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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2008-0849; Directorate Identifier 2008-NM-080-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Two operators of A300 aircraft fitted with General Electric (GE) CF6-50 engine series have reported cracks on the lower side of Rib 5 in the pylon box. Investigations disclosed that these cracks are due to the stresses resulting from the pressure applied by the thrust reverser cowl bumpers. Cracking of the engine pylons could result in reduced structural integrity of the engine support structure. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. 

# DATES:

We must receive comments on this proposed AD by September 8, 2008. 

# ADDRESSES:

You may send comments by any of the following methods: 
      -  Federal eRulemaking Portal:                          Go to                          http://www.regulations.gov . Follow the instructions for submitting comments.                     
      -  Fax:                          (202) 493-2251.                     
      -  Mail:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.                     
      -  Hand Delivery:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                     

## 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 in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after receipt.                 

# FOR FURTHER INFORMATION CONTACT:

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149. 

# SUPPLEMENTARY INFORMATION:

## Comments Invited 

                    We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the                     **ADDRESSES**                     section. Include “Docket No. FAA-2008-0849; Directorate Identifier 2008-NM-080-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on 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 we receive about this proposed AD.                 

## Discussion 

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2008-0066, dated March 31, 2008 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Two operators of A300 aircraft fitted with General Electric (GE) CF6-50 engine series have reported cracks on the lower side of Rib 5 in the pylon box. 

The concerned area is similar on A310 aircraft fitted with GE CF6-80A or CF6-80C series engines. 

Investigations disclosed that these cracks are due to the stresses resulting from the pressure applied by the thrust reverser cowl bumpers. 

As a result of the A310 Extended Service Goal (ESG) study, an inspection programme of this area is required by this Airworthiness Directive (AD). 

A similar inspection programme is being contemplated for A300 and A300-600 series aircraft. 

Cracking of the engine pylons could result in reduced structural integrity of the engine support structure. Corrective actions include modifying the Rib 5 in the pylon box. You may obtain further information by examining the MCAI in the AD docket. 

## Relevant Service Information 

Airbus has issued Service Bulletins A310-54-2032, Revision 01, dated October 8, 2007, and A310-54-2036, Revision 02, dated September 28, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI. 

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

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. 

## Differences Between This AD and the MCAI or Service Information 

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information. 

We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the proposed AD. 

## Costs of Compliance 

                    Based on the service information, we estimate that this proposed AD would affect about 33 products of U.S. registry. We also estimate that it would take about 8 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $21,120, or $640 per product, per inspection cycle.                           ( print page 45892)    

## 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 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 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. 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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. 

# 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 FAA 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 AD:

**Airbus:**                                 Docket No. FAA-2008-0849; Directorate Identifier 2008-NM-080-AD.                             

## Comments Due Date 

(a) We must receive comments by September 8, 2008. 

## Affected ADs 

(b) None. 

## Applicability 

(c) This AD applies to Airbus Model A310-203, -204 and -304 airplanes, all serial numbers, certificated in any category; excluding airplanes that have received Airbus Modification 11110 during production or that have been modified in service in accordance with Airbus Service Bulletin A310-54-2032 (Airbus Modification 11109). 

## Subject 

(d) Air Transport Association (ATA) of America Code 54: Nacelles/Pylons. 

## Reason 

(e) The mandatory continuing airworthiness information (MCAI) states: 

Two operators of A300 aircraft fitted with General Electric (GE) CF6-50 engine series have reported cracks on the lower side of Rib 5 in the pylon box. 

The concerned area is similar on A310 aircraft fitted with GE CF6-80A or CF6-80C series engines. 

Investigations disclosed that these cracks are due to the stresses resulting from the pressure applied by the thrust reverser cowl bumpers. 

As a result of the A310 Extended Service Goal (ESG) study, an inspection programme of this area is required by this Airworthiness Directive (AD). 

A similar inspection programme is being contemplated for A300 and A300-600 series aircraft. 

Cracking of the engine pylons could result in reduced structural integrity of the engine support structure. Corrective actions include modifying the Rib 5 in the pylon box. 

## Actions and Compliance 

(f) Unless already done, do the following actions. 

(1) Perform a high frequency eddy current (HFEC) inspection and a detailed visual inspection on the lower side of Rib 5 of the left-hand and right-hand pylons, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A310-54-2036, Revision 02, dated September 28, 2007. Do the inspections at the times specified in paragraph (f)(1)(i) or (f)(1)(ii) of this AD, as applicable. 

(i) For Model A310-203 and -204 airplanes: Inspect at the later of the times specified in paragraphs (f)(1)(i)(A) and (f)(1)(i)(B) of this AD. 

(A) Prior to the accumulation of 40,000 total flight cycles or 60,000 total flight hours, whichever occurs first. 

(B) Within 250 flight hours after the effective date of this AD. 

(ii) For Model A310-304 airplanes: Inspect at the later of the times specified in paragraphs (f)(1)(ii)(A) and (f)(1)(ii)(B) of this AD. 

(A) Prior to the accumulation of 35,000 total flight cycles or 60,000 total flight hours, whichever occurs first. 

(B) Within 250 flight hours after the effective date of this AD. 

(2) If no crack is found during any inspection required by paragraph (f)(1) of this AD: Repeat the inspections thereafter at intervals not to exceed 15,000 flight hours. 

(3) If any crack is found during any inspection required by paragraph (f)(1) of this AD: Before further flight, modify Rib 5 in the pylon box in accordance with the Accomplishment Instructions of Airbus Service Bulletins A310-54-2032, Revision 01, dated October 8, 2007. Accomplishment of this modification ends the repetitive inspections required by this AD. 

(4) Accomplishment of the HFEC and detailed visual inspections before the effective date of this AD in accordance with Airbus Service Bulletin A310-54-2036, Revision 01, dated September 14, 1999, meets the corresponding requirements of paragraph (f) of this AD. 

(5) Accomplishment of the modification before the effective date of this AD in accordance with Airbus Service Bulletin A310-54-2032, dated May 29, 1996, meets the corresponding requirements of paragraph (f) of this AD. 

(6) Submit the initial inspection results specified in Appendix 01 of Airbus Service Bulletin A310-54-2036, Revision 02, dated September 28, 2007, at the time specified in paragraph (f)(6)(i) or (f)(6)(ii) of this AD. 

(i) If the inspections were done after the effective date of this AD: Within 30 days after accomplishing the inspections required by paragraph (f)(1) of this AD. 

(ii) If the inspections were done prior to the effective date of this AD: Within 30 days after the effective date of this AD. 

## FAA AD Differences 

# Note:

This AD differs from the MCAI and/or service information as follows: Although the MCAI allows further flight after cracks are found during compliance with the required action, this AD requires that you repair the crack(s) before further flight.

## Other FAA AD Provisions 

(g) The following provisions also apply to this AD: 

                                (1)                                 *Alternative Methods of Compliance (AMOCs):*                                 The Manager, International Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to                                 *Attn:*                                 Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2125; fax (425) 227-1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.                             

                                (2)                                 *Airworthy Product:*                                 For any requirement in this AD to obtain corrective actions from                                       ( print page 45893)                                    a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.                             

                                (3)                                 *Reporting Requirements:*                                 For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.                             

## Related Information 

(h) Refer to MCAI EASA Airworthiness Directive 2008-0066, dated March 31, 2008, and Airbus Service Bulletins A310-54-2032, Revision 01, dated October 8, 2007; and A310-54-2036, Revision 02, dated September 28, 2007; for related information. 

Issued in Renton, Washington, on July 29, 2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. E8-18210 Filed 8-6-08; 8:45 am] 

BILLING CODE 4910-13-P