Discussion
The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified us that an unsafe condition may exist on certain Airbus Model A320-111 airplanes and Model A320-200 series airplanes. The DGAC advises that it received a report that, during taxi-out, the flightcrew of a Model A320 airplane felt the brake at wheel position 3 of the main landing gear (MLG) dragging, and saw a rise in brake temperature. An inspection of wheel position 3 revealed that the axle nut had separated from the axle, the axle sleeve had started to move out, and that the wheel assembly, including the outer bearing, had been severely damaged. An inspection of the other three wheel positions on that airplane revealed that the axle nuts on those wheels were not secured with locking bolts and had started to move out. An investigation revealed that the locking bolts that were intended to secure the axle nut to the axle were most likely not installed during production. Absence of the locking bolts, if not detected and corrected, could result in separation of a wheel(s) from the axle and consequent reduced controllability of the airplane during takeoff and landing, and possible injury to people on the ground.
Relevant Service Information
Airbus has issued All Operators Telex (AOT) A320-32A1303, dated July 4, 2005. The AOT describes procedures for doing a one-time visual inspection of the axle nut on each MLG wheel for the presence of locking bolts and associated hardware (nuts, washers, and pins); doing related investigative and corrective actions as applicable; and reporting inspection results. The related investigative and corrective actions are:
Doing a visual inspection of the debris guard, fan impeller or hubcap, tachometer mounting sleeve, and other related components for any damage;
Ensuring the correct torque for the axle nut;
Doing a general visual inspection of the axle sleeve, retaining ring, and wheel for any damage if the axle nut has not been torqued properly;
Replacing any damaged components; and
Installing locking bolts and associated hardware.
The DGAC mandated the service information and issued French emergency airworthiness directive UF-2005-128, dated July 13, 2005, to ensure the continued airworthiness of these airplanes in France.
FAA's Determination and Requirements of this AD
These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 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 we need to issue an AD for products of this type design that are certificated for operation in the United States.
Therefore, we are issuing this AD to detect and correct missing locking bolts on the MLG wheels. Absence of the locking bolts could result in separation of a wheel(s) from the axle and consequent reduced controllability of the airplane during takeoff and landing, and possible injury to people on the ground. This AD requires accomplishing the actions specified in the service information described previously.
Clarification of Inspection Terminology
In this AD, the "visual inspection" specified in the Airbus service information is referred to as a "general visual inspection." We have included the definition for a general visual inspection in a note in the AD.
Interim Action
This is considered to be interim action. The inspection reports that are required by this AD will enable the manufacturer to obtain better insight into the extent of the missing locking bolts and associated hardware in the fleet to develop final action to address the unsafe condition. Once final action has been identified, the FAA may consider further rulemaking.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include "Docket No. FAA-2005- 22142; Directorate Identifier 2005-NM-153-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.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 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 (800) 647- 5227) 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.
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 the 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 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 adding the following new airworthiness directive (AD):