01-21106. Airworthiness Directives; Airbus Model A300 B2, A300 B4, A300 B4-600, and A300 B4-600R Series 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 B2 and A300 B4 series airplanes, and all A300 B4-600, A300 B4-600R, and A300 F4-600R (collectively called A300-600) series airplanes. The original notice of proposed rulemaking (NPRM) would have required repetitive inspections for cracking of certain fittings, corrective action if necessary, and, for certain airplanes, a modification; and would have provided for optional terminating action for the repetitive inspections. That proposal was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. This supplemental NPRM revises the original NPRM by including additional variables for determination of the compliance times, allowing an optional repair for certain cracking conditions, and removing certain airplanes from the applicability. The actions specified by this new proposed AD are intended to detect and correct propagation of cracks on the frame 40 aft fittings due to local stress concentrations at the frame 40 upper flange runout, which could result in reduced structural integrity of the airplane.

DATES:

Comments must be received by September 17, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-86-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. 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-86-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 [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 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 Number 99-NM-86-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-86-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 B2 and A300 B4 series airplanes, and all Model A300 B4-600, A300 B4-600R, and A300 F4-600R (collectively called A300-600) series airplanes, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on January 9, 2001 (66 FR 1612). That original NPRM would have required modifying the frame 40 aft fittings for certain airplanes. For all airplanes, the original NPRM would have required repetitive nondestructive test inspections to detect cracking of the frame 40 aft fittings, and corrective action if necessary; and would have provided for optional terminating action for the repetitive inspections. The original NPRM was prompted by reports that cracks were found on the frame 40 aft fittings at stringer 33 on the left and right sides of the fuselage; the cracks were caused by a local stress concentration at the frame 40 upper flange runout. That condition, if not corrected, could result in reduced structural integrity of the airplane.

Comments

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

Request To Include Flight Hours in Compliance Time Determination

One commenter, the manufacturer, requests that flight hours also be included as a variable in the compliance time determination for the initial and repetitive inspections. The manufacturer and the FAA have agreed that both flight cycles and flight hours should be considered when determining the appropriate compliance threshold and repetitive interval for the inspections.

The FAA concurs with the request, finding that this method of determining the compliance times will ensure an adequate level of safety. The compliance times in Table 3 of this supplemental NPRM have been revised accordingly.

Request To Allow Repair for Certain Conditions

One commenter requests that the original NPRM be revised to allow rework of cracks in the aft fitting (in accordance with Airbus Service Bulletin A300-53-0296 or A300-53-6048) if the cracks are 10 mm or less in length. (The original NPRM would have required replacement of the cracked fitting.) The commenter considers that immediate replacement of a cracked fitting (in accordance with Airbus Service Bulletin A300-53-0297 or A300-57-6053) for these smaller cracks is not economically acceptable.

The FAA concurs. The FAA has determined that, for cracks that are 10 mm or less in length, either reworking the cracked area or replacing the cracked fitting would be acceptable for affected airplanes to continue to safely operate until the next inspection. For cracks that are more than 10 mm in length, this supplemental NPRM would require either replacement of the cracked fitting in accordance with the applicable service bulletin referenced above, or a repair in accordance with a method approved by the FAA or the DGAC. These conditional actions based on crack length are consistent with those actions described in Service Bulletin A300-53-0296 or A300-53-6048. Therefore, this supplemental NPRM has been revised to simply state that repair would be required in accordance with those service bulletins. 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.

Request To Remove Certain Airplanes From Applicability

One commenter requests that Model A300 F4-622R series airplanes be removed from the applicability of the original NPRM to correspond to the applicability of the revised parallel French airworthiness directive, which specifically excludes those airplanes because the actions proposed by this supplemental NPRM have been accomplished on those airplanes in production.

The FAA concurs and has accordingly revised the applicability of this supplemental NPRM.

Request for Credit for Inspection

Two commenters request that the proposed AD be revised to provide credit for an inspection already performed in accordance with the original issue of Airbus Service Bulletin A300-53-6048. (The original NPRM would have required compliance in accordance with Revision 01 or 03, and would have provided credit for Revision 02.) The original issue of the parallel French airworthiness directive (1998-481-270(B)) was based on the original service bulletin.

The FAA concurs. The actions specified by the original service bulletin do not vary significantly from those proposed in this supplemental NPRM. Note 2 of this supplemental NPRM has been revised to add credit for an inspection done in accordance with the original service bulletin.

Request To Change Sequence of Certain Actions

One commenter suggests that the original NPRM be revised to change the sequence of the subparagraphs of paragraph (d) so that subparagraph (d)(3) immediately precedes paragraph (d)(1). The modification specified by Service Bulletins A300-53-0297 and A300-57-6053 cancels the inspection specified by Service Bulletins A300-53-0268 and A300-57-6052; therefore, the commenter suggests that the corrective actions of paragraph (d) of the original NPRM list the inspection requirement before the modification requirement.

The FAA agrees that the sequence of instructions as written in the original NPRM may be confusing. This supplemental NPRM has been revised to distinguish the terminating action as a separate action, which is included as new paragraph (e).

Request To Provide for Optional Terminating Action for Certain Conditions

Two commenters request that the original NPRM be revised to provide for optional terminating action on Model A300 B4-600 and A300 B4-600R series airplanes if no cracks are found and no subsequent rework is required.

The FAA partially concurs. Paragraph (b)(8) of the original NPRM does provide for Service Bulletin A300-57-6053 (and Airbus Service Bulletin A300-53-0297 for Model A300 B2 and A300 B4 series airplanes) as terminating action—whether cracks are found or not. However, the FAA agrees that clarification of the associated text in the original NPRM may be necessary. Therefore, paragraph (b)(8) and new paragraph (e) of this supplemental NPRM have been revised to clarify that the modification would terminate the proposed requirements, regardless of the inspection results.

Additional Change to Original NPRM

Airbus Service Bulletin A300-53-6048, described previously, refers to Airbus Service Bulletin A300-53-6063 as an additional source of service information for accomplishment of certain repairs. New Note 3 of this supplemental NPRM identifies this secondary reference.

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.

Cost Impact

The FAA estimates that 70 airplanes of U.S. registry would be affected by this proposed AD.

For affected airplanes, it would take approximately 92 work hours per airplane to accomplish the proposed modification, at an average labor rate of $60 per work hour. Required parts would cost as much as $874 per airplane. Based on these figures, the cost impact of the proposed modification is estimated to be as much as $6,394 per airplane.

It would take approximately 10 work hours per airplane to accomplish the proposed inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $42,000, or $600 per airplane, per inspection cycle.

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 planning time, time required to gain access and close up, 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 adding the following new airworthiness directive:

Airbus Industrie: Docket 99-NM-86-AD.

Applicability: All Model A300 B2, A300 B4, A300 B4-600, and A300 B4-600R series 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 (g) 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 propagation of cracks on the frame 40 aft fittings due to local stress concentrations at the upper flange runout of frame 40, which could result in reduced structural integrity of the airplane, accomplish the following:

Modification

(a) For airplanes on which Airbus Modification 10430 has not been done before the effective date of this AD: Concurrently with the inspection required by paragraph (b) of this AD, modify the profile of frame 40 aft fittings per the service information specified in Table 1, as follows:

Table 1.—Service Information

For model	Do the actions in accordance with either	Of airbus service bulletin	Dated
(1) A300 B2 and A300 B4 series airplanes	(i) Revision 01 or (ii) Revision 02	A300-53-0296 A300-53-0296	September 30, 1998. May 12, 1999.
(2) A300 B4-600 and A300 B4-600R series airplanes	(i) Revision 01 or (ii) Revision 03	A300-53-6048 A300-53-6048	September 30, 1998. February 21, 2000.

Note 2:

For Model A300 B4-600 and A300 B4-600R series airplanes: Actions performed in accordance with Airbus Service Bulletin A300-53-6048, dated January 16, 1996; or Revision 02, dated May 12, 1999, are acceptable for compliance with the applicable requirements of this AD.

Note 3:

Airbus Service Bulletin A300-53-6048 refers to Airbus Service Bulletin A300-53-6063 as an additional source of service information for accomplishment of certain repairs.

Inspection

(b) For all airplanes, inspect the airplane per Table 2, as follows:

Table 2.—Inspection Requirements

Requirements	Description
(1) Area to inspect	The frame 40 AFT fitting.
(2) Type of inspection	Nondestructive test (NDT).
(3) Compliance time	As specified by paragraph (c) of this AD.
(4) Discrepancies to detect	Cracking.
(5) Service information	Inspect in accordance with the applicable service bulletin listed in Table 1 of this AD.
(6) Follow-on actions if you find no cracking	Repeat the inspection thereafter at the applicable interval specified by Table 3 of this AD.
(7) Corrective actions if you find cracking	Do the actions specified by paragraph (d) of this AD.
(8) Terminating action	The modification specified by paragraph (e) of this AD terminates the requirements of this AD.

Note 4:

An NDT per Part 6 53-15-30 procedure C of the NDT manual is also acceptable for compliance with the requirements of paragraph (b) of this AD.

