06-3063. Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes)

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A300-600 series airplanes. This AD requires modifying nine bolt holes in the vertical flange to prevent cracking before the inspection threshold of AD 98-18-02. This AD results from reports of cracking in the vertical web of the center spar sealing angles of the wing earlier than the inspection interval specified in the existing AD. We are issuing this AD to prevent crack formation in the sealing angles; such cracks could rupture the sealing angle and lead to subsequent crack formation in the bottom skin of the wing, and resultant reduced structural integrity of the center spar section of the wing.

DATES:

This AD becomes effective April 17, 2006.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of April 17, 2006.

We must receive comments on this AD by May 30, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Tim Backman, Aerospace Engineer, ANM-116, International Branch, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

On August 19, 1998, we issued AD 98-18-02, amendment 39-10718 (63 FR 45689, August 27, 1998), for certain Airbus Industrie Model A300-600 series airplanes. That AD requires inspections to detect cracks in the center spar sealing angles adjacent to the pylon rear attachment and in the adjacent butt strap and skin panel, and correction of discrepancies. That AD was prompted by reports of cracking in the vertical web of the center spar sealing angles of the wing. We issued that AD to prevent crack formation in the sealing angles; such cracks could rupture and lead to subsequent crack formation in the bottom skin of the wing, and resultant reduced structural integrity of the center spar section of the wing.

Since we issued AD 98-18-02, the Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that the manufacturer conducted further investigations based on an operator's report of cracks on an airplane in service that occurred before the inspection interval required by AD 98-18-02. The DGAC therefore advises us that a modification of the center spar sealing angles that was previously not required in AD 98-18-02 is now necessary to extend the inspection threshold and prevent cracking of the unmodified structure before the mandated inspection interval. French airworthiness directive 91-253-128(B)R1, dated March 1, 1995, is the parallel French airworthiness directive to AD 98-18-02, and has been replaced by French airworthiness directive 2003-290(B) R1, dated October 1, 2003.

Relevant Service Information

Airbus has issued Service Bulletin A300-57-6033, Revision 01, dated December 18, 2003. The service bulletin describes procedures for modifying nine bolt holes in the vertical flange of the center spar sealing angles outboard of rib 8, adjacent to the pylon attachment fitting. The modification involves removing the nine bolts from the vertical flange of the sealing angle, re-machining the spot faces, cold-expanding the nine bolt holes in the vertical flange, installing oversize bolts in the vertical flange, and installing new oversize bolts at the skin attachment fittings if necessary. The modification also involves the related investigative action of doing high-frequency eddy current inspections for cracks of all bolt holes from which bolts have been removed, including the skin bolt holes. If any crack is found, Airbus Service Bulletin A300-57-6033 specifies that these findings should be reported to Airbus and that the crack should be repaired in accordance with Airbus Service Bulletin A300-57-6027, Revision 06, dated March 2, 2005. (Earlier revisions of Service Bulletin A300-57-6027 were cited as the source of service information for doing the inspections and corrective actions in AD 98-18-02.) The repair includes replacing the forward and aft sealing angles with improved sealing angles, and cold-expanding the attachment holes. The DGAC mandated the service information and issued French airworthiness directive 2003-290(B) R1, dated October 1, 2003, to ensure the continued airworthiness of these airplanes in France.

FAA's Determination and Requirements of This AD

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 the FAA informed of the situation described above. We have examined the DGAC's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.

Therefore, we are issuing this AD to prevent crack formation in the sealing angles; such cracks could rupture the sealing angle and lead to subsequent crack formation in the bottom skin of the wing, and resultant reduced structural integrity of the center spar section of the wing. This AD requires accomplishing the actions specified in the service information described previously.

Operators should note that after doing Airbus Modification 8609 (modification of the nine bolt holes of the vertical flange) in accordance with Airbus Service Bulletin A300-57-6033, Revision 01, post-modification inspection is required in accordance with AD 98-18-02. Airbus Modification 8608, installed during production, introduces new strengthened sealing angles with repositioned bolt holes done in production. Holes in the web, flange, and skin are all cold-worked. Airplanes with Airbus Modification 8608 installed during production are not subject to the requirements of this AD.

Difference Between This AD and the French Airworthiness Directive

We have determined that either Airbus Modification 8608 has been accomplished in production or Airbus Modification 8609 has been accomplished through Airbus Service Bulletin A300-57-6033 on all airplanes of U.S. Registry, and therefore no airplanes of U.S. Registry are affected by the requirements of this AD. All airplanes of U.S. Registry are equipped with either strengthened sealing angles with repositioned holes (production modification 8608) or have had the nine holes of the sealing angle outboard of rib 8 cold-worked in accordance with Airbus Service Bulletin A300-57-6033 (modification 8609). The post-modification 8609 U.S.-registered airplanes continue to be subject to the post-Modification inspection requirements of AD 98-18-02, paragraph (d). Therefore, unlike the French airworthiness directive, the applicability of this AD also includes the A300-600 series airplanes that have incorporated Airbus Modification 8609. The actions in this new AD apply only to affected airplanes that might be imported and placed on the U.S. Register in the future and that do not have the modification. Therefore, although the French airworthiness directive requires accomplishing repetitive inspections of post-modification 8609 airplanes in accordance with Airbus Service Bulletin A300-57-6027, Revision 06, this AD does not include those inspections. Those inspections are included in AD 98-18-02.

Clarification of Compliance Time

The French airworthiness directive gives a compliance time for doing the modification that is based on accomplishment of previous inspections. As discussed above, this AD does not require those inspections. Therefore, the compliance time for doing the modification in this AD is 500 flight cycles after the effective date of this AD. In developing an appropriate compliance time for this AD, we considered the manufacturer's recommendation, the degree of urgency associated with the subject unsafe condition, and the average utilization of the affected fleet. In light of all of these factors, we find that a 500-flight-cycle compliance time represents an appropriate interval of time for affected airplanes to continue to operate without compromising safety.

Costs of Compliance

None of the airplanes affected by this action are on the U.S. Register. All airplanes affected by this AD are currently operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, we consider this AD necessary to ensure that the unsafe condition is addressed if any affected airplane is imported and placed on the U.S. Register in the future.

If an affected airplane is imported and placed on the U.S. Register in the future, the required modification would take about 25 work hours per airplane, at an average labor rate of $80 per work hour. Required parts would cost about $1,249 per airplane. Based on these figures, the estimated cost of the AD would be $3,249 per airplane.

FAA's Determination of the Effective Date

No airplane affected by this AD is currently on the U.S. Register. Therefore, providing notice and opportunity for public comment is unnecessary before this AD is issued, and this AD may be made effective in less than 30 days after it is published in the Federal Register.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include “Docket No. FAA-2006-24124; Directorate Identifier 2004-NM-272-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2006-07-07 Airbus: Amendment 39-14534. Docket No. FAA-2006-24124; Directorate Identifier 2004-NM-272-AD.

Effective Date

(a) This AD becomes effective April 17, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to A300 B4-600, B4-600R, and F4-600R series airplanes, and Model C4-605R variant F airplanes (collectively called A300-600 series airplanes); certificated in any category; except those on which Airbus Modification 8608 or 8609 is incorporated.

Unsafe Condition

(d) This AD results from reports of cracking in the vertical web of the center spar sealing angles of the wing earlier than the inspection interval specified in AD 98-18-02, amendment 39-10718. We are issuing this AD to prevent crack formation in the sealing angles; such cracks could rupture the sealing angle and lead to subsequent crack formation in the bottom skin of the wing, and resultant reduced structural integrity of the center spar section of the wing.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Modification

(f) Within 500 flight cycles after the effective date of this AD: Modify nine bolt holes in the vertical flange of the center spar sealing angles outboard of rib 8, adjacent to the pylon attachment fitting, and do any applicable related investigative and corrective actions before further flight; by doing all the actions in and in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300-57-6033, Revision 01, dated December 18, 2003. If any crack is found during the related investigative action: Before further flight, repair in accordance with the Accomplishment Instructions of Airbus Service Bulletin A300-57-6027, Revision 06, dated March 2, 2005.

No Reporting Required

(g) Although Airbus Service Bulletin A300-57-6033, Revision 01, dated December 18, 2003, specifies to report crack findings to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(h)(1) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

(3) Airbus Repair Drawing R571-40588 or R571-40942, as referenced in paragraphs (c) and (d) of AD 98-18-02, is an AMOC for the modification in paragraph (f) of this AD.

Related Information

(i) French airworthiness directive 2003-290(B) R1, dated October 1, 2003, also addresses the subject of this AD.

Material Incorporated by Reference

(j) You must use Airbus Service Bulletin A300-57-6027, Revision 06, dated March 2, 2005; and Airbus Service Bulletin A300-57-6033, Revision 01, dated December 18, 2003; as applicable; to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov;​; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on March 15, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.