Airworthiness Directives; Airbus Model A310 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 A310 series airplanes. This proposal would require repetitive inspections for fatigue cracking of the area around the fasteners of the landing plate of the aileron access doors of the bottom skin panel of the wings, and related corrective action. The proposal also provides for an optional terminating action, which would end the repetitive inspections. This action is necessary to prevent fatigue cracking of the area around the fasteners of the landing plate of the aileron access doors and the bottom skin panel of the wings, which could result in reduced structural integrity of the wings. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 18, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-279-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-279-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, 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-279-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-279-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, has notified the FAA that an unsafe condition may exist on certain Airbus Model A310 series airplanes. The DGAC advises that full-scale fatigue testing of a Model A310 airplane on which Airbus Modification 5106 had been done revealed skin cracking in the modified area. The cracking had initiated from one of the attachment holes of the landing plate of the aileron access door. In addition, during routine maintenance of a post-modification 5106 Model A310 airplane, a 62-millimeter crack was found on the right-hand wing in the bottom skin panel. Fatigue cracking of the area around the fasteners of the landing plate of the aileron access doors and the bottom skin panel of the wings could result in reduced structural integrity of the wings.

The manufacturer has developed an inspection program for Model A310 series airplanes on which Airbus Modification 5106 has been done. The manufacturer is also conducting a review of the inspection program developed for airplanes on which Airbus Modification 5106 has not been done.

Related Rulemaking

On December 8, 1998, the FAA issued AD 98-26-01, amendment 39-10942 (63 FR 69179, December 16, 1998) applicable to all Airbus Model A310 series airplanes. That AD requires various inspections to detect fatigue cracks at certain locations on the fuselage, horizontal stabilizer, wings and tail; repair or modification, if necessary; and installation of doublers. The actions specified by that AD are intended to prevent reduced structural integrity of the fuselage, horizontal stabilizer, and wings.

Explanation of Relevant Service Information

Airbus has issued the following service information:

• Airbus Service Bulletin A310-57-2004, Revision 2, dated March 5, 1990, which describes procedures for modification of the landing plate of the access door of the bottom skin panel of the left and right wings. The modification includes removing the existing clearance fit bolts from the landing plate of the aileron access door on the left and right wings, and installing reamed oversized interference fit bolts. Accomplishment of the modification eliminates the need for the repetitive inspections.
• Airbus Service Bulletin A310-57-2081, dated June 11, 2002, which describes procedures for modification of the access door and the bottom skin panel of the left and right wings. The modification includes a high frequency eddy current inspection of the fastener holes of the modification areas for cracking, and repair per Service Bulletin A310-57-2082, if cracking is found. The service bulletin also specifies contacting the manufacturer for repair instructions if cracking is found outside the modification areas. If no cracking is found, the service bulletin describes procedures for cutting the landing plate of the aileron access door into three parts, cold expanding of the fastener holes of the landing plate, installing an interference plug; installing an external reinforcement plate, cold expanding of the attachment holes of the reinforcement plate, and installing interference fit fasteners.
• Airbus Service Bulletin A310-57-2082, dated June 11, 2002, which describes procedures for a high frequency eddy current inspection for cracking of the area around the fasteners of the landing plate of the aileron access doors of the bottom skin panel of the left and right wings, and related corrective action. The related corrective action includes doing a permanent repair (installing a repair plate and new landing plates), or a temporary repair (crack-stop drilling) followed by repetitive inspections until a permanent repair is done.

Accomplishment of the actions specified in the service information is intended to adequately address the identified unsafe condition. The DGAC classified this service information as mandatory and issued French airworthiness directive 2003-242(B), dated June 25, 2003, to ensure 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 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 us informed of the situation described above. We have 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 information described previously, except as discussed below. This proposed AD also would provide for optional terminating action for the 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 find cracking before it represents a hazard to the airplane.

Differences Among French Airworthiness Directive, Service Information, and Proposed AD

Unlike the procedures described in Service Bulletin A310-57-2082, and the French airworthiness directive, this proposed AD would not permit further flight if cracks are found in the area around the fasteners of the landing plate of the aileron access doors of the wings. The service bulletin specifies the option of a temporary repair (crack-stop drilling) if cracking is found in the landing plate and wing skin panel, and follow-on repetitive inspections until a permanent repair is done. We have determined that, because of the safety implications and consequences associated with such cracking, no temporary repair is allowed and a permanent repair must be done before further flight. However, under the provisions of paragraph (e) of the proposed AD, we may approve requests for a temporary repair provided that data are submitted to substantiate that (1) the crack is not part of multi-site damage, (2) crack growth is easily detectable, and (3) established inspection procedures would detect cracked structure at intervals permitting a permanent repair to be done before reduced structural integrity of the wings can occur.

Service Bulletin A310-57-2081 specifies that operators may contact the manufacturer for disposition of certain repair conditions, but this proposed AD would require operators to repair those conditions per 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 unsafe condition, and consistent with existing bilateral airworthiness agreements, we have 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.

For airplanes on which Airbus Modification 5106 has been done, the French airworthiness directive specifies an inspection threshold of a certain number of flights “since new.” However, this proposed AD specifies an inspection threshold of a certain number of flight cycles since the date of issuance of the original Airworthiness Certificate or the date of issuance of the original Export Certificate of Airworthiness, whichever is first. This decision is based on our determination that “since new” may be interpreted differently by different operators. We find that our proposed terminology is generally understood within the industry and records will always exist that establish these dates with certainty.

Cost Impact

We estimate that 46 airplanes of U.S. registry would be affected by this proposed AD, that it would take about 2 work hours per airplane to do the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the inspection proposed by this AD on U.S. operators is estimated to be $5,980, or $130 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.

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.