2010-20854. Airworthiness Directives; Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R, A300 F4-600R Series Airplanes, and Model A300 C4-605R Variant F Airplanes (Collectively Called A300-600 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. 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: The ball screw nut assemblies of the first 70 Trimmable Horizontal Stabilizer Actuators (THSA) manufactured by Goodrich were fitted with an upper attachment gimbal having a thickness of 58 mm (2.28 in), which is different from the design of the final production standard. The gimbal installed on the subsequent THSAs (final production standard) is more robust, having a thickness of 70mm (2.76 in). During the fatigue life demonstration of the THSA upper attachment primary load path elements, only a gimbal having a thickness of 70mm (2.76 in) was used. Thereafter, no additional justification work to demonstrate the robustness of the upper attachment fitted with a gimbal of 58 mm was accomplished. In case of failure of this gimbal, the THSA upper attachment primary load path would be lost and the THSA upper attachment secondary load path would engage. Because the upper attachment secondary load path will only withstand the loads for a limited period of time, the condition where it would be engaged and not detected could lead to failure of the secondary load path, which would likely result in loss of control of the aeroplane. 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 October 7, 2010.

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 Airbus SAS—EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone [phone]; fax [phone]; e-mail: [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 425-227-1221.

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-2010-0803; Directorate Identifier 2010-NM-124-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 2010-0092, dated May 21, 2010 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

The ball screw nut assemblies of the first 70 Trimmable Horizontal Stabilizer Actuators (THSA) manufactured by Goodrich were fitted with an upper attachment gimbal having a thickness of 58 mm (2.28 in), which is different from the design of the final production standard. The gimbal installed on the subsequent THSAs (final production standard) is more robust, having a thickness of 70 mm (2.76 in).

During the fatigue life demonstration of the THSA upper attachment primary load path elements, only a gimbal having a thickness of 70mm (2.76 in) was used. Thereafter, no additional justification work to demonstrate the robustness of the upper attachment fitted with a gimbal of 58 mm was accomplished.

In case of failure of this gimbal, the THSA upper attachment primary load path would be lost and the THSA upper attachment secondary load path would engage.

Because the upper attachment secondary load path will only withstand the loads for a limited period of time, the condition where it would be engaged and not detected could lead to failure of the secondary load path, which would likely result in loss of control of the aeroplane.

As the affected ball screw nut assemblies (including the gimbal) could have been moved from one THSA to another during maintenance operation and because the change from the old design to the final production standard design is not identified through a dedicated THSA Part Number, a gimbal with thickness of 58 mm (2.28 in) can be fitted on any A310 or A300-600 aeroplane.

For the reasons described above, this AD requires the identification of the THSA which have a 58 mm (2.28 in) gimbal installed, repetitive [general visual] inspections to check whether there is engagement of the secondary load path and, depending on findings, associated corrective action(s).

Corrective actions include contacting Airbus for repair instructions and doing the repair. You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Airbus has issued Mandatory Service Bulletins A300-27A6067, Revision 01, including Appendix 01, dated May 12, 2010; and A310-27A2104, Revision 01, including Appendix 01, dated May 12, 2010. 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 170 products of U.S. registry. We also estimate that it would take about 2 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $28,900, or $170 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-2010-0803; Directorate Identifier 2010-NM-124-AD.

Comments Due Date

(a) We must receive comments by October 7, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Airbus Model A300 B4-601, B4-603, B4-620, B4-622, B4-605R, B4-622R, F4-605R, and F4-622R airplanes; Model A300 C4-605R Variant F airplanes; and Model A310-203, -204, -221, -222, -304, -322, -324, and -325 airplanes; certificated in any category, all certified models, all manufacturer serial numbers.

Subject

(d) Air Transport Association (ATA) of America Code 27: Flight controls.

Reason

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

The ball screw nut assemblies of the first 70 Trimmable Horizontal Stabilizer Actuators (THSA) manufactured by Goodrich were fitted with an upper attachment gimbal having a thickness of 58 mm (2.28 in), which is different from the design of the final production standard. The gimbal installed on the subsequent THSAs (final production standard) is more robust, having a thickness of 70mm (2.76 in).

