ``* * * if

the oil quantity indicates 5 gallons (20 quarts) or more'' should be

changed to ``* * * if the oil quantity indicates 5.5 gallons or more on

Boeing 747-200/300 aircraft or 22 units or more on all other

applications.'' The commenter notes that this change would avoid

unnecessary maintenance action. Operator feedback shows that there were

too many aircraft making unnecessary trips back to the gate. The

additional margin of 0.5 gallons and 2 units was established because

there was no contamination when the previous limit of 5 gallons (20

quarts) was exceeded. Both quarts and liters are used by different

operators, and in this situation the difference between quarts and

liters is negligible. The FAA concurs and has revised this final rule

accordingly.

The commenter further states that in paragraph (d) of the

compliance section the clause ``* * * replace the fan mid shaft

assembly, the mid fan duct assembly'' should be changed to ``* * *

replace the small diameter mid fan duct assembly (CVT).'' The commenter

notes that GE CF6-80C2 SB No. 72-095, Revision 2, dated January 11,

1993, introduces into production a new fan mid shaft assembly, mid fan

duct assembly (CVT), No. 6 bearing plug, preformed packing, and new

retaining ring. That SB also provides accomplishment instructions to

remove the small diameter CVT and replace it with a larger diameter CVT

that will accommodate the flame arrestor. The SB does not require

replacement of the fan mid shaft. The FAA concurs and has revised this

final rule accordingly.

The commenter further states that 14 center vent tube extension

hardware kits have been provided to the fleet. Installation of the CVT

extension in accordance with GE CF6-80C2 Service Evaluation Bulletin

(SEB) No. 72-628, dated July 15, 1993, should be an acceptable means of

compliance for this AD. The FAA concurs and has revised this final rule

accordingly by adding a new paragraph (f).

One commenter states that the oil quantity to initiate inspection

action should be 22 quarts instead of 20. The commenter notes that

operating experience on Boeing aircraft led to a revision in the Boeing

Operations Bulletin to use the 22 quart figure. The FAA concurs in

part. This final rule has been revised to refer to 22 units rather than

quarts, as described in a previous response.

The economic analysis in the proposed rule included all 1,570

engines in the fleet. The manufacturer has advised the FAA that this

number is overly conservative and that there are only approximately 300

engines installed on aircraft of U.S. registry. Out of the 300 engines,

an estimated 96% have accomplished the requirements of this AD. The

economic analysis of this final rule has been revised accordingly.

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. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

The FAA estimates that 300 engines installed on aircraft of U.S.

registry will be affected by this AD, that it will take approximately 8

work hours per engine to accomplish the required actions, and that the

average labor rate is $55 per work hour. Required parts will cost

approximately $2,316 per engine. Out of the 300 engines, the

manufacturer has advised the FAA that 96% of the fleet have

accomplished the requirements of this AD. Based on these figures, the

total cost impact of the AD on U.S. operators is estimated to be

$33,072.

The regulations adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

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 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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-20-06 General Electric Company: Amendment 39-9034. Docket 94-ANE-

02.

Applicability: General Electric Company (GE) CF6-80C2 series

turbofan engines installed on, but not limited to, Airbus A300 and

A310 series, Boeing 747 and 767 series, and McDonnell Douglas MD-11

series aircraft.

Compliance: Required as indicated, unless accomplished

previously.

To prevent an uncontained engine failure and inflight engine

shutdown due to fuel contamination of the oil system, accomplish the

following:

(a) Before each flight, perform an oil quantity inspection for

fuel contamination at least 30 seconds after the engine reaches

stabilized idle but prior to taxi. If the oil quantity indicates 5.5

gallons or more on Boeing 747-200/300 aircraft or 22 units or more

on all other applications, maintenance investigation is required

prior to takeoff.

(b) If the oil quantity indicates 5.5 gallons or more on Boeing

747-200/300 aircraft or 22 units or more on all other applications,

flush and troubleshoot the oil system for fuel contamination prior

to further flight.

(c) For engines with No. 6 bearing plug, Part Number (P/N)

1375M78G01, replace the No. 6 bearing plug with center vent tube

(CVT) flame arrestor plug support (FAPS) in accordance with GE CF6-

80C2 Service Bulletin (SB) No. 72-648, Revision 1, dated January 11,

1993, prior to January 23, 1995.

(d) For engines with No. 6 bearing plug, P/N 9362M36G01, replace

the small diameter mid fan duct assembly CVT and the retaining ring,

in accordance with GE CF6-80C2 SB No. 72-095, Revision 2, dated

January 11, 1993, and replace the No. 6 bearing plug with CVT FAPS

in accordance with GE CF6-80C2 SB No. 72-648, Revision 1, dated

January 11, 1993, prior to January 23, 1995.

(e) Installation of the CVT FAPS in accordance with paragraphs

(c) or (d) of this AD, constitutes terminating action for paragraphs

(a) and (b) of this AD.

(f) Installation of the center vent tube extension in accordance

with GE CF6-80C2 Service Evaluation Bulletin (SEB) No. 72-628, dated

July 15, 1993, constitutes an acceptable means of compliance with

this AD.

(g) The oil quantity inspection required by paragraph (a) of

this AD may be performed by the pilot. The checks must be recorded

in accordance with Federal Aviation Regulation (FAR) Section 43.9,

and records maintained by the owner/operator as required by FAR

Section 121.380(a)(2)(v), or 91.417(a)(2)(v), as applicable.

(h) 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. The

request should be forwarded through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Engine Certification Office.

Note: Information concerning the existence of approved

alternative methods of compliance with this airworthiness directive,

if any, may be obtained from the Engine Certification Office.

(i) 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.

(j) The replacement of the CVT FAPS shall be done in accordance

with the following service bulletins:

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Document No. Pages Revision Date

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GE CF6-80C2, SB No. 72- 1-15 2 January 11, 1993.

095.

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Total pages......... 15

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GE CF6-80C2, SB No. 72- 1-16 1 January 11, 1993.

648.

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Total pages......... 16

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GE CF6-80C2, SEB No. 72- 1-13 Original July 15, 1993.

628.

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Total pages......... 13

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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, CF6 Distribution Clerk, Room 132, 111 Merchant Street,

Cincinnati, OH 45246. Copies may be inspected at the FAA, New

England Region, Office of the Assistant Chief 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.

(k) This amendment becomes effective on December 27, 1994.

Issued in Burlington, Massachusetts, on September 23, 1994.

Mark C. Fulmer,

Acting Manager, Engine and Propeller Directorate, Aircraft

Certification Service.

[FR Doc. 94-25192 Filed 10-24-94; 8:45 am]

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