05-16709. Airworthiness Directives; General Electric Company CF34 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines. That AD currently requires a onetime inspection, and if necessary replacing certain fan disks for electrical arc-out indications. That AD also reduces the life limit of certain fan disks. This proposed AD would require the same actions and adds one disk part number (P/N) and serial number (SN) to the affected fan disks. This proposed AD results from an error in the first part number and serial number listed in Table 1 of the original AD. We are proposing this AD to prevent rupture of the fan disk due to cracks that initiate at an electrical arc-out, which could result in an uncontained failure of the engine.

DATES:

We must receive any comments on this proposed AD by October 24, 2005.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-42-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from GE Aircraft Engines, 1000 Western Avenue, Lynn, MA 01910; Attention: CF34 Product Support Engineering, Mail Zone: 34017; telephone [phone]; fax [phone].

You may examine the AD docket at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Eugene Triozzi, 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

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2000-NE-42-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On May 7, 2001, the FAA issued AD 2001-10-13, Amendment 39-12229 (66 FR 27017, May 16, 2001). That AD requires a onetime inspection, and if necessary replacing certain fan disks for electrical arc-out indications. That AD also reduces the life limit of certain fan disks. That AD resulted from a report of a crack that was found during a visual inspection as part of routine engine maintenance. That condition, if not corrected, could result in rupture of the fan disk due to cracks that initiate at an electrical arc-out, which could result in an uncontained failure of the engine.

Actions Since AD 2001-10-13 Was Issued

Since we issued that AD, we discovered that the first fan disk part number and the first fan disk serial number listed in Table 1, Fan Disks that Require Removal Based on Blended Callouts are incorrect. This proposed AD would correct those numbers. In all other respects, the proposed AD remains the same as AD 2001-10-03.

Relevant Service Information

We have reviewed and approved the technical contents of GE Aircraft Engines (GEAE) Alert Service Bulletin (ASB) CF34-BJ 72-A0088, Revision 1, dated October 30, 2000; and ASB CF34-AL 72-A0103, dated August 4, 2000. These ASB's provide procedures for inspections of certain disks for electrical arc-out indications, and if necessary, replacement of the disk with a serviceable disk.

Differences Between the Proposed AD and the Service Information

Although fan disk part number (P/N) 5922T01G02 is not specified by ASB CF34-BJ 72-A0088, Revision 1, dated October 30, 2000, fan disk P/N 5922T01G02 is subject to the requirements specified in this AD.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require requires an inspection of fan disks, P/N's 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06, for electrical arc-out indications and, if necessary, replacement of the fan disk with a serviceable disk. This AD would also require replacing certain fan disks with blended callouts and listed byP/N and serial number (SN) in this AD before achieving a new reduced life limit. The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that one General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engine of U.S. registry would be affected by this proposed AD. We also estimate that it would take approximately six work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost approximately $140,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $140,390.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2000-NE-42-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends § 39.13 by removing Amendment 39-12229 FR 27017, May 16, 2001, and by adding a new airworthiness directive to read as follows:

General Electric Company: Docket No. 2000-NE-42-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by October 24, 2005.

Affected ADs

(b) This AD supersedes AD 2001-10-03, Amendment 39-12229.

Applicability

(c) This AD applies to General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan engines. These engines are installed on, but not limited to, Bombardier, Inc. Canadair airplane models CL-600-2A12, -2B16, and -2B19.

Unsafe Condition

(d) This AD results from a report of a crack that was found during a visual inspection as part of routine engine maintenance. We are issuing this AD to prevent rupture of the fan disk due to cracks that initiate at an electrical arc-out, which could result in an uncontained failure of the engine,

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Removal of Certain Fan Disks From Service

(f) On disk P/N's 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06, that are listed by P/N and serial number (SN) in the following Table 1 of this AD and that have less than 8,000 cycles-since-new (CSN) on the effective date of this AD, replace fan disk P/N's before accumulating 8,000 CSN:

Table 1.—Fan Disks That Require Removal Based on Blended Callouts

Disk part No.	Disk serial No.
6078T57G02	GAT6306N
6078T00G01	GAT3860G
6078T57G02	GAT1924L
5922T01G04	GAT9599G
6078T57G04	GEE05831
6078T57G04	GEE06612
6078T57G04	GEE06618
6078T57G04	GEE06974
6078T57G04	GEE06980
6078T57G05	GEE143FY
6078T57G05	GEE1453G
6078T57G05	GEE14452
6078T57G05	GEE145NA
6078T57G04	GEE08086
6078T57G04	GEE09287
6078T57G04	GEE09337
6078T57G05	GEE12720
6078T57G05	GEE14214
6078T57G05	GEE142YT
6078T57G05	GEE146GT

(g) For disks with SN's listed in Table 1 of this AD that have 8,000 CSN or greater on the effective date of this AD, replace the disk within 30 days after the effective date of this AD.

Inspection of All Other Fan Disks

(h) Inspect all other fan disks, P/N's 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 6078T57G05, and 6078T57G06 in accordance with paragraphs 3.A.(1) through 3.E.(2) of the Accomplishment Instructions of Alert Service Bulletin (ASB) CF34-BJ 72-A0088, Revision 1, dated October 30, 2000 or paragraphs 3.A.(1) through 3.A.(2)(f) of the Accomplishment Instructions of ASB CF34-AL 72-A0103, dated August 4, 2000. Use the compliance times specified in the following Table 2:

Table 2.—Fan Disk Inspection Compliance Times

Fan disk operating CSN	Inspect by
(1) Fewer than 8,000 CSN or the effective date of this AD	Before accumulating 8,000 CSN or by the next hot section inspection after the effective date of this AD, whichever occurs earlier.
(2) 8,000 CSN or greater on the effective date of this AD	Within 120 days after the effective date of this AD.

Definitions

(i) For the purposes of this AD, the following definitions apply:

(1) A serviceable fan disk is defined as a fan disk that has been inspected as specified in paragraph (h) of this AD and is not listed in Table 1 of this AD.

(2) Cycles-since-new for fan disk P/N's 5922T01G04 or 5922T01G05 is defined as total cycles accrued since new as P/N 6078T57G02 or 6078T57G03, added to total cycles accrued after modification from P/N 6078T57G02 or 6078T57G03.

Alternative Methods of Compliance

(j) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.Special Flight Permits

Related Information

(k) None.

Issued in Burlington, Massachusetts, on August 17, 2005.

Richard Noll,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.