05-18518. Airworthiness Directives; Airbus Model A318-100, A319-100, A320-200, A321-100, and A321-200 Series Airplanes; and Model A320-111 Airplanes

AGENCY:

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

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A318-100, A319-100, A320-200, A321-100, and A321-200 series airplanes; and Model A320-111 airplanes. This AD requires modification of the electrical bonding of all structures and systems installed inside the center fuel tank. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent electrical arcing in the center fuel tank due to inadequate bonding, which could result in an explosion of the center fuel tank and consequent loss of the airplane.

DATES:

This AD becomes effective October 26, 2005.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of October 26, 2005.

ADDRESSES:

You may examine the 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., Nassif Building, Room PL-401, Washington, DC.

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

FOR FURTHER INFORMATION CONTACT:

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

SUPPLEMENTARY INFORMATION:

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 street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Airbus Model A318, A319, A320, and A321 series airplanes. That NPRM was published in the Federal Register on May 12, 2005 (70 FR 24997). That NPRM proposed to require modification of the electrical bonding of all structures and systems installed inside the center fuel tank.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Support for the Proposed AD

One commenter supports the proposed AD.

Request To Consider Effect of Other Rulemaking

One commenter requests that we revise the “Discussion” and “FAA's Determination and Requirements of the Proposed AD” sections of the proposed AD to describe the relationship of the proposed AD to the NPRM on Reducing Fuel Tank Flammability (referred to after this as the “FTF rule”), which was announced by the FAA Administrator in February 2004. The commenter notes that airplanes affected by the proposed AD are included in the applicability of the FTF NPRM. Further, the commenter expects that the unsafe condition addressed by the proposed AD would be mitigated by doing the requirements of the FTF rule, so the FTF rule would preclude the need for the proposed AD. The commenter concludes that the FAA did not consider all pertinent data when it issued the proposed AD and, consequently, the FAA's determination and requirements of the proposed AD may be flawed.

While the commenter asks for specific changes only to the preamble of the proposed AD, we infer that the commenter is requesting that we withdraw the proposed AD. We do not concur. Reducing flammability and minimizing potential ignition sources comprise the FAA's two-pronged, balanced approach to fuel tank safety. Since the introduction of turbine-powered airplanes, the FAA's primary means of protection from fuel tank explosions has been to eliminate ignition sources. The fuel tank rules are based on the assumption that fuel tanks will always contain flammable vapors. However, one of the important lessons learned as a result of the fuel tank safety reviews required by Special Federal Aviation Regulation No. 88 (“SFAR 88,” amendment 21-78, and subsequent amendments 21-82 and 21-83) is that unanticipated failures and maintenance errors will continue to generate unexpected ignition sources. Thus, we have concluded that we are unlikely ever to identify and eradicate all possible sources of ignition.

Our balanced approach means that, while we pursue reducing flammability through efforts such as the Fuel Tank Flammability (FTF) rule, we will also continue to eliminate identified ignition sources, such as those identified as a result of the SFAR 88 fuel tank safety reviews. This AD is consistent with that effort. We have not changed the AD in this regard.

Request To Extend Compliance Time

One commenter requests that we extend the compliance time from 58 months to 72 months after the effective date of the AD. The commenter states that many operators have increased their heavy maintenance interval from 5 years to 6 years. Thus, the commenter states that increasing the compliance time to 72 months would allow for minimum disruption to its operating schedule.

We do not concur. We have determined that the 58-month compliance time, as proposed, represents the maximum interval of time allowable for the affected airplanes to continue to operate safely before the modification is done. In developing an appropriate compliance time for this AD, we considered, among other factors, the manufacturer's recommendation and the degree of urgency associated with the subject unsafe condition. We have not changed this AD in this regard.

Request To Increase Estimated Costs of Compliance

Two commenters request that we revise the estimated costs of compliance stated in the proposed AD. One commenter states that the service bulletin to which the proposed AD refers estimates that the modification will take 132 to 141 work hours, but the commenter's own experience indicates that the modification will take 200 to 215 work hours. The other commenter states that the service bulletin estimates the total work hours as 129 to 146.5, but it estimates up to 443 work hours (including time required for fuel tank guard personnel) will be needed.

We do not concur. The estimates of 129 to 146.5 work hours specified in the service bulletin include time for gaining access and closing up. The cost analysis in AD rulemaking actions, however, typically does not include costs such as the time required to gain access and close up, time necessary for planning, or time necessitated by other administrative actions. Those incidental costs may vary significantly among operators and are almost impossible to calculate. We recognize that, in doing the actions required by an AD, operators may incur incidental costs in addition to the direct costs. However, the estimate of 49 to 64 work hours, as proposed and as specified in this AD, represents the time necessary to perform only the actions actually required by this AD. We have not changed the AD in this regard.

Explanation of Change to Applicability

The FAA has revised the applicability of this AD to identify model designations as published in the most recent type certificate data sheet for the affected models.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

This AD affects about 506 airplanes of U.S. registry. The required actions take between 49 and 64 work hours per airplane depending on the airplane's configuration. The average labor rate is $65 per work hour. Required parts cost between $10 and $370 per airplane, depending on the airplane's configuration. Based on these figures, the estimated cost of this AD for U.S. operators is between $1,616,670 and $2,292,180, or between $3,195 and $4,530 per airplane.

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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under 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

• Aircraft
• Air transportation
• 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):

2005-19-14 Airbus: Amendment 39-14279. Docket No. FAA-2005-21189; Directorate Identifier 2005-NM-055-AD.

Effective Date

(a) This AD becomes effective October 26, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Airbus Model A318-111 and -112 airplanes; A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; A320-111, -211, -212, -214, -231, -232, and -233 airplanes; and A321-111, -112, -131, -211 and -231 airplanes; certificated in any category; except airplanes that have received Airbus Modification 31892 in production.

Unsafe Condition

(d) This AD was prompted by results of fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent electrical arcing in the center fuel tank due to inadequate bonding, which could result in an explosion of the center fuel tank and consequent loss 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.

Inspection and Related Investigative and Corrective Actions

(f) Within 58 months after the effective date of this AD: Modify the electrical bonding of all structures and systems installed inside the center fuel tank by accomplishing all of the actions in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-28-1104, Revision 01, dated December 8, 2004.

Actions Accomplished According to Previous Issue of Service Bulletin

(g) Actions done before the effective date of this AD in accordance with Airbus Service Bulletin A320-28-1104, dated December 2, 2003, are acceptable for compliance with the corresponding requirements of paragraph (f) of this AD.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, 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

(i) French airworthiness directive F-2005-028, dated February 16, 2005, also addresses the subject of this AD.

Material Incorporated by Reference

(j) You must use Airbus Service Bulletin A320-28-1104, Revision 01, dated December 8, 2004, 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 this document 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/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on September 9, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.