01-511. Airworthiness Directives; Airbus Model A300 B2 and A300 B4 Series Airplanes, and Model A300 B4-600, A300 B4-600R, and A300 F4-600R (A300-600) Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Airbus Model A300 B2 and A300 B4 series airplanes, and all A300 B4-600, A300 B4-600R, and A300 F4-600R (A300-600) series airplanes. For certain airplanes, this proposal would require modifying the frame 40 aft fittings. For all airplanes, this proposal would require repetitive nondestructive test inspections to detect cracking of the frame 40 aft fittings; a modification would be required as corrective action for cracking or provided as optional terminating action for the repetitive inspections. 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 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 February 8, 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 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue; e.g., discuss a request to change a compliance time and a request to change a service bulletin reference as two issues.
• For each issue, state the specific change requested to the proposed AD.
• 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 ++.” 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

The Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on all Airbus Model A300 B2 and A300 B4 series airplanes, and all Model A300 B4-600, A300 B4-600R, and A300 F4-600R (A300-600) series airplanes. The DGAC reports that cracks have been 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. This condition, if not corrected, could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

Airbus has issued the following service bulletins:

Model	Service bulletin	Revision level	Date
A300	A300-53-0296	01 02	Sep. 30, 1998. May 12, 1999.
A300-600	A300-53-6048	01 03	Sep. 30, 1998. Feb. 21, 2000.
A300	A300-53-0268	4	Aug. 16, 1995.
A300-600	A300-57-6052	02	April 4, 1997.
A300	A300-53-0297	2	Oct. 31, 1995.
A300-600	A300-57-6053	1 02	Oct. 31, 1995. June 2, 1999.

Service Bulletins A300-53-0296 and A300-53-6048 describe procedures for modification of the frame 40 aft fittings on certain airplanes, and repetitive nondestructive test inspections to detect cracking of the frame 40 aft fittings on all airplanes. Corrective actions for cracking involve trimming the front spar angle and vertical stiffener; drilling, reaming, and spotfacing attachment holes; installing a new frame 40 aft fitting and pick-up angles; and inspecting (by a detailed visual, high frequency eddy current, or liquid penetrant method) to detect cracking of the frame 40 forward fittings.

Those service bulletins refer to Service Bulletins A300-53-0268 and A300-57-6052 as additional sources of service information for corrective actions if cracking is found in the frame 40 aft fitting. Service Bulletins A300-53-0268 and A300-57-6052 describe procedures for, among other things, an inspection (detailed visual, eddy current, or liquid penetrant) to detect cracking of the forward fitting at frame 40.

Service Bulletins A300-53-0296 and A300-53-6048 also refer to Service Bulletins A300-53-0297 and A300-57-6053 as additional sources of service information to modify the aft angle fittings at frame 40. The modification involves replacing the angle fittings with new larger fittings. The service bulletins recommend the modification to repair cracked fittings and eliminate the need for the repetitive inspections.

Accomplishment of the actions specified in the service bulletins described above is intended to adequately address the identified unsafe condition. The DGAC classified Airbus Service Bulletins A300-53-0296 and A300-53-6048 as mandatory, and issued French airworthiness directive 1998-481-270(B) R1, dated July 12, 2000, to ensure the continued airworthiness of these airplanes in France.

FAA's Conclusions

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 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 require accomplishment of the actions specified in the service bulletins described previously, except as discussed below.

For airplanes on which no cracking is found, this proposed AD would also provide for optional terminating action for the repetitive inspections. Operators should note that, to be consistent with the findings of the DGAC, the FAA has determined that the repetitive inspections proposed by this AD can be allowed to continue in lieu of accomplishment of a terminating action. In making this determination, the FAA considers that, in this case, long-term continued operational safety will be adequately ensured by accomplishing the repetitive inspections to detect cracking before it represents a hazard to the airplane.

Differences Between Proposed AD and Relevant Service Information

Operators should note that the service bulletins provide a method of adjustment of the inspection thresholds and intervals, relative to average flight times, of various groups of airplanes. The service bulletins provide a complicated method of determining the thresholds and intervals for various groups of airplanes. The FAA has determined that it would be difficult to enforce the implementation of that method for determining the compliance times. Therefore, this proposed AD does not provide for adjustments to the compliance times to accommodate average flight times that vary among operators. The FAA has established a single threshold and interval for each identified group of airplanes. In developing appropriate compliance times for this AD, the FAA considered not only the manufacturer's method for determining the compliance times, but the degree of urgency associated with addressing the subject unsafe condition and the average utilization of the affected fleet. The compliance times in this proposed AD are derived from the average flight times for affected airplanes as follows:

Model	Average flight time (in minutes)
A300 B2 series	65
A300 B4-100 series	80
A300 B4-200 series	125
A300-600 series	125

In light of these factors, the FAA finds the proposed thresholds and intervals to be warranted, in that they represent appropriate intervals of time for affected airplanes to continue to operate without compromising safety. However, the provisions of paragraph (e) of this proposed AD would enable the FAA to approve requests for adjustments to the compliance time if data are submitted that substantiate an acceptable level of safety provided by such an adjustment.

Operators should further note that, unlike the procedures described in Airbus Service Bulletins A300-57-6052 and A300-53-0268, this proposed AD would not permit further flight if cracking is detected in the frame 40 forward fitting. The FAA has determined that, because of the safety implications and consequences associated with such cracking, any cracked subject fitting must be repaired or modified before further flight.