(c) Perform the inspection required by paragraph (b) of this AD per the schedule in Table 3 of this AD. For airplanes on which this inspection has been accomplished before the effective date of this AD, the initial compliance time may be extended by the repetitive interval following the date the inspection was accomplished. Table 3 follows:

Table 3.—Compliance Times for Inspection

For Model	If the total flight cycles accumulated on the airplane as of the effective date of this AD is	Then inspect	And repeat the inspection at least every
(1) A300 B4-600 and A300 B4-600R series airplanes, pre-Modification 10430	(i) Fewer than 6,200	Before the airplane accumulates 7,700 total flight cycles or 17,710 total flight hours, whichever occurs first	7,500 flight cycles or 17,250 flight hours, whichever occurs first.
	(ii) At least 6,200 and fewer than 9,700	Within 1,500 flight cycles or 3,450 flight hours after the effective date of this AD, whichever occurs first	7,500 flight cycles or 17,250 flight hours, whichever occurs first.
	(iii) At least 9,700	Within 750 flight cycles or 1,725 flight hours after the effective date of this AD, whichever occurs first	7,500 flight cycles or 17,250 flight hours, whichever occurs first.
(2) A300 B4-600 and A300 B4-600R series airplanes, post-Modification 10430	(i) Fewer than 19,600	Before the airplane accumulates 21,100 total flight cycles or 48,530 total flight hours, whichever occurs first	7,500 flight cycles, or 17,250 flight hours, whichever occurs first.
	(ii) At least 19,600 and fewer than 23,100	Within 1,500 flight cycles or 3,450 flight hours after the effective date of this AD, whichever occurs first	7,500 flight cycles or 17,250 flight hours, whichever occurs first.
	(iii) At least 23,100	Within 750 flight cycles or 1,725 flight hours after the effective date of this AD, whichever occurs first	7,500 flight cycles or 17,250 flight hours, whichever occurs first.
(3) A300 B2 series airplanes	(i) Fewer than 12,000	Before the airplane accumulates 14,000 total flight cycles or 15,120 total flight hours, whichever occurs first	5,500 flight cycles or 5,940 flight hours, whichever occurs first.
	(ii) At least 12,000 and fewer than 17,000	Within 2,000 flight cycles or 2,160 flight hours after the effective date of this AD, whichever occurs first	5,500 flight cycles or 5,940 flight hours, whichever occurs first.
	(iii) At least 17,000	Within 1,000 flight cycles or 1,080 flight hours after the effective date of this AD, whichever occurs first	5,500 flight cycles or 5,940 flight hours, whichever occurs first.
(4) A300 B4-100 series airplanes	(i) Fewer than 9,500	Before the airplane accumulates 11,500 total flight cycles or 15,295 total flight hours, whichever occurs first	4,500 flight cycles or 5,985 flight hours, whichever occurs first.
	(ii) At least 9,500 and fewer than 14,500	Within 2,000 flight cycles or 2,660 flight hours after the effective date of this AD, whichever occurs first	4,500 flight cycles or 5,985 flight hours, whichever occurs first.
	(iii) At least 14,500	Within 1,000 flight cycles or 1,330 flight hours after the effective date of this AD, whichever occurs first	4,500 flight cycles or 5,985 flight hours, whichever occurs first.
(5) A300 B4-200 series airplanes	(i) Fewer than 8,500	Before the airplane accumulates 10,500 total flight cycles or 21,840 total flight hours, whichever occurs first	4,000 flight cycles or 8,320 flight hours, whichever occurs first.
	(ii) At least 8,500 and fewer than 13,500	Within 2,000 flight cycles or 4,160 flight hours after the effective date of this AD, whichever occurs first	4,000 flight cycles or 8,320 flight hours, whichever occurs first.
	(iii) At least 13,500	Within 1,000 flight cycles or 2,080 flight hours after the effective date of this AD, whichever occurs first	4,000 flight cycles or 8,320 flight hours, whichever occurs first.

Note 5:

An NDT inspection is also required by AD 98-25-07, amendment 39-10933, to be repetitively performed on Model A300 B4-600 and A300 B4-600R series airplanes on which Airbus Modification 10453 has not been installed. For those airplanes, if the inspection is done within the applicable compliance time specified by paragraph (c) of this AD, the threshold for the initial inspection of paragraph (b) of this AD may be extended by 1,500 flight cycles.

Corrective Actions

(d) If any cracking is found during any inspection required by paragraph (b) of this AD: Except as required by paragraph (f) of this AD, prior to further flight, perform all applicable corrective actions in accordance with the applicable service bulletin identified in Table 1 of this AD.

Terminating Action

(e) Accomplishment of the applicable modification specified by paragraph (e)(1) or (e)(2) of this AD terminates the requirements of this AD.

(1) For Model A300 B4-600 and A300 B4-600R series airplanes: Perform the modification in accordance with Airbus Service Bulletin A300-57-6053, Revision 1, dated October 31, 1995; or Revision 02, dated June 2, 1999.

(2) For Model A300 B2 and A300 B4 series airplanes: Perform the modification in accordance with Airbus Service Bulletin A300-53-0297, Revision 2, dated October 31, 1995.

Exceptions to Service Bulletin Instructions

(f) During any inspection required by this AD, if the service bulletin specifies to contact the manufacturer for an appropriate action: Prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Direction Générale de l'Aviation Civile (DGAC) (or its delegated agent).

Alternative Methods of Compliance

(g) 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 6:

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

(h) 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 7:

The subject of this AD is addressed in French airworthiness directive 1998-481-270(B) R1, dated July 12, 2000.

Issued in Renton, Washington, on August 15, 2001.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.