Airworthiness Directives; Aerospatiale Model ATR42-500 and ATR72-212A 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 Aerospatiale Model ATR42-500 and ATR72-212A series airplanes. This proposal would require repetitive inspections for cracking of the upper closing rib of the vertical fin, related investigative actions, and corrective actions if necessary. This action is necessary to prevent interference between the upper closing rib and the rudder, which could result in a rudder jam and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 16, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-301-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-301-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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Dan Rodina, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2125; fax (425) 227-1149.

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-301-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-301-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 Aerospatiale Model ATR42-500 and ATR72-212A series airplanes. The DGAC advises that rudder operation difficulties occurred on a Model ATR42-500 series airplane while the airplane was on the ground. Investigation revealed interference between the rudder and the upper closing rib of the vertical fin. This interference was subsequently attributed to failure of parts of the upper closing rib of the vertical fin due to fatigue cracking induced by installation stress. This condition, if not corrected, could result in a rudder jam and consequent reduced controllability of the airplane.

The subject area on certain Model ATR72-212A series airplanes is almost identical to that on the affected Model ATR42-500 series airplanes. Therefore, those Model ATR72-212A series airplanes may be subject to the unsafe condition revealed on the Model ATR42-500 series airplanes.

Explanation of Relevant Service Information

Aerospatiale has issued Avions de Transport Regional Service Bulletin ATR42-55-0011, dated September 26, 2002 (for Model ATR42-500 series airplanes); and Avions de Transport Regional Service Bulletin ATR72-55-1003, Revision 1, dated November 13, 2002 (for Model ATR72-212A series airplanes). These service bulletins describe procedures for repetitive detailed visual inspections for cracking of the upper closing rib of the vertical fin, and related investigative actions.

The related investigative actions involve measuring the planarity of the upper closing rib and measuring the gap between the rudder horn and the upper closing rib of the vertical fin. If any crack, wave, or anomaly is found, or if any measurement is outside the limits specified in the service bulletin, the service bulletin specifies further actions, which include:

• Removing the fairing of the vertical fin.
• Performing an internal detailed visual inspection of the fin tip closure rib in the area of the fairing, to detect and determine the extent of any cracking.
• Performing a measurement of the fin tip closure rib position.
• Performing an additional measurement of the planarity of the fin tip closure rib.
• Contacting the manufacturer for repair information.

Accomplishment of the actions specified in the applicable service bulletin is intended to adequately address the identified unsafe condition.

The DGAC classified these service bulletins as mandatory and issued French airworthiness directive 2002-506(B) R1, dated December 24, 2002, to ensure the continued airworthiness of these airplanes in France.

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 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 AD

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, except as discussed below.

Differences Between Proposed AD and Service Bulletins

Although the service bulletins specify that operators may contact the manufacturer for disposition of certain repair conditions, this proposed AD would require operators to repair those conditions per a method approved by either the FAA or the DGAC (or its delegated agent). In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair approved by either the FAA or the DGAC would be acceptable for compliance with this proposed AD.

Operators should note that, although the Accomplishment Instructions of the referenced service bulletins describe procedures for submitting inspection results to the manufacturer, this proposed AD would not require that action.

Interim Action

We consider this proposed AD interim action. If final action is later identified, we may consider further rulemaking then.

Cost Impact

The FAA estimates that 2 Model ATR42-500 series 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 actions, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $260, or $130 per airplane.

Currently, there are no affected Model ATR72-212A series airplanes on the U.S. Register. However, if an affected airplane is imported and placed on the U.S. Register in the future, it would be subject to the same per-airplane cost specified above for the Model ATR42-500 series airplanes.

The cost impact figures discussed above are 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.