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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2008-0174; Directorate Identifier 2008-NE-03-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

# ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

# SUMMARY:

This supplemental NPRM revises an earlier proposed airworthiness directive (AD), applicable to CFM International, S.A. CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/P; and -5B9/P turbofan engines. That proposed AD would have required initial and repetitive eddy current inspections (ECIs) of certain part number (P/N) low-pressure (LP) turbine rear frames. That proposed AD resulted from a refined lifing analysis by the engine manufacturer that shows the need to identify initial and repetitive inspection thresholds for inspecting certain LP turbine rear frames. This supplemental NPRM revises the proposed AD to add two LP turbine rear frame P/Ns to the applicability, to add 11 engine models to the applicability, and to clarify the commercial and corporate engines/LP turbine rear frames applicability. This supplemental NPRM results from CFM International, S.A. revising the service information to add LP turbine rear frame P/Ns and engine models, and from comments received on the proposed AD. This supplemental NPRM also results from a refined lifing analysis by the engine manufacturer that shows the need to identify initial and repetitive inspection thresholds for inspecting certain LP turbine rear frames. We are proposing this AD to detect low-cycle-fatigue cracks in the LP turbine rear frame, which could result in an engine separating from the airplane, causing damage to, and possibly leading to loss of control of, the airplane.

# DATES:

We must receive any comments on this proposed AD by June 8, 2009.

# ADDRESSES:

Use one of the following addresses to comment on this proposed AD.
      -  Federal eRulemaking Portal:                          Go to                          http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                    
      -  Mail:                          Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.                    
      -  Hand Delivery:                          Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                    
      -  Fax:                          (202) 493-2251.                    

You can get the service information identified in this proposed AD from CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-2816.

# FOR FURTHER INFORMATION CONTACT:

                        Stephen Sheely, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail:                         *stephen.k.sheely@faa.gov;*                         telephone (781) 238-7750; fax (781) 238-7199.                    

#                     SUPPLEMENTARY INFORMATION:                          ( print page 18663)    

## Comments Invited

                    We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under                     **ADDRESSES**                    . Include “Docket No. FAA-2008-0174; Directorate Identifier 2008-NE-03-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.                

                    We will post all comments we receive, without change, to                     *http://www.regulations.gov*, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the                     **Federal Register**                     published on April 11, 2000 (65 FR 19477-78).                

## 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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is the same as the Mail address provided in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                

## Discussion

                    On April 29, 2008, we issued a proposal to amend part 39 of the Code of Federal Regulations (14 CFR part 39) to add an AD, applicable to CFM International, S.A. CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/P; and -5B9/P turbofan engines. The proposed AD published as an NPRM in the                     **Federal Register**                     on May 7, 2008 (73 FR 25597). That NPRM proposed to require initial and repetitive ECIs of certain P/N LP turbine rear frames.                

Since we issued that NPRM, we became aware of two additional LP turbine rear frame P/Ns affected, and 11 additional engine models affected that were not listed in the proposed AD applicability. CFM International, S.A. subsequently superseded Service Bulletin (SB) No. CFM56-5B S/B 72-0620, Revision 1, dated December 20, 2007, to add those LP turbine rear frame P/Ns and engine models. We added LP turbine rear frame P/Ns 338-171-751-0; and 338-171-752-0, and CFM56-5B1/3; -5B2/3; -5B3/3; -5B4/3; -5B5/3; -5B6/3; -5B7/3; -5B8/3; -5B9/3; -5B3/3B1; and -5B4/3B1 engine models to the applicability of the supplemental NPRM. We also clarified the commercial and corporate engines/LP turbine rear frames applicability. Because we added those CFM56 engine models and added those LP turbine rear frame P/Ns, this supplemental NPRM reopens the comment period to include those added engine models and added P/Ns, and to reference the superseding service bulletin.

As we stated in the original proposed AD, CFM International, S.A. performed a refined lifing analysis that shows the need to identify initial and repetitive inspection thresholds for inspecting LP turbine rear frames. This condition, if not corrected, could result in an engine separating from the airplane, causing damage to, and possibly leading to loss of control of the airplane.

## Comments

We provided the public the opportunity to participate in the development of this proposed AD. We have considered the comments received.

## Consider Expanding the Engine Model Applicability

One commenter, Virgin Airlines, requests that we consider expanding the applicability in the proposed AD by adding the CFM56-5B4/3 and CFM56-5B6/3 turbofan engines.

We agree that those engines are affected. We added them to this supplemental NPRM.

## Disagreement With Proposed AD Applicability

One commenter, CFM International S.A., disagrees with the proposed AD applicability, specifically, the listing of all of the engines as certified for corporate application. They state that only the CFM56-5B6/P and CFM56-5B7/P engine models certified for corporate application need to be covered by the proposed AD, because they were initially certified with a 22,500-cycle life. They now have a first inspection at 19,000 cycles. All of the other -5B/P engine models in the corporate application were certified with the first inspection at 19,000 cycles, and do not need to be covered by the proposed AD.

We agree. We corrected and clarified the applicability in the supplemental NPRM.

## Request To Give Credit

One commenter, Airbus, requests that we give credit for inspections previously done using CFM International, S.A. Service Bulletin No. CFM56-5B S/B 72-0620, dated May 3, 2007.

We agree. We changed the supplemental NPRM to give credit for previous initial and repetitive inspections of turbine rear frames done before the effective date of the proposed AD using the original or Revision 1 of CFM International, S.A. Service Bulletin No. CFM56-5B S/B 72-0620.

## Correction to How Many Engines Affected

Since we issued the original NPRM, we discovered that we incorrectly estimated how many engines are affected. We stated that about 426 engines are affected that are installed on airplanes of U.S. registry. That number actually reflects how many engines are installed on airplanes of U.S. registry, regardless of the LP turbine rear frame P/N. We corrected the estimated number of affected engines to 282, which reflects those engines with the affected LP turbine rear frames listed in this supplemental NPRM.

## FAA's Determination and Requirements of the Proposed AD

We 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 will require initial and repetitive ECIs of certain P/N LP turbine rear frames. This proposed AD results from a refined lifing analysis by the engine manufacturer that shows the need to identify initial and repetitive inspection thresholds for inspecting certain LP turbine rear frames. This proposed AD would require you to use the service information described previously to perform the inspections.

## Costs of Compliance

                    We estimate that this proposed AD would affect 282 CFM56-5B series turbofan engines installed on airplanes of U.S. registry. We estimate that it would take about 3 work-hours to perform an eddy current inspection of an LP turbine rear frame. The average labor rate is $80 per work-hour. A replacement LP turbine rear frame costs                           ( print page 18664)                        about $102,240. If all 282 LP turbine rear frames needed replacement, we estimate the total cost of the proposed AD to U.S. operators to be $28,899,360.                

## 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 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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the                     **ADDRESSES**                     section for a location to examine the regulatory evaluation.                

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Incorporation by reference
      - Safety

## The Proposed Amendment

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

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

**CFM International, S.A.:**                                 Docket No. FAA-2008-0174; Directorate Identifier 2008-NE-03-AD.                            

## Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by June 8, 2009.

## Affected ADs

(b) None.

## Applicability

(c) This AD applies to:

(1) CFM International, S.A. turbofan engines with a low-pressure (LP) turbine rear frame, part number (P/N) 338-171-703-0; 338-171-704-0; 338-171-705-0; or 338-171-706-0 installed, as follows:

(i) Commercial application CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/P; -5B9/P turbofan engines.

(ii) Corporate application CFM56-5B6/P and -5B7/P turbofan engines.

(2) CFM International, S.A. turbofan engines with an LP turbine rear frame, P/N 338-171-751-0; or 338-171-752-0 installed, on corporate and commercial applications of CFM56-5B1/P; -5B2/P; -5B3/P; -5B3/P1; -5B4/P; -5B4/P1; -5B5/P; -5B6/P; -5B7/P; -5B8/P; -5B9/P; -5B1/3; -5B2/3; -5B3/3; -5B4/3; -5B5/3; -5B6/3; -5B7/3; -5B8/3; -5B9/3; -5B3/3B1; and -5B4/3B1 turbofan engines.

(3) These engines are installed on, but not limited to, Airbus A318, A319, A320, and A321 series airplanes.

## Unsafe Condition

(d) This AD results from a refined lifing analysis by the engine manufacturer that shows the need to identify initial and repetitive inspection thresholds for inspecting certain LP turbine rear frames. We are issuing this AD to detect low-cycle-fatigue cracks in the LP turbine rear frame, which could result in an engine separating from the airplane, causing damage to, and possibly leading to loss of control of the airplane.

## 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.

## Initial Inspection

(f) Perform an initial eddy current inspection (ECI) of the LP turbine rear frame using paragraphs 3.A. through 3.A.(7)(d) of the Accomplishment Instructions of CFM International, S.A. Service Bulletin (SB) No. CFM56-5B S/B 72-0620, Revision 2, dated December 1, 2008, at the following compliance times:

(1) For commercial engine applications, within 25,000 cycles-since-new (CSN) on the LP turbine rear frame.

(2) For corporate engine applications, within 19,000 CSN on the LP turbine rear frame.

(3) For engines with unknown LP turbine rear frame CSN, within 300 cycles-in-service from the effective date of this AD.

## Repetitive Inspections

(g) Perform repetitive ECIs of the LP turbine rear frame using paragraphs 3.A. through 3.A.(7)(d) of the Accomplishment Instructions of CFM International, S.A. SB No. CFM56-5B S/B 72-0620, Revision 2, dated December 1, 2008. Use the inspection intervals in paragraph 3.A.(8) of the Accomplishment Instructions of CFM International, S.A. SB No. CFM56-5B S/B 72-0620, Revision 2, dated December 1, 2008.

## LP Turbine Rear Frame Removal Criteria

(h) Remove LP turbine rear frames from service that have a single crack length of 2.56 inches (65 mm) or longer, or multiple cracks with an accumulated crack length of 2.56 inches (65 mm) or longer.

## Previous Credit

(i) Initial and repetitive inspections done before the effective date of this AD using CFM International, S.A. SB No. CFM56-5B S/B 72-0620, dated May 3, 2007, or SB No. CFM56-5B S/B 72-0620, Revision 1, dated December 20, 2007, comply with the initial and repetitive inspection requirements specified in this AD. Operators must continue performing the repetitive inspections required in paragraph (g) of this AD.

## 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.

## Related Information

(k) European Aviation Safety Agency AD 2007-0221, dated August 13, 2007, also addresses the subject of this AD.

                                (l) Contact Stephen Sheely, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail:                                 *stephen.k.sheely@faa.gov;*                                 telephone (781) 238-7750; fax (781) 238-7199, for more information about this AD.                            

Issued in Burlington, Massachusetts, on April 17, 2009.

Peter A. White,

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

[FR Doc. E9-9443 Filed 4-23-09; 8:45 am]

BILLING CODE 4910-13-P