AD FAA-2020-0338

The FAA is adopting a new airworthiness directive (AD) for certain Airbus SAS Model A350-941 and -1041 airplanes. This AD was prompted by the results of laboratory tests on non-rechargeable lithium batteries installed in certain emergency locator transmitters (ELTs), which highlighted a lack of protection against current injections of 28 volts direct current (DC) or 115 volts alternating current (AC) that could lead to thermal runaway and a battery fire. This AD requires modifying a certain ELT by installing a diode between the ELT and the terminal block, 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.