Airworthiness Directives; Airbus Model A300 B4-600 and A300 B4-600R Series Airplanes, and Model A300 F4-605R Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to all Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R series airplanes, that would have superseded an existing AD. The existing AD requires repetitive inspections to detect cracks of certain attachment holes, installation of new fasteners, and follow-on inspections or repair if necessary. The proposed AD would have reduced the inspection threshold and repetitive intervals and expanded the area to be inspected. This supplemental notice of proposed rulemaking (NPRM) would further expand the area to be inspected, and would require a modification of the angle fittings of frame FR47. This supplemental NPRM would also remove certain airplanes from the applicability. The actions specified by this supplemental NPRM 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 December 14, 2001.

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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. 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:

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2125; 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 action 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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket 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 99-NM-322-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to all Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R series airplanes, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on July 20, 2000 (65 FR 44991). That original NPRM proposed to supersede AD 97-16-06, amendment 39-10097 (62 FR 41257, August 1, 1997), which is applicable to all Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R series airplanes. A correction to AD 97-16-06 was published in the Federal Register on August 25, 1997 (62 FR 44888). The original NPRM proposed to continue to require repetitive inspections to detect cracks of certain attachment holes, installation of new fasteners, and follow-on inspections or repair if necessary. The original NPRM would have reduced the inspection threshold and repetitive intervals and expanded the area to be inspected. The original NPRM was prompted by reports of cracking in the internal angle fittings of the wing center box at fuselage frame FR47 on airplanes that had not reached the inspection threshold required by AD 97-16-06, and cracking around certain fastener holes that were not required to be inspected by AD 97-16-06. Such fatigue cracking, if not corrected, could result in reduced structural integrity of the frame.

Actions Since Issuance of Original NPRM

Since the issuance of the original NPRM, the FAA has been advised by the Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, of recent inspection results that warrant a revision of the existing inspection program for certain areas of fuselage frame FR47. Specifically, an investigation of new crack findings indicates the need for an inspection of additional holes (holes A, B, C, D, E, F, G, P, Q, and S) of the baseplate/horizontal section of the angle fittings of the wingbox. The investigation further revealed fatigue sensitivity of additional holes (holes Y, U, V, W, and X) of the angle web fitting on airplanes on which a particular modification had not been correctly embodied in production.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A300-57-6049, Revision 4, dated July 27, 2000, which describes procedures for repetitive rotating probe inspections to detect cracking of holes in the left and right internal angles of the wing center box. Corrective actions include reaming, drilling, drill-stopping holes, chamfering, follow-on inspections, and installing new or oversize fasteners. The original version of this service bulletin was cited as the appropriate source of service information for the inspections required by AD 97-16-06. Revision 3 was described in the original NPRM and cited as the appropriate source of service information for the proposed inspections. Revision 4 includes minor procedural changes not included in Revision 3, and includes procedures for the inspection of additional holes (holes Y, U, V, W, and X) on certain airplanes.

Airbus has also issued Service Bulletin A300-57-6086, dated June 6, 2000, which describes procedures for repetitive rotating probe inspections to detect cracking of ten holes (holes A, B, C, D, E, F, G, P, Q, and S) in the horizontal flange of the internal corner angle fitting at frame FR47. For crack repair, this service bulletin provides corrective actions that include inspecting hole T if any cracking is found around hole G, reaming the holes, and installing oversize fasteners.

Airbus has also issued Service Bulletin A300-57-6050, Revision 02, dated February 10, 2000, which describes procedures for a modification of the angle fittings at frame FR47, which involves performing a rotating probe inspection to detect cracking of fasteners holes most sensitive to fatigue, cold expanding the holes, and installing new medium interference fitting bolts. The modification is intended to improve the fatigue life of the subject area.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified these service bulletins as mandatory and issued French airworthiness directive 2000-533-328(B), dated December 27, 2000, to ensure the continued airworthiness of these airplanes in France.

Comments

Due consideration has been given to comments received in response to the original NPRM.

Request To Remove Certain Airplanes From Applicability

One commenter requests that Model A300 F4-622R airplanes be removed from the applicability of the original NPRM to correspond to the revised French airworthiness directive, which was issued specifically to exclude those airplanes.

The FAA concurs. Model A300 F4-622R airplanes are not subject to the identified unsafe condition. The applicability of this supplemental NPRM has been revised to remove those airplanes.

Request To Revise Compliance Times

Several commenters request that the grace periods for inspection of holes H, I, K, L, M, and N, as specified in the original NPRM, be revised to correspond to the grace periods specified in Airbus Service Bulletin A300-57-6049. The commenters state that the grace periods provided in the service bulletin are intended to allow operators to properly plan the required work, and will ensure safety via a longer grace period for newer airplanes and a shorter grace period for older airplanes. One commenter, an operator, states that its newest airplanes would be subject to out-of-sequence inspections and potential modifications, at significant cost to the operator. The operator contends that the grace periods provided in the service bulletin would provide an “equivalent level of safety.”

The FAA concurs, for the reasons provided by the commenters. Paragraphs (a) and (b) of this supplemental NPRM refer to the compliance thresholds and repetitive intervals specified in paragraph 1.A.(2), Planning Information, of the service bulletin.

Request To Remove Restriction on Flight With Cracks

One commenter requests that the original NPRM be revised to remove the exception to Service Bulletin A300-57-6049 regarding flight with cracks. The original NPRM had included a provision that would prohibit further flight with cracking detected in the attachment holes. The commenter states that the service bulletin does not allow flight with a free crack but rather recommends corrective action to eliminate the crack immediately or repair it temporarily until it can be eliminated.

The FAA partially concurs. In the section titled “Differences Between the Proposed Rule and Relevant Service Information,” the original NPRM incorrectly interpreted the service bulletin as allowing flight with cracks, in contrast to FAA policy. The service bulletin does provide for temporary repair with follow-up repetitive inspections, but specifies that, for certain conditions, operators must contact the manufacturer for further instructions prior to further flight. The original NPRM specified that corrective actions be performed in accordance with the service bulletin. To clarify the requirements for repair, this supplemental NPRM specifies that repair of cracking be done by “applicable corrective actions” in accordance with the service bulletin.

Conclusion

Since these changes expand the scope of the original NPRM, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Explanation of Proposed Requirements of This Supplemental NPRM

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, this supplemental NPRM would require accomplishment of the actions specified in the service bulletins described in this supplemental NPRM, except as discussed below.

Differences Between This Supplemental NPRM and the Service Bulletins

Operators should note that, although the service bulletins specify that the manufacturer may be contacted for disposition of certain repair conditions, this supplemental NPRM would require the repair of those conditions to be accomplished in accordance with a method approved by either the FAA or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this supplemental NPRM, a repair approved by either the FAA or the DGAC would be acceptable for compliance with this supplemental NPRM.

Furthermore, Airbus Service Bulletins A300-57-6049 and A300-57-6086 specify that operators need not count touch-and-go landings in determining the total number of landings between consecutive inspections, when those landings represent less than five percent of the landings between inspection intervals. However, fatigue cracking, which 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. Therefore, the FAA has determined that all touch-and-go landings must be counted in determining the total number of flight cycles between two consecutive inspections.

Cost Impact

The FAA estimates that 74 airplanes of U.S. registry would be affected by this proposed AD. The average labor rate is $60 per work hour. The FAA provides the following cost estimates for the actions proposed by this supplemental NPRM:

The cost impact figures discussed above are 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. 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.