A lithium-ion battery pack erupted in flames inside a Beta Technologies shipping container at the company’s facilities near Burlington International Airport in Vermont last week. Beta Technologies is working with the local fire department to determine what caused the fire.
“There were no injuries or damage to our current test equipment or aircraft and the fire was quickly extinguished,” a company spokesperson told FutureFlight. “We are grateful to the first responders who arrived on the scene, and that the response plans and safety precautions we have in place worked effectively. An investigation into the root cause of the incident is underway.”
The blaze began at approximately 12:30 a.m. EDT on Friday, August 26, in a shipping container in a parking lot across from Beta’s headquarters. Beta is an eVTOL aircraft developer that has been conducting test flights for the past few years with its all-electric Alia 250 prototype aircraft, which is configured to carry three standard cargo pallets and a pilot. The company aims to begin commercial operations in 2025, pending FAA approval.
Beta says the fire started in a reassembled lithium-ion battery pack that had been stored in the shipping container while awaiting end-of-line testing. Because the reassembled battery pack had not yet been through the testing process, it had not been approved for flight, according to Beta.
South Burlington fire marshal Terry Francis told local news outlet WCAX that the lithium-ion battery underwent a thermal runaway event, in which its temperature skyrockets uncontrollably. Several things can trigger thermal runaway events, such as battery damage, mechanical failures, and exposure to high temperatures.
“Something happened in one of the battery packs and it had a thermal event," Francis told WCAX. "We’re not sure exactly what, but that thermal event cascaded the fire alarm system. The smoke alarm picked up that there was a fire starting [and] notified us immediately, but within a two-minute span we had a pretty significant fire in a metal container that wasn’t gonna go anywhere,” he added. The blaze was isolated to just one shipping container, and firefighters were able to douse the flames in about 30 minutes.
This wasn’t the first fire to erupt from a lithium-ion battery at Beta Technologies. In 2019, the company experienced another such fire inside a storage container at the same facility, according to WCAX.
While lithium-ion battery fires are relatively rare, they do pose a risk that electric aircraft developers need to take seriously. According to Luminati Aerospace CEO Daniel Preston, just about every major eVTOL developer has experienced a fire caused by lithium-ion batteries, though these incidents are not always reported to the public.
One recent high-profile fire took place in January 2020, when a battery fire severely damaged Eviation’s Alice all-electric commuter aircraft during ground testing at Prescott Regional Airport in Arizona. Just a few weeks later, Lilium Air Mobility’s first full-scale eVTOL technology demonstrator was destroyed when a battery fire broke out during ground maintenance activities at the company’s headquarters near Munich.