Airworthiness Directives; Airbus Model A300-600 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A300-600 series airplanes, that requires repetitive ultrasonic inspections to detect cracks on the forward fittings in the radius of frame 40 adjacent to the tension bolts in the center section of the wings, and various follow-on actions. This amendment is prompted by reports of cracking due to fatigue-related stress in the radius of frame 40 adjacent to the tension bolts at the center/outer wing junction. The actions specified by this AD are intended to detect and correct fatigue cracking on the forward fittings in the radius of frame 40 adjacent to the tension bolts in the center section of the wings, which could result in reduced structural integrity of the wings.

DATES:

Effective March 28, 2000.

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

ADDRESSES:

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 Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 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:

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 all Airbus Model A300-600 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on November 24, 1998 (63 FR 64918). That action proposed to require repetitive ultrasonic inspections to detect cracks on the forward fittings in the radius of frame 40 adjacent to the tension bolts in the center section of the wings, and various follow-on actions.

Comments

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, an operator, has no comments on the proposed supplemental NPRM, except to report that the ultrasonic inspections have been accomplished on part of its fleet, with no findings of cracking as yet.

Clarification of Flight Hour Thresholds

One commenter, the manufacturer, states that it cannot determine how the flight hour thresholds specified in the supplemental NPRM were calculated by the FAA. The FAA infers that the commenter is requesting clarification regarding the requirement to accomplish the initial inspection at “7,250 total landings or 17,700 total flight hours, whichever occurs first,” as specified in paragraph (a)(1)(i) of the supplemental NPRM.

The FAA herewith provides the requested information. The threshold of 7,600 total landings specified in Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997, is calculated using the “adjustment-for-range” formula and a fatigue rating of 0.13, and is valid for airplanes having an average flight time (AFT) of 2.1 hours. (Airbus Service Bulletin A300-57-6062, Revision 02, was referenced in the supplemental NPRM as the appropriate source of service information for this AD.) At the time the supplemental NPRM was developed, the AFT for all Airbus Model A300-600 airplanes operated in the United States was 2.45 hours. The FAA used the 2.45 AFT and the “adjustment-for-range” formula to obtain an adjustment factor appropriate for airplanes on the U.S. Register, as follows:

1−[(2.45−2.1) * 0.13] = 0.9545

0.9545 7,600 = 7,254.

Additionally, the FAA multiplied the 2.45 AFT by the adjusted landing threshold to obtain an approximation of the corresponding flight hours, as follows:

7,254 * 2.45 = 17,773.

Using these calculations, the FAA determined appropriate landing and flight-hour thresholds, previously described, for the requirements of this AD.

Request To Revise Compliance Threshold

The same commenter requests that the supplemental NPRM be revised to replace the compliance thresholds with thresholds calculated using a new method. The commenter states that the flight-hour thresholds specified in the supplemental NPRM seem to be overly conservative for operators utilizing airplanes in long-range operations; such thresholds will penalize those operators by requiring inspections earlier than necessary. The commenter states that, in order to avoid using the current “adjustment-for-range” formula for calculating compliance times, an alternative method has been developed. This new method will provide constant flight-hour thresholds and intervals in addition to the flight cycle-based thresholds and intervals. The commenter proposes to provide these additional thresholds to the FAA, calculated in accordance with the new method.

The FAA does not concur. The FAA has reviewed the alternative method proposed by the manufacturer for calculating flight-hour thresholds, and has discussed the requirements of this AD further with the manufacturer and with the Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France. The FAA concurs technically with use of such flight-hour and flight-cycle thresholds and intervals. However, the revised thresholds have not yet been made available to the FAA for its review, and the manufacturer advises that there has been a delay in internal review and approval of the thresholds. The FAA does not consider it appropriate to further delay issuance of this AD while awaiting the receipt of these data. Therefore, the FAA has determined that it is necessary to issue the AD with the currently specified thresholds. Once revised thresholds are made available, the FAA will review them and determine if further rulemaking is necessary. Additionally, under the provisions of paragraph (d)(1) of the AD, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such adjustments of the compliance time would provide an acceptable level of safety.

Conclusion

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 as proposed.

Cost Impact

The FAA estimates that 35 airplanes of U.S. registry will be affected by this AD. It will take approximately 2 work hours per airplane (1 work hour per side) to accomplish the required ultrasonic inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $4,200, or $120 per airplane, per inspection cycle.

The cost impact figure discussed above 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.

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.

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 it 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.

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

2000-03-20 Airbus Industrie: Amendment 39-11580. Docket 95-NM-150-AD.

Applicability: All Model A300-600 airplanes, 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 (d)(1) 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 fatigue cracking on the forward fittings in the radius of frame 40 adjacent to the tension bolts in the center section of the wings, which could result in reduced structural integrity of the wings, accomplish the following:

Inspections and Corrective Actions

(a) Perform an ultrasonic inspection to detect cracking on the forward fittings in the radius of frame 40 adjacent to the tension bolts in the center section of the wings, in accordance with Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997, at the applicable time specified in either paragraph (a)(1) or (a)(2) of this AD.

(1) For airplanes that have accumulated fewer than 9,100 total landings or 22,300 total flight hours as of the effective date of this AD: Inspect at the later of the times specified in either paragraph (a)(1)(i) or (a)(1)(ii) of this AD.

(i) Prior to the accumulation of 7,250 total landings or 17,700 total flight hours, whichever occurs first.

(ii) Within 1,500 landings after the effective date of this AD.

(2) For airplanes that have accumulated 9,100 total landings or more and 22,300 total flight hours or more as of the effective date of this AD: Inspect within 750 landings after the effective date of this AD.

Note 2:

Inspections that were accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A300-57-6062, Revision 1, dated July 23, 1995, are considered acceptable for compliance with paragraph (a) of this AD.

(b) If no crack is detected during the inspection required by paragraph (a) of this AD, repeat the ultrasonic inspection required by that paragraph thereafter at intervals not to exceed 6,500 landings or 16,000 flight hours, whichever occurs first; in accordance with Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997.

(c) If any crack is detected during any inspection required by paragraph (a) or (b) of this AD, prior to further flight, install an access door, and perform an eddy current inspection to confirm the presence of a crack; in accordance with Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997. Accomplishment of this eddy current inspection terminates the repetitive inspection requirement of paragraph (b) of this AD.

(1) If no crack is detected during the eddy current inspection, repeat the eddy current inspection, in accordance with the service bulletin, thereafter at intervals not to exceed 6,500 landings or 16,000 flight hours, whichever occurs first.

(2) If any crack is detected during any eddy current inspection performed in accordance with paragraph (c) or (c)(1) of this AD, prior to further flight, blend out the crack and repeat the eddy current inspection in accordance with the service bulletin.

(i) If the eddy current inspection performed after the blend-out shows that the crack has been removed, and if the blend-out is equal to or less than 50 millimeters (mm) long and equal to or less than 2 mm deep, thereafter repeat the eddy current inspection at intervals not to exceed 2,800 landings or 7,000 flight hours, whichever occurs first.

(ii) If the eddy current inspection performed after the blend-out shows that the crack has not been removed, or if the blend-out is more than 50 mm long or more than 2 mm deep, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Generale de l'Aviation Civile (or its delegated agent).

Alternative Methods of Compliance

(d)(1) 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.

(2) Operators may request an extension to the compliance times of this AD in accordance with the “adjustment-for-range” formula found in Paragraph 1.B.(5) of Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997; and provided in A300-600 Maintenance Review Board, Section 5, Paragraph 5.4. The average flight time per flight cycle (landing) in hours used in this formula should be for an individual airplane. Average flight time for a group of airplanes may be used if all airplanes of the group have flight times differing by no more than 10 percent. If compliance times are based on the average flight time for a group of airplanes, the flight times for individual airplanes of the group must be included for FAA review.

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

(e) 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.

Incorporation by Reference

(f) Except as required by (c)(2)(ii) of this AD, the actions shall be done in accordance with Airbus Service Bulletin A300-57-6062, Revision 02, dated January 29, 1997, which contains the specified effective pages:

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 95-063-177(B)R3, dated July 2, 1997.

(g) This amendment becomes effective on March 28, 2000.