Airworthiness Directives; Airbus Model A300 B2 and B4 Series Airplanes; and 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:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede two existing airworthiness directives (AD) that apply to certain Airbus Model A300 B2, A300 B4, and A300-600 series airplanes. One AD currently requires an inspection for cracks of the lower outboard flange of gantry No. 4 in the main landing gear (MLG) bay area, and repair if necessary. The other AD currently requires, among other actions, repetitive inspections of the gantry lower flanges, and repair if necessary. The proposed AD also would require new repetitive inspections for cracks in the lower flange of certain gantries, and repair if necessary, which would end the existing inspection requirements. The proposed AD also would provide for optional terminating actions for the new repetitive inspections. This proposed AD results from a report of a large fatigue crack along the outboard flange of beam No. 4 and a subsequent determination that existing inspections are inadequate. We are proposing this AD to detect and correct fatigue cracks in the lower flanges of gantries 1 through 5 inclusive in the MLG bay area, which could result in reduced structural integrity of the fuselage, and consequent rapid decompression of the airplane.

DATES:

We must receive comments on this proposed AD by February 27, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed 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: (202) 493-2251.
• 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 proposed AD.

FOR FURTHER INFORMATION CONTACT:

Thomas Stafford, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1622; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “Docket No. FAA-2006-23690; Directorate Identifier 2004-NM-133-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

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 proposed 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 (800) 647-5227) 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.

Discussion

On December 23, 2003, we issued AD 2003-26-10, amendment 39-13408 (69 FR 867, January 7, 2004), for certain Airbus Model A300 B2 and B4 series airplanes, and Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model C4-605R Variant F airplanes (collectively called A300-600 series airplanes). That AD requires a one-time inspection for cracking of the lower outboard flange of gantry No. 4 in the main landing gear (MLG) bay area, and repair if necessary. That AD resulted from a report of cracks found on the lower outboard flange of gantry No. 4 in the MLG bay area. We issued that AD to find and fix cracking of the lower outboard flange of gantry No. 4, which could result in reduced structural integrity of the fuselage, and consequent rapid decompression of the airplane.

On August 31, 2004, we issued AD 2004-18-13, amendment 39-13792 (69 FR 55329, September 14, 2004), for certain Airbus Model A300 B2 and B4 series airplanes, and Model A300 B4-601, B4-603, B4-605R, B4-620, B4-622R, C4-605R Variant F, and F4-605R airplanes. For certain airplanes, that AD requires a one-time inspection for cracking of the gantry lower flanges, and repair if necessary. That AD also requires repetitive inspections of the gantry lower flanges; repair if necessary; and reinforcement of the left-hand and right-hand gantry. That AD resulted from the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. We issued that AD to detect and correct cracking of the gantry lower flanges in the MLG bay area, which could result in decompression of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2004-18-13, we have received a report that, during an inspection required by that AD, a large fatigue crack running along the outboard flange of beam No. 4 was found. The report also indicates that the inspection requirements of ADs 2004-18-13 and 2003-26-10 do not adequately detect cracks in the lower flange of the left and right gantries 1 through 5 inclusive in the MLG bay area. Such cracks, if not detected and corrected, could result in reduced structural integrity of the fuselage, and consequent rapid decompression of the airplane.

Relevant Service Information

Airbus has issued Revision 01 of Service Bulletins A300-53-0379 (for Model A300 B2 and B4 series airplanes) and A300-53-6152 (for Model A300-600 series airplanes), both dated October 4, 2005. The service bulletins describe procedures for doing repetitive ultrasonic inspections or high frequency eddy current inspections, including rework of the pressure diaphragm, for cracks in the lower flange of the left and right gantries 1 through 5 inclusive between FR47 and FR54; and repairing any crack. The threshold for the compliance time ranges between 1,950 and 54,000 total flight cycles depending on the airplane configuration; the grace period is 1,500 flight cycles.

Accomplishing the actions specified in the service information described previously is intended to adequately address the unsafe condition. The DGAC mandated that service information and issued French airworthiness directive F-2005-091 R1, September 28, 2005, to ensure the continued airworthiness of these airplanes in France. The DGAC also approved the following service information as optional terminating actions for the repetitive ultrasonic and high frequency eddy current inspections described previously:

• Airbus Service Bulletins A300-53-0380, dated August 5, 2005 (for Model A300 B2 and B4 series airplanes), and A300-53-6153, dated August 24, 2005 (for Model A300-600 series airplanes). The service bulletins describe procedures for reinforcing the flanges of the left and right portals 1 through 5 inclusive between FR47 and FR54 of the landing gear, including a rotating probe inspection for cracks of the holes and repair if necessary.
• Airbus Service Bulletins A300-53-0360, dated May 3, 2002 (for Model A300 B2 and B4 series airplanes), and A300-53-6132, dated February 5, 2002 (for Model A300-600 series airplanes). The service bulletins describe procedures for reinforcing portals 3, 4, and 5 of the plates/skin.

FAA's Determination and Requirements of the Proposed AD

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. We have examined the DGAC's findings, evaluated all pertinent information, and determined that AD action is necessary for airplanes of this type design that are certificated for operation in the United States.

This proposed AD would supersede ADs 2003-26-10 and 2004-18-13 and retain certain requirements of AD 2003-26-10 and all requirements of AD 2004-18-13. This proposed AD also would require accomplishing the actions specified in Airbus Service Bulletins A300-53-0379 and A300-53-6152 described previously and would provide for optional terminating actions specified in the remaining service information described previously, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between the Proposed AD and Service Information

The service information specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions using a method that we or the DGAC (or its delegated agent) approve. 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 we or the DGAC approve would be acceptable for compliance with this proposed AD.

Change to Existing AD

Since ADs 2003-26-10 and 2004-18-13 were issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:

Costs of Compliance

This proposed AD would affect about 165 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD. Not all actions must be completed on all airplanes.

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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 proposed 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
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.