AD 2021-10-20 Prompted By Reports Of Temporary Loss Of All Display Units

The FAA is adopting a new airworthiness directive (AD) for certain ATR-GIE Avions de Transport Regional Model ATR42-500 and ATR72-212A airplanes.

This AD was prompted by reports of temporary loss of all display units and the integrated electronic standby instrument (IESI). This AD requires revising the existing aircraft flight manual (AFM) and applicable corresponding operational procedures to update a systems limitation, limiting dispatch with certain equipment inoperative, performing an operational test of a certain contactor and an electrical test of a certain battery toggle switch, and corrective actions if necessary, 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 becomes effective May 14, 2021.

Supplementary Information: EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA Emergency AD 2021-0120-E, dated May 3, 2021 (EASA Emergency AD 2021-0120-E) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for certain ATR¡VGIE Avions de Transport Regional Model ATR42-500 and ATR72-212A airplanes.
This AD was prompted by reports of temporary loss of all display units and the IESI. The investigation is ongoing and the root cause is not yet known, but the initial investigation revealed that the battery toggle switch functional item number (FIN) 7PA and the contactor FIN 1PA were two potential contributors to the reported cases. The FAA is issuing this AD to address temporary loss of all display units and the IESI, which could result in loss of control of the airplane. See the MCAI for additional background information.

FMI: www.regulations.gov