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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 2000-NM-139-AD; Amendment 39-11776; AD 2000-11-27] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Final rule; request for comments. 

# SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Airbus Model A319, A320, and A321 series airplanes. This action requires a one-time ultrasonic inspection to detect disbonding of the skin attachments at the stringers and spars of the vertical stabilizer, and repair, if necessary. This action is necessary to detect and correct disbonding of the vertical stabilizer structure, which could result in reduced structural integrity of the spar boxes of the vertical stabilizer. 

# DATES:

Effective June 28, 2000. 

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of June 28, 2000. 

Comments for inclusion in the Rules Docket must be received on or before July 13, 2000. 

# ADDRESSES:

                        Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-139-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this                               ( print page 37030)                            location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: 9-anm-iarcomment@faa.gov. Comments sent via the Internet must contain “Docket No. 2000-NM-139-AD” in the subject line and need not be submitted in triplicate.                     

The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 

# FOR FURTHER INFORMATION CONTACT:

Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149. 

# SUPPLEMENTARY INFORMATION:

The Direction Geúneúrale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A319, A320, and A321 series airplanes. The DGAC advises that localized disbonding has been detected on the skin attachments at the stringers and spars of the spar boxes of the vertical stabilizer. During the manufacturing process, pre-cured parts (attachments of the stringers, spars, and ribs) are installed on the skin panel before the final curing process. A peel ply is used to protect the contact surfaces of the attachment angles of the skin panels of the vertical stabilizer until the pre-cured parts are ready for installation. Investigation revealed that, after the peel ply was removed from the attachment angles, a residue of polymer finish contaminated the contact surfaces of some pre-cured parts. This contamination reduced the adhesive strength of the bond and, in some cases, caused debonding (disbonding) of the skin attachments. This condition, if not detected and corrected, could result in reduced structural integrity of the spar boxes of the vertical stabilizer. 

## Explanation of Relevant Service Information 

The manufacturer has issued Airbus Service Bulletin A320-55A1027, dated May 12, 2000, which describes procedures for a one-time ultrasonic inspection to detect disbonding of the skin attachments at the stringers and spars of the vertical stabilizer, left-and right-hand sides, and repair, if necessary. If any disbonding (damage) is detected and the area of damage is greater than 300 square millimeters (mm2), or if multiple damage is detected on one specific component (stringer-spar attachment), the repair involves installing additional fasteners in the affected areas. The amount of damage determines the number of additional fasteners to be installed in the affected area. 

Additionally, Airbus Service Bulletin A320-55A1027 references Airbus Service Bulletin A320-55-1026, Revision 01, dated May 20, 1999, which, for certain airplanes, describes procedures for prior or concurrent modification of the vertical stabilizer to ensure proper reinforcement of the structure-skin attachments.

The DGAC classified Airbus Service Bulletin A320-55-A1027 as mandatory and issued French airworthiness directive T2000-208-148(B) R1, dated May 17, 2000, in order to assure the continued airworthiness of these airplanes in France.

## FAA's Conclusions

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of § 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. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. 

## Explanation of Requirements of Rule 

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to detect and correct disbonding of the vertical stabilizer structure, which could result in reduced structural integrity of the spar boxes of the vertical stabilizer. This AD requires a one-time ultrasonic inspection to detect disbonding of the skin attachments at the stringers and spars of the vertical stabilizer, and repair, if necessary. The actions are required to be accomplished in accordance with the service bulletin described previously. 

## Interim Action 

This is considered interim action. The manufacturer has advised that it is currently developing a repetitive inspection program to positively address the unsafe condition addressed by this AD. Once this repetitive inspection program is developed, approved, and available, the FAA may consider additional rulemaking. 

## Determination of Rule's Effective Date 

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. 

## Comments Invited 

                    Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption                     **ADDRESSES.**                     All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.                 

Submit comments using the following format: 
    - Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
    - For each issue, state what specific change to the AD is being requested.
    - Include justification ( e.g.,                      reasons or data) for each request.                 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. 

                    Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped                           ( print page 37031)                        postcard on which the following statement is made: “Comments to Docket Number 2000-NM-139-AD.” The postcard will be date stamped and returned to the commenter.                 

## Regulatory Impact 

The regulations adopted herein will 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132. 

                    The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption                     **ADDRESSES.**

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Incorporation by reference
      - Safety

## Adoption of the Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive: 

**2000-11-27 Airbus Industrie:**                             Amendment 39-11776. Docket 2000-NM-139-AD.                         

*Applicability:*                             Model A319, A320, and A321 series airplanes; certificated in any category; as listed in Airbus Service Bulletin A320-55A1027, dated May 12, 2000.                         

# Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

*Compliance:*                             Required as indicated, unless accomplished previously.                         

To detect and correct disbonding of the vertical stabilizer structure, which could result in reduced structural integrity of the spar boxes of the vertical stabilizer, accomplish the following: 

## Ultrasonic Inspection 

(a) Within 60 days after the effective date of this AD, perform a one-time ultrasonic inspection to detect disbonding (damage) of the skin attachments at the stringers and spars of the vertical stabilizer, left-and right-hand sides, in accordance with Airbus Service Bulletin A320-55A1027, dated May 12, 2000. 

(1) If no damage is detected or if a single area of damage is less than or equal to an area of 300 square millimeters (mm2), no further action is required by this AD. 

(2) If any damage is detected and the area of damage is greater than 300 mm2, or if multiple damage is detected on one specific component (stringer/spar attachment), prior to further flight, accomplish applicable repairs in accordance with the service bulletin. 

## Modification (for Certain Airplanes) 

(b) For airplanes with manufacturer's serial numbers listed in paragraph B of the Planning Information of Airbus Service Bulletin A320-55A1027, dated May 12, 2000: Prior to or concurrent with the ultrasonic inspection required by paragraph (a) of this AD, modify the vertical stabilizer to ensure proper reinforcement of the structure/skin attachments, in accordance with Airbus Service Bulletin A320-55-1026, Revision 01, dated May 20, 1999. 

# Note 2:

Accomplishment of the modification required by paragraph (b) of this AD, prior to the effective date of this AD, in accordance with Airbus Service Bulletin A320-55-1026 dated March 29, 1999, is considered acceptable for compliance with the applicable requirement of this AD. 

## Alternative Methods of Compliance 

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116. 

# Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

## Special Flight Permits 

(d) Special flight permits may be issued in accordance with § 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. 

## Incorporation by Reference 

(e) The actions shall be done in accordance with Airbus Service Bulletin 

A320-55A1027, dated May 12, 2000, and Airbus Service Bulletin A320-55-1026, Revision 01, dated May 20, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 

Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 

# Note 4:

The subject of this AD is addressed in French airworthiness directive T2000-208-148(B) R1, dated May 17, 2000.

(f) This amendment becomes effective on June 28, 2000.

Issued in Renton, Washington, on June 2, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 00-14432 Filed 6-12-00; 8:45 am] 

BILLING CODE 4910-13-U