Airworthiness Directives; Airbus Model A330, A340-200, and A340-300 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 certain Airbus Model A330, A340-200, and A340-300 series airplanes. This proposal would require initial and repetitive inspections of certain frame stiffeners to detect cracking. If any cracking is found, this proposal would require replacement of the stiffener with a new, reinforced stiffener. Replacement of the stiffener would constitute terminating action for certain inspections. This proposal would also require a one-time inspection of any new, reinforced stiffeners; and repair or replacement of the new, reinforced stiffener if any cracking is found during the one-time inspection. This proposal also provides for an optional terminating action for certain requirements of this AD. This action is necessary to prevent fatigue failure of certain frame stiffener fittings, which could result in reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by May 3, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-256-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. 2003-NM-256-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 or 2000 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:

Tim Backman, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2797; 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 Number 2003-NM-256-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. 2003-NM-256-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A330, A340-200, and A340-300 series airplanes. The DGAC advises that, during a scheduled inspection, cracks were detected at the upper horizontal flange of the frame 12A stiffener fitting at the level of the floor cross beam attachment on both the left-hand and right-hand sides of the airplane. These cracks were caused by a high level of longitudinal forces at the fitting, which came from cabin pressurization and bending induced by thermal effects. This condition, if not corrected, could result in fatigue failure of the fitting, which could result in reduced structural integrity of the airplane.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A330-53-3135, Revision 01, dated July 7, 2003; and Service Bulletin A340-53-4141, Revision 01, dated July 7, 2003. These service bulletins describe procedures for conducting a high-frequency eddy current (HFEC) inspection of the FR12A stiffener fitting to detect cracking. These service bulletins permit further flight with stiffeners that are cracked within certain limits.

For airplanes on which no cracking is detected, these service bulletins describe procedures for repeating the HFEC inspection for each side on which no cracking is found, until replacement of the FR12A stiffener fitting with a new, reinforced fitting.

For airplanes on which cracking is found, these service bulletins describe procedures for replacing the damaged stiffener with a new, reinforced stiffener fitting; and for conducting a final HFEC inspection of the stiffener fitting at a specified interval following the installation. This replacement eliminates the need for the repetitive inspections described previously, only for the side on which the replacement is made.

Accomplishment of the actions specified in these service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified these service bulletins as mandatory and issued French airworthiness directives 2003-205(B), dated May 28, 2003, and 2003-206(B), dated May 28, 2003, to ensure the continued airworthiness of these airplanes in France.

Airbus has also issued Service Bulletin A330-53-3130, Revision 01, dated October 10, 2003; and Service Bulletin A340-53-4137, Revision 01, dated October 10, 2003. These service bulletins describe procedures for replacing the FR12A stiffeners with new, reinforced stiffeners; installing new, reinforced junction fittings between FR12A/FR13 and FR13/FR13A at the stringer 26 level; and installing a new shear web that joins the fitting to the cabin floor track. This replacement eliminates the need for the repetitive inspections and the final HFEC inspection described previously, only for the side on which the replacement is made.

FAA's Conclusions

These airplane models are manufactured in France and are 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 require accomplishment of the actions specified in the Airbus Service Bulletins A330-53-3135, and A340-53-4141, described previously, except as discussed below. This proposed AD also would provide for optional terminating action for certain repetitive inspections.

Consistent with the findings of the DGAC, the proposed AD would allow repetitive inspections to continue in lieu of the terminating action. In making this determination, we considered that long-term continued operational safety in this case will be adequately ensured by repetitive inspections to detect cracking before it represents a hazard to the airplane.

Differences Among the Proposed Rule, the Service Bulletins, and the French Airworthiness Directives

Although the French airworthiness directives and Service Bulletins A330-53-3135 and A340-53-4141 recommend accomplishing the initial inspection before the accumulation of 13,000 total flight cycles, we find that a compliance time of within 13,000 flight cycles or 6 months after the effective date of the proposed AD, whichever occurs later, represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety. In developing an appropriate compliance time for this proposed AD, we considered the degree of urgency associated with the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection (4 hours).

Operators should note that, unlike the procedures described in Service Bulletins A330-53-3135 and A340-53-4141, this proposed AD would not permit further flight with any cracking detected in the fittings. The FAA has determined that, due to the safety implications and consequences associated with such cracking, all fittings that are cracked must be replaced prior to further flight.

Although the service bulletins specify that operators may contact the manufacturer for disposition of certain conditions, this proposal would require operators to repair those conditions or replace per a method approved by either the FAA or the DGAC (or its delegated agent). In light of the type of repair or replacement that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair or replacement approved by either the FAA or the DGAC would be acceptable for compliance with this proposed AD.

Although the Accomplishment Instructions of Service Bulletins A330-53-3135 and A330-53-4141 describe procedures for submitting certain information to the manufacturer, this proposed AD would not require those actions.

Cost Impact

The FAA estimates that 9 Model A330 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $2,340, or $260 per airplane, per inspection cycle.

The cost impact figure discussed above is 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.

If an operator chooses to do the optional terminating action rather than continue the repetitive inspections, it would take about 74 work hours per airplane to accomplish the installations, at an average labor rate of $65 per work hour. Required parts would cost about $7,860 per airplane. Based on these figures, we estimate the cost of this optional terminating action to be $12,670 per airplane.

Currently, there are no affected Model A340-200 or A340-300 series airplanes on the U.S. Register. However, if an affected airplane is imported and placed on the U.S. Register in the future, it would take approximately 4 work hours to accomplish the proposed inspection, at an average labor rate of $65 per work hour. Based on these figures, we estimate the cost of this AD to be $260 per airplane, per inspection cycle.

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.