Airworthiness Directives; Aerospatiale Model ATR72 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Aerospatiale Model ATR72 series airplanes, that currently requires initial and repetitive inspections to detect fatigue cracking in certain areas of the fuselage, and corrective actions if necessary. For certain airplanes, this action would require a new inspection for oversized fastener holes and cracking, and repair if necessary. The actions specified by the proposed AD are intended to prevent fatigue cracking of the fuselage and the passenger and service doors, which could result in reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by December 29, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-376-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. 2001-NM-376-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:

Tony Jopling, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2190; 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 2001-NM-376-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. 2001-NM-376-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On February 17, 2000, the FAA issued AD 2000-04-13, amendment 39-11596 (65 FR 10381, February 28, 2000), applicable to certain Aerospatiale Model ATR72 series airplanes, to require initial and repetitive inspections to detect fatigue cracking in certain areas of the fuselage, and corrective actions if necessary. That action was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The requirements of that AD are intended to prevent fatigue cracking of the fuselage and the passenger and service doors, which could result in reduced structural integrity of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of AD 2000-04-13, the Direction Générale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may continue to exist on certain ATR72 series airplanes on which Aerospatiale Modification 3191 (specified in Service Bulletin ATR72-52-1018, dated May 18, 1995, which is required by the existing AD) has not been done, but Aerospatiale Modification 3184 (accomplished during production and unrelated to the actions of the existing AD) has been done. Investigation revealed that during fatigue testing of these airplanes, damage was found at the attachment holes at the hinge fitting of the cargo compartment door outer skin due to oversized fastener holes drilled during incorporation of Modification 3184.

Explanation of Relevant Service Information

The manufacturer has issued Avions de Transport Regional Service Bulletin ATR72-52-1018, Revision 1, dated March 13, 2001. The original issue of the service bulletin was referenced as the appropriate source of service information for the accomplishment of certain inspections and corrective actions specified in the existing AD. For airplanes on which Aerospatiale Modification 3191 has not been done, but Aerospatiale Modification 3184 has been done, Revision 1 adds procedures for a detailed visual inspection of the fastener holes at the hinge fitting of the cargo compartment doors to determine if the holes are oversized, and the outer skin around the fastener holes for cracking, and repair of any discrepancies found. For airplanes on which neither modification 3191 nor 3184 has been done, the new actions specified in Revision 1 of the service bulletin need not be done. The DGAC classified this service bulletin as mandatory and issued French airworthiness directive 2001-142-056(B), dated April 18, 2001, to ensure the continued airworthiness of these airplanes in France. The new French airworthiness directive covers all the service bulletins specified in the existing AD, and replaces French airworthiness directive 92-046-012(B)R4, dated November 5, 1997; which was referenced in the existing AD.

FAA's Conclusions

This airplane model is manufactured in France and is 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 us informed of the situation described above. We have 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 supersede AD 2000-04-13 to continue to require initial and repetitive inspections to detect fatigue cracking in certain areas of the fuselage, and corrective actions if necessary. For certain airplanes, the proposed AD also would require repair of oversized fastener holes. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed below.

Differences Between Proposed AD and Service Bulletin

The service bulletin specifies that the manufacturer should be notified if the measured diameter of the fastener holes is out of tolerance, but this proposed AD does not include such a requirement.

The service bulletin also describes procedures for completing an inspection report and submitting it to the manufacturer, but this proposed AD would not require those actions. We do not need this information from operators.

Cost Impact

There are approximately 39 airplanes of U.S. registry that would be affected by this proposed AD.

The actions that are currently required by AD 2000-04-13 are as follows:

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1018 (14 U.S.-registered airplanes), it takes approximately 250 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Required parts will cost approximately $9,880 per airplane. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $365,820, or $26,130 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-52-1013, Revision 2 (2 U.S.-registered airplanes), it will take approximately 3 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $390, or $195 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-52-1019, Revision 2 (2 U.S.-registered airplanes), it will take approximately 100 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $13,000, or $6,500 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-52-1028 (2 U.S.-registered airplanes), it will take approximately 5 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $650 or $325 per airplane, per inspection cycle.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-52-1033, and ATR72-52-1029, Revision 1 (2 U.S.-registered airplanes), it will take approximately 145 work hours per airplane to accomplish the required door stop fitting replacement, at an average labor rate of $65 per work hour. Required parts are provided by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the stop fittings replacement required by this AD on U.S. operators is estimated to be $18,850 or $9,425 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1021, Revision 1 (2 U.S.-registered airplanes) it will take approximately 30 work hours per airplane to accomplish the proposed actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $3,900, or $1,950 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1014, Revision 2 (2 U.S.-registered airplanes), it will take approximately 8 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $1,040, or $520 per airplane.

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1020 (14 U.S.-registered airplanes), it will take approximately 6 work hours per airplane to accomplish the required actions, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of these actions required by this AD on U.S. operators is estimated to be $5,460, or $390 per airplane.

The new actions proposed in this AD are as follows:

For airplanes identified in Avions de Transport Regional Service Bulletin ATR72-53-1018, Revision 1, accomplishment of the new proposed actions, if required, would take approximately 250 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts would cost approximately $9,880 per airplane. Based on these figures, the cost impact of the new actions proposed by this AD on U.S. operators is estimated to be $26,130 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or 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.