A new FAA Safety Alerts for Operators (SAFO 25002) highlights the continuing fire risks associated with the carriage of lithium batteries—and the devices that operate off them—in aircraft passenger and crew compartments.
In addition, the alert emphasizes the importance of identifying all potential hazards and implementing risk mitigation strategies to manage thermal runaway events, which are self-sustaining, uncontrolled increases in pressure and temperature.
Recent FAA data shows a number of safety events involving lithium batteries. “Lithium batteries stored in passenger overhead bins and/or in carry-on baggage may be obscured, difficult to access, or not readily monitored by passengers or crew members,” notes the alert. “Because of this, detection of thermal runaway and firefighting measures may be delayed in flight, increasing the risk to safety.”
The FAA warns that traditional firefighting methods may not work. “Use of Halon extinguishers can briefly suppress open flames; however, they do not halt the thermal runaway process. The primary response involves using large amounts of water to cool the battery and suppress flames. Cooling the device with water is essential to prevent the reaction from continuing until all cells have discharged their energy.”
Since lithium batteries have become common power sources in personal devices, the FAA, the EU Aviation Safety Agency (EASA), and other authorities have issued a number of advisories to emphasize the risks and mitigation measures.