In addition, although the service bulletins specify that the manufacturer may be contacted for disposition of certain repair conditions, this proposal would require that those conditions be repaired 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 proposed AD, a repair approved by either the FAA or the DGAC would be acceptable for compliance with this proposed AD.

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 and A300 B4 series airplanes, and Model A300 B4-600, A300 B4-600R, and A300 F4-600R (A300-600) 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 (e) 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: When you do 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 of this AD. Table 1 is as follows:

Table 1.—Service Information for Modification and Inspection

Model	Service Bulletin	Revision level	Date
A300	A300-53-0296	Revision 01 Or Revision 02	Sept. 30, 1998. May 12, 1999.
A300-600	A300-53-6048	Revision 01 Or Revision 03	Sept. 30, 1998. Feb. 21, 2000

Note 2: Modification per Airbus Service Bulletin A300-53-6048, Revision 02, dated May 12, 1999, is acceptable for compliance with paragraph (a) of this AD for Model A300-600 series airplanes.

Inspection

(b) For all airplanes, inspect the airplane per Table 2 of this AD, 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) Required service information	As specified by Table 1 of this AD.
(6) Follow-on actions if you find no cracking	Repeat the inspection thereafter at the intervals 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	Paragraph (d) terminates paragraph (b) of this AD.

Note 3: A nondestructive test (NDT) per Part 6 53-15-30 procedure C of the NDT manual, is also acceptable for compliance with paragraph (b) of this AD.

Note 4: Accomplishment of an inspection per Airbus Service Bulletin A300-53-6048, Revision 02, dated May 12, 1999, is acceptable for compliance with the requirements of paragraph (b) of this AD for Model A300-600 series airplanes.

(c) Perform the inspection of paragraph (b) of this AD per the schedule in Table 3, as follows:

Table 3.—Compliance Thresholds for Inspection

For model . . .	If the total flight cycles accumulated on the airplane is . . .	Then inspect . . .	And repeat the inspection at least every . . .
A300-600 series airplanes, pre-Modification 10430S20428	Fewer than 6,200	Before the airplane accumulates 7,700 total flight cycles	7,500 flight cycles.
	At least 6,200 and fewer than 9,700	Within 1,500 flight cycles after the effective date of this AD
	At least 9,700	Within 750 flight cycles after the effective date of this AD
A300-600 series airplanes, post-Modification 10430S20428	Fewer than 19,600	Before the airplane accumulates 21,100 total flight cycles	7,500 flight cycles.
	At least 19,600 and fewer than 23,100	Within 1,500 flight cycles after the effective date of this AD
	At least 23,100	Within 750 flight cycles after the effective date of this AD
A300 B2 series airplanes	Fewer than 12,000	Before the airplane accumulates 14,000 total flight cycles	5,500 flight cycles.
	At least 12,000 and fewer than 17,000	Within 2,000 flight cycles after the effective date of this AD
	At least 17,000	Within 1,000 flight cycles after the effective date of this AD
A300 B4-100 series airplanes	Fewer than 9,500	Before the airplane accumulates 11,500 total flight cycles	4,500 flight cycles.
	At least 9,500 and fewer than 14,500	Within 2,000 flight cycles after the effective date of this AD
	At least 14,500	Within 1,000 flight cycles after the effective date of this AD
A300 B4-200 series airplanes	Fewer than 8,500	Before the airplane accumulates 10,500 total flight cycles	4,000 flight cycles.
	At least 8,500 and fewer than 13,500	Within 2,000 flight cycles after the effective date of this AD
	At least 13,500	Within 1,000 flight cycles after the effective date of this AD

Note 5:

An NDT inspection is also required by AD 98-25-07, amendment 39-10933, to be repetitively performed on Model A300-600 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 crack is found during any inspection of a frame 40 aft fitting required by this AD, prior to further flight, accomplish the actions specified by paragraph (d)(1) or (d)(2), as applicable, and paragraph (d)(3) of this AD. Accomplishment of the actions of this paragraph terminates the repetitive inspection requirements of paragraph (b) of this AD.

(1) For Model A300-600 series airplanes: Replace the angle fittings with new, larger fittings, 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 series airplanes listed in Airbus Service Bulletin A300-53-0297, Revision 2, dated October 31, 1995: Replace the angle fittings with new, larger fittings, in accordance with the service bulletin.

(3) For all airplanes: Perform a detailed visual, high frequency eddy current (HFEC), or liquid penetrant inspection, as applicable, to detect cracking in the frame 40 forward fitting in accordance with Airbus Service Bulletin A300-57-6052, Revision 02, dated April 4, 1997 (for Model A300-600 series airplanes), or Airbus Service Bulletin A300-53-0268, Revision 4, dated August 16, 1995 (for Model A300 series airplanes); as applicable.

(i) If no crack is found: No further action is required by this AD.

(ii) Except as provided by paragraph (d)(3)(iii) of this AD: If any crack is found, during an inspection required by paragraph (d)(3) of this AD, prior to further flight, repair per the applicable service bulletin.

(iii) If any crack is detected during any inspection required by paragraph (d)(3) of this AD, and the applicable 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, FAA, Transport Airplane Directorate; or the Direction Gonorale 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) 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

(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 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 January 3, 2001.

Dorenda D. Baker,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.