2010-14819. Airworthiness Directives; CFM International, S.A. CFM56-5, -5B, and -7B Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for CFM International, S.A. CFM56-5, -5B, and -7B series turbofan engines. This AD requires removing from service, nine stage 3 low-pressure turbine (LPT) disks, identified by serial number (S/N). This AD results from the discovery of a material nonconformity requiring removal of the disk before the certified disk life of certain stage 3 LPT disks. We are issuing this AD to prevent uncontained failure of the stage 3 LPT disk and damage to the airplane.

DATES:

This AD becomes effective July 26, 2010.

ADDRESSES:

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

FOR FURTHER INFORMATION CONTACT:

Antonio Cancelliere, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to CFM International, S.A. CFM56-5, -5B, and -7B series turbofan engines. We published the proposed AD in the Federal Register on March 18, 2010 (75 FR 13045). That action proposed to require removing from service, nine stage 3 LPT disks, identified by S/N.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received. Two commenters support the proposal as written.

Remove the Airbus A340 Reference

One commenter, CFM International, S.A., requests that we remove the reference to the Airbus A340 airplane from the applicability paragraph, as the engines used on that airplane are CFM56-5C engines, and use a different disk P/N not affected by this AD.

We agree. We removed the A340 reference from the AD.

Request To Reference the Disk Part Number

CFM International, S.A., requests that we reference the disk part number of 336-002-006-0, along with the affected disk serial numbers, in the applicability paragraph to help identify the parts to be removed.

We agree. We added the disk part number to the applicability paragraph.

Request To Clarify the Applicability Paragraph

CFM International, S.A., requests clarification of the applicability paragraph that none of these affected disk S/Ns were originally installed on any CFM56-5 turbofan engines, however, that disk P/N is certified for use on CFM56-5 engines.

We agree and changed the applicability paragraph.

Request To Reference European Aviation Safety Agency (EASA) Related AD

CFM International, S.A., requests that we reference the EASA related AD in our AD.

We agree and added a reference to EASA AD 2009-0270 in the AD.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

We estimate that this AD will affect two engines installed on airplanes of U.S. registry. The pro-rated cost of the replacement parts is $40,375 per engine. We estimate that no additional labor costs will be incurred to perform the required disk removals, because the removals will be done at time of engine shop visit. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $80,750.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

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 this AD:

(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.

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 at the address listed under ADDRESSES.

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 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 adding the following new airworthiness directive:

2010-13-09 CFM International, S.A.: Amendment 39-16340. Docket No. FAA-2010-0026; Directorate Identifier 2010-NE-03-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective July 26, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to:

(1) CFM International CFM56-5, -5B, and -7B series turbofan engines with stage 3 low-pressure turbine (LPT) disks part number (P/N) 336-002-006-0, installed with the following serial numbers (S/Ns), DE255844, DE256388, DE256622, DE256623, DE256625, DE256627, DE256628, DE256631, and DE256637.

(2) CFM International, S.A. has stated that none of these affected disk S/Ns were originally installed on any CFM56-5 turbofan engine, however, that disk P/N is certified for use on CFM56-5 engines.

(3) The -5 and -5B series engines are installed on, but not limited to, Airbus A318, A319, A320, and A321 airplanes, and the -7B series engines are installed on, but not limited to, Boeing 737 series airplanes.

Unsafe Condition

(d) This AD results from the discovery of a material nonconformity requiring removal of the disk before the certified disk life of certain stage 3 LPT disks. We are issuing this AD to prevent uncontained failure of the stage 3 LPT disk and damage to the airplane.

Compliance

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

Removal of Affected Stage 3 LPT Disks From Service

(f) Before accumulating 9,500 cycles-since-new, remove stage 3 LPT disks from service.

(g) After the effective date of this AD, do not reinstall any stage 3 LPT disk removed from service per paragraph (f) of this AD into any engine.

Alternative Methods of Compliance

(h) 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.

Related Information

(i) Contact Antonio Cancelliere, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

(j) European Aviation Safety Agency AD 2009-0270, dated December 17, 2009, also addresses the subject of this AD.

(k) CFM International, S.A. Service Bulletin (SB) No. CFM56-5B S/B 72-0733, dated October 26, 2009, and SB No. CFM56-7B S/B 72-0743, dated October 26, 2009, pertain to the subject of this AD. Contact CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone [phone]; fax [phone], for a copy of this service information.

Material Incorporated by Reference

(l) None.

Issued in Burlington, Massachusetts, on June 15, 2010.

Peter A. White,

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