E6-972. 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: [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 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 [phone]; fax [phone].

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 [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.

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:

Revised Paragraph Identifiers

Requirement in AD 2003-26-10	Corresponding requirement in this proposed AD
Paragraph (a)	Paragraph (f).
Paragraph (b)	Paragraph (g).
Requirement in AD 2004-18-13	Corresponding requirement in this proposed AD
Paragraph (a)	Paragraph (h).
Paragraph (b)	Paragraph (i).
Paragraph (c)	Paragraph (j).

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.

Estimated Costs for Required Actions

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
One-time inspection (required by AD 2003-26-10)	1	$65	None	$65	23	$1,495.
One-time inspection (required by AD 2004-18-13)	4	65	None	260	43	11,180.
Repetitive inspections (required by AD 2004-18-13)	12	65	None	780, per inspection cycle	78	60,840, per inspection cycle.
Repetitive inspections (new proposed actions)	16	65	None	1,040, per inspection cycle	78	81,120, per inspection cycle.

Estimated Costs for Optional Actions

Optional action	Work hours	Average labor rate per hour	Parts	Cost per airplane	Number of U.S.-registered airplanes
Reinforcement specified in Airbus Service Bulletin A300-53-0380, dated August 5, 2005	807	$65	Between $87,100 and $121,560 depending on kit purchased	Between $139,555 and $174,015 depending on airplane configuration	23
Reinforcement specified in Airbus Service Bulletin A300-53-6153, dated August 24, 2005	807	65	Between $82,460 and $87,070 depending on kit purchased	Between $134,915 and $139,525 depending on airplane configuration	120
Reinforcement specified in Airbus Service Bulletin A300-53-0360, dated May 3, 2002	Between 24 and 128 depending on airplane configuration	65	Between $250 and $1,000 depending on kit purchased	Between $1,810 and $9,320 depending on airplane configuration	23
Reinforcement specified in Airbus Service Bulletin A300-53-6132, dated February 5, 2002	109	65	Between $260 and $950 depending on kit purchased	Between $7,345 and $8,035 depending on airplane configuration	120

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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendments 39-13408 (69 FR 867, January 7, 2004) and 39-13792 (69 FR 55329, September 14, 2004) and adding the following new airworthiness directive (AD):

Airbus: Docket No. FAA-2006-23690; Directorate Identifier 2004-NM-133-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by February 27, 2006.

Affected ADs

(b) This AD supersedes ADs 2003-26-10 and 2004-18-13.

Applicability

(c) This AD applies to Airbus airplanes identified in Table 1 of this AD, certificated in any category.

Table 1.—Applicability

Affected Airbus airplanes	Except for those airplanes on which—
(1) All Model A300 B2-1A, B2-1C, B2K-3C, and B2-203 airplanes	None.
(2) All Model A300 B4-2C, B4-103, and B4-203 airplanes	None.
(3) Model A300 B4-601, B4-603, B4-620, and B4-622 airplanes	Airbus Modification 12169 has been incorporated in production.
(4) Model A300 B4-605R and B4-622R airplanes	Airbus Modification 12169 has been incorporated in production.
(5) Model A300 F4-605R and F4-622R airplanes	Airbus Modification 12169 has been incorporated in production.
(6) Model A300 C4-605R Variant F airplanes	Airbus Modification 12169 has been incorporated in production.

Unsafe Condition

(d) This AD results from a report of a large fatigue crack along the outboard flange of beam No. 4. We are issuing this AD to detect and correct fatigue cracks in the lower flanges of the left and right gantries 1 through 5 inclusive in the main landing gear (MLG) bay area, which 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.

Restatement of Requirements of AD 2003-26-10

One-Time Inspection

(f) For airplanes on which Airbus Modification 10147 has not been done: At the later of the times specified in paragraphs (f)(1) and (f)(2) of this AD: Do a one-time detailed inspection for cracking of the lower outboard flange of gantry No. 4 in the main landing gear bay area per paragraph 4.2.1 of Airbus All Operators Telex (AOT) A300-53A0371, Revision 01 (for Model A300 B2 and B4 series airplanes); or AOT A300-53A6145, Revision 01 (for Model A300-600 series airplanes); both dated September 10, 2003; as applicable.

(1) Before the accumulation of 8,000 total flight cycles since the date of issuance of the original Airworthiness Certificate or the date of issuance of the Export Certificate of Airworthiness, whichever is first.

(2) Within 30 days after January 22, 2004 (the effective date AD 2003-26-10).

Note 1:

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

Repair

(g) Repair any cracking found during the inspection required by paragraph (f) of this AD before further flight, per a method approved by either the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA; or the Direction Generale de l'Aviation Civile (or its delegated agent).

Restatement of Requirements of AD 2004-18-13

One-time Inspection and Corrective Action

(h) For Model A300 B2-1A, B2-1C, B2K-3C, and B2-203 airplanes, and Model A300 B4-2C, B4-103, and B4-203 airplanes, on which Airbus Modification 3474 has been done: Prior to the accumulation of 16,300 total flight cycles, or within 500 flight cycles after July 30, 1998 (the effective date of AD 98-13-37), whichever occurs later, perform a one-time ultrasonic inspection for cracking of the gantry lower flanges in the MLG bay area, in accordance with Airbus AOT 53-11, dated October 13, 1997.

(1) If any cracking is detected, prior to further flight, repair in accordance with the AOT.

(2) If no cracking is detected, no further action is required by this paragraph.

Repetitive Inspections and Corrective Actions

(i) For Model A300 B4-601, B4-603, B4-605R, B4-620, B4-622R, C4-605R Variant F airplanes, and F4-605R airplanes, on which Airbus Modification 12169 has not been done in production: Perform the requirements of paragraphs (i)(1), (i)(2), (i)(3), and (i)(4) of this AD, in accordance with Airbus Service Bulletin A300-53-6128, dated March 5, 2001.

(1) At the later of the times specified in paragraphs (i)(1)(i) and (i)(1)(ii) of this AD, perform initial ultrasonic inspections or high-frequency eddy current inspections for cracks of the lower flanges of gantries 3, 4, and 5 between fuselage frames FR47 and FR54, in accordance with the Accomplishment Instructions, including the Synoptic Chart contained in Figure 2, sheets 1 through 5 inclusive, of the service bulletin.

(i) In accordance with the thresholds specified in the Synoptic Chart contained in Figure 2, sheets 1 through 5 inclusive, of the service bulletin; or

(ii) Within 200 flight cycles after October 19, 2004 (the effective date AD 2004-18-13).

(2) Perform repetitive ultrasonic inspections or high-frequency eddy current inspections for cracks of the lower flanges of gantries 3, 4, and 5 between fuselage frames FR47 and FR54, in accordance with the thresholds and Accomplishment Instructions, including the Synoptic Chart contained in Figure 2, sheets 1 through 5 inclusive, of the service bulletin.

(3) Perform repairs and reinforcements, in accordance with the thresholds and the Accomplishment Instructions, including the Synoptic Chart contained in Figure 2, sheets 1 through 5 inclusive, of the service bulletin, except as specified in paragraph (i)(4) of this AD.

(4) If a new crack is found during any action required by paragraph (i)(1), (i)(2) or (i)(3) of this AD and the Synoptic Chart contained in Figure 2, sheets 1 through 5 inclusive, of the service bulletin specifies to contact Airbus for appropriate action: Prior to further flight, repair per a method approved by the Manager, International Branch, ANM-116, or the Direction Generale de l'Aviation Civile (DGAC) (or its delegated agent).

Credit for Inspections Accomplished in Accordance With AOT

(j) Any inspection accomplished before October 19, 2004, in accordance with Airbus AOT 53-11, dated October 13, 1997, is acceptable for compliance with the corresponding inspection specified in paragraph (i)(1) of this AD, for that inspection area only. Operators must do the applicable inspections in paragraph (i)(1) of this AD for the remaining inspection areas.

New Requirements of This AD

Repetitive Inspections

(k) At the later of the applicable times specified in the “Threshold (FC)” and “Grace Period” columns of Tables 1 and 2 in paragraph 1.E of the applicable service bulletin in Table 2 of this AD: Do an ultrasonic inspection or high frequency eddy current (HFEC) inspection, including rework of the pressure diaphragm, for cracks in the lower flanges of the left and right gantries 1 through 5 inclusive between FR47 and FR54, in accordance with the Accomplishment Instructions of the applicable service bulletin in Table 2 of this AD. Repeat the inspection at the applicable times specified in the “Interval (FC)” column of Tables 1 and 2 in paragraph 1.E of the applicable service bulletin in Table 2 of this AD. Accomplishment of the initial inspection ends the inspections required by paragraphs (f), (h), and (i) of this AD.

Table 2.—Service Bulletins

Airbus service bulletin—	For airplanes identified in—
(1) A300-53-0379, Revision 01, dated October 4, 2005	Paragraphs (c)(1) and (c)(2) of this AD inclusive.
(2) A300-53-6152, Revision 01, dated October 4, 2005	Paragraphs (c)(3) through (c)(6) of this AD inclusive.

Corrective Action

(l) If any crack is detected during any ultrasonic or HFEC inspection required by paragraph (k) of this AD, before further flight, repair the crack in accordance with the Accomplishment Instructions of the applicable service bulletin in Table 2 of this AD, except as provided by paragraph (n) of this AD.

Optional Terminating Actions

(m) Accomplishment of the actions specified in Table 3 of this AD ends the repetitive inspections required by paragraph (k) of this AD.

Table 3.—Optional Terminating Actions

Before or at the same time with—	Reinforce—	By doing all the actions in accordance with the accomplishment instructions of—	For airplanes identified in—
(1) The actions required by paragraph (k) of this AD and the action specified in paragraph (m)(2) of this AD	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 holes and repair if necessary	Airbus Service Bulletin A300-53-0380, dated August 5, 2005, except as provided by paragraph (n) of this AD	Paragraphs (c)(1) and (c)(2) of this AD inclusive.
		Airbus Service Bulletin A300-53-6153, dated August 24, 2005, except as provided by paragraph (n) of this AD	Paragraphs (c)(3) through (c)(6) of this AD inclusive.
(2) The actions required by paragraph (k) of this AD	Portals 3, 4, and 5 of the plates/skin	Airbus Service Bulletin A300-53-0360, dated May 3, 2002, except as provided by paragraph (n) of this AD	Paragraphs (c)(1) and (c)(2) of this AD inclusive.
		Airbus Service Bulletin A300-53-6132, dated February 5, 2002, except as provided by paragraph (n) of this AD	Paragraphs (c)(3) through (c)(6) of this AD inclusive.

Repair of Certain Cracks

(n) Where the applicable service bulletin recommends contacting Airbus for appropriate action: Before further flight, repair the crack in accordance with a method approved by the Manager, International Branch, ANM-116; or the DGAC (or its delegated agent).

Credit for Original Service Bulletins

(o) Accomplishing the inspections and repair before the effective date of this AD in accordance with Airbus Service Bulletin A300-53-0379, dated May 9, 2005; or Airbus Service Bulletin A300-53-6152, dated May 9, 2005; as applicable; is acceptable for compliance with the corresponding requirements of paragraphs (k) and (l) of this AD.

No Inspection Report

(p) Although the service bulletins in this AD specify to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(q)(1) The Manager, International Branch, ANM-116, 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.

Related Information

(r) French airworthiness directive F-2005-091 R1, issued September 28, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on January 19, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.