05-9879. Airworthiness Directives; Airbus Model A300 B2 and B4 Series Airplanes; Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600); and Model A310 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to certain Airbus airplane models, as specified above. The original NPRM would have required modifying the thermal insulation system of certain fuselage frames, and modifying the fuselage drainage system. The original NPRM would also have required revising the FAA-approved maintenance inspection program to include inspections for corrosion or cracking in the subject areas. The original NPRM was prompted by reports of corrosion in the lower part of the pressure bulkhead at certain fuselage frames. This action revises the original NPRM by expanding the applicability to include additional airplanes. We are proposing this supplemental NPRM 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 supplemental NPRM by June 13, 2005.

ADDRESSES:

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

• 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.

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. This docket number is FAA-2004-19534; the directorate identifier for this docket is 2004-NM-99-AD.

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this supplemental NPRM. Send your comments to an address listed under ADDRESSES. Include “Docket No. 2000-FAA-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 this supplemental NPRM. We will consider all comments received by the closing date and may amend this supplemental NPRM in light of those comments.

We will post all comments submitted, 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 supplemental NPRM. 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.

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 [phone]) is located on the plaza level in the Nassif Building at the DOT street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

We proposed to amend 14 CFR part 39 with a notice of proposed rulemaking (NPRM) for an airworthiness directive (AD) (the “original NPRM”). The original NPRM applies to 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 original NPRM was published in the Federal Register on November 5, 2004 (69 FR 64530). The original NPRM proposed to require modifying the thermal insulation system of certain fuselage frames, and modifying the fuselage drainage system. That action also proposed to require revising the FAA-approved maintenance inspection program to include inspections for corrosion or cracking in the subject areas.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the original NPRM.

Request To Revise Applicability

One commenter notes that the applicability statement of the original NPRM excludes airplanes on which Airbus Modification 5946 was done during production. The commenter states that this is incorrect. Airplanes modified in accordance with Airbus Modification 5946 should still be modified in accordance with Airbus Modification 8057. (Airbus Modification 8057 accomplishes the intent of Airbus Service Bulletin A300-53-0201, which would have been required by paragraph (f) of the original NPRM and would be required by this supplemental NPRM.) The commenter points out that the applicability statement should exclude only airplanes on which both Airbus Modifications 5946 and 8057 were done during production.

We concur. We inadvertently omitted the reference to Airbus Modification 8057 from the applicability statement of the original NPRM. We have revised paragraph (c), Applicability, in this supplemental NPRM to exclude airplanes on which both Airbus Modifications 5946 and 8057 were done during production.

Request To Refer to Other Service Bulletin Revisions

One commenter, the airplane manufacturer, notes that the original NPRM does not identify certain revisions of the referenced service bulletins that should be acceptable for compliance with the proposed actions. Paragraph (f) of the original NPRM refers to Airbus Service Bulletins A300-21-0116, Revision 02, dated June 13, 2003; A300-21-6025, Revision 01, dated June 13, 2003; A310-21-2041, Revision 02, dated June 13, 2003; and A300-53-0201, Revision 04, dated May 2, 2003; as applicable sources of service information for certain actions required by that paragraph. The commenter observes that referencing additional service bulletin revisions would eliminate the need for operators to request an alternative method of compliance (AMOC). This table lists the additional service bulletins that the commenter suggests be included:

Additional Service Bulletins

Models	Airbus service bulletin	Revision level	Date
A300 B2 and B4 series	A300-21-116	1	March 24, 1992.
A300 B2 and B4 series	A300-21-0116	03	January 29, 2004.
A300-600	A300-21-6025	02	January 29, 2004.
A310 series	A310-21-2041	1	December 10, 1990.
A310 series	A310-21-2041	03	January 29, 2004.
A300 B2 and B4 series	A300-53-0201	05	July 15, 2004.

Another commenter requests that we revise paragraph (g) of the original NPRM to give credit for modifications to the fuselage drainage system that were accomplished before the effective date of the AD in accordance with Airbus Service Bulletin A300-53-6008, Revision 02, dated August 10, 1989. (For Model A300-600 airplanes, paragraph (g) of the original NPRM gives credit for modifications done in accordance with Airbus Service Bulletin A300-53-6008, Revision 03, dated November 6, 1990; or Revision 04, dated April 28, 2003.) The commenter states that no technical changes to the drainage system in the area of fuselage frames 39 and 54 were made to Revision 02 of the service bulletin or later revisions.

We concur with the commenters' requests. We have revised paragraph (f) of this supplemental NPRM to refer to the latest issues of the referenced service bulletins as the appropriate source of service information for the actions proposed by that paragraph. We have also revised paragraph (g) of this supplemental NPRM to give credit for actions accomplished previously in accordance with the service bulletins listed in the table below.

Service Bulletins For Which We Give Credit

Models—	Airbus service bulletin—	Revision level	Date
A300 B2 and B4 series	A300-21-116	1	March 24, 1992.
A300 B2 and B4 series	A300-21-0116	02	June 13, 2003.
A300 B2 and B4 series	A300-53-0201	04	May 2, 2003.
A300-600	A300-21-6025	01	June 13, 2003.
A300-600	A300-53-6008	02	August 10, 1989.
A300-600	A300-53-6008	03	November 6, 1990.
A300-600	A300-53-6008	04	April 28, 2003.
A310 series	A310-21-2041	1	December 10, 1990.
A310 series	A310-21-2041	02	June 13, 2003.
A310 series	A310-53-2027	02	November 6, 1990.
A310 series	A310-53-2027	03	May 2, 2003.

Request To Revise Airbus Maintenance Planning Document (MPD) Reference

Two commenters request that we revise paragraph (h) of the original NPRM to correct references to certain tasks in the Airbus MPD. One commenter states that Task Number 541531-01-1 does not exist. The commenter states that the correct reference is to MPD Task Number 531531-01-1, which describes detailed inspections of the lower bulkhead at frame 39. Another commenter notes that there is a reference in the same paragraph to MPD Task Number 538295-0603-01. The commenter states that the correct reference is to MPD Task Number 538295-0603-1.

We concur with the commenter's request. The incorrect references were typographical errors. We have revised paragraph (h) of this supplemental NPRM accordingly.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

The change to the applicability statement discussed above expands the scope of the original NPRM; therefore, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment on this supplemental NPRM.

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.

Estimated Costs

Action	Models	Work hours	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Modifying the Thermal Insulation System	A300 B2/B4	5	$567	$892	23	$20,516
Modifying the Thermal Insulation System	A300 B4-600, B4-600R, and F4-600R series; and A300 C4-605R Variant F (collectively called A300-600)	4	567	827	116	95,932
Modifying the Thermal Insulation System	A310	4	567	827	47	38,869
Modifying the Fuselage Drainage System	A300 B2/B4	38	1,857	4,327	23	99,521
Modifying the Fuselage Drainage System	A300 B4-600, B4-600R, and F4-600R series; and A300 C4-605R Variant F (collectively called A300-600)	36	1,378	3,718	116	431,288
Modifying the Fuselage Drainage System	A310	27	1,451	3,206	47	150,682
Maintenance Program Revision	All	1	None	65	186	12,090

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 supplemental NPRM. 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Airbus: Docket No. FAA-2004-19534; Directorate Identifier 2004-NM-99-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by June 13, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Airbus Model A300 B2 and B4 series airplanes; Model A300 B4-600, B4-600R, and F4-600R series airplanes, and C4-605R Variant F airplanes (collectively called A300-600); and A310 series airplanes; certificated in any category; except those on which both Airbus Modifications 5946 and 8057 were done during production.

Unsafe Condition

(d) This AD was prompted by reports of corrosion in the lower part of the pressure bulkhead at fuselage frames (FR) 39 and 54. We are issuing this AD to prevent accumulation of condensation in the insulation blankets of certain fuselage FRs, which could cause corrosion that could result in reduced structural integrity of the fuselage and consequent rapid decompression of the airplane.

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 of Thermal Insulation and Fuselage Drainage Systems

(f) Within 22 months after the effective date of this AD, modify the thermal insulation system of applicable fuselage frames and modify the fuselage drainage system, by doing all actions in the Accomplishment Instructions of the applicable service bulletins specified in Table 1 of this AD.

Table 1.—Relevant Service Bulletins

For Airbus models—	Modify the thermal insulation according to Airbus Service Bulletin—	And modify the fuselage drainage system according to Airbus Service Bulletin—
A300 B2 and B4 series	A300-21-0116, Revision 03, dated January 29, 2004	A300-53-0201, Revision 05, dated July 15, 2004.
A300 B4-600, B4-600R, and F4-600R series; and A300 C4-605R Variant F (collectively called A300-600)	A300-21-6025, Revision 02, dated January 29, 2004	A300-53-6008, Revision 05, dated July 15, 2004.
A310 series	A310-21-2041, Revision 03, dated January 29, 2004	A310-53-2027, Revision 04, dated July 15, 2004.

Modifications Accomplished According to Previous Issues of Service Bulletins

(g) Modifications accomplished before the effective date of this AD according to the service bulletins listed in Table 2 are considered acceptable for compliance with the corresponding action specified in paragraph (f) of this AD.

Table 2.—Additional Service Bulletins

Models	Airbus Service Bulletin	Revision	Date level
A300 B2 and B4 series	A300-21-116	1	March 24, 1992.
A300 B2 and B4 series	A300-21-0116	02	June 13, 2003.
A300 B2 and B4 series	A300-53-0201	04	May 2, 2003.
A300-600	A300-21-6025	01	June 13, 2003.
A300-600	A300-53-6008	02	August 10, 1989.
A300-600	A300-53-6008	03	November 6, 1990.
A300-600	A300-53-6008	04	April 28, 2003.
A310 series	A310-21-2041	1	December 10, 1990.
A310 series	A310-21-2041	02	June 13, 2003.
A310 series	A310-53-2027	02	November 6, 1990.
A310 series	A310-53-2027	03	May 2, 2003.

Maintenance Program Revision

(h) Within 90 days after doing the actions required by paragraph (f) of this AD, or within 90 days after the effective date of this AD, whichever is later: Incorporate into the FAA-approved maintenance inspection program repetitive detailed inspections for corrosion or cracking of fuselage structure from FR 38.2 to 39, and at FR 54, as applicable, as described in Airbus Maintenance Planning Document Task Numbers 538295-0603-1 (for Airbus Model A300 B2 and B4 series airplanes), and 531531-01-1 and 531533-01-1 (for Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and C4-605R Variant F airplanes (collectively called A300-600); and Model A310 series airplanes). Then, thereafter, comply with the applicable requirements.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Alternative Methods of Compliance (AMOCs)

(i) 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.

Related Information

(j) French airworthiness directive 2003-317(B), dated August 20, 2003, also addresses the subject of this AD.

Issued in Renton, Washington, on May 11, 2005.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.