01-25080. Airworthiness Directives; General Electric Company CF6-80A, CF6-80C2, and CF6-80E1 Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), applicable to General Electric Company (GE) CF6-80A, CF6-80C2, and CF6-80E1 series turbofan engines, that currently requires revisions to the Life Limits Section of the manufacturer's Instructions for Continued Airworthiness (ICA) to include required inspection of selected critical life-limited parts at each piece-part exposure. This action would add additional mandatory inspections for certain high pressure compressor (HPC), low pressure turbine (LPT), and high pressure turbine (HPT) parts. An FAA study of in-service events involving uncontained failures of critical rotating engine parts has indicated the need for mandatory inspections. The mandatory inspections are needed to identify those critical rotating parts with conditions, which if allowed to continue in service, could result in uncontained failures. The actions specified by this proposed AD are intended to prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Comments must be received by December 4, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-49-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: “[e-mail]”. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Karen Curtis, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone], fax [phone].

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 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 action 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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 98-ANE-49-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

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. 98-ANE-49-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On April 14, 2000, the FAA issued AD 2000-08-12, Amendment 39-11698 (65 FR 21638, April 24, 2000), to require revisions to the Life Limits Section of the manufacturer's Instructions for Continued Airworthiness (ICA) for General Electric Company (GE) CF6-80A, CF6-80C2, and CF6-80E1 series turbofan engines to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure.

Additional Inspection Procedures

Since the issuance of that AD, an FAA study of in-service events involving uncontained failures of critical rotating engine parts has indicated the need for additional mandatory inspections. The mandatory inspections are needed to identify those critical rotating parts with conditions, which if allowed to continue in service, could result in uncontained engine failures. This proposal would modify the airworthiness limitations section of the manufacturer's manual and an air carrier's approved continuous airworthiness maintenance program to incorporate additional inspection requirements.

This proposal will also differentiate between standard HPTR and R88DT HPTR inspections and add a dovetail slot bottom eddy current inspection for the -80C2 HPT Stage 1 disk.

Proposed Actions

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 2000-08-12 to add additional inspections for certain HPC, LPT and HPT components. These inspections would be required at each piece-part opportunity.

Economic Analysis

The FAA estimates that 790 engines installed on airplanes of US registry would be affected by this proposed AD, that it would take approximately 10 work hours per engine to accomplish the proposed additional inspections and that the average labor rate is $60 per work hour. The total cost of the new inspections per engine would be approximately $600. The FAA estimates that there will be approximately 327 shop visits per year that result in piece-part-exposure of the added affected components, therefore, the total annual cost for the additional inspections is estimated to be $196,200.

Regulatory Analysis

This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule.

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 effect, 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:

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.

§ 39.13

[Amended]

2. Section 39.13 is amended by removing Amendment 39-11698 (65 FR 21638, April 24, 2000), and by adding a new airworthiness directive, to read as follows:

General Electric Company: Docket No. 98-ANE-49-AD. Supersedes AD 2000-08-12, Amendment 39-11698.

Applicability: This airworthiness directive (AD) is applicable to General Electric Company (GE) CF6-80A, CF6-80C2, and CF6-80E1 series turbofan engines, installed on but not limited to Airbus Industrie A300, A310, and A330 series, Boeing 747 and 767 series, and McDonnell Douglas MD-11 series airplanes.

Note 1:

This 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: Compliance with this AD is required as indicated, unless already done.

To prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane, accomplish the following:

Inspections

(a) Within the next 30 days after the effective date of this AD, revise the manufacturer's Life Limits Section of the Instructions for Continued Airworthiness (ICA), and for air carrier operations revise the approved continuous airworthiness maintenance program, by adding the following:

“ MANDATORY INSPECTIONS

(1) Perform inspections of the following parts at each piece-part opportunity in accordance with the instructions provided in the applicable manual provisions:

Part nomenclature	Part No. (P/N)	Inspect per engine manual chapter
For CF6-80A Engines:
Disk, Fan Rotor Stage 1	All	72-21-03 Paragraph 3. Fluorescent-Penetrant Inspect, and 72-21-03 Paragraph 4. Eddy Current Inspect.
Fan Forward Shaft	All	72-21-05 Paragraph 2. Magnetic Particle Inspect.
Fan Mid Shaft	All	72-24-01 Paragraph 2. Magnetic Particle Inspect.
Disk, HPC Rotor, Stage One	All	72-31-04 Paragraph 3. Fluorescent-Penetrant Inspect.
Disk, HPC Rotor, Stage Two	All	72-31-05 Paragraph 3. Fluorescent-Penetrant Inspect.
Spool, HPC Rotor, Stage3-9	All	72-31-06 Paragraph 3. Fluorescent-Penetrant Inspect.
Disk, HPC Rotor, Stage 10	All	72-31-07 Paragraph 3. Fluorescent-Penetrant Inspect.
Spool, HPC Rotor, Stage 11-14	All	72-31-08 Paragraph 3.A. Fluorescent-Penetrant Inspect.
Rotating CDP Seal	All	72-31-10 Paragraph 3. Fluorescent-Penetrant Inspect.
Disk Shaft, HPT Rotor Stage One	All	72-53-02 Paragraph 3. Fluorescent-Penetrant-Inspect per 70-32-02, and 72-53-02 Paragraph 6.C. Eddy Current Inspection, and 72-53-02 Paragraph 6.D. Disk Bore Area Eddy Current Inspection.
Disk, HPT Rotor Stage Two	All	72-53-06 Paragraph 3. Fluorescent-Penetrant Inspection, and 72-53-06 Paragraph 6. Eddy Current Inspection of Rim Boltholes for Cracks, and 72-53-06 Paragraph 7. Disk Bore Area Eddy Current Inspection.
Disk, LPT Rotor Stage 1-4	All	72-57-02 Paragraph 3. Fluorescent-Penetrant Inspection.
Shaft, LPT Rotor	All	72-57-03 Paragraph 3. Fluorescent-Penetrant Inspection, and 72-57-03 Paragraph 6. Eddy Current Inspection.
For All CF6-80C2 Engines:
Disk, Fan Rotor Stage One	All	Task 72-21-03-200-000-004 Fluorescent-Penetrant Inspection, and Task 72-21-03-200-000-008 Eddy Current Inspect Fan Rotor Disk Stage 1 Bore, Forward and Aft Hub Faces, and Bore Radii.
Shaft, Fan Forward	All	Task 72-21-05-200-000-001 Fluorescent Penetrant Inspection, and Task 72-21-05-200-000-005 Vent Hole Eddy Current Inspection.
HPCR Stage 1 Disk	All	Task 72-31-04-200-000-002 Fluorescent Penetrant Inspection.
HPCR Stage 2 Disk	All	Task 72-31-05-200-000-002 Fluorescent Penetrant Inspection.
HPCR Stage 3-9 Spool	All	Task 72-31-06-200-000-001 Fluorescent Penetrant Inspection.
HPCR Stage 10 Disk	All	Task 72-31-07-200-000-001 Fluorescent Penetrant Inspection.
HPCR Stage 11-14 Spool/Shaft	All	Task 72-31-08-200-000-002 Fluorescent Penetrant Inspection.
No. 4 Bearing Rotating (CDP) Air Seal	All	Task 72-31-10-200-000-001 Fluorescent Penetrant Inspection or Task 72-31-10-200-000-A01 Fluorescent Penetrant Inspection.
HPCR Stage 10-14 Spool/Shaft	All	Task 72-31-22-200-000-002 Fluorescent Penetrant Inspection.
Fan Mid Shaft	All	Task 72-24-01-200-000-003 Magnetic Particle Inspection.
Disk Shaft, HPT Rotor Stage One	All	Task 72-53-02-200-000-001 Fluorescent-Penetrant Inspect, and Task 72-53-02-200-000-005 Disk Rim Bolt Hole Eddy Current Inspection, and Task 72-53-02-200-000-006 Disk Bore Area Eddy Current Inspection, and Task 72-53-02-200-000-007 Disk Dovetail Slot Bottom Eddy Current.
Disk, HPT Rotor Stage Two	All	Task 72-53-06-200-000-002 Fluorescent-Penetrant Inspect, and Task 72-53-06-200-000-006 Disk Rim Bolt Hole Eddy Current Inspection Rim Boltholes, and Task 72-53-06-200-000-007 Disk Bore Area Eddy Current Inspection.
