AD 2021-07-04 Requires Revising The Existing Aircraft Flight Manual (AFM)

The FAA is adopting a new airworthiness directive (AD) for all ATR-GIE Avions de Transport Régional Model ATR42 airplanes and Model ATR72 airplanes. This AD was prompted by in-service data, which revealed that the minimum operating airspeeds in severe icing conditions, computed to provide adequate stall margins, do not provide sufficient margins to stall speeds at high bank angle while exiting severe icing conditions.

This AD requires revising the existing aircraft flight manual (AFM) and applicable corresponding operational procedures to provide emergency procedures and limitations for operating in severe icing conditions, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective May 10, 2021.

Supplementary Information: The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0177, dated August 11, 2020 (EASA AD 2020-0177) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for all ATR-GIE Avions de Transport Régional Model ATR42-200, -300, -320, -400, and -500 airplanes; and Model ATR72 airplanes. Model ATR42-400 airplanes are not certificated by the FAA and are not included on the U.S. type certificate data sheet; this AD therefore does not include those airplanes in the applicability.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all ATR-GIE Avions de Transport Régional Model ATR42-200, -300, -320, and -500 airplanes; and Model ATR72-101, -102, -201, -202, -211, -212, and -212A airplanes.

The NPRM published in the Federal Register on December 8, 2020 (85 FR 78974). The NPRM was prompted by in-service data, which revealed that the minimum operating airspeeds in severe icing conditions, computed to provide adequate stall margins, do not provide sufficient margins to stall speeds at high bank angle while exiting severe icing conditions. The NPRM proposed to require revising the existing AFM and applicable corresponding operational procedures to provide emergency procedures and limitations for operating in severe icing conditions, as specified in EASA AD 2020-0177.

The FAA is issuing this AD to address airplane stalling due to inadvertent exposure to severe icing conditions, which could result in loss of control of the airplane. See the MCAI for additional background information.

FMI: www.regulations.gov