Are lithium batteries safe? Rising number of incidents on airplanes worry pilots, flight attendants

Saindy Pyles thought she was going to die with her baby son, Liam, clutched to her chest as she flew home to Wichita from Miami after photographing a wedding. 

Midway through the flight Pyles said smoke filled the cabin after she saw sparks and fire burst from a bag in the seat directly behind her. 

"Honestly, I thought we were going to die," she said. "I looked and all I saw was flashes, just like flashes. I'm like, 'Oh my God, like, what is that?' And [the owner of the bag] is like, 'I don't know. I don't know.'" 

"Then I took my baby and I ran to the first class. I don't know how I got there. I think I hurt my arm." 

Quick action by the flight crew contained the smoky flashing lithium battery, which had begun smoldering in a carry-on bag right behind the seats where Pyles, her son and mother-in-law had been sitting. Airport fire trucks met the plane on the runway and everyone evacuated safely. However, it's an experience Pyles said she'll never forget, one she shared on social media to make others aware. 

A CBS News Investigation has discovered similar incidents have been happening much more frequently in the skies over the United States. The FAA verifies the number of lithium-Ion battery fires jumped more 42% in the last five years. 

A CBS News analysis of the FAA's data found that since 2021 there's been at least one lithium battery incident on a passenger plane somewhere in the US, on average, once every week.  

To see just how dangerous a lithium-ion battery can be, CBS News went behind the scenes at the lab operated by the University of Texas Fire Research Group (UTFRG) in Austin. 

For eight years, engineering professor and UTFRG director "Deke" Ezekoye and his team have been testing everyday devices like cellphones, laptop computers, hoverboards and power tools that run on lithium-ion batteries. They do this to study how these batteries in all their different forms interact, overheat, catch on fire and explode. 

"As the failure (of the battery) occurs… all of those things will start heat generation within the cell as the heat generates," said Ezekoye. "Within the cell, there's a process called 'thermal runaway' that occurs." 

The team showed CBS News how the batteries, as designed, supply their own oxygen when they burn, and how the characteristics of the batteries can add to the volatility of the devices. In in one demonstration, the burning lithium-ion battery supplied its own fuel to the flames as the cell burns out of control — underwater! 

"You can't put it out. It's a fire within the cell," Ezekoye said. "So, you've got fuel, oxygen, heat in the cell, all." 

That can become a big problem on an airplane 35,000 feet in the air. 

"It can cause an accident that the aircraft crew and the airplane cannot manage," Exekoye said. 

"I saw smoke," flight attendant Christopher Lee said of another incident involving a lithium-ion battery on a flight he was working a couple of months ago.  

Lee spoke to CBS News as a representative of his union, the Association of Flight Attendants-CWA. 

"I thought to myself, 'I know someone is not smoking on this aircraft.' That was my initial reaction," Lee said. "Smoke filled the cabin. I saw the sparks. I saw the flames." 

Lee rushed to fight the smoldering fire, which had started in a lithium battery contained in a vape device that had been placed a bag in the overhead bin on the March 1 Spirit Airlines flight between Dallas-Fort Worth, Texas, and Orlando, Florida. Lee, with the help of fellow flight attendants and passengers, put it out with a fire extinguisher.  

Lee says he worries about what might have happened had he not acted so decisively. 

"Fear didn't kick in until after it was all over with," Lee said. "And I think that I will say, thanks to the training that we receive" from the airline, it all worked out.  

Otherwise, he said, "We could have had a bad situation."

Pilots are acutely aware that this is a serious issue in stored or checked bags. Some say passenger education about the dangers of things such as lithium-ion batteries could be a matter of life or death. 

"It's the difference between being kept safe or being harmed," said Captain Dennis Tajer, spokesman for the Allied Pilots Association, the union for American Airlines' pilots. "When folks check in their bags, they're asked, 'Do you have any lithium batteries or e-cigarettes?' And that's just one of the dangerous goods that we're concerned about." 

CBS News analyzed a decade's worth of hazardous materials incident data from the U.S. Department of Transportation's Pipeline and Hazardous Materials Administration. 

There were eight incidents involving Bay Area flights from 2017 to 2022:

• 8/12/2022 -- United Airlines -- during a flight from Newark to San Francisco a passenger dropped a cellular phone between the seats. The passenger attempted to retrieve the phone by adjusting the seat crushing it in the process. The phone began to smoke. Flight attendants retrieved the device and secured it in a Thermal Containment Bag.

• 7/22/2022 --  Alaska Airlines -- during a flight from San Francisco to Las Vegas, a passenger's e-cigarette overheated. The incident occurred during decent. Flight Attendants placed the device in a Thermal Containment Bag and carefully monitored it. Fire Department personnel were alerted and boarded the plane upon landing to remove the device.

• 8/15/2021 --  United Airlines -- An iPad went into thermal runaway during a flight from Korea to San Francisco International Airport over the Pacific Ocean. The incident was contained by airline personnel. There were no injuries reported.
•  6/22/2019 -- Skywest Airlines -- On a SkyWest flight from San Francisco to Austin -- a passenger's portable battery charger began to heat up and would not turn off, it then began to smoke. The flight attendant placed the device in a battery containment bag and monitored the device.
• 11/30/2017 -- Alaska Airlines -- A passenger on flight 827 from Oakland to Honolulu ran off the aircraft during the boarding process and dumped her purse in the boarding bridge because a hole had burned through it. The Captain assisted her in putting out the fire and found her e-cigarette had caught fire. The captain removed the lithium battery from the unit and asked if she had any spares. The passenger said she had one more in her carry-on and two more in her checked bag. The captain ordered them removed from the checked bag and the carry-on. The batteries were turned over to the Alaska Airlines manager on duty. The aircraft departed without any further incident
•  7/22/2017 -- United Airlines -- United Airlines Flight 1536, while taxiing to the gate after landing from San Francisco to Jackson, Wyoming declared an emergency due to a lithium-ion battery related incident in the aircraft cabin. A sunglass case containing a small spare lithium battery for a personal headlamp and a set of keys began to smolder. The flight attendant put the battery in a container of ice which stopped the smoldering of the battery.

• 5/8/2017 -- United Airlines --  At the San Francisco airport, during security screening TSA discovered a battery pack in a customers bag that had overheated. The unit expanded so much that it opened. It was removed from the customer's bag and held at the SFO airport.

• 5/30/2017 -- JetBlue Airways -- On flight lfrom New York to San Francisco a battery in a passenger's backpack overheated and caused the backpack to melt and burn a hole in the side of it. The flight diverted to Grand Rapids. The fire department responded and took possession of the battery which is a LG HG2 18650. No injuries were reported.

According to the analysis, the most common hazmat incidents (29.06%) involve lithium-ion batteries. The rest involved other hazardous materials such as aerosols, live ammunition, paint and poisons. 

According to the PHMSA data, from March 2018 through March 2023, there were 5.319 incidents on all airplanes, including cargo planes, in the United States. Almost 700 of those (695) occurred on passenger planes. 

That