Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAApublic contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a selfaddressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 2001NM71AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM114, Attention: Rules Docket No. 2001NM71AD, 1601 Lind Avenue, SW., Renton, Washington 980554056.

Discussion

The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on certain Airbus Model A319, A320, and A321 series airplanes. The DGAC advises that, during deployment tests of the escape slide, in two cases the slide bar detached from the door sill and the escape slide failed to inflate. It was found that the carbonsteel trigger spring was ruptured due to severe corrosion. The function of the trigger spring is to hold the trigger in a certain position to mechanically secure the telescopic slide bar in the extended position. If the trigger spring ruptures, the slide bar may be unlocked and then held in an extended position only by two internal springs. This condition, if not corrected, could result in incorrect locking of the slide bar and, during deployment of the escape slide, lead to a delay in evacuating passengers in an emergency.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320521102, Revision 01, dated November 25, 1999, which describes procedures for replacement of the carbonsteel slide bar trigger spring with a stainless steel spring. Accomplishment of the action specified in the service bulletin is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 2001063(B), dated February 21, 2001, in order to assure the continued airworthiness of these airplanes in France. Difference Between Proposed Rule and Service Bulletin

Airbus Service Bulletin A320521102, Revision 01, dated November 25, 1999, specifies that Airbus Service Bulletin A320521068 is to be accomplished concurrently. However, French airworthiness directive 2001063(B), dated February 21, 2001, provides that simultaneous (or concurrent) accomplishment of Airbus Service Bulletin A320521068 is not required. Similarly, this proposed rule would not require concurrent accomplishment of Airbus Service Bulletin A320521068. FAA's Conclusions

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
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described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously. Cost Impact

The FAA estimates that 152 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 8 work hours per airplane to accomplish the proposed replacement, and that the average labor rate is $60 per work hour. Required parts will be provided at no charge by the manufacturer. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $72,960, or $480 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39AIRWORTHINESS 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. Section 39.13 is amended by adding the following new airworthiness directive:

Airbus Industrie: Docket 2001NM71AD.

Applicability: Model A319, A320, and A321 series airplanes, all serial numbers having received Airbus Modification 20234
(installation of telescopic girt bar for slide raft) or Airbus Service Bulletin A320251055 without Airbus Modification 28212 in production or Airbus Service Bulletin A320521102, Revision 01, dated November 25, 1999, in service; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent corrosion of the trigger spring on the slide bar of the forward and aft passenger doors, which could result in incorrect locking of the slide bar during deployment of the escape slide and lead to a delay in evacuating passengers in an emergency, accomplish the following:
Replacement
(a) Within 18 months of the effective date of this AD or within 30 months from the date of manufacture of the airplane, whichever occurs later: Replace the carbonsteel trigger spring having part number (P/N) D5211046420000 on each of the forward and aft passenger doors with a stainless steel trigger spring having P/N
D5211046420200, in accordance with Airbus Service Bulletin A32052 1102, Revision 01, dated November 25, 1999. Spares
(b) As of the effective date of this AD, no person shall install a carbonsteel trigger spring having P/N D5211046420000, on any airplane.
Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM116, Transport Airplane Directorate, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM116.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Manager, International Branch, ANM116.
Special Flight Permits
(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Note 3: The subject of this AD is addressed in French airworthiness directive 2001063(B), dated February 21, 2001.

Issued in Renton, Washington, on August 24, 2001. Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 0121974 Filed 83001; 8:45 am] BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT

Tamra Elkins, Aerospace Engineer, International Branch, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington, telephone (425) 2272669, fax (425) 2271149.