00-18403. Airworthiness Directives; Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R Series Airplanes (A300-600)

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 all Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R series airplanes (A300-600), that currently requires an inspection to detect cracks of certain attachment holes; and installation of new fasteners and follow-on inspections or repair, if necessary. This action would require a reduction in the inspection threshold and repetitive intervals and an increase in the number of attachment holes to be inspected. 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 fatigue cracking of the forward fitting of fuselage frame FR47, which could result in reduced structural integrity of the frame.

DATES:

Comments must be received by August 21, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-322-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 99-NM-322-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

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 [phone]; fax [phone].

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.

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 proposed 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 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 99-NM-322-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. 99-NM-322-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On July 25, 1997, the FAA issued AD 97-16-06, amendment 39-10097 (62 FR 41257, August 1, 1997) [A correction was published in the Federal Register on August 25, 1997 (62 FR 44888)], applicable to all Airbus Model A300 B4-600 (A300-600), A300 B4-600R, and A300 F4-600R series airplanes (A300-600), to require an inspection to detect cracks of certain attachment holes; and installation of new fasteners and follow-on inspections or repair, if necessary. That action was prompted by reports of cracking on the forward fitting of fuselage frame FR47 at the level of the last fastener of the external angle fitting. The requirements of that AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of the airframe.

Actions Since Issuance of Previous Rule

Since the issuance of AD 97-16-06, the Direction Gonorale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has informed the FAA that cracks have been found in the internal angle fittings of the wing center box at fuselage frame FR 47 on airplanes that had not reached the threshold of the fastener hole inspections required by AD 97-16-06. The DGAC also has informed the FAA that cracks have been found in additional fastener holes that were not required to be inspected by AD 97-16-06.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A300-57-6049, Revision 3, dated December 15, 1998, which describes procedures for performing a rotating probe inspection to detect cracks of the attachment holes H, I, K, L, M and N, and various follow-on actions. (These follow-on actions include reaming/drilling holes and installing new fasteners.) The service bulletin also describes procedures for repair of certain cracking conditions. The repair procedures include reaming/drilling holes, re-inspecting the hole, and trimming the external fitting. The service bulletin permits further flight, under certain conditions, with attachment holes that are cracked within certain limits. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 1999-147-279(B) R1, dated July 12, 2000, in order to assure the continued airworthiness of these airplanes in France.

FAA's Conclusions

This airplane model is manufactured in France and is 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 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 97-16-06 to require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between the Proposed Rule and Relevant Service Information

Operators should note that, unlike the procedures described in the referenced service bulletin, this proposed AD would not permit further flight with cracking detected in the attachment holes. The FAA has determined that, due to safety implications and consequences associated with such cracking, the subject attachment holes that are found to be cracked must be repaired prior to further flight. Repairs would be required to be accomplished in accordance with a method approved by the FAA, the DGAC (or its delegated agent), or the service bulletin described previously, as applicable.

Operators also should note that, unlike particular provisions in the service bulletin regarding adjustment of the compliance times using an “adjustment-for-range” formula, this proposed AD would not permit formulaic adjustments of the inspection compliance times. The FAA has determined that such adjustments may present difficulties in determining if the applicable inspections and modifications have been accomplished within the appropriate time frame. Further, while such adjustable compliance times are utilized as part of the Maintenance Review Board program, they do not fit practically into the AD tracking process for operators or for Principal Maintenance Inspectors attempting to ascertain compliance with AD's. Therefore, the FAA has determined that fixed compliance times should be specified for accomplishment of the actions required by this AD.

Additionally, after discussions with the DGAC and the manufacturer, the FAA has determined that flight-hour maximums should be included as part of the compliance threshold and repetitive intervals for the inspections required by this proposed AD. Inclusion of a compliance threshold in terms of total flight hours as well as total flight cycles, and requiring inspection at the earlier of those times, will ensure that airplanes with longer-than-average flight times are inspected at a threshold and intervals necessary to maintain safety. Accordingly, the FAA has specified that the initial inspection must be accomplished at the earliest time an airplane reaches certain accumulated total flight cycles or total flight hours, and that repetitive inspections are to be accomplished at intervals not to exceed certain flight cycles or flight hours, whichever occurs first.

Furthermore, the service bulletin specifies that operators need not count touch-and-go landings in determining the total number of landings between two consecutive inspections, when those landings are less than five percent of the landings between inspection intervals. Since fatigue cracking that was was found on the forward fitting of fuselage frame FR47 at the level of the last fastener of the external angle fitting is aggravated by landing, the FAA finds that all touch-and-go landings must be counted in determining the total number of landings between two consecutive inspections.