LPTR Stage 1-5 Disks	All	Task 72-57-02-200-000-001 Fluorescent-Penetrant Inspection.
LPTR Shaft	All	Task 72-57-03-200-000-002 Fluorescent-Penetrant Inspect, and Task 72-57-03-200-000-006 Eddy Current Inspection.
For CF6-80C2 Engines configured with the R88DT Turbine (Models CF6-80C2B2F, 80C2B4F, 80C2B6F, 80C2B7F, 80C2B8F):
Disk Shaft, HPT Rotor Stage One (R88DT, No Rim Bolt Holes	All	Task 72-53-16-200-000-001 Fluorescent-Penetrant Inspect, and Task 72-53-16-200-000-XXX Disk Bore Area Eddy Current Inspection.
Disk, HPT Rotor Stage Two (R88DT, No Rim Bolt Holes)	All	Task 72-53-18-200-000-002 Fluorescent-Penetrant Inspect, and Task 72-53-18-200-000-XXX Disk Bore Area Eddy Current Inspection.
Rotating Interstage Seal (R88DT)	All	Task 72-53-17-200-000-001 Fluorescent-Penetrant Inspect, and Task 72-53-17-200-000-XXX Seal Bore Area Eddy Current.
Forward Outer Seal (R88DT)	All	Task 72-53-21-200-000-001 Fluorescent-Penetrant Inspect, and Task 72-53-21-200-000-XXX Seal Bore Area Eddy Current.
For CF6-80E1 Engines:
Disk, Fan Rotor Stage One	All	Sub Task 72-21-03-230-051 Fluorescent-Penetrant Inspection, and Sub Task 72-21-03-250-051 or 72-21-03-250-052 Disk Bore Eddy Current Inspection.
Shaft, Fan Forward	All	Sub Task 72-21-05-230-051 Fluorescent Penetrant Inspection, and Sub Task 72-21-05-250-051 Vent Hole Eddy Current Inspection.
Compressor Rotor, Stage 1 Disk	All	Sub Task 72-31-04-230-051 Fluorescent Penetrant Inspection.
Compressor Rotor, Stage 2 Disk	All	Sub Task 72-31-05-230-051 Fluorescent Penetrant Inspection.
Compressor Rotor, Stage 3-9 Spool	All	Sub Task 72-31-06-230-051 Fluorescent Penetrant Inspection.
Compressor Rotor, Stage 10 Disk (Pre SB 72-0150)	All	Sub Task 72-31-07-230-051 Fluorescent Penetrant Inspection.
Compressor Rotor Spool/Shaft, Stage 11-14 (Pre SB 72-0150)	All	Sub Task 72-31-08-230-051 Fluorescent Penetrant Inspection.
Compressor Rotor Spool/Shaft, Stage 10-14 (SB 72-0150)	All	Sub Task 72-31-23-230-052 Fluorescent Penetrant Inspection.
Compressor Rotor No. 4 Bearing Rotating Air Seal (CDP Rotating Seal)	All	Sub Task 72-31-10-230-051 Fluorescent Penetrant Inspection.
HPT Disk/Shaft, Stage 1	All	Sub Task 72-53-02-230-051 Fluorescent-Penetrant Inspection, and Sub Task 72-53-02-250-051 Eddy Current Inspection, Rim Bolt Holes, and Sub Task 72-53-02-250-054 Eddy Current Inspection, Disk Bore Area.
HPT Disk, Stage 2	All	Sub Task 72-53-06-230-051 Fluorescent-Penetrant Inspection, and Sub Task 72-53-06-250-051 Eddy Current Inspection, RimBolt Holes, and Sub Task 72-53-06-250-054 Eddy Current Inspection, Disk Bore Area.
LPT Rotor Shaft	All	Sub Task 72-55-01-240-051 Magnetic Particle Inspect.
LPT Disks, Stages 1-5	All	Sub Task 72-57-02-230-051 Fluorescent-Penetrant Inspect.
LPT Rotor Torque Cone	All	Sub Task 72-57-03-220-051 Fluorescent-Penetrant Inspect.
For CF6-80E1 Engines configured with the R88DT Turbine:
Disk Shaft, HPT Rotor Stage 1 (R88DT, No Rim Bolt Holes)	All	Sub Task 72-53-16-230-052 Fluorescent-Penetrant Inspect, and Sub Task 72-53-16-250-XXX Disk Bore Area Eddy Current Inspection.
Disk, HPT Rotor Stage 2 (R88DT, No Rim Bolt Holes)	All	Sub Task 72-53-18-230-051 Fluorescent-Penetrant Inspect, and Sub Task 72-53-18-250-XXX Disk Bore Area Eddy Current Inspection.
HPT Rotor Rotating Interstage Seal (R88DT)	All	Sub Task 72-53-17-230-051 Fluorescent-Penetrant Inspect, and Sub Task 72-53-17-250-XXX Seal Bore Area Eddy Current.
HPT Rotor Forward Outer Seal (R88DT)	All	Sub Task 72-53-21-230-051 Fluorescent-Penetrant Inspect, and Sub Task 72-53-21-250-XXX Seal Bore Area Eddy Current.

(2) For the purposes of these mandatory inspections, piece-part opportunity means:

(i) The part is considered completely disassembled when accomplished in accordance with the disassembly instructions in the manufacturer's engine manual; and

(ii) The part has accumulated more than 100 cycles-in-service since the last piece-part opportunity inspection, provided that the part was not damaged or related to the cause for its removal from the engine.”

(b) Except as provided in paragraph (c) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections shall be performed only in accordance with the Life Limits Section of the manufacturer's ICA.

Alternative Methods of Compliance

(c) 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 Engine Certification Office (ECO). Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector (PMI), who may add comments and then send it to the ECO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

Continuous Airworthiness Maintenance Program

(d) FAA-certificated air carriers that have an approved continuous airworthiness maintenance program in accordance with the record keeping requirement of § 121.369 (c) of the Federal Aviation Regulations [14 CFR 121.369 (c)] of this chapter must maintain records of the mandatory inspections that result from revising the Life Limits Section of the Instructions for Continuous Airworthiness (ICA) and the air carrier's continuous airworthiness program. Alternately, certificated air carriers may establish an approved system of record retention that provides a method for preservation and retrieval of the maintenance records that include the inspections resulting from this AD, and include the policy and procedures for implementing this alternate method in the air carrier's maintenance manual required by § 121.369 (c) of the Federal Aviation Regulations [14 CFR 121.369 (c)]; however, the alternate system must be accepted by the appropriate PMI and require the maintenance records be maintained either indefinitely or until the work is repeated. Records of the piece-part inspections are not required under § 121.380 (a) (2) (vi) of the Federal Aviation Regulations [14 CFR 121.380 (a) (2) (vi)]. All other Operators must maintain the records of mandatory inspections required by the applicable regulations governing their operations.

Note 3:

The requirements of this AD have been met when the engine manual changes are made and air carriers have modified their continuous airworthiness maintenance plans to reflect the requirements in the engine manuals.

Issued in Burlington, Massachusetts, on October 1, 2001.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.