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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 97-NM-184-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Industrie Model A300 B2 and B4 series airplanes, that currently requires inspection of the fuselage longitudinal lap joints and circumferential joints, and of the stringers and doublers for bonding delamination and cracks; and repairs, as necessary. This action would require expansions of certain inspection areas; revisions of certain inspection thresholds or intervals; changes in references to inspection methods; and the addition of a modification to certain longitudinal lap joints. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent delamination and cracking of the fuselage, which could result in rapid decompression of the airplane. 

# DATES:

Comments must be received by July 3, 2000. 

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-184-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. 

The service information referenced in the proposed rule 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. 

# 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:

## Comments Invited 

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. 

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. 

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 97-NM-184-AD.” The postcard will be date stamped and returned to the commenter. 

## Availability of NPRMs 

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 97-NM-184-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 

## Discussion 

On March 27, 1985, the FAA issued AD 85-07-09, amendment 39-5033 (50 FR 13548, April 5, 1985), applicable to certain Airbus Industrie Model A300 B2 and B4 series airplanes, to require inspection of the fuselage longitudinal lap joints and circumferential joints, and of the stringers and doublers for bonding delamination and cracks; and repairs, as necessary. That action was prompted by reports of bonding delamination of these components. The requirements of that AD are intended to prevent rapid decompression of the airplane. 

## Actions Since Issuance of Previous Rule 

                    Since the issuance of AD 85-07-09, the manufacturer has issued three revised service bulletins that describe expansions of certain inspection areas; revisions of certain inspection thresholds or intervals; and certain changes in references to inspection methods. The manufacturer also has issued a service bulletin that describes procedures for a modification to certain longitudinal lap joints. The Direction Ge                                        ne                                        rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has advised that those revised or additional actions are necessary in order to adequately protect against bonding delamination or bulging of the fuselage longitudinal lap joints and circumferential joints, or delamination of fuselage stringers and doublers.                 

## Explanation of Relevant Service Information 

Airbus has issued Service Bulletin A300-53-148, Revision 11, dated September 8, 1998, which describes procedures for inspection of certain fuselage bonded lap joints and circumferential joints to detect bonding delamination; and repair, if necessary.

Airbus also has issued Service Bulletin A300-53-178, Revision 10, dated September 8, 1998, which describes procedures for inspection of certain fuselage bonded lap joints and circumferential joints to detect corrosion and cracks; and repair, if necessary. 

                    Airbus also has issued Service Bulletin A300-53-149, Revision 14, dated September 8, 1998, which describes procedures for inspection of bonded stringers and doublers to detect debonding; and repair, if necessary.                           ( print page 34994)    

The DGAC classified these service bulletins as mandatory and issued French airworthiness directive 1984-140-064(B) R3, dated October 6, 1999, in order to assure the continued airworthiness of these airplanes in France. 

Airbus also has issued Service Bulletin A300-53-0209, Revision 10, dated July 5, 1999, which describes procedures for the modification of bonded longitudinal lap joints. The modification involves the installation of doublers on longitudinal lap joints at stringers 29 and 35 in section 18. This modification is intended to eliminate the need for bonded lap joint inspections for stringers 29 and 35 in section 18, as specified in Airbus Service Bulletin A300-53-148, Revision 11. The DGAC classified Service Bulletin A300-53-0209 as mandatory and issued French airworthiness directive 97-371-235(B), dated December 3, 1997, in order to assure the continued airworthiness of these airplanes in France. 

Accomplishment of the actions specified in the service bulletins described in this section is intended to adequately address the identified unsafe condition. 

## FAA's Conclusions 

This airplane model is manufactured in France and is 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. 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 Proposed 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, the proposed AD would supersede AD 85-07-09 to require accomplishment of the actions specified in the service bulletins described previously, except as discussed below. Additionally, repetitive inspections are required in paragraph (c) of AD 85-07-09 (as indicated by paragraph (c)(2)), but have been more clearly specified in this proposed AD. 

## Differences Between Proposed Rule and Service Information 

Operators should note that, unlike certain procedures described in the service information, this proposed AD would not permit further flight if cracking or corrosion is detected in the fuselage longitudinal lap joints or circumferential joints, or in the bond of the stringers and doublers. The FAA has determined that, because of the safety implications and consequences associated with such cracking and corrosion, any subject longitudinal lap joint, circumferential joint, or bond of the stringers and doublers that is found to be cracked or corroded must be repaired or modified prior to further flight. 

## Cost Impact 

There are approximately 20 airplanes of U.S. registry that would be affected by this proposed AD. 

The inspection of the bonded longitudinal lap joints and circumferential joints to detect bonding delamination that is currently required by AD 85-07-09, and retained in this AD, takes approximately 146 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these currently required actions on U.S. operators is estimated to be $175,200, or $8,760 per airplane, per inspection cycle. 

The inspection of the bonded longitudinal lap joints and circumferential joints in to detect corrosion and cracking that is currently required by AD 85-07-09, and retained in this AD, takes approximately 72 work hours per airplane to accomplish. Based on these figures, the cost impact of these currently required actions on U.S. operators is estimated to be $86,400, or $4,320 per airplane, per inspection cycle. 

The inspections of the bonded stringers and doublers to detect debonding that are currently required by AD 85-07-09, and retained in this AD, take approximately 129 work hours per airplane to accomplish. Based on these figures, the cost impact of these currently required actions on U.S. operators is estimated to be $154,800, or $7,740 per airplane, per inspection cycle. 

The modification of the bonded longitudinal lap joint that is proposed in this AD action would take as much as 581 work hours (not including access and close) per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost as much as $16,148 per airplane, depending on kits purchased. Based on these figures, the cost impact of the proposed modification on U.S. operators is estimated to be as high as $1,020,160, or $51,008 per airplane. 

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. 

## Regulatory Impact 

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132. 

                    For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption                     **ADDRESSES**                    .                

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Safety

## The Proposed Amendment 

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 removing amendment 39-5033 (50 FR 13548, April 5, 1985), and by adding a new airworthiness directive (AD), to read as follows:
      ( print page 34995)    
**Airbus Industrie:**                                 Docket 97-NM-184-AD. Supersedes AD 85-07-09, Amendment 39-5033.                            

*Applicability:*                                 Model A300 B2 and B4 series airplanes, manufacturer serial numbers 003 through 156 inclusive, certificated in any category.                            

# 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 (f) 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 prevent rapid decompression of the airplane due to bonding delamination and cracking of the fuselage, accomplish the following: 

## Restatement of Requirements of AD 85-07-09 

### Delamination Inspections of Longitudinal Lap and Circumferential Joints 

(a) Except as required by paragraph (d) of this AD: Prior to the threshold limits specified in Table 1 of Airbus Service Bulletin A300-53-148, Revision 6, dated October 10, 1984, or within 6 months after May 13, 1985 (the effective date of AD 85-07-09), whichever occurs later, inspect the fuselage longitudinal lap joints and circumferential joints for bonding delamination, in accordance with the service bulletin. 

(1) If no delamination is detected, repeat these inspections in accordance with the schedule shown in Table 1 of the service bulletin. 

(2) If delamination is detected during any inspection, prior to further flight, perform the actions indicated in Figure 3, “Follow-up Action,” of the service bulletin. 

### Corrosion and Crack Inspections of Longitudinal Lap and Circumferential Joints

(b) Except as required by paragraph (d) of this AD: Prior to the threshold limits specified in Figure 1, “Inspection Program,” of Airbus Service Bulletin A300-53-178, Revision 4, dated October 10, 1984, or within 6 months after May 13, 1985, whichever occurs later, visually inspect for corrosion and cracks, and repair if necessary, the bonded longitudinal lap joints and circumferential joints specified in Figure 1 of the service bulletin, in accordance with the service bulletin. Repeat the inspections thereafter in accordance with the schedule shown in Figure 1 of the service bulletin. 

### Delamination Inspections of Stringers and Doublers 

(c) Except as required by paragraph (d) of this AD: Prior to the threshold limits specified in Figure 1, “Inspection Frequency,” of Airbus Service Bulletin A300-53-149, Revision 6, dated October 10, 1984, or within 6 months after May 13, 1985, whichever occurs later, inspect for debonding, and repair, if necessary, bonded stringers and bonded doublers in the area between frame 1 and frame 18 and between frame 40 and frame 80 on all airplanes up to and including serial number 156, and in the area between frame 18 and frame 40 on all airplanes up to and including serial number 104. Repeat the inspections thereafter at intervals specified in Figure 1 of the service bulletin, except for repaired areas. The inspections of stringers are divided into three areas, as indicated in Figure 2 of the service bulletin, with the following options: 

(1) Inspection in Area 1 is not required if Modification No. 2904, described in Airbus Service Bulletin A300-53-146, dated November 28, 1980, has been incorporated. 

(2) Preventive riveting of stringers located in Area 2 in accordance with Airbus Service Bulletin A300-53-197, dated October 10, 1984, allows for an extension of the interval of subsequent repetitive inspections to the interval required for Area 3. 

## New Requirements of This AD 

### Later Service Bulletin Revisions 

(d) After the effective date of this new AD, only the following service bulletin revisions shall be used for compliance thresholds and intervals and for accomplishment instructions for the actions required by this AD, as specified in paragraphs (d)(1), (d)(2), and (d)(3) of this AD. For any airplane that, as of the effective date of this AD, has exceeded a revised threshold or interval for any specified action, accomplish that action within 6 months after the effective date of this AD. 

(1) Airbus Service Bulletin A300-53-148, Revision 11, dated September 8, 1998, shall be used for the requirements of paragraph (a) of this AD. For corrective actions and follow-on inspections, Figure 5, “Follow-up Action,” of the service bulletin shall be used. 

(2) Airbus Service Bulletin A300-53-178, Revision 10, dated September 8, 1998, shall be used for the requirements of paragraph (b) of this AD. For inspection thresholds and intervals, Paragraph C., “Description,” of the service bulletin shall be used. 

(3) Airbus Service Bulletin A300-53-149, Revision 14, including Appendix 01, dated September 8, 1998, shall be used for the requirements of paragraph (c) of this AD. For inspection thresholds and intervals, Figure 1, Sheet 1, “Inspection Frequency,” of the service bulletin shall be used. 

### Modification of Lap Joints (Partial Terminating Action) 

(e) Within 60 months after the effective date of this AD, modify the bonded longitudinal lap joints in accordance with Airbus Service Bulletin A300-53-0209, Revision 10, dated July 5, 1999. Accomplishment of the modification terminates the repetitive inspections required by paragraph (a) of this AD for stringers 29 and 35 in section 18 only. 

### Alternative Methods of Compliance 

(f) 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 2:

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 

(g) Special flight permits may be issued in accordance with sections 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. 

# Note 3:

The subject of this AD is addressed in French airworthiness directives 97-371-235(B), dated December 3, 1997, and 1984-140-064(B)R3, dated October 6, 1999.

Issued in Renton, Washington, on May 25, 2000.

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 00-13695 Filed 5-31-00; 8:45 am] 

BILLING CODE 4910-13-U