The service bulletin also recommends a grace period of 1,500 flight cycles (after receipt of the service bulletin) for accomplishing the rotating probe inspection, unless the threshold has been exceeded by more than 2,000 flight cycles; in which case, the grace period is 750 flight cycles (after receipt of the service bulletin). The FAA has determined that a grace period of 750 flight cycles and 1,700 flight hours, as applicable, would address the identified unsafe condition in a timely manner. In developing an appropriate grace period for this AD, the FAA considered not only the manufacturer's recommendation, but the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection (7 work hours). In light of all of these factors, the FAA finds a grace period of 750 flight cycles and 1,700 flight hours, as applicable, for initiating the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Explanation of Change to Applicability

The applicability throughout AD 97-16-06 reads “all Model A300-600 series airplanes.” The FAA has revised the applicability of this proposed AD to identify the specific affected model designations as published on the type certificate data sheet [i.e., Model A300 B4-600 (A300-600), A300 B4-600R, and A300 F4-600R series airplanes].

Cost Impact

There are approximately 74 airplanes of U.S. registry that would be affected by this proposed AD.

The actions that are proposed in this AD action would take approximately 7 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost as much as $6,327 per airplane. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to cost as much as $499,278, or $6,747 per airplane, per inspection cycle.

The cost impact figure discussed above is 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

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

[Amended]

2. Section 39.13 is amended by removing amendment 39-10097 (62 FR 44888, August 25, 1997), and by adding a new airworthiness directive (AD), to read as follows:

Airbus Industrie: Docket 99-NM-322-AD. Supersedes AD 97-16-06, Amendment 39-10097.

Applicability: All Model A300 B4-600, A300 B4-600R, and A300 F4-600R series airplanes (A300-600), 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 (e)(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 prevent fatigue cracking of the forward fitting of fuselage frame FR47, which could result in reduced structural integrity of the airframe, accomplish the following:

Inspection of Holes H, I, K, L, M, and N

(a) Perform a rotating probe inspection to detect cracks of the attachment holes H, I, K, L, M, and N on the left and right internal angles of the wing center box, in accordance with Airbus Service Bulletin A300-57-6049, Revision 3, dated December 15, 1998, at the applicable time specified in paragraph (a)(1) or (a)(2) of this AD.

(1) For airplanes on which Airbus Modification 10454 (reference Airbus Service Bulletin A300-57-6050) and Airbus Modification 10155 have not been installed: Inspect at the earlier of the times specified in paragraph (a)(1)(i) or (a)(1)(ii) of this AD.

(i) Prior to the accumulation of 10,400 total flight cycles, or within 750 flight cycles after the effective date of this AD, whichever occurs later; or

(ii) Prior to the accumulation of 23,900 total flight hours, or within 1,700 flight hours after the effective date of this AD, whichever occurs later.

(2) For airplanes on which Airbus Modification 10454 (reference Airbus Service Bulletin A300-57-6050) or Airbus Modification 10155 has been installed: Inspect at the earlier of the times specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD.

(i) Prior to the accumulation of 14,200 total flight cycles, or within 750 flight cycles after the effective date of this AD, whichever occurs later; or

(ii) Prior to the accumulation of 32,600 total flight hours, or within 1,700 flight hours after the effective date of this AD, whichever occurs later.

No Cracking Found: Installation of New Fastener and Repetitive Inspections

(b) If no crack is found during any rotating probe inspection required by paragraph (a) of this AD, prior to further flight, install new fasteners in accordance with Airbus Service Bulletin A300-57-6049, Revision 3, dated December 15, 1998. Repeat the rotating probe inspection thereafter at intervals not to exceed 5,900 flight cycles or 13,500 flight hours, whichever occurs first.

Cracking Found: Corrective Actions

(c) If any crack is found during any rotating probe inspection required by paragraph (a) of this AD that is within the limits specified in Airbus Service Bulletin A300-57-6049, Revision 3, dated December 15, 1998, prior to further flight, except as required by paragraph (d) of this AD, accomplish all applicable corrective actions (including reaming, drilling, drill-stopping holes, chamfering, follow-on inspections, and installing new or oversize fasteners), in accordance with the service bulletin. Repeat the rotating probe inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 5,900 flight cycles or 13,500 flight hours, whichever occurs first.

(d) If any crack is found during any rotating probe inspection required by paragraph (a) of this AD that exceeds the limits specified in Airbus Service Bulletin A300-57-6049, Revision 3, dated December 15, 1998, or if any cracking remains after the applicable repairs required by paragraph (c) of this AD, prior to further flight, repair the crack in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Direction Générale de l'Aviation Civile (DGAC) (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

(e)(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.

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.

(2) Alternative methods of compliance, approved previously in accordance with AD 97-16-06, amendment 39-10097, are approved as alternative methods of compliance with this AD.

Special Flight Permits

(f) 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.

Note 3:

The subject of this AD is addressed in French airworthiness directive 1999-147-279(B) R1, dated July 12, 2000.

Issued in Renton, Washington, on July 14, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.