Lithium-ion (Li-ion) batteries in cargo is not a new risk in aviation, but it is growing rapidly. In 2022, the US Federal Aviation Administration (FAA) recorded 64 incidents where such batteries caused smoke, heat or fire on board an aircraft.

The consulting company McKinsey estimates that the demand for and market uptake of such batteries will increase by 30 per cent every single year until 2030.

Compared to the relevant alternatives, Li-ion batteries are affordable and energy efficient. Therefore, they are becoming more and more prevalent in all kinds of applications, such as PCs, mobile phones, hand tools and toys.

Low probability, worrying impact

Normally, it is very unlikely that flammable heat will occur in Li-ion batteries, but if it were to happen, the consequences could be serious. Li-ion batteries contain a lot of energy per volume unit.

Nordisk Aviation Products has extensive experience in developing fire-resistant air cargo containers (ULDs in the technical language).

In collaboration with, among others, RISE Fire Research and Altitec, Nordisk Aviation is testing its air freight containers on a full scale to gain a better understanding of the fire risk lithium-ion batteries in the cargo can entail.

Says project engineer Markus Meier in Nordisk Aviation Products:

“We do this on behalf of the entire aviation industry. Nordisk Aviation Products wants to contribute to a better common assessment of risk among customers and providers of air freight, and to develop even safer regulation and test standards in aviation.”

Insufficient knowledge

As of today, no regulations or standards regulate airfreight containers and the fire risk that Li-ion batteries can entail.

“Providers of airfreight containers and their customers have no common knowledge base, and this leads to uncertainty and indecision. We at Nordisk Aviation Products believe that tests based on scientific methods at an accredited test partner such as RISE Fire Research adds value for all parties”, says Markus Meier.

This is how the tests were carried out:

RISE Fire Research and Nordisk Aviation Products tested the containers several times with two set-ups. In one set-up, the container was loaded with cardboard and paper. In the second set-up, we loaded with typical travel luggage: suitcases and bags filled with clothes, shoes, hairspray, and yes, of course, a few bottles of alcohol.

In addition, we put several Li-ion batteries inside the load. The number of batteries, type of battery, charge status, and location varied from test to test. Each fire test was carefully planned and designed by the parties involved: RISE Fire Research, Altitec, Nordisk Aviation Products and the company's customers.

The test team from RISE Fire Research heated up Li-on battery cells inside the load to make them go into so-called thermal runaway. A thermal runaway is an uncontrollable breakdown inside the battery cells. The heat and flammable gases developed during such a thermal runaway can lead to a fire that spreads from the battery to nearby objects.

Each test lasted six hours, and the temperature on the inside and outside of the Nordic containers was carefully monitored along the way. The fire must not spread out of the container and the temperature on the outside must not exceed 204 degrees Celsius.

“The knowledge we gain from these fire tests is important for Nordisk Aviation Products when we continue to develop and improve our fire-resistant containers (FireShieldTM)”, says project engineer Markus Meier.

If you whish to learn more about fire resistance or battery abuse tests at RISE Fire Research, please contact our group manager for testing & inspection, Robert Olofsson on mobile (+47) 45 20 56 94 or email: robert.olofsson@risefr.no.

Facts about Nordisk Aviation Products

• Nordisk Aviation Products is a world-leading supplier of containers and pallets for airfreight, which, in technical terms, are called unit load devices (ULDs).
• Nordisk Aviation Products has more than 300 customers worldwide, mainly airlines and courier companies.
• Since its inception in 1970, Nordisk Aviation has garnered unique experience and research-based expertise in the design and production of light constructions in aluminium.