Airworthiness Directives; CFM International (CFMI) CFM56-5C Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment revises an existing airworthiness directive (AD) for CFMI CFM56-5C series turbofan engines. That AD currently establishes new life limits for certain high pressure turbine rotor (HPTR) front shafts, HPTR front air seals, and booster spools. This action removes the booster spool, part number (P/N) 337-005-210-0, and the HPTR front shaft, P/Ns 1498M40P03, 1498M40P05, and 1498M40P06, from the parts listed with lowered life limits in the existing AD. This amendment results from a life management review completed by the manufacturer. We are issuing this AD to prevent low-cycle fatigue (LCF) failure of certain HPTR front air seals, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective October 14, 2004.

We must receive any comments on this AD by November 8, 2004.

ADDRESSES:

Use one of the following addresses to submit comments on this AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 95-ANE-64-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: (781) 238-7055.
• By e-mail: 9-ane-adcomment@faa.gov.

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:

Robert Green, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7754; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

On March 19, 2003, the FAA issued AD 97-09-02R2, Amendment 39-13094 (68 FR 14312, March 25, 2003). That AD reduces the LCF retirement lives of certain HPTR front shafts, HPTR front air seals, HPTR disks, booster spools, and LPTR stage 3 disks.

Actions Since AD 97-09-02R2 Was Issued

After we issued AD 97-09-02R2, the manufacturer conducted an extensive life management program for the HPTR front shaft and booster spool listed in the AD. The results indicated higher LCF retirement lives for those HPTR front shafts and booster spools than the lives published in AD 97-09-02R2. Those LCF retirement lives are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-TP.SM.8. This AD revision removes HPTR front shafts, part numbers (P/Ns) 1498M40P03, 1498M40P05, and 1498M40P06; and booster spools, P/N 337-005-210-0, from the parts listed with lower LCF retirement lives. The LCF retirement lives of the HPTR front air seals P/N 1523M34P02 and 1523M34P03 remain unchanged.

FAA's Determination and Requirements of This AD

Although no airplanes that are registered in the United States use these affected engine models, the possibility exists these engine models could be used on airplanes that are registered in the United States in the future. This AD requires the LCF retirement lives of HPTR front air seals P/N 1523M34P02 and P/N 1523M34P03 to remain as published in AD 97-09-02R2.

FAA's Determination of the Effective Date

Since there are currently no domestic operators of this engine model, notice and opportunity for public comment before issuing this AD are unnecessary, and a situation exists that allows the immediate adoption of this regulation.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 95-ANE-64-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 rule that might suggest a need to modify it. If a person contacts us verbally, and that contact relates to a substantive part of this 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 AD in light of those comments.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You may get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

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.

Regulatory Findings

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

We prepared a summary of the costs to comply with this AD 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. 95-ANE-64-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

Adoption of the Amendment

Accordingly, under 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. 106(g), 40113, 44701.

2. The FAA amends § 39.13 by removing Amendment 39-13094 68 FR 14312, March 25, 2003, and by adding a new airworthiness directive, Amendment 39-13791, to read as follows:

97-09-02R3 CFM International: Amendment 39-13791. Docket No. 95-ANE-64-AD.

Applicability

This airworthiness directive (AD) is applicable to CFM International (CFMI) CFM56-5C2/G, -5C3/G, and -5C4 series turbofan engines. These engines are installed on, but not limited to, Airbus Industrie A340 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 (i) 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 low cycle fatigue (LCF) failure of the high pressure turbine rotor (HPTR) front air seal, which could result in an uncontained failure and damage to the airplane, do the following:

(a) LCF retirement lives for HPTR front shafts, part numbers (P/Ns) 1498M40P03, 1498M40P05, and 1498M40P06, are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-TP.SM.8.

(b) Remove from service HPTR front air seals, P/Ns 1523M34P02 and 1523M34P03, before accumulating 4,000 cycles-since-new, and replace with a serviceable part.

(c) LCF retirement lives for HPTR disks P/N 1498M43P04 are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-TP.SM.8.

(d) LCF retirement lives for booster spools, P/N 337-005-210-0, are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CMFI-TP.SM.8.

(e) For CFM56-5C4 engines, LCF retirement lives for low pressure turbine rotor (LPTR) stage 3 disks, P/Ns 337-001-602-0 and 337-001-605-0 are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CMFI-TP.SM.8.

(f) For CFM56-5C2/G and -5C3/G engines, LCF retirement lives for LPTR stage 3 disks, P/Ns 337-001-602-0 and 337-001-605-0 are now the same as originally calculated and are in agreement with the current airworthiness limitations section of Chapter 05 of the CFM56-5C Engine Shop Manual, CMFI-TP.SM.8.

(g) This action establishes the new LCF retirement lives stated in paragraphs (a) through (f) of this AD, which are published in Chapter 05 of the CFM56-5C Engine Shop Manual, CMFI-TP.SM.8.

(h) For the purpose of this AD, a serviceable part is one that has not exceeded its respective new life limit as set out in this AD.

Alternative Methods of Compliance

(i) 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 (ECO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, 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.

Special Flight Permits

(j) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be done.

Effective Date

(k) This amendment becomes effective on October 14, 2004.