Airworthiness directives: Airbus,

 
CONTENT

[Federal Register: October 21, 1999 (Volume 64, Number 203)]

[Proposed Rules]

[Page 56712-56715]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr21oc99-22]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-248-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A300 B2 and B4 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A300 B2 and B4 series airplanes. This proposal would require repetitive inspections to detect cracking of the inner skin panel of the longitudinal lap joint; and repair, or modification and new repetitive inspections, if necessary. 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 detect and correct stress corrosion cracking of the inner skin panel of the longitudinal lap joint, which could result in rapid depressurization of the airplane.

DATES: Comments must be received by November 22, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-248-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

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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 filedin 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 98-NM-248-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. 98-NM-248-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Direction Generale 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 A300 B2 and B4 series airplanes. The DGAC advises that, on four in-service Airbus Model A300 series airplanes, cracking of the inner skin panel of the longitudinal lap joint was detected between frames 67 and 70 at stringer 57. The cracking of the fuselage skin panel was attributed to stress corrosion. On two of the airplanes, corrosion was found previously in the long lap joints, and those areas were reworked beyond the limits provided in the Airbus A300 Structural Repair Manual. Subsequent stress corrosion cracking is attributed to the improper rework. Such cracking of the inner skin panel of the longitudinal lap joint, if not corrected, could result in rapid depressurization of the airplane.

Explanation of Relevant Service Information

The manufacturer has issued Airbus Service Bulletin A300-53-305, Revision 1, dated January 29, 1999. That service bulletin describes procedures for repetitive external and internal eddy current inspections to detect cracking of the inner skin panel of the longitudinal lap joint between frames 65 and 72 at stringer 57, and repair, if necessary. For repaired areas, the service bulletin also specifies new repetitive inspections. The DGAC classified the service bulletin as mandatory and issued French airworthiness directive 98-150- 246(B), dated April 8, 1998, in order to assure the continued airworthiness of these airplanes in France.

The manufacturer also has issued Airbus Service Bulletin A300-53- 306, dated September 5, 1995, which describes procedures for modification of the inner skin panel of the longitudinal lap joint between frames 65 and 72 at stringer 57 by installation of a doubler. That modification is intended to delay the onset of cracking of the inner skin panel of the longitudinal lap joint, and would eliminate the need to accomplish the repetitive inspections described in Airbus Service Bulletin A300-53-305, Revision 1, for all modified areas.

The manufacturer also has issued Airbus Service Bulletin A300-53- 211, Revision 5, dated April 29, 1999. That service bulletin describes inspection criteria to detect cracking of, among other areas, the inner skin panel of the longitudinal lap joint between frames 65 and 72 at stringer 57 after it has been modified in accordance with Airbus Service Bulletin A300-53-306.

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 require accomplishment of the actions specified in the service bulletins described previously, except as discussed below.

Difference Between Proposed Rule and Service Bulletins

Operators should note that, unlike the procedures described in Airbus Service Bulletin A300-53-305, Revision 1, and Airbus Service Bulletin A300-53-211, Revision 5, this proposed AD would not permit further flight if a crack is detected in the inner skin panel of the longitudinal lap joint. The FAA has determined that, because of the safety implications and consequences associated with such cracking, any subject inner skin panel that is found to be cracked must be repaired or modified prior to further flight.

Difference Between Proposed Rule and Foreign Airworthiness Directive

Operators should note that, although French airworthiness directive 98-150-246(B) states that no inspections in accordance with that airworthiness directive are necessary after accomplishment of Airbus Service Bulletin A300-53-306, this proposed AD would require repetitive inspections in accordance with Airbus Service Bulletin A300-53-211, Revision 5, for areas modified in accordance with Airbus Service Bulletin A300-53-306. The modification described in Airbus Service Bulletin A300-53-306 is intended to delay the onset of cracking of the inner skin panel of the longitudinal lap joint. However, cracking may still occur in the modified area. The FAA finds that repetitive inspections of the modified area are necessary to ensure that any cracking is detected in a timely manner.

Other Relevant Rulemaking

On May 28, 1996, the FAA issued AD 96-12-02, Amendment 39-9644 (61 FR 28497, June 5, 1996). The applicability statement of that AD is the same as for this proposed AD. That AD requires measurements of the thickness of the inner skin of, and inspections to detect cracking of, the longitudinal lap joint from the inside of the fuselage at certain stringers, and repair, if necessary, in accordance with Airbus All Operator Telex (AOT) 53-05, Revision 1, dated August 16, 1993. Airbus Service Bulletin A300-53-305, Revision 1, specifies separate compliance times for airplanes on which Airbus AOT 53-05, Revision 1, has been accomplished. Because the actions specified in that AOT are already required by AD 96-12-02, this proposed AD does not specify compliance times for airplanes on

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which the AOT has not been accomplished.

Cost Impact

The FAA estimates that 3 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed eddy current inspection (either internal or external), and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $720, or $240 per airplane, per inspection cycle.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the 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 substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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.

    Sec. 39.13 [Amended]

  2. Section 39.13 is amended by adding the following new airworthiness directive:

    Airbus Industrie: Docket 98-NM-248-AD.

    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 detect and correct stress corrosion cracking of the inner skin panel of the longitudinal lap joint, which could result in rapid depressurization of the airplane, accomplish the following:

    Initial Inspection

    (a) Within 400 flight cycles after the effective date of this AD, perform an external eddy current inspection for cracking of the inner skin panel of the longitudinal lap joint between frames 65 and 72 at stringer 57, in accordance with Airbus Service Bulletin A300- 53-305, Revision 1, dated January 29, 1999.

    Repetitive Inspections

    (b) If no cracking is detected during the inspection performed in accordance with paragraph (a) of this AD: Thereafter, perform an internal or external eddy current inspection, as specified in paragraphs (b)(1) and (b)(2) of this AD, as applicable; at intervals not to exceed 1,250 flight cycles or 7 months, whichever occurs first; in accordance with Airbus Service Bulletin A300-53-305, Revision 1, dated January 29, 1999; until the requirements of paragraph (e) of this AD have been accomplished.

    (1) If the most recent inspection was an internal eddy current inspection, perform an external eddy current inspection of the inner skin panel of the longitudinal lap joint.

    (2) If the most recent inspection was an external eddy current inspection, perform an internal eddy current inspection of the inner skin panel of the longitudinal lap joint.

    Corrective Actions

    (c) If any cracking is detected during any inspection performed in accordance with paragraph (a) or (b) of this AD, prior to further flight, accomplish the actions required by either paragraph (c)(1) or paragraph (c)(2) of this AD.

    (1) Repair the inner skin panel of the longitudinal lap joint in accordance with Airbus Service Bulletin A300-53-305, Revision 1, dated January 29, 1999. Thereafter, repeat the inspection of areas in which no cracking is detected at the interval specified in, and in accordance with, paragraph (b) of this AD; and repeat the inspection of the repaired area at the intervals specified in the service bulletin, in accordance with the service bulletin. If any cracking is found in the repaired area during any repetitive inspection, prior to further flight, repair in accordance with the service bulletin.

    Note 2: Airbus Service Bulletin A300-53-305, Revision 1, dated January 29, 1999, references Airbus Structural Repair Manual Chapter 53-17-00, as an additional source of service information to accomplish the repair specified in paragraph (c)(1) of this AD.

    (2) Modify the inner skin panel of the longitudinal lap joint in accordance with Airbus Service Bulletin A300-53-306, dated September 5, 1995, and accomplish the requirements of paragraph (d) of this AD.

    (d) For airplanes modified in accordance with Airbus Service Bulletin A300-53-306, dated September 5, 1995: Inspect the modified inner skin panel of the longitudinal lap joint to detect cracking at the applicable threshold and repetitive intervals specified in Table 1A, 1B, or 2 of Airbus Service Bulletin A300-53-211, Revision 5, dated April 29, 1999, in accordance with Airbus Service Bulletin A300-53-211, Revision 5. If any cracking is found during any repetitive inspection, prior to further flight, repair in accordance with Airbus Service Bulletin A300-53-211, Revision 5.

    Optional Modification

    (e) Modification of the inner skin panel of the longitudinal lap joint in accordance with Airbus Service Bulletin A300-53-306, dated September 5, 1995, constitutes terminating action for the repetitive inspections required by paragraph (b) of this AD. Such modification does not terminate the repetitive inspections required by paragraph (d) of this AD.

    Alternative Method 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. 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.

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    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 4: The subject of this AD is addressed in French airworthiness directive 98-150-246(B), dated April 8, 1998.

    Issued in Renton, Washington, on October 15, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

    [FR Doc. 99-27565Filed10-20-99; 8:45 am]

    BILLING CODE 4910-13-P