03-25978. Airworthiness Directives; Airbus Model A319, A320, and A321 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A319, A320, and A321 series airplanes. This proposal would require repetitive inspections of the left- and right-side main landing gear (MLG) side-stay cuff lugs and down-lock spring attachments for evidence of cracked or fractured side-stay cuff lugs or down-lock spring attachments, and repair if necessary. This action would also provide for optional terminating action for the repetitive inspections. This action is necessary to prevent failure of the MLG side-stay cuff lugs or down-lock spring attachments, which could result in improper down-lock of the MLG during a freefall extension, and possible collapse of the MLG. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 14, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-49-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-49-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Airbus Industries, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Tim Dulin, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 FAA-public 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 self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-49-AD.” 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, ANM-114, Attention: Rules Docket No. 2002-NM-49-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

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 A320 series airplanes. The DGAC advises that it has received reports of failure of the MLG side-stay cuff lugs on certain Model A320 series airplanes. Investigation has revealed that the failures were due to stress-corrosion cracks attributed to moisture ingress. In one case the failed cuff lugs resulted in the disconnection of the side-stay down-lock springs from the lock-stay links. Failure of the side-stay cuff lugs or down-lock spring attachments could result in improper down-lock of the MLG during a freefall extension, and possible collapse of the MLG.

The MLG down-lock mechanism on Airbus Model A319 and A321 series airplanes is similar to that on the affected Model A320 series airplanes. Therefore, those airplanes may be subject to the unsafe condition revealed on the Model A320 series airplanes.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-32A1224, dated January 18, 2001, which describes procedures for repetitive detailed inspections of the MLG lock-springs and side-stay center joint links for evidence of cracked or fractured lugs; and repair if necessary. The inspections are to be repeated until accomplishment of Airbus Service Bulletin A320-32-1223, dated March 5, 2001.

Airbus Service Bulletin A320-32-1223 describes procedures for installation of MLG side-stay cuffs and links manufactured from new, improved material that has a higher stress-corrosion resistance than the current material. Accomplishment of this service bulletin eliminates the need for the repetitive inspections specified in Airbus Service Bulletin A320-32A1224.

Accomplishment of the actions specified in Airbus Service Bulletin A320-32A1224 is intended to adequately address the identified unsafe condition. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 2002-075(B), dated January 23, 2002, to ensure the continued airworthiness of these airplanes in France. The French airworthiness directive specifies that accomplishment of the actions specified in Airbus Service Bulletin A320-32-1223 cancels the requirement of that AD.

FAA's Conclusions

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of § 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. 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 Airbus Service Bulletin A320-32A1224, described previously, and provides for an optional terminating action for the repetitive inspections.

Cost Impact

The FAA estimates that 367 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 2 work hours per airplane to accomplish the proposed repetitive inspections, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD is estimated to be $130 per airplane, per inspection cycle.

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 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 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Airbus: Docket 2002-NM-49-AD.

Applicability: Model A319, A320, and A321 series airplanes; certificated in any category; except those airplanes on which Airbus Modification 30648 has been installed.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the MLG side-stay cuff lugs or down-lock spring attachments, which could result in improper down-lock of the MLG during a freefall extension, and possible collapse of the MLG, accomplish the following:

Inspection

(a) Do a detailed inspection of the left- and right-side main landing gear (MLG) side-stay cuff lugs and down-lock spring attachments to detect failures (cracked or fractured lugs), in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-32A1224, dated January 18, 2001, at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD.

(1) Within 60 months from the first entry into service of the MLG, or before the accumulation of 9,000 total flight hours on the MLG, whichever occurs first.

(2) Within 500 flight hours on the MLG after the effective date of this AD.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(b) If during any inspection required by paragraph (a) of this AD no crack or fracture is detected: Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 500 flight cycles until the actions specified in paragraph (e) of this AD are accomplished.

(c) If during any inspection required by paragraph (a) of this AD any crack or fracture is detected: Before further flight, replace any discrepant part with a new part of the same type in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-32A1224, dated January 18, 2001. Repeat the inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 500 flight cycles until the actions specified in paragraph (e) of this AD are accomplished.

Credit for Actions Done per the Maintenance Planning Document

(d) Compliance with task number 321119.01.1, “Visual Check of Main Landing Gear Downlocking Springs,” of the Airbus A319/A320/A321 Maintenance Planning Document, Revision 25, dated October 2001, is considered acceptable for compliance with the inspection requirements of paragraph (a) of this AD. Operators should note that this task requires repetitive inspections at 8-day intervals, instead of intervals not to exceed 500 flight cycles.

Optional Terminating Action

(e) Replacement of the MLG side-stay lugs and links on the left and right sides of the airplane with lugs and links made of new, improved material, in accordance with Airbus Service Bulletin A320-32-1223, dated March 5, 2001, terminates the repetitive inspections required by paragraphs (b) and (c) of this AD.

Alternative Methods of Compliance

(f) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in French airworthiness directive 2002-075(B), dated January 23, 2002.

Issued in Renton, Washington, on October 7, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.