Airworthiness Directives; Airbus Model A300 B2 and B4 Series Airplanes; Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model A300 C4-605R Variant F Airplanes (Collectively Called A300-600); and Model A310 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus airplane models, as specified above. This proposed AD would require modifying the thermal insulation system of certain fuselage frames, and modifying the fuselage drainage system. This proposed AD would also require revising the FAA-approved maintenance inspection program to include inspections for corrosion or cracking in the subject areas. This proposed AD is prompted by reports of corrosion in the lower part of the pressure bulkhead at certain fuselage frames. We are proposing this AD to prevent accumulation of condensation in the insulation blankets of certain fuselage frames, which could cause corrosion that 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 December 6, 2004.

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.
• By 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.

For service information identified in this proposed AD, contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Technical Information: Dan Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2125; fax (425) 227-1149.

Plain Language Information: Marcia Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2004-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2004-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

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 under ADDRESSES. Include “Docket No. FAA-2004-19534; Directorate Identifier 2004-NM-99-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 submitted 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 our docket 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 can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

You can 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 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 DMS receives them.

Discussion

The Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that an unsafe condition may exist on certain Airbus Model A300 B2 and B4 series airplanes; Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called A300-600); and Model A310 series airplanes. The DGAC advises that corrosion has been found in the lower part of the pressure bulkhead at fuselage frame (FR) 54 and, on certain airplanes, FR 39. Investigation revealed that the rear face of FR 54, and the front face of FR 39 on certain airplanes, are completely thermally insulated; no drainage is provided at the insulation blankets. The lack of drainage results in condensation being trapped. This condition, if not corrected, could result in corrosion that could result in reduced structural integrity of the fuselage and consequent rapid decompression of the airplane.

Relevant Service Information

Airbus has issued the service bulletins listed in the table below, which describe procedures for modifying the thermal insulation system using the specific procedures identified in the table below.

Airbus has also issued the service bulletins listed in the table below, which describe procedures for modifying the fuselage drainage system using the specific procedures identified in the table below.

Airbus has also issued Maintenance Planning Documents containing Task Numbers 538295-0603-01 (for Airbus Model A300 B2 and B4 series airplanes), and 541531-01-1 and 531533-01-1 (for Airbus Model A300-600 and Model A310 series airplanes). These task numbers describe procedures for repetitive detailed visual inspections for corrosion or cracking of fuselage structure from FR 38.2 to 39, and at FR 54, as applicable. These tasks are necessary for airplanes modified in accordance with the service information described previously.

Accomplishing the actions specified in the applicable service information is intended to adequately address the unsafe condition. The DGAC mandated the service information and issued French airworthiness directive 2003-317(B), dated August 20, 2003, to ensure the continued airworthiness of these airplanes in France.

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 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 proposing this AD, which would require accomplishing the actions specified in the service information described previously. This proposed AD would also require revising the FAA-approved maintenance inspection program to include detailed inspections for corrosion and cracking in the area of FRs 39 and 54, as described in the Maintenance Planning Document task numbers identified previously.

Differences Between the Proposed AD and French Airworthiness Directive

The applicability of French airworthiness directive 2003-317(B) excludes airplanes that accomplished Airbus Service Bulletin A300-53-0201, A300-53-6008, or A310-53-2027 in service. However, we have not excluded those airplanes in the applicability of this proposed AD; rather, this proposed AD includes a requirement to accomplish the actions specified in those service bulletins. This requirement would ensure that the actions specified in the service bulletins and that would be required by this proposed AD are accomplished on all affected airplanes. Operators must continue to operate the airplane in the configuration that would be required by this proposed AD unless we approve an alternative method of compliance.

French airworthiness directive 2003-317(B) specifies that airplanes modified in accordance with the service information described previously must be inspected in accordance with the Maintenance Planning Document tasks described previously. However, no compliance time is given for revising the maintenance program. This proposed AD would require revising the maintenance program to include these tasks within 90 days after doing the modifications specified in the service information described previously, or within 90 days after the effective date of the AD, whichever is later. We find that this represents an appropriate interval of time in which this action may be accomplished by all affected operators without jeopardizing continued flight safety.

Clarification of Inspection Terminology

In this proposed AD, the “detailed visual inspections” specified in Maintenance Planning Document Task Numbers 538295-0603-01 (for Airbus Model A300 B2 and B4 series airplanes), and 541531-01-1 and 531533-01-1 (for Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and A300 C4-605R Variant F airplanes (collectively called A300-600); and Model A310 series airplanes), are referred to as “detailed inspections.” We have included the definition for a detailed inspection in a note in the proposed AD.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD, at an average labor rate of $65 per work hour.

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. 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.