During the fatigue life demonstration of the THSA upper attachment primary load path elements, only a gimbal having a thickness of 70mm (2.76 in) was used. Thereafter, no additional justification work to demonstrate the robustness of the upper attachment fitted with a gimbal of 58 mm was accomplished.

In case of failure of this gimbal, the THSA upper attachment primary load path would be lost and the THSA upper attachment secondary load path would engage.

Because the upper attachment secondary load path will only withstand the loads for a limited period of time, the condition where it would be engaged and not detected could lead to failure of the secondary load path, which would likely result in loss of control of the aeroplane.

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.

Actions

(g) Within 130 flight cycles or 650 flight hours after the effective date of this AD, whichever occurs first, measure the thickness of the trimmable horizontal stabilizer actuators (THSA) upper attachment gimbal, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010 (for Model A300-600 series airplanes); or A310-27A2104, Revision 01, dated May 12, 2010 (for Model A310 series airplanes).

(1) If, during the measurement required by paragraph (g) of this AD, the gimbal thickness is 58 mm (2.28 in.) ± 5 mm (0.20 in.), before further flight, do a general visual inspection of the THSA upper attachment to determine if the THSA upper attachment secondary load path is engaged, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010 (for Model A300-600 series airplanes); or A310-27A2104, Revision 01, dated May 12, 2010 (for Model A310 series airplanes). Repeat the inspection thereafter at intervals not to exceed 130 flight cycles or 650 flight hours, whichever occurs first, in accordance with the Accomplishment Instructions of Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010 (for Model A300-600 series airplanes); or A310-27A2104, Revision 01, dated May 12, 2010 (for Model A310 series airplanes).

(2) If, during the measurement required by paragraph (g) of this AD, the gimbal thickness is not 58 mm (2.28 in.) ± 5 mm (0.20 in.), except for the requirements of paragraph (k) of this AD, no further action is required of this AD.

(h) If, during any inspection required by paragraph (g)(1) of this AD, the THSA upper attachment secondary load path is found to be engaged, before further flight, contact Airbus for repair instructions and do the repair.

Actions Accomplished According to Previous Issue of Service Bulletin

(i) Actions accomplished before the effective date of this AD in accordance with Airbus Mandatory Service Bulletin A300-27A6067 (for Model A300-600 series airplanes) or A310-27A2104 (for Model A310 series airplanes), both dated May 6, 2010, are considered acceptable for compliance with the corresponding action specified in this AD.

Reporting Requirement

(j) Submit a report of the findings (both positive and negative) of the measurement required by paragraph (g) of this AD to Airbus, as identified in Appendix 01 of Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010 (for Model A300-600 series airplanes); or A310-27A2104, Revision 01, dated May 12, 2010 (for Model A310 series airplanes); at the applicable time specified in paragraph (l)(1) or (l)(2) of this AD. The report must include the information specified in Appendix 01 of Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010 (for Model A300-600 series airplanes); or A310-27A2104, Revision 01, dated May 12, 2010 (for Model A310 series airplanes).

(1) If the measurement was done on or after the effective date of this AD: Submit the report within 30 days after the inspection.

(2) If the measurement was done before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

Parts Installation

(k) As of the effective date of this AD, no person may install, on any airplane, a THSA, unless it is in compliance with the requirements of this AD.

FAA AD Differences

Note 1:

This AD differs from the MCAI and/or service information as follows: The MCAI does not include a reporting requirement; however, the service bulletin recommends reporting. Paragraph (j) of this AD specifies a reporting requirement.

Other FAA AD Provisions

(l) 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. 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 [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 (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(m) Refer to MCAI EASA Airworthiness Directive 2010-0092, dated May 21, 2010; Airbus Mandatory Service Bulletin A300-27A6067, Revision 01, dated May 12, 2010; and Airbus Mandatory Service Bulletin A310-27A2104, Revision 01, dated May 12, 2010; for related information.

Issued in Renton, Washington, on August 16, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.