Hello aviation professionals, and welcome to Podcast 22: Lithium Battery Fires.
Most of our industry is in tough times, and I hope that everyone is healthy and safe. It’s easy to become distracted. For those of you still flying, please take care to follow your sterile cockpit procedures and concentrate on the task at hand. I have flown a few times recently, and it can be stressful simply going to work. Let’s all get through this as healthy and as safe as possible. I listen to many different podcasts, and they are inundated with COVID-19 content. I felt like stepping back into the flying world and talking about lithium battery fires. As always, feel free to email me with any suggestions you have for topics.
Incidents and Accidents
On February 13, 2020, a British Airways Boeing 777, while crossing the Atlantic Ocean, diverted to Bermuda after the cabin filled with smoke. The aircraft was operating from London Gatwick to Tampa, Florida, with 241 people on board.
When the smoke started, the flight crew were unaware that the source of the smoke was a smartphone. The flight crew declared an emergency and diverted to Bermuda. The aircraft landed safely on Runway 30, and passengers were deplaned normally using airstairs. After a short investigation, the cause of the smoke was found to be a smartphone that became lodged in one of the passenger seats. The lithium-ion battery was damaged, which caused it to overheat. Fortunately, the thermal runaway did not cause further damage to the aircraft. The takeaway for me on this occurrence is that one smartphone diverted a wide-body airliner.
In 2016, a SkyWest flight 4449 scheduled to fly from Salt Lake City to Bozeman, Montana, had the smell of smoke in the cabin just before takeoff. The crew did not take off, and initiated a search of the cargo area which revealed an exploded lithium-ion battery in a toiletry bag in checked luggage.
While the FAA does not prohibit lithium-ion batteries on board aircraft, airlines have prohibited them in checked baggage. This includes so-called “smart luggage,” which relies on lithium-ion batteries to work. According to FAA records, there were 46 incidents with lithium-ion batteries on aircraft in 2017–up from 31 in 2016.
The situation underscores the importance of removing lithium-ion batteries from luggage going into the cargo area or inaccessible area of the airplane. Even if you can access this area, the battery could be difficult to locate.
If a lithium battery fire started in your cargo area, would you know about it? Is there fire detection in your cargo area? Is the cargo area accessible in flight?
Procedures for The Transportation of Lithium Batteries
Spare Lithium Batteries in Carry-on Baggage
For spare lithium batteries in carry-on baggage, the FAA says to ensure personnel understand the following:
- Each spare lithium battery must be individually protected so as to prevent short circuits (g., by placement in original retail packaging, by otherwise insulating terminals by taping over exposed terminals, or placing each battery in a separate plastic bag or protective pouch).
- Spare batteries must not come in contact with metal objects such as coins, keys, or jewelry. Steps should be taken to prevent crushing, puncturing, or pressure of such objects on the battery.
The FAA recommends that any devices containing lithium-ion batteries be kept in carry-on bags only. But, as we saw in the British Airways occurrence, even having access to the device with the battery does not mean the situation will be easy to resolve. You just have to spend a few minutes on YouTube watching a lithium battery thermal runaway to get the very clear sense of how lethal a situation this could become. The heat and smoke generated is astonishing. What’s more concerning is that there are so many batteries out there. Many are in children’s toys.
The number of incidents is on the rise so we need to think about where these batteries are hiding. In February 2016, ICAO banned all shipments of lithium-ion batteries in the cargo hold on passenger planes. This ban only applies to spare lithium-ion batteries such as power banks, not those contained in personal devices carried by passengers or crew.
The International Aviation Transport Association (IATA) Dangerous Goods Table 2.3.A is a very good resource for the details of what can and can’t be carried especially for Non-carry Dangerous Goods (DG) operators (which is most of business aviation). This table tells you that mace or pepper spray is not allowed to be carried in checked or non-checked baggage. It also says that baggage with non-removable lithium-ion batteries exceeding 0.3 gram lithium metal or 2.7 Watt-hours (Wh) are prohibited. This is the so-called “smart luggage” I mentioned earlier that has batteries installed in the luggage. I don’t own this type of luggage, but business aviation probably flies people that own this type of luggage. Smart luggage can have non-removable or removable batteries. If you can remove the batteries, then they must be removed from the luggage and carried in the cabin and, if the smart luggage battery is larger than 0.3 gram lithium metal or 2.7 Wh, it is prohibited to fly unless it can be removed.
The IATA chart goes on to say that spare or loose separate batteries, including power banks must not exceed 2 grams and for lithium ion batteries the Watt-hour rating must not exceed 100 Wh.
The IATA has four questions for each dangerous good, so this is for spare batteries:
- The approval of the operator is required: NO.
- Permitted in or as checked baggage: NO.
- Permitted in or as carry-on baggage: YES.
- The pilot-in-command must be informed of the location: NO.
I recommend you have a look at this chart. I put a link in the show notes to the online version. You can also find it in the No-Carry Operator Dangerous Goods training available at TrainingPort.net.
From a business aviation perspective, we need to ensure lithium batteries are in the passenger cabin or accessible cargo area only. If a thermal runaway happens, we must have a plan to get the battery cooled and extinguished and the toxic smoke dealt with.
According to data collected by industry providers, there are three smoke events every day in U.S. airspace.
Thermal Runaway of Lithium-ion Batteries
What Happens in The Battery to Start A Thermal Runaway?
Lithium-ion batteries consist of several battery cells and a battery management system.
The battery management system ensures that the battery remains in its specified working range. This requires extremely precise measurement of the charge and discharge currents, cell voltage, and temperature. With regard to thermal runaway, also known as “venting with flame,” the temperature is decisive.
Lithium-ion batteries have a narrow operating temperature range of between +15 and +45 degrees Celsius (°C). The battery must remain in this temperature range to remain safe. If the temperature exceeds a critical level, thermal runaway occurs.
What Is Thermal Runaway?
Thermal runaway of the lithium-ion battery initiates an unstoppable chain reaction. The temperature rises rapidly within milliseconds and the energy stored in the battery is suddenly released. At temperatures of around 400 °C or about 800 degrees Fahrenheit (°F), the battery becomes gaseous, and a fire erupts that can be difficult to extinguish. The risk of thermal runaway begins at a temperature of 60 °C and becomes extremely critical at 100 °C. When the battery catches fire depends on the specific cause.
How Does Thermal Runaway of A Lithium-ion Battery Occur?
It can happen in the following ways:
- Internal short circuit: Due to an accident or impact,
- External short circuit: Deformation of the battery cell can cause an external short circuit, and
- Overcharging the battery beyond the maximum voltage specified for the battery.
Hey, but It’s Not All Doom and Gloom!
The National Research Council (NRC) in Canada performed numerous tests on lithium-ion batteries with regards to aviation. I have a link to the report in the show notes. One of the most interesting tests was the altitude test up to 50,000 ft which was designed to replicate the maximum possible altitude a cargo airplane could experience. Therefore, even during a de-pressurization event, cells should withstand the pressure drop without producing an event or battery cell failure.
Procedures for Dealing with Lithium Battery Fires
The Smoke/Fire/Fumes checklist is one of the longest checklists in the airplane I fly and it has been revised lately. One of the first items on the checklist says, “Do NOT delay landing in an attempt to complete all the following steps.” This is a smart statement as these battery fires are explosive and generate a lot of smoke very quickly. One awesome experience I had training years ago was when the simulator instructor used theatrical smoke in the simulator during a smoke event. The longer we took with the checklist, the more smoke he pumped into the simulator. I’ll never forget the sound of the machine pumping out more smoke—apparently, we needed to go faster. We could barely read the checklist, let alone fly the airplane. And this smoke smelled like candy and did not bother our eyes. The smoke from a lithium-ion battery is flammable, carcinogenic, and toxic.
What to Do if A Battery Catches Fire
If a battery overheats and catches fire, it must be cooled and extinguished. Use water to cool it and Halon to put it out. Here are some general steps:
- Put on your mask and establish communications if required.
- Refer to your aircraft’s Smoke/Fire/Fumes checklist.
- Consider an immediate diversion to a suitable airport.
- There will be a lot going right now as the battery burns hot and toxic smoke fills the cabin. Try to extinguish the fire using a fire extinguisher or any non-flammable liquid. The FAA does not recommend the usage of containment kits, a fire box or fire containment bag at this point, to extinguish a device fire due to the dangers associated with picking up the device while it is in an unstable condition. A battery in thermal runaway can create temperatures of 1,000 °F.
The device is considered unstable if the fire is still actively burning or the device appears to be expanding or popping from heat.
Do not cover the device or use ice to cool the device! Ice or other materials insulate the device, which could increase the likelihood that additional battery cells will reach thermal runaway. This will cause more fire.
What to Do once The Fire Is out
- Once the fire is out, ensure the battery is continually cooled to prevent reigniting the same battery cells or adjacent cells. This cooling can be accomplished by submerging the device and battery in any non-flammable liquid, or by placing it in a fire containment bag or box using fire retardant gloves. Follow the manufacturer’s instructions if you are equipped with a fire containment bag or box.
- Notify ATC of your intentions and have fire personnel available to collect and dispose of the device or battery upon arrival.
- After landing, coordinate with fire professionals to offload the device or battery to a safe area.
These steps are included in compliant EFB training on the TrainingPort.net website.
What Are Your Operation’s Procedures for Lithium-ion Batteries?
- If a passenger decides at the last minute to put one of there bags in the cargo area, is it checked for lithium batteries?
Even with these precautions, a lithium battery fire is a major event and should be reviewed regularly. Many of the points I’ve discussed today came from TrainingPort.net topics Electronic Flight Bag and No-carry Operator Dangerous Goods.
In The News
Let’s changes gears for a moment. In The News is a segment of the podcast where I talk about other happenings in aviation. Very briefly:
The North Atlantic Datalink Mandate (NAT DLM) has been suspended for three months by ICAO’s North Atlantic System Planning Group to provide more flexibility for operations and to expedite the flow of traffic over the Atlantic during the COVID-19 pandemic. So until June 30, aircraft in the NAT DLM do not require FANS 1/A, CPDLC or ADS-C from FL290 to FL410. Other rules postponed include ADS-B in Europe requirements being pushed from June to December of this year.
Thanks for listening, and have a great day!
Charpentreau, Clement. (2020, February 14). Damaged phone forces British Airways flight to divert. AeroTime Hub. https://www.aerotime.aero/clement.charpentreau/24560-damaged-phone-forces-british-airways-flight-to-divert?utm_source=newsletter&utm_medium=email
International Aviation Transport Association. (2020, January 1). Dangerous Goods Regulations – TABLE 2.3.A Provisions for Dangerous Goods Carried by Passengers or Crew (Subsection 2.3). https://www.iata.org/contentassets/6fea26dd84d24b26a7a1fd5788561d6e/dgr-61-en-2.3a.pdf
Transport Canada. (2019, November 19). Lithium Battery Transport Research Program. Government of Canada. https://www.tc.gc.ca/eng/tdg/publications-menu-1307.html