AD 94-20-06

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.

Final rule.

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 andtroubleshoot 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 ServiceEvaluation 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:

Document No.
Pages
Revision
Date
GE CF6-80C2 SB No. 72-095
1-15
2
January 11, 1993
Total Pages: 15.

GE CF6-80C2 SB No. 72-648
1-16
1
January 11, 1993
Total Pages: 16.

GE CF6-80C2 SEB No. 72-628
1-13
Original
July 15, 1993
Total Pages: 13.

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.

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 fanmid 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 thecriteria 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. 39.13 - [AMENDED]
2. Section 39.13 is amended by adding the following new airworthiness directive: