A highly experienced airline captain and accident investigator has voiced his fears over the danger of lithium ion batteries. 

Shem Malmquist (pictured left) says the risk of these batteries catching fire is very real and has revealed what can be done to try to mitigate the risk. 

He states: “Few events strike more fear in the hearts of aviators than an inflight fire. While there have been many sources of fires over the years, lithium batteries have been recognised as a primary risk factor.

“While the risk of lithium battery fires was not mentioned, last spring the United States implemented a policy (now rescinded) requiring carriers operating from several Middle Eastern countries to ban the carriage of laptop computers in carry-on luggage. This resulted in those computers being shipped in checked baggage, placed in an inaccessible location on the aircraft. While this may have addressed a security concern, it raised the issue of relatively large lithium batteries being placed out of reach of human intervention.

“This only exacerbated an already dire situation. A 2014 Royal Aeronautical Society paper stated that ‘on a typical flight a single aisle jet carrying 100 passengers could have over 500 lithium batteries on board.’ 

“A Royal Aeronautical Society paper stated that ‘these devices are not tested or certified nor are they necessarily maintained to manufacturer's recommendations. Replacement batteries from questionable sources ('grey' market) can be contained within devices." 

“While the newer systems certainly mitigate the risk in those devices, there remain many older devices and other types of devices that do not include such safeguards.

"The fact is that unknown quantities of lithium batteries are being shipped in baggage in an unknown state. When they are in checked baggage they have a reasonable probability, as outlined in an International Civil Aviation Organisation (ICAO) working paper in October 2017 of being in close proximity of flammable toiletry items such as aerosol cans of seemingly innocuous dry shampoo or more clearly flammable substances such as nail polish remover, hand sanitiser or hair sprays.

"The Federal Aviation Administration (FAA) found that when a lithium fire was initiated near one of these types of products it could lead to an explosion that could compromise the class C cargo compartment such that the fire protection in that compartment would no longer be effective.

“The risk of known shipments of lithium batteries is well known. It is suspected that lithium batteries have resulted in the loss of several cargo aircraft plus several close calls. ICAO tasked the Society of Automotive Engineers to establish a Lithium Battery Packaging Committee that is currently working to find ways to safety package known shipments of batteries, but that does little to prevent the shipment of batteries from the public.

“In the October ICAO working paper the FAA recognised that there is no way to prevent the carriage of these batteries entirely. 

“This limits us to attempting to control the factors that are possible. While it may be possible to increase the integrity of cargo compartments, such a change would be costly in terms of initial investment and increases in weight. Further, it would take time to implement such changes. While better technological solutions are being sought, at present it is left to the humans in the system to mitigate the risk.

“Ground crew can be alert to any signs of luggage or cargo catching fire and be careful in the loading so as not to potentially damage any batteries. The pilots can have a large part in preventing a disaster should a fire start through understanding the factors that might propagate the spread of a fire that as breached a compartment. Aircraft manufactures should develop procedures to minimise the risk of a loss of the aircraft and airlines should train these procedures. 

“While the design of cargo compartments and batteries should be improved, we have no choice but to depend on the skills of well trained professionals until they do.”

* AvSax fire containment bags are now on board several major airlines worldwide.

They have been deployed on aircraft 20 times so far this year and means they don’t need to make an emergency landing and can continue the flight confident the bag has solved the problem. The average cost of an emergency diversion in the USA is $400,000.

If an electronic device starts to seriously overheat or emit smoke the cabin crew will pour at least two litres of water into an AvSax and then drop the burning device into the bag, adding additional water as required. The water activates the polymer gel inside the bag causing it to expand around the device. Should the device keep on venting then the AvSax is tough enough to absorb the force.

The AvSax cools the batteries in the device, reducing the likelihood of the battery catching fire but if it does go into what is known as thermal runaway when all the battery cells catch fire at incredibly hot temperatures it is all contained within the bag.

Amazingly, the water is absorbed into the internal lining of the bag so the device is dry when it is removed.