Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that supersedes AD 2006-03-10, amendment 39-14474 (71 FR 6665, February 9, 2006). The existing AD applies to certain Airbus Model A318-100 and A319-100 series airplanes; A320-111 airplanes; A320-200 series airplanes; and A321-100 and A321-200 series airplanes. That NPRM was published in the Federal Register on January 9, 2008 (73 FR 1558). That NPRM proposed to discontinue the existing requirements and instead require installing a hinge pin stopper on the internal door of the 103VU electrical panel. This AD results from a report indicating that electrical wire damage was found in the 103VU electrical panel due to contact between the hinge pin and the adjacent electrical wire harness.
Comments
We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been received on theNPRM.
Request for Additional Action
The Air Transport Association (ATA), on behalf of one of its members, Northwest Airlines (NWA), notes that the proposed modification prevents only outboard migration of the pins, and requests that the AD be changed to require a hinge pin stopper to be added to both ends of the hinge to completely contain the hinge pin and prevent inboard migration.
We do not agree with ATA's request. We are issuing this AD to address potential wire damage due to outboard migration of the hinge pin. There is no potential of wire damage due to inboard migration of the pin. However, if additional data show that inboard migration of the hinge pin causes an unsafe condition, we might consider further rulemaking. We have not changed the AD in this regard.
Request for Alternate Modification
The ATA, on behalf of NWA, requests that the AD be changed to allow the hinge stoppers to be installed using the existing hole in the lower angle fitting (part number D92510153000) adjacent to the end hinge mounting hole, instead of drilling a new hole through the hinge assembly. NWA states that this change would eliminate the need for any drilling during modification, and would more easily facilitate accomplishment within the line maintenance environment, providing greater scheduling flexibility.
We do not agree with ATA's request. Airbus Mandatory Service Bulletin A320-25-1535, dated April 27, 2007, specifies drilling a hole on the hinge. The commenter did not provide sufficient data to substantiate that using the existing hole would address the identified unsafe condition. To use a different method from the one specified in that service bulletin, operators may request approval of an alternative method of compliance (AMOC) according to paragraph (g) of the AD. We have not changed the AD 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 as proposed.
Costs of Compliance
This AD affects about 658 Airbus Model A318-100 and A319-100 series airplanes; A320-111 airplanes; A320-200 series airplanes; and A321-100 and A321-200 series airplanes of U.S. registry. The new actions take about 1 work hour per airplane, at an average labor rate of $80 per work hour. Required parts cost about $20 per airplane. Based on these figures, the estimated cost of the new actions specified in this AD for U.S. operators is $65,800, or $100 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
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 Federal Aviation Administration (FAA) amends Sec. 39.13 by removing amendment 39-14474 (71 FR 6665, February 9, 2006) and byadding the following new airworthiness directive (AD):