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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2005-22794; Directorate Identifier 2005-NM-097-AD] 
          - RIN 2120-AA64 

# AGENCY:

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

# ACTION:

Notice of proposed rulemaking (NPRM). 

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Model A318-100 and A319-100 series airplanes; Model A320-111 airplanes; and Model A320-200, A321-100, and A321-200 series airplanes. This proposed AD would require repetitive detailed inspections of the trimmable horizontal stabilizer actuator (THSA) attachments for proper clearances, and any crack, damage, or metallic particles; related corrective actions if necessary; and a report of the inspection results to the manufacturer. This proposed AD results from a report that during lab testing to verify the performance of the THSA's secondary load path with a simulated failure of the THSA's primary load path, the secondary load path's nut did not jam (as it was supposed to do.) We are proposing this AD to ensure the integrity of the THSA's primary load path, which if failed, could result in latent (undetected) loading and eventual failure of the THSA's secondary load path and consequent uncontrolled movement of the horizontal stabilizer and loss of control of the airplane. 

# DATES:

We must receive comments on this proposed AD by November 28, 2005. 

# ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD. 
      - DOT Docket Web site: Go to http://dms.dot.gov                          and follow the instructions for sending your comments electronically.                     
      - Government-wide rulemaking Web site: Go to http://www.regulations.gov                          and follow the instructions for sending your comments electronically.                     
      - Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, Washington, DC 20590.
      - Fax: (202) 493-2251.
      - Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for service information identified in this proposed AD. 

# FOR FURTHER INFORMATION CONTACT:

Tim Dulin, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2141; fax (425) 227-1149. 

# SUPPLEMENTARY INFORMATION:

      ( print page 61923)    

## Comments Invited 

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Include the docket number “FAA-2005-22794; Directorate Identifier 2005-NM-097-AD” at the beginning 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://dms.dot.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 that Web site, anyone can find and read the comments in any of our dockets, including 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), or you may visit                     *http://dms.dot.gov*.                 

## Examining the Docket 

                    You may examine the AD docket on the Internet at                     *http://dms.dot.gov*, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the                     **ADDRESSES**                     section. Comments will be available in the AD docket shortly after the Docket Management System receives them.                 

## Discussion 

The Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that an unsafe condition may exist on all Airbus Model A318-100, A319-100, A320, and A321 series airplanes. The DGAC advises that, during lab testing to verify the performance of the secondary load path of the trimmable horizontal stabilizer actuator (THSA) with a simulated loss of the THSA's primary load path, the secondary load path's nut did not jam the THSA (as it was supposed to do). The THSA was designed to jam in the event of a primary load path failure, to indicate to the flightcrew that a component of the THSA (the primary load path) had failed and would need repair. Without the jamming of the secondary load path's nut, there would be no indications of failure of the THSA primary load path, and it is possible that the airplane would continue to be unknowingly operated with a failed component and continuous loading of the secondary load path. The secondary load path is not designed to tolerate continued loading during multiple flights. In the event of a secondary load path failure in addition to a primary load path failure, the flightcrew would not be able to control the position of the THSA. This condition, if not corrected, could result in uncontrolled movement of the horizontal stabilizer and consequent loss of control of the airplane. 

## Relevant Service Information 

Airbus has issued Service Bulletin A320-27-1164, Revision 02, dated March 30, 2005. The service bulletin describes procedures for repetitive detailed inspections of the THSA attachments for proper clearances, and for any crack, damage, or metallic particles; related corrective actions if necessary; and a report of the inspection results to the manufacturer. The detailed inspections involve doing a check for the clearances between the secondary nut trunnions and junction plates at the lower THSA attachment; and doing a visual inspection of the upper THSA attachment structure/area for any crack, damage, or metallic particles. The corrective actions involve replacing the THSA if any clearance is not correct, or if any crack or damage is found; and contacting the manufacturer for further instructions if any metallic particles are found. The DGAC mandated the service information and issued French airworthiness directive F-2005-051, dated March 30, 2005, to ensure the continued airworthiness of these airplanes in France. 

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

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. We have examined the DGAC's findings, evaluated all pertinent information, and determined that we need to issue an AD for airplanes of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Bulletin.”

## Differences Between the Proposed AD and the Service Bulletin

The service bulletin specifies that you may contact the manufacturer for instructions if any metallic particles are found, but this proposed AD would require you to repair the THSA using a method that we or the DGAC (or its delegated agent) approve. In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair we or the DGAC approve would be acceptable for compliance with this proposed AD.

The service bulletin refers only to a “check” and a “visual inspection” for inspections of the THSA attachments for proper clearances; and for any crack, damage, or metal particles. We have determined that the procedures for both actions in the service bulletin should be described as “detailed inspections.” Note 1 has been included in this proposed AD to define this type of inspection.

## Interim Action

This is considered to be interim action. The inspection reports that are required by this AD will enable the manufacturer to obtain better insight into the nature, cause, and extent of the problem, and eventually to develop final action to address the unsafe condition. Once final action has been identified, the FAA may consider further rulemaking.

## Costs of Compliance

This proposed AD would affect about 700 airplanes of U.S. registry. The proposed actions would take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $45,500, or $65 per airplane, per inspection cycle.

## 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.                          ( print page 61924)    

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. 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. 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
      - 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

**Airbus:**                                 Docket No. FAA-2005-22794; Directorate Identifier 2005-NM-097-AD.                            

## Comments Due Date

(a) The FAA must receive comments on this AD action by November 28, 2005.

## Affected ADs

(b) None.

## Applicability

(c) This AD applies to all Airbus Model A318-111 and -112 airplanes, Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes, Model A320-111 airplanes, Model A320-211, -212, -214, -231, -232, and -233 airplanes, Model A321-111, -112, and -131 airplanes, and Model A321-211 and -231 airplanes, certificated in any category.

## Unsafe Condition

(d) This AD results from a report that during lab testing to verify the performance of the trimmable horizontal stabilizer actuator's (THSA's) secondary load path with a simulated failure of the THSA's primary load path, the secondary load path's nut did not jam (as it was supposed to do.) We are issuing this AD to ensure the integrity of the THSA's primary load path, which if failed, could result in latent (undetected) loading and eventual failure of the THSA's secondary load path and consequent uncontrolled movement of the horizontal stabilizer and 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.

## Repetitive Inspections and Corrective Action

(f) Within 20 months since first flight, or within 600 flight hours after the effective date of this AD, whichever occurs later, do detailed inspections of the THSA attachments for proper clearances and any crack, damage, or metallic particles, and do related corrective actions as applicable, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-27-1164, Revision 02, dated March 30, 2005, except as described in paragraph (g) of this AD. Do corrective actions before further flight. Thereafter, repeat the inspections at intervals not to exceed 20 months.

# Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

                                (g) If any metallic particles are detected during the inspection required by paragraph (f) of this AD: Before further flight, repair the damage according to a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Ge                                                                ne                                                                rale de l'Aviation Civile (DGAC) (or its delegated agent).                            

## Inspection Reports

                                (h) Submit a report of the findings (both positive and negative) of the inspection required by paragraph (f) of this AD to Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, at the applicable time specified in paragraph (h)(1) or (h)(2) of this AD. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501*et seq.*), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.                            

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

(2) If any inspection was accomplished prior to the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

## Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

## Related Information

(j) French airworthiness directive F-2005-051, dated March 30, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on October 18, 2005.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 05-21434 Filed 10-26-05; 8:45 am]

BILLING CODE 4910-13-P