E9-16762. Airworthiness Directives; Construcciones Aeronauticas, S.A. (CASA), Model CN-235 Series Airplanes

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 that would supersede an existing AD. 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:

* * * [C]racks [were originally] detected on some CN-235 aircraft in flap fittings P/N 35-15501-0101, -0102, -0201 and -0202, attaching the structure of the outer flaps to their rear supports and, in the adjacent structure, DGAC Spain issued AD Nr. 01/97[.] * * * Since AD 1/97 Rev.1 was published, similar cracks have been detected in flaps longerons. * * *

* * * * *

Fatigue cracking of the rear internal support fittings and longerons of the outer flap structure could result in failure of the outer flaps, and consequent reduced controllability of the airplane. 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 August 14, 2009.

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: [phone].
• 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.

For service information identified in this proposed AD, contact EADS-CASA, Military Transport Aircraft Division (MTAD), Integrated Customer Services (ICS), Technical Services, Avenida de Aragón 404, 28022 Madrid, Spain; telephone [phone]; fax [phone]; e-mail [e-mail]; Internet http://www.eads.net. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

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 [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Shahram Daneshmandi, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

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-2009-0637; Directorate Identifier 2008-NM-183-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

On March 23, 1999, we issued AD 99-07-13, Amendment 39-11098 (64 FR 15659, April 1, 1999). That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 99-07-13, the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, notified us of an additional report of similar cracks in flaps longerons. EASA has issued EASA Airworthiness Directive 2008-0119, dated June 27, 2008 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

As a consequence of cracks detected on some CN-235 aircraft, in flap fittings P/N 35-15501-0101, -0102, -0201 and -0202, attaching the structure of the outer flaps to their rear supports and, in the adjacent structure, DGAC Spain issued AD Nr. 01/97 which required, pending the analysis of the problem, boroscopic inspections of the attachment zones between both outer flaps to their rear support. After concluding that process and based on the investigation results, DGAC Spain issued AD Nr. 1/97 Rev. 1 [which corresponds to FAA AD 99-07-13] to require the replacement of the outer flaps with new designed parts, as specified in EADS-CASA Service Bulletin (SB) 235-57-20.

Since AD 1/97 Rev. 1 was published, similar cracks have been detected in flaps longerons. EADS-CASA issued SB 235-57-20 Revision 1, extending the scope of the inspection to these flaps longerons, instructing the drilling of holes to facilitate the inspection and introducing an improved outer flap replacement kit that included a new improved longeron. SB 235-57-20 Revision 2 has been issued to add useful references and to update the applicability.

For the reasons described above, this new EASA AD retains the requirements of DGAC Spain AD Nr. 1/97 Rev. 1, which is superseded, and confirms the approval of additional outer flaps replacement options, as specified in paragraph 2 E.2 of EADS-CASA SB 235-57-20 R2.

Fatigue cracking of the rear internal support fittings and longerons of the outer flap structure could result in failure of the outer flaps, and consequent reduced controllability of the airplane. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

CASA has issued Service Bulletin SB-235-57-20, Revision 2, dated March 30, 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 8 products of U.S. registry. We also estimate that it would take about 69 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $193,603 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of the proposed AD on U.S. operators may be $1,592,984, or $199,123 per product.

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
• Incorporation by reference
• 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

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-11098 and adding the following new AD:

Construcciones Aeronauticas, S.A. (CASA): Docket No. FAA-2009-0637; Directorate Identifier 2008-NM-183-AD.

Comments Due Date

(a) We must receive comments by August 14, 2009.

Affected ADs

(b) This AD supersedes AD 99-07-13.

Applicability

(c) This AD applies to CASA Model CN-235, CN-235-100, CN-235-200, CN-235-300 airplanes, all serial numbers, if part number (P/N) 35-15501-0001, -0002, -0003, or -0004, or P/N 35-A0736-0001 or -0002 outer flaps are installed.

Subject

(d) Air Transport Association (ATA) of America Code 57: Wings.

Reason

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

As a consequence of cracks detected on some CN-235 aircraft, in flap fittings P/N 35-15501-0101, -0102, -0201 and -0202, attaching the structure of the outer flaps to their rear supports and, in the adjacent structure, DGAC Spain issued AD Nr. 01/97 which required, pending the analysis of the problem, borescopic inspections of the attachment zones between both outer flaps to their rear support. After concluding that process and based on the investigation results, DGAC Spain issued AD Nr. 1/97 Rev.1 [which corresponds to FAA AD 99-07-13] to require the replacement of the outer flaps with new designed parts, as specified in EADS-CASA Service Bulletin (SB) 235-57-20.

Since AD 1/97 Rev.1 was published, similar cracks have been detected in flaps longerons. EADS-CASA issued SB 235-57-20 Revision 1, extending the scope of the inspection to these flaps longerons, instructing the drilling of holes to facilitate the inspection and introducing an improved outer flap replacement kit that included a new improved longeron. SB 235-57-20 Revision 2 has been issued to add useful references and to update the applicability.

For the reasons described above, this new EASA AD retains the requirements of DGAC Spain AD Nr. 1/97 Rev.1, which is superseded, and confirms the approval of additional outer flaps replacement options, as specified in paragraph 2 E.2 of EADS-CASA SB 235-57-20 R2.

Fatigue cracking of the rear internal support fittings and longerons of the outer flap structure could result in failure of the outer flaps, and consequent reduced controllability of the airplane.

Actions and Compliance

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

(1) For airplanes equipped with P/N 35-A0736-0001 or -0002 outer flaps: Within 300 flight cycles after the effective date of this AD, do a borescopic inspection to detect cracking of the outer flaps fittings and longerons, in accordance with the Accomplishment Instructions of CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007.

(2) For airplanes equipped with Part Number (P/N) 35-15501-0001, -0002, -0003, or -0004 outer flaps: At the earlier of the times specified in paragraphs (f)(2)(i) and (f)(2)(ii) of this AD, do a borescopic inspection to detect cracking of the outer flaps fittings; and within 300 flight cycles after the effective date of this AD, do a borescopic inspection to detect cracking of the longerons. Do the inspections in accordance with the Accomplishment Instructions of CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007.

(i) Within 600 flight cycles after the most recent inspection done in accordance with AD 99-07-13, or within 14 days after the effective date of this AD, whichever occurs later.

(ii) Within 300 flight cycles after the effective date of this AD.

(3) If, during any inspection required by paragraph (f)(1) or (f)(2) of this AD, no crack is detected, repeat the borescopic inspections of the outer flap fittings and longerons in accordance with the Accomplishment Instructions of CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007, thereafter at intervals not to exceed 300 flight cycles or 6 months, whichever occurs first, until the replacement specified in paragraph (f)(4) or (f)(5) of this AD is accomplished.

(4) If any crack is detected during any inspection required by paragraph (f)(1), (f)(2), or (f)(3) of this AD, prior to further flight, replace the outer flap with a new or retrofitted flap in accordance with the Accomplishment Instructions of CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007. Such replacement constitutes terminating action for the repetitive borescopic inspection required by this AD for the replaced outer flap only.

(5) For affected parts that have not been replaced in accordance with paragraph (f)(4) of this AD: At the later of the times specified in paragraphs (f)(5)(i) and (f)(5)(ii) of this AD, replace each outer flap with a new or retrofitted outer flap in accordance with the Accomplishment Instructions of CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007. Replacing all outer flaps terminates the requirements of this AD.

(i) Before the accumulation of 4,000 total flight cycles on the flap.

(ii) Within 1,200 flight cycles or 24 months after the effective date of this AD, whichever occurs first.

(6) Actions done before the effective date of this AD in accordance with CASA Service Bulletin SB-235-57-20, dated December 23, 1997; or Revision 1, dated April 30, 2004; are acceptable for compliance with the corresponding requirements of paragraph (f)(2) of this AD.

FAA AD Differences

Note 1:

This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

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

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, Transport Airplane Directorate, 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: Shahram Daneshmandi, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from 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 2008-0119, dated June 27, 2008; and CASA Service Bulletin SB-235-57-20, Revision 2, dated March 30, 2007; for related information.

Issued in Renton, Washington, on July 2, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.