The FAA proposed to amend 14 CFR part 39 with an AD for certain Airbus Model A319, A320, and A321 series airplanes. That action, published in the Federal Register on January 31, 2005 (70 FR 4789), proposed to require replacing the cargo ventilation extraction duct at frame 65 with a new duct, and relocating the temperature sensor in the aft cargo compartment.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments from a single commenter that have been submitted on the proposed AD.
Request To Reference Revised Service Information
The commenter requests that we change the proposed AD to refer to Airbus Service Bulletin A320-21-1141, Revision 01, dated December 17, 2004. The proposed AD refers to Airbus Service Bulletin A320-21-1141, dated April 7, 2004, as the acceptable source of service information for the accomplishment of the proposed actions.
We agree with the commenter's request. The procedures in Revision 01 of the referenced service bulletin are essentially the same as those in the original issue. Accordingly, we have revised paragraph (f) of this AD to refer to Revision 01 of the service bulletin as the appropriate source of service information for accomplishing the required actions. We have also added a new paragraph (g) (and re- identified subsequent paragraphs accordingly) to state that modifications accomplished before the effective date of this AD per the original issue of the service bulletin are acceptable for compliance with this AD.
Request To Reference Related Service Information
The commenter notes that Airbus Service Bulletin A320-52-1124, Revision 01, dated December 17, 2004, is mentioned in the referenced French airworthiness directive and the referenced service information. The commenter states that Service Bulletin A320-52-1124 is also considered necessary to accomplish the restriction of airflow through the aft cargo compartment. The commenter adds that since airworthiness directives are issued to address safety concerns, and not portions of a safety concern, both modifications should be mandated in this proposed AD. The commenter states that combining these requirements into one AD also provides the added benefit of a central reference point in the case that an operator may need to make a future determination on whether the safety concern was fully addressed on an airplane or fleet of airplanes. The commenter adds that issuing separate ADs for the same safety concern seems to complicate the process.
We acknowledge the commenter's request; however, Service Bulletin A320-52-1124 was referenced in another rulemaking action, which was issued on February 22, 2005 (Docket No. FAA-2005-20453; Directorate Identifier 2004-NM-270-AD). That proposed AD was issued in response to French airworthiness directive F-2004-172, dated October 27, 2004. That proposed AD would require replacing the water drainvalves in the forward and aft cargo doors with new valves. The proposed compliance time is 6 months. In light of the fact that the compliance times are different, and the actions were addressed in two separate French airworthiness directives, the rulemaking actions will not be combined. No change to the AD is made in this regard.
Request To Change Compliance Time
The commenter states that it agrees with the need to accomplish the proposed changes to meet airworthiness standards; however, it has not seen any data that lend this issue a high degree of urgency. The commenter recommends that the compliance time specified in the proposed AD be changed to the next heavy maintenance visit or S-check, instead of the 24-month compliance time. The commenter adds that this change would reduce the economic impact to operators, such as the commenter, who would be forced to take airplanes out of revenue service in order to meet the 24-month window.
We do not agree with the commenter. In developing an appropriate compliance time for this action, we considered the safety implications, operators' normal maintenance schedules, and the compliance time recommended by the airplane manufacturer for the timely accomplishment of the required actions. The compliance time of 24 months after the effective date of this AD is based on airplane utilization overall, and is consistent with the compliance time specified in the French airworthiness directive. In addition, the operator provided no data to indicate that a compliance time extension will ensure safety. In consideration of these items, we have determined that compliance within 24 months after the effective date of this AD will provide an acceptable level of safety and is an appropriate interval of time wherein the required actions can be accomplished during scheduled maintenance intervals for the majority of affected operators. However, according to the provisions of paragraph (h) of this AD, we may approve a request to adjust the compliance time if the request includes data that justify that a different compliance time would provide an acceptable level of safety. No change to the AD is made in this regard.
Request To Change Costs of Compliance Section
The commenter disagrees with the labor estimates specified in the proposed AD. The commenter states that the FAA has reduced the estimates in the original issue of the referenced service bulletin by approximately one-third. The commenter adds that the airplane manufacturer typically underestimates, rather than overestimates, manpower requirements for repair and modification service bulletins. The commenter recommends that the FAA consider the average estimate of 51.3 work hours, as specified in the referenced service bulletin, to be a minimum labor cost; however, 75 work hours per airplane is a better estimate for accomplishing the actions specified in the referenced service information.
We do not agree that it is necessary to change the workhours in this AD. This number represents the time necessary to perform only the actions actually required by the AD. The actions in this final rule reflect only the direct costs of the specific required actions based on the best data available from the manufacturer. The cost analysis in AD rulemaking actions typically does not include incidental 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, which may vary significantly among operators, are almost impossible to calculate. The compliance time in this AD should allow ample time for operators to do the required actions at the same time as scheduled major airplane inspection and maintenance activities, which would reduce the additional time and costs associated with special scheduling. No change to the AD is made in this regard.
Conclusion
We have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD with the change described previously. This change will neither increase the economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
The following table provides the estimated costs for U.S. operators to comply with this AD.
Estimated Costs
Action
Work hours
Average labor rate per hour
Parts
Cost per airplane
Number of U.S.-
registered airplanes
Fleet cost
Replacement of duct/relocation of temperature sensor in aft cargo compartment.
34
$65
Between $7,000
and $11,640.
Between $9,210
and $13,850.
643
Between
$5,922,030 and
$8,905,550.
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. 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, 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.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):