Electronic Flight Bag – Thermal Runaway Dangers
The NBAA reports that incidents involving smoke, extreme heat, or fire from lithium-ion batteries occur more than once a week on U.S. aircraft. It’s crucial for operators to understand the risks and know how to respond properly to a thermal runaway. A runaway occurs when a lithium-ion battery overheats due to previous damage that creates a short circuit, the unit continues a catastrophic internal chain reaction until it melts or catches fire.
Causes
Most thermal runaway occurrences begin when the owner drops or damages their electronic device. Just think about all the cracked screens on phones these days and you will get an idea of how many devices are at risk. Another leading cause is the use of off-market charging devices. These cheap chargers have a much higher rate of causing battery overheat than factory direct chargers and cables.
Corrective Action
Pilots will want to know the best way to fight lithium-ion fires and avoid thermal runaway. Halon extinguishers will extinguish an open flame but will not stop a thermal runaway. Additionally, placing the device in a fire bag may make the situation worse if the runaway is not addressed first. Enclosed spaces will make the reaction even hotter.
The batteries MUST be cooled inside the device to stop a thermal runaway. The only way to do this is to submerge it in a liquid, hopefully in a sink or a metal garbage can. Simply putting it in ice does not work, nor does a bottle or two of water or some other liquid. It must be a concentrated effort to drown the device to begin the cooling process.
Equipment Needed
Because the temperature of a thermal runaway can approach 1300 degrees Fahrenheit, it is impossible to fight them without protective equipment. Containment bags are the last step in the process and can only be used if the unit has been cooled first. At the very least, the following items are suggested to be onboard every flight before departure:
- Fireproof gloves to pick up the device.
- A face shield to protect against exploding white-hot metal bits
- An ample supply of liquid and a metal garbage can or sink.
- Ideally, a specialized fire extinguisher capable of fighting thermal runaway, such as Spectrum FX
- A containment bag
Conclusion
A successful outcome for a thermal runaway is only possible with proper training and advanced planning. Even if you have all the necessary equipment on board, if the flight crew or passengers have no idea how to really use it all correctly and in the right order, the situation may get out of hand very quickly. Don’t just buy a containment bag and put it in a drawer. There is much more to Electronic Flight Bag safety, and it just might save your life.
