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AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Notice of proposed rulemaking (NPRM).
SUMMARY:
The FAA proposes to adopt a new airworthiness directive (AD) for certain ATR—GIE Avions de Transport Régional Model ATR42-500 and ATR72-212A airplanes. This proposed AD was prompted by a report of the possible use of improper material during the manufacturing of vertical stabilizer to horizontal stabilizer junction fittings. This proposed AD would require inspections of affected parts, applicable repairs, and eventual replacement of certain affected parts, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). The FAA is proposing this AD to address the unsafe condition on these products.
DATES:
The FAA must receive comments on this proposed AD by December 16, 2024.
ADDRESSES:
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
- Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments.
- Fax: 202-493-2251.
- Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
- Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-2416; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
- For EASA material identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; emailADs@easa.europa.eu; website easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu. It is also available at regulations.gov under Docket No. FAA-2024-2416.
- You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195.
FOR FURTHER INFORMATION CONTACT:
Shahram Daneshmandi, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3220; email shahram.daneshmandi@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2024-2416; Project Identifier MCAI-2024-00491-T” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Shahram Daneshmandi, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3220; email shahram.daneshmandi@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.
Background
EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2024-0171, dated August 27, 2024 (EASA AD 2024-0171) (also referred to as the MCAI), to correct an unsafe condition for certain ATR—GIE Avions de Transport Régional Model ATR42-500 and ATR72-212A airplanes. The MCAI states that a report was received of the possible use of improper material during the manufacturing of vertical stabilizer to horizontal stabilizer junction fittings. Subsequent review identified the population of affected parts and the airplanes equipped with those affected parts. Vertical stabilizer to horizontal stabilizer junction fittings manufactured with improper material, if not addressed, could reduce the structural integrity of the airplane.
The FAA is proposing this AD to address the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2024-2416.
Material Incorporated by Reference Under 1 CFR Part 51
EASA AD 2024-0171 specifies procedures for a special detailed inspection (SDI) (conductivity measurement, hardness test, and X-ray fluorescence (XRF) inspection) to determine the material tolerance of affected vertical to horizontal stabilizer junction fittings installed on group 1 or 2 airplanes; repair of parts not within the tolerances of material AL7075-T73 (except those within the tolerances of material AL7050-T7452); repetitive detailed visual inspections for any damage (including corrosion and dents) of each affected part that is within the tolerances of material AL7050-T7452 or is installed on a group 3 airplane; repair of damaged parts; and eventual replacement of any affected part that is within the tolerances of material AL7050-T7452 or installed on a group 3 airplane. EASA AD 2024-0171 also specifies reporting the inspection results of the SDI to ATR. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.
FAA's Determination
This product has been approved by the aviation authority of another country and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop in other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified in EASA AD 2024-0171 described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2024-0171 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2024-0171 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2024-0171 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2024-0171. Material required by EASA AD 2024-0171 for compliance will be available at regulations.gov under Docket No. FAA-2024-2416 after the FAA final rule is published.
Interim Action
The FAA considers that this proposed AD would be an interim action. The inspection reports specified in this proposed AD will provide the manufacturer additional data for determining the extent of the improper material usage, and to determine if further action is needed to address the unsafe condition.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 36 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:
Estimated Costs for Required Actions
| Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|
| Up to 26 work-hours × $85 per hour = $2,210 | $0 | Up to $2,210 | Up to $79,560. |
Estimated Costs of On-Condition Actions
| Labor cost | Parts cost | Cost per product |
|---|---|---|
| Up to 523 work-hours × $85 per hour = $44,455 | $6,340 | $50,795 |