AD 2024-15-14

This AD is effective October 23, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of October 23, 2024.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2023-1987; 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 final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu; website easa.europa.eu. You may find this material on the EASA website ad.easa.europa.eu.

• You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available at regulations.gov under Docket No. FAA-2023-1987.

Shahram Daneshmandi, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 206-231-3220; email Shahram.Daneshmandi@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2021-17-02, Amendment 39-21685 (86 FR 48490, August 31, 2021) (AD 2021-17-02). AD 2021-17-02 applied to all ATR-GIE Avions de Transport Régional Model ATR42-200, -300, and -320 airplanes. AD 2021-17-02 required a one-time inspection for discrepancies of the wire bundles between the left- and right-hand AOA probes and the crew alerting computer, and, depending on findings, applicable corrective actions. AD 2021-17-02 also required for certain airplanes, modifying the captain stick shaker wiring, and for all airplanes, revising the existing AFM and applicable corresponding operational procedures to incorporate procedures for the stick pusher/shaker. The FAA issued AD 2021-17-02 to address false activation of the stall warning system due to wiring damage on the wire bundle between an AOA probe and the crew alerting computer, which could result in loss of control of the airplane during take-off and landing phases.

The NPRM published in the Federal Register on October 5, 2023 (88 FR 69102). The NPRM was prompted by AD 2023-0134, dated July 5, 2023 (EASA AD 2023-0134), issued by EASA, which is the Technical Agent for the Member States of the European Union. EASA AD 2023-0134 states final modification instructions of the affected wiring were developed.

In the NPRM, the FAA proposed to require installing a new AOA power supply unit and revising the existing AFM, as specified in EASA AD 2023-0134.

The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to supersede AD 2021-17-02. The SNPRM published in the Federal Register on May 21, 2024 (89 FR 44568). The SNPRM was prompted by additional modification of the affected wiring for certain airplanes, and by the issuance of EASA AD 2023-0191, dated November 2, 2023 (EASA AD 2023-0191) (also referred to as the MCAI). In the SNPRM, the FAA proposed to retain all of the requirements of AD 2021-17-02. The NPRM also proposed to require installing a new AOA power supply unit and removing the AFM amendment. The FAA is issuing 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-2023-1987.

The FAA received one comment, from Air Line Pilots Association, International (ALPA), who supported the SNPRM without change.

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 reviewed the relevant data, considered the comment received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on this product. Except for minor editorial changes this AD is adopted as proposed in the SNPRM. None of the changes will increase the economic burden on any operator.

EASA AD 2023-0191 specifies procedures for a one-time inspection for discrepancies of the wire bundles between the left- and right-hand AOA probes and the crew alerting computer, and, depending on findings, applicable corrective actions (repair). EASA AD 2023-0191 also specifies procedures, for certain airplanes, for modifying the captain stick shaker wiring, and for all airplanes, revising the existing AFM to incorporate procedures for the stick pusher/shaker. Finally, EASA AD 2023-0191 specifies procedures for installing the AOA power supply unit, removing the AFM amendment, and accomplishing additional modification of the affected wiring.

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.

The FAA estimates that this AD affects 26 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

The FAA has received no definitive data on which to base the cost estimates for the on-condition actions specified in this AD.

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

This AD will not have federalism implications under Executive Order 13132. This AD will 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Will not affect intrastate aviation in Alaska, and

(3) 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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

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

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive 2021-17-02, Amendment 39-21685 (86 FR 48490, August 31, 2021); and

b. Adding the following new Airworthiness Directive: