AD 95-17-16

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AD Number:
95-17-16
Document Type:
AD Final Rules
Docket Number:
94-ANE-41
Subject Heading:
Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines
Subject:
Compressor Rear Frame
Status:
Current
Citation:
Federal Register: September 08, 1995 (Volume 60, Number 174)
Citation Publish Date:
09/08/1995
Effective Date:
11/07/1995
Make:
General Electric Company
Model:
CF6-80A | CF6-80A1 | CF6-80A2 | CF6-80A3
Product Type:
Engine
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 [60 FR 46760 NO. 174 9/8/95]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 95-17-16
CITATION:   [Federal Register: September 08, 1995 (Volume 60, Number 174)]

PAGE NUMBER:   [Page 46760]

DOCKET NUMBER:   94-ANE-41

AMENDMENT:   39-9347

AD NUMBER:   95-17-16

SUBJECT HEADING:   Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines

ACTION:   Final rule.

SUMMARY:   This amendment adopts a new airworthiness directive (AD), applicable to General Electric Company (GE) CF6-80A series turbofan engines, that requires an initial and repetitive on-wing eddy current inspection or an on-wing spot fluorescent penetrant inspection of the compressor rear frame (CRF) midflange for cracks, and replacement, if necessary, with serviceable parts. This amendment also requires removal from service of certain CRF's as a terminating action to the on-wing inspection program. This amendment is prompted by a report of a CRF separation that resulted in a rejected takeoff. The actions specified by this AD are intended to prevent a CRF separation, which could result in a rejected takeoff and damage to the aircraft.

DATES:   Effective November 7, 1995. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of November 7, 1995.

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:   Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-7136; 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) CF6-80A series turbofan engines was published in the Federal Register on February 22, 1995 (60 FR 9792). That action proposed to require an initial and repetitive on-wing eddy current inspection or on-wing spot fluorescent penetrant inspection of the compressor rear frame (CRF) midflange for cracks, and replacement, if necessary, with serviceable parts. This action also proposed to require removal from service of non-modified CRF's as a terminating action to the on- wing inspection program. The actions would be required to be accomplished in accordance with GE CF6-80A Service Bulletin (SB) No. 72-593, Revision 2, dated March 19, 1992.

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

Three commenters request that the FAA move the compliance end date ahead one year to December 31, 1997. One commenter based that request on that commenter's planned acquisition of some affected engines that have not undergone the required modifications. The FAA does not concur. The commenters all recognize and accept the FAA's determination that AD action is necessary. The stated reasons for the requested extension in complying with the AD is the added cost of non-scheduled engine removals to perform the required modifications, and since the on-wing inspections have been successful in detecting cracks to date. The FAA has already considered the fleet-wide costs to operators in complying with this AD. In the normal course of that analysis, the FAA has determined that December 31, 1996, fairly and reasonably balances the safety need to eliminate this unsafe condition from the fleet as quickly as possible with operators' needs to avoid unscheduled maintenance actions. Individual operators who believe their circumstances warrant relief from this compliance schedule may submit requests for alternative methods of compliance or adjustments to the compliance times.

One commenter requests that the FAA broaden its economic analysis to include items beyond direct labor and parts costs to accomplish the required actions of the AD, such as maintenance scheduling costs. The FAA does not concur. In making a finding that an unsafe condition exists, the FAA has determined that the level of safety attained by the approved type design is no longer achieved, and the required actions are necessary to restore that level of safety. Because the type design must maintain that level of safety, necessary actions to restore that level of safety do not add additional regulatory requirements, and do not require a full cost-benefit analysis. The cost analysis is therefore limited to the direct costs of performing the required actions to restore the type design to that level of safety. When establishing compliance times, however, the FAA does try to strike a balance between the need to restore the type design to its certified level of safety with operators' need to avoid unscheduled maintenance actions.

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 as proposed.

The FAA estimates that 81 engines installed on aircraft of U.S. registry will be affected by this AD, that it will take approximately 85 work hours per engine to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $20,644 per engine. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $2,085,264.

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 USC 106(g), 40101, 40113, 44701. §39.13 - [AMENDED]

2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:   95-17-16 General Electric Company: Amendment 39-9347. Docket 94-ANE-41.

Applicability: General Electric Company (GE) CF6-80A series turbofan engines installed on, but not limited to, Airbus A310 series and Boeing 767 series aircraft. NOTE: 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 use the authority provided in paragraph (d) to request approval from the Federal Aviation Administration (FAA). This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any engine from the applicability of this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent a compressor rear frame (CRF) separation, which could result in a rejected takeoff and damage to the aircraft, accomplish the following:

(a) Inspect CRF, Part Numbers (P/N) 9283M77G07, 9283M77G08, 9283M77G09, 9283M77G11, 9283M77G14, 7283M77G15, 9283M77G16, 9283M77G17, 9283M77G18, 9283M77G19, 1338M77G01, 1338M77G02, 1338M77G03, 1338M77G04, 1338M77G05, and 1338M77G06, that have not accomplished the midflange rework or replacement in accordance with any revision level of GE CF6-80A Service Bulletin (SB) No. 72-600 or 72-611, prior to the effective date of this AD, as follows:

(1) Perform an on-wing eddy current inspection (ECI) or an on-wing spot fluorescent penetrant inspection (FPI) of the CRF midflange for cracks in accordance with the Accomplishment Instructions and the schedule outlined in Table 1 of GE CF6-80A SB No. 72-593, Revision 2, dated March 19, 1992, or within 1,000 cycles in service since the last shop level FPI, whichever occurs later, after the effective date of this AD.

(2) Thereafter, reinspect the CRF midflange for cracks in accordance with the Accomplishment Instructions and schedule outlined in Table 2 of GE CF6-80A SB No. 72-593, Revision 2, dated March 19, 1992.

(3) Remove from service prior to further flight CRF's with cracked midflanges that exceed the on-wing serviceable limits specified in Table 2 of GE CF6-80A SB No. 72-593, Revision 2, dated March 19, 1992, and replace with a serviceable part.

(b) Remove from service CRF's identified in paragraph (a) of this AD at the next piece-part exposure, or by December 31, 1996, whichever occurs earlier, and replace with a serviceable part. Removal and replacement of CRF's in accordance with this paragraph constitutes terminating action to the on-wing inspection requirements of paragraph (a) of this AD.

(c) For the purpose of this AD, a serviceable part is defined as a CRF that has accomplished the midflange rework or replacement in accordance with any revision level of GE CF6- 80A SB No. 72-600 or 72-611.

(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. 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.

(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.

(f) The actions required by this AD shall be done in accordance with the following SB:
Document No.	Pages	Revision	Date
			
GE CF6-80A SB No. 72-593	1-4	2	March 19, 1992
	5-8	1	October 30, 1991
	9	2	March 19, 1992
	10-12	1	October 30, 1991
	13-15	2	March 19, 1992
	16-22	1	October 30, 1991
Total Pages: 22			

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.

(g) This amendment becomes effective on November 7, 1995.

FOOTER: