AD 94-18-02

This amendment adopts a new airworthiness directive (AD), applicable to Airbus Industrie Model A300 series airplanes, that requires the implementation of a corrosion prevention and control program, either by revising the maintenance program or by accomplishing specific inspection procedures. This amendment is prompted by reports of incidents involving corrosion and fatigue cracking in transport category airplanes that are approaching or have exceeded their economic design goal; these incidents have jeopardized the airworthiness of the affected airplanes. The actions specified by this AD are intended to prevent degradation of the structural capabilities of the airplane due to the problems associated with corrosion.

Final rule.

94-18-02 AIRBUS: Amendment 39-9015. Docket 91-NM-23-AD.

Applicability: Model A300 series airplanes, (excluding Model A300-600 series), certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

NOTE 1: This AD references Airbus Industrie Document, "A300 Corrosion Prevention and Control Program," dated November 1992, for corrosion instructions, compliance times, and reporting requirements. In addition, this AD specifies inspection and reporting requirements beyond those included in that Document. Where there are differences between the AD and the Document, the AD prevails.

NOTE 2: As used throughout this AD, the term "the FAA" is defined differently for different operators, as follows: For those operators complying with paragraph (a) of this AD, "the FAA" is defined as "the Manager of the Standardization Branch, ANM-113, FAA, Transport Airplane Directorate." For those operators operating under Federal Aviation Regulations (FAR) part 121 or 129 (14 CFR part 121 or part 129), and complying with paragraph (b) of this AD, "the FAA" is defined as "the cognizant Principal Maintenance Inspector (PMI)." For those operators operating under FAR part 91 or 125 (14 CFR part 91 or part 125), and complying with paragraph (b) of this AD, "the FAA" is defined as "the cognizant Maintenance Inspector at the appropriate FAA Flight Standards office."

To prevent degradation of the structural capabilities of the airplane due to the problems associated with corrosion damage, accomplish the following:

(a) Except as provided in paragraph (b) of this AD, complete each of the corrosion instructions specified in Section 5 of Airbus Industrie Document, "A300 Corrosion Prevention and Control Program," dated November 1992 (hereinafter referred to as "the Document"), in accordance with the procedures of the Document, and the schedule specified in paragraphs (a)(1) and (a)(2) of this AD.

NOTE 3: A "corrosion instruction," as defined in Section 5 of the Document, includes inspections; procedures for a corrective action, including repairs, under identified circumstances; application of corrosion inhibitors; and other follow-on actions.

NOTE 4: Corrosion instructions completed in accordance with the Document before the effective date of this AD may be credited for compliance with the initial corrosion instruction requirements of paragraph (a)(1) of this AD.

NOTE 5: Where non-destructive inspection (NDI) methods are employed, in accordance with Section 5 of the Document, the standards and procedures used must be acceptable to the Administrator in accordance with FAR section 43.13 (14 CFR 43.13).

NOTE 6: Procedures identified in the Document as "informational only" are not required to be accomplished by this AD.

(1) Complete the initial corrosion instruction of each "corrosion inspection area" defined in Section 5 of the Document as follows:
(i) For aircraft areas that have not yet reached the "implementation age" (IA) as of one year after the effective date of this AD, initial compliance must occur no later than the IA plus the "repeat interval" (RI).
(ii) For aircraft areas that have exceeded the IA as of one year after the effective date of this AD, initial compliance must occur within the RI for the area, measured from a date one year after the effective date of this AD.
(iii) For airplanes that are 20 years old or older as of one year after the effective date of this AD, initial compliance must occur for all areas within one RI, or within six years, measured from a date one year after the effective date of this AD, whichever occurs first.
(iv) Notwithstanding paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this AD, accomplish the initial task, for each area that exceeds the IA for that area, at a minimum rate of one such area per year, beginning one year after the effective date of this AD.

NOTE 7: This paragraph does not require inspection of any area that has not exceeded the IA for that area.

NOTE 8: This minimum rate requirement may cause a hardship on some small operators. In those circumstances, requests for adjustments to the implementation rate will be evaluated on a case-by-case basis under the provisions of paragraph (h) of this AD.

(2) Repeat each corrosion instruction at a time interval not to exceed the RI specified in the Document for that task.

(b) As an alternative to the requirements of paragraph (a) of this AD: Prior to one year after the effective date of this AD, revise the FAA-approved maintenance/inspection program to include the corrosion prevention and control program specified in the Document; or to include an equivalent program that is approved by the FAA. In all cases, the initial corrosion instruction for each corrosion inspection area must be completed in accordance with the compliance schedule specified in paragraph (a)(1) of this AD.
(1) Any operator complyingwith paragraph (b) of this AD may use an alternative recordkeeping method to that otherwise required by FAR section 91.417 (14 CFR 91.417) or section 121.380 (14 CFR 121.380) for the actions required by this AD, provided it is approved by the FAA and is included in a revision to the FAA-approved maintenance/inspection program.
(2) Subsequent to the accomplishment of the initial corrosion instruction, extensions of RI's specified in the Document must be approved by the FAA.

(c) To accommodate unanticipated scheduling requirements, it is acceptable for an RI to be increased by up to 10%, but not to exceed 6 months. The FAA must be informed, in writing, of any such extension within 30 days after such adjustment of the schedule.

(d) (1) If, as a result of any inspection conducted in accordance with paragraph (a) or (b) of this AD, Level 3 corrosion is determined to exist in any area, accomplish either paragraph (d)(1)(i) or (d)(1)(ii) of this AD within 7 days after such determination:
(i) Submit a report of that determination to the FAA and complete the corrosion instruction in the affected areas on all Model A300 series airplanes in the operator's fleet; or
(ii) Submit to the FAA for approval one of the following:
(A) A proposed schedule for performing the corrosion instructions in the affected areas on the remaining Model A300 series airplanes in the operator's fleet, which is adequate to ensure that any other Level 3 corrosion is detected in a timely manner, along with substantiating data for that schedule; or
(B) Data substantiating that the Level 3 corrosion found is an isolated occurrence.

NOTE 9: Notwithstanding the provisions of Section 2 of the Document, which would permit corrosion that otherwise meets the definition of Level 3 corrosion (i.e., which is determined to be a potentially urgent airworthiness concern requiring expeditious action) to be treated as Level 1 if the operator finds that it "can be attributed to an event not typical of the operator's usage of other airplanes in the same fleet," this paragraph requires that data substantiating any such finding be submitted to the FAA for approval.
(2) The FAA may impose schedules other than those proposed, upon finding that such changes are necessary to ensure that any other Level 3 corrosion is detected in a timely manner.
(3) Within the time schedule approved under paragraph (d)(1) or (d)(2) of this AD, accomplish the corrosion instructions in the affected areas of the remaining Model A300 series airplanes in the operator's fleet.

(e) If, as a result of any inspection, after the initial inspection, conducted in accordance with paragraph (a) or (b) of this AD, it is determined that corrosion findings exceed Level 1 in any area, within 60 days after such determination a means approved by the FAA must be implemented to reduce future findings of corrosion in that area to Level 1 or better.

(f) Before any operator places into service any airplane subject to the requirements of this AD, a schedule for the accomplishment of corrosion instructions required by this AD must be established in accordance with paragraph (f)(1) or (f)(2) of this AD, as applicable:
(1) For airplanes previously maintained in accordance with this AD, the first corrosion instruction in each area to be performed by the new operator must be accomplished in accordance with the previous operator's schedule or with the new operator's schedule, whichever would result in the earlier accomplishment date for that task. After each corrosion instruction has been performed once, each subsequent task must be performed in accordance with the new operator's schedule.
(2) For airplanes that have not been previously maintained in accordance with this AD, the first corrosion instruction for each area to be performed by the new operator must be accomplished prior to further flight or in accordance with a schedule approved by the FAA.

(g) Reports of Level 2 and Level 3corrosion must be submitted at least quarterly to Airbus in accordance with Section 6 of the Document.
NOTE 10: Reporting of Level 2 and Level 3 corrosion found as a result of any opportunity inspection is highly desirable.

(h) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through the cognizant Maintenance Inspector at the appropriate FAA Flight Standards office, who may concur or comment and then send it to the Manager, Los Angeles ACO.

NOTE 11: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(i) 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.

(j) Reports of corrosion inspection results required by this AD have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

(k) The actions shall be done in accordance with Airbus Industrie Document, "A300 Corrosion Prevention and Control Program," dated November 1992. 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.

(l) This amendment becomes effective on October 11, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to Airbus Model A300 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on May 27, 1993 (58 FR 30722). That action proposed to require the implementation of a corrosion prevention and control program, either by revising the maintenance program or by accomplishing specific inspection procedures.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

One commenter supports the proposal.

Several commenters request that the proposed rule specify whether or not the proposed requirements are applicable to Airbus Model A300-600 series airplanes. These commenters consider that the rule should not be applicable to the Model A300-600, since the ruleis intended to address problems associated with structural failure of aging airplanes, and the Model A300-600 fleet is not close to reaching its economic design goal. The FAA acknowledges that some clarification of the applicability of the rule is warranted. The FAA did not intend for the rule to be applicable to the Model A300-600. Therefore, to eliminate any confusion that may arise among affected operators, the FAA has revised the applicability of the final rule to indicate clearly that the requirements of the rule are not applicable to Model A300-600 series airplanes.

Another commenter requests that NOTE 2 of the proposal be expanded to explain the extent of FAA involvement in paragraphs (c), (d), (e), and (f). The FAA does not consider that any additional explanation is necessary. NOTE 2 specifically defines the term "FAA" for affected operators conducting their operations under various parts of the Federal Aviation Regulations. The information presented in NOTE 2 is valid for each use of the term "FAA" throughout the AD.

This same commenter requests that, in order to ensure consistent implementation of the program and to provide a reliable statistical data base, the proposal be revised to indicate that credit for completion of the initial task is limited to only those inspections that are accomplished at a time beyond the implementation age (IA) for the particular area. In support of this request, the commenter refers to NOTE 7 of the proposal, which states that paragraph (a) does not require inspection of any area that has not exceeded the implementation age for that area. The FAA does not agree. If an operator elects to perform an inspection prior to the IA for a certain area, that inspection must then be repeated at the appropriate repeat interval (RI). The FAA considers that this will ensure a consistent implementation of the program.

In its comments to the notice, the manufacturer requests that the FAA clarify the fact that the issuance of the revised Airbus Industrie Document, "A300 Corrosion Prevention and Control Program," was intended only to help improve the understanding and handling of the inspection procedures described in the baseline corrosion prevention and control program (CPCP). However, the baseline program itself, as detailed in the original issuance of that Document, was not changed in the revised version. The FAA acknowledges this information.

The manufacturer also notes that the economic impact information contained in the preamble to the notice presented the CPCP as if it were a program separate from the affected operators' current maintenance programs, and that the calculated costs would be supplemental to those costs currently incurred through regular maintenance practices. The commenter points out that many of the tasks listed in the CPCP existed as part of operators' maintenance programs prior to the issuance of the Airbus CPCP document (and, thus, prior to the issuance of this AD).Therefore, the commenter considers that the economic impact of the rule should be adjusted accordingly. The FAA acknowledges this information, and has revised the economic impact information, below, to clarify this aspect.

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Economic Impact

The FAA estimates that 54 airplanes of U.S. registry will be affected by this AD.

There are 50 corrosion inspection areas called out in the Airbus Industrie Document, and it will take approximately 16 work hours per area to accomplish the required actions. The average labor rate is approximately $55 per work hour. Based on these figures, the total impact of this AD on U.S. operators is approximately $2,376,000, or $44,000 per airplane, for the initial 6-year inspection cycle. This total cost impact figure is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

The FAA points out that the total cost impact figure discussed above is presented as if the actions required by this AD were to be conducted as "stand alone" actions. However, in actual practice, these actions will be accomplished coincidentally or in combination with normally scheduled airplane inspections and other maintenance program tasks. Some affected operators already have been performing these actions as part of their regular maintenance program. Therefore, the actual number of necessary "additional" work hours and associated labor costs will be minimal in many instances. Additionally, any costs associated with special airplane scheduling also will be minimal.

Regulatory Impact

The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of itmay 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: