2011-28833. Airworthiness Directives; Airbus Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-2C, B4-103, and B4-203 airplanes; Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model C4-605R Variant F airplanes (collectively called A300-600 series airplanes); and Model A310 series airplanes. 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:

During a routine visual inspection on two A310 in-service aeroplanes, cracks were found in the wing MLG [main landing gear] rib 5 aft bearing forward lug. Laboratory examination of the cracked ribs confirmed that the cracks were the result of pitting corrosion in the forward lug hole. Also on both aeroplanes, medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. * * * This situation, if not corrected, could affect the structural integrity of the MLG attachment [which could result in the collapse of the MLG].

* * * * *

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 December 23, 2011.

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 W12-140, 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 Airbus SAS-EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; email [e-mail]; Internet http://www.airbus.com. 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 [phone].

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:

Dan Rodina, 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-2011-1225; Directorate Identifier 2010-NM-269-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 2010-0251, dated November 29, 2010 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

During a routine visual inspection on two A310 in-service aeroplanes, cracks were found in the wing MLG rib 5 aft bearing forward lug. Laboratory examination of the cracked ribs confirmed that the cracks were the result of pitting corrosion in the forward lug hole. Also on both aeroplanes, medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. Similarly to A310 aeroplanes, although there have been no reports of crack findings on any A300, A300-600 or A300-600ST aeroplanes, the differences in MLG rib 5 design compared to A310 aeroplanes does not allow the exclusion of the possibility of cracks. This situation, if not corrected, could affect the structural integrity of the MLG attachment [which could result in the collapse of the MLG].

In order to ensure the detection of any crack at an early stage in the forward lug of the RH and LH MLG rib 5 aft bearing forward lug, Airbus developed inspection programs which were rendered mandatory, initially by EASA AD 2006-0372-E [which corresponds with FAA AD 2007-03-18, Amendment 39-14929] and now by AD 2010-0250 applicable to A300B4/C4/F4 and A300-600 aeroplanes and AD 2007-0195 [which corresponds with FAA AD 2008-17-02, Amendment 39-15640] applicable to A310 aeroplanes.

More recently, it has been determined that the installation of new bushes with increased interference fit adequately corrects the unsafe condition and ensures the structural integrity of the MLG attachment. Installation of these bushes constitutes terminating action for the repetitive inspection requirements of the existing EASA AD 2010-0250 for A300B4/C4/F4 and A300-600 aeroplanes, and AD 2007-0195 for A310 aeroplanes.

For the reasons described above, this new AD requires installation of bushes with increased interference fit in the gear rib 5 aft bearing forward lug.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Airbus has issued the following service bulletins:

• Airbus Mandatory Service Bulletin A300-57-0249, Revision 02, dated June 18, 2010 (for Airbus Model A300 B4-2C, B4-103, and B4-203 airplanes).
• Airbus Service Bulletin A300-57-6106, Revision 02, dated June 18, 2010 (for Airbus Model A300-600 series airplanes).
• Airbus Mandatory Service Bulletin A310-57-2090, Revision 02, dated June 18, 2010 (for Airbus Model A310 series airplanes).

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 215 products of U.S. registry. We also estimate that it would take about 38 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Required parts would cost about $4,590 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 to be $1,681,300, or $7,820 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 adding the following new AD:

Airbus: Docket No. FAA-2011-1225; Directorate Identifier 2010-NM-269-AD.

Comments Due Date

(a) We must receive comments by December 23, 2011.

Affected ADs

(b) This AD affects AD 2007-03-18, Amendment 39-14929 (72 FR 5919, February 8, 2007); and AD 2008-17-02, Amendment 39-15640 (73 FR 47032, dated August 13, 2008).

Applicability

(c) This AD applies to airplanes, certified in any category, as specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.

(1) Airbus Model A300 B4-2C, B4-103, and B4-203 airplanes; all serial numbers; except airplanes where the main landing gear (MLG) rib 5 forward lugs of the left hand (LH) and right hand (RH) wing have been repaired by installation of oversized interference fit bushes per Airbus Repair Instruction R57240221, or those where the LH and RH wing have had Airbus Mandatory Service Bulletin A300-57-0249 embodied in service.

