We found some interesting research into thermal runaway in aircraft, in an article that we link to below. The authors propose a way to detect and monitor thermal runaway in batteries that use lithium-ion chemistry.
Their key warning signs of thermal runaway in aircraft include changes in internal pressure, state of charge, voltage, gas evolution, and temperature. But they discovered several critical trends:
- The gas during early thermal runaway is mostly vapor from lithium-ion battery solvent electrolyte.
- The amount of vapor increases with higher states of charge, as thermal runaway continues.
- Lower atmospheric pressure suppresses the generation of hydrogen, carbon dioxide, and hydrocarbons.
- Internal combustion is more complete at 75% state of charge, than in typical open conditions.
So much for the theory, but what should pilots and cabin crew do, if there is a lithium-ion battery fire on their aircraft?
Combating Battery Thermal Runaway in Flight
We came across another interesting article by UL Laboratories Standards and Engagement, that we also link to below. They describe a true story. A passenger has managed to drop their laptop down the aircraft sidewall into the aircraft’s cargo hold.
In this instance the pilot told traffic control, “We don’t know the status of it, we can’t access it, we can’t see it. So we are returning to find the laptop before we fly over the ocean.”
Aircraft Crew Have Advanced Fire Safety Training
Aircraft cabin crew have advanced safety training covering thermal runaway in aircraft, especially incidents in passenger space. They should therefore know how to deal with battery devices overheating, swelling, or smoking in accessible areas.
They have an average 19 minutes to contain a fire, if they have a battery fire containment product with UL 5880 certification, or similar. This should suppress the fire for up to six hours, allowing time for the aircraft to land safely.
Battery fire containment products include insulated bags or boxes that reduce the impact of smoke and fire. These combine fire-resistant materials, insulation materials and inner liners, and secure closures that work together, and allow more time to reach the nearest airport.
More Information
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Aircraft Battery Fires Smouldering On
Preview Image: Any Batteries to Declare
