Examining the Docket
You may examine the airworthiness directive (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 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 March 3, 2005 (70 FR 10342). That NPRM proposed to require replacing the water drain valves in the forward and aft cargo doors with new valves.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.
Support for NPRM
The Air Line Pilots Association and United Airlines support the NPRM.
Requests To Extend Compliance Time
Airbus states that the Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has issued French airworthiness directive F-2004-172 R1, dated April 13, 2005, to extend the compliance time from April 30, 2005 to December 31, 2005. (We referenced French airworthiness directive F- 2004-172, dated October 27, 2004, with a compliance time of 6 months in the NPRM.) Airbus further states that our NPRM should not be more restrictive than the French airworthiness directive. We infer the commenter would like us to extend the compliance time to 14 months to correspond with the revised French airworthiness directive.
Northwest Airlines (NWA) requests that we extend the compliance time to 2 years to match the compliance time of related AD 2005-12-19. NWA points out that both rulemaking actions are necessary to reduce therate of air renewal in the cargo compartments. NWA further states that revising the compliance time in the NPRM would allow operators to accomplish both modifications during the same maintenance visit, eliminating the effect on line operations and potential for grounding airplanes.
US Airways 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. U.S. Airways recommends extending the compliance time to allow replacement of the water drain valves at the next C-check or 18 months, whichever is later, instead of the proposed 6-month compliance time. U.S. Airways 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 6-month window.
We agree with Airbus and have revised paragraph (f) of this AD accordingly. We referenced French airworthiness directive F-2004-172 in the NPRM because French airworthiness directive F-2004-172 R1 was issued after we published our NPRM. Consequently, we have also revised paragraph (i) of this AD to reference French airworthiness directive F- 2004-172 R1, dated April 13, 2005. In developing an appropriate compliance time for this action, we considered not only the degree of urgency associated with addressing the subject unsafe condition, but the DGAC's recommendation for an appropriate compliance time, the availability of required parts, and the practical aspect of installing the required modification within an interval of time that corresponds to the typical scheduled maintenance for the majority of affected operators. We also considered the time required for the rulemaking process. In addition, NWA and US Airways provided no data to indicate that a further extension of the compliance time will ensure safety. In consideration of these items, we have determined that compliance within 14 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.
While we agree with NWA that the actions required by both this AD and AD 2005-12-19 are necessary to correct the unsafe condition, we do not agree to match the compliance times of the ADs. The compliance times of these ADs instead match the compliance times of the corresponding French airworthiness directives. Furthermore, those compliance times differ because the number of affected airplanes and overall exposure to the unsafe condition is not the same for both ADs. Also, we note that the new 14-month compliance time from the effective date of this AD is closer to the compliance time of AD 2005-12-19, which is within 24 months after July 29, 2005. 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.
Request To Reference Later-Approved Service Bulletin
United Airlines states that the effectivity of Airbus Service Bulletin A320-52-1124, dated May 6, 2004, is not up to date, and that Airbus issued Telex SEM4/914.482/05 announcing it plans to publish a revision to the service bulletin to correct the effectivity. United Airlines therefore requests that we reference any later-approved service bulletin in the NPRM.
We partially agree. As policy, we do not reference "later- approved'' service bulletins in ADs. However, since Airbus subsequently issued Revision 01, dated May 31, 2005, to Service Bulletin A320-52- 1124, we agree to reference Revision 01 in paragraph (f) of this AD. The procedures in Revision 01 of the service bulletin are essentially the same as those in the original issue. Therefore, we have added a new paragraph (g) to this AD to give credit for actions done in accordance with the original issue of the service bulletin and have reidentified the subsequent paragraphs accordingly. We point out that referencing Revision 01 does not change the applicability specified in paragraph (c) of this AD, since the applicability depends only on whether certain modifications are accomplished in production or in-service.
Request To Combine Related Rulemaking
US Airways notes that Airbus Service Bulletin A320-21-1141, Revision 01, dated December 17, 2004, is mentioned in French airworthiness directive F-2004-172, dated October 27, 2004, and is related to Airbus Service Bulletin A320-52-1124. (We referenced French airworthiness directive F-2004-172 and Airbus Service Bulletin A320-52- 1124 in the NPRM.) US Airways states that Airbus Service Bulletin A320- 21-1141 is also considered necessary to accomplish the restriction of airflow through the aft cargo compartment. US Airways adds that since ADsare issued to address safety concerns, and not portions of a safety concern, both modifications should be mandated by the same AD. US Airways 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. US Airways adds that issuing separate ADs for the same safety concern seems to complicate the process.
We acknowledge US Airways' request; however, Airbus Service Bulletin A320-21-1141, Revision 01, dated December 17, 2004, was referenced in AD 2005-12-19, amendment 39-14135 (70 FR 36476, June 24, 2005), which we issued on June 14, 2005. We issued AD 2005-12-19 to address air leakage around the aft cargo temperature sensor, in response to French airworthiness directive F-2004-123, dated July 21, 2004. That AD requires replacing the cargo ventilation extraction duct at frame65 with a new duct, and relocating the temperature sensor in the aft cargo compartment. The compliance time is 24 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 this AD is made in this regard.
Request To Reference Part Numbers
The Modification and Replacement Parts Association (MARPA) requests that we either identify the manufacturer of the affected water drain valves and the part numbers, or publish the referenced service bulletin with the AD. As justification for its request, MARPA states that the affected water drain valves are identified in proprietary service information that is not available to the general public. The commenter asserts that, under 14 CFR 21.303, there are many valves that could be approved replacement parts for the affected water drain valves. If replacement parts do exist, MARPA adds that they may contain the same defect as those addressed in the NPRM. MARPA further states that repair facilities and part houses, which do not have access to proprietary service information to determine the applicability of the AD, may inadvertently provide defective parts manufacturer approval (PMA) valves in the future.
We agree to identify the part number of the affected water drain valves and have revised paragraph (f) of this AD accordingly. We also concur with MARPA's general request that, if we know that an unsafe condition also exists in PMA parts, the AD should address those parts, as well as the original parts. At this time, we are not aware of other PMA parts equivalent to the affected water drain valves. MARPA's remarks are timely in that the Transport Airplane Directorate currently is in the process of reviewing this issue as it applies to transport category airplanes. We acknowledge that there may be other ways of addressing this issue to ensure that unsafe PMA parts are identified and addressed. Once we have thoroughly examined all aspects of this issue, including input from industry, and have made a final determination, we will consider whether our policy regarding addressing PMA parts in ADs needs to be revised. We consider that to delay this AD action would be inappropriate, since we have determined that an unsafe condition exists and that replacement of certain parts must be accomplished to ensure continued safety. Therefore, no additional change has been made to the final rule in this regard.
Explanation of Change to Applicability
We have revised the applicability of this AD to identify model designations as published in the most recent type certificate data sheet for the affected models.
Clarification of Alternative Method of Compliance (AMOC) Paragraph
We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.
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 changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.
Costs of Compliance
This AD affects about 434 airplanes of U.S. registry. The actions in this AD take about 3 to 5 work hours per
airplane, depending on airplane configuration, at an average labor rate of $65 per work hour. Required parts cost about $120 to $200 per airplane, depending on airplane configuration. Based on these figures, the estimated cost of the AD for U.S. operators is between $136,710 and $227,850, or between $315 and $525 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 authorityof 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 amongthe 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
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 authoritycitation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):