(2) Airbus Model A300 B4-601, B4-603, B4-620, and B4-622 airplanes; Airbus Model A300 B4-605R and B4-622R airplanes; Airbus Model A300 F4-605R and F4-622R airplanes; and Airbus Model A300 C4-605R Variant F airplanes; all serial numbers; except airplanes where the MLG rib 5 forward lugs of the LH and RH wing have been repaired by installation of oversized interference fit bushes per Airbus Repair Instruction R57240221, or those where the LH and RH wing have had Airbus Service Bulletin A300-57-6106 embodied in service.

(3) Airbus Model A310-203, -204, -221, -222, -304, -322, -324, and -325 airplanes; all serial numbers; except airplanes where the MLG rib 5 forward lugs of the LH and RH wing have been repaired by installation of oversized interference fit bushes per Airbus Repair Instruction R57249121, or those where the LH and RH wing have had Airbus Mandatory Service Bulletin A310-57-2090 embodied in service.

Subject

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

Reason

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

During a routine visual inspection on two A310 in-service aeroplanes, cracks were found in the wing MLG rib 5 aft bearing forward lug. Laboratory examination of the cracked ribs confirmed that the cracks were the result of pitting corrosion in the forward lug hole. Also on both aeroplanes, medium to heavy corrosion was found in the forward lugs on the opposite wing after removal of the bushes. * * *. This situation, if not corrected, could affect the structural integrity of the MLG attachment [which could result in the collapse of the MLG].

* * * * *

Compliance

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

Inspection and Corrective Actions

(g) Within 30 months after the effective date of this AD, install new bushes with increased interference fit in the gear rib 5 aft bearing forward lug on the RH and LH wing, in accordance with the Accomplishment Instructions of the applicable service bulletins specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD; except as specified in paragraph (h) of this AD.

(1) Airbus Mandatory Service Bulletin A300-57-0249, Revision 02, dated June 18, 2010 (for Model A300 B4-2C, B4-103, and B4-203 airplanes);

(2) Airbus Service Bulletin A300-57-6106, Revision 02, dated June 18, 2010 (for Model A300-600 series airplanes); and

(3) Airbus Mandatory Service Bulletin A310-57-2090, Revision 02, dated June 18, 2010 (for Airbus Model A310 series airplanes).

(h) If one wing had rib 5 forward lugs of the MLG repaired by installing oversized interference fit bushes in accordance with Airbus Repair Instruction R57240221 or Airbus Repair Instruction R57249121, as applicable to the airplane model, then installing new bushes with increased interference fit in the aft bearing forward lug of the gear rib, as specified in paragraph (h) of this AD, is required for the opposite wing only.

Terminating Action for Inspections Required by AD 2007-03-18, (72 FR 5919, February 8, 2007); and AD 2008-17-02, (73 FR 47032, Dated August 13, 2008)

(i) Installation of new bushes, as specified in paragraph (h) of this AD, is terminating action for the repetitive inspections required AD 2007-03-18, Amendment 39-14929 (72 FR 5919, February 8, 2007); and AD 2008-17-02, Amendment 39-15640 (73 FR 47032, dated August 13, 2008).

Credit for Actions Accomplished in Accordance With Previous Service Information

(j) Installations accomplished before the effective date of this AD, according to the applicable service bulletins specified paragraphs (j)(1), (j)(2), and (j)(3) of this AD, are considered acceptable for compliance with the corresponding installations specified in this AD.

(1) Airbus Service Bulletin A300-57-0249, dated May 22, 2007; or Airbus Service Bulletin A300-57-0249, Revision 01, dated December 19, 2007 (for Model A300 B4-2C, B4-103, and B4 203 airplanes);

(2) Airbus Service Bulletin A300-57-6106, May 22, 2007; or Airbus Service Bulletin A300-57-6106, Revision 01, January 28, 2008 (for Model A300-600 series airplanes); and

(3) Airbus Service Bulletin A310-57-2090, dated May 22, 2007; or Airbus Service Bulletin A310-57-2090, Revision 01, dated December 19, 2007 (for Model A310 series airplanes).

FAA AD Differences

Note 1:

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

Other FAA AD Provisions

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

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the International Branch, send it to Attn: Dan Rodina, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Information may be emailed to: [e-mail]. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding 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.

Related Information

(l) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2010-0251, dated November 29, 2010; Airbus Mandatory Service Bulletin A300-57-0249, Revision 02, dated June 18, 2010; Airbus Service Bulletin A300-57-6106, Revision 02, dated June 18, 2010; and Airbus Mandatory Service Bulletin A310-57-2090, Revision 02, dated June 18, 2010; for related information.

Issued in Renton, Washington, on October 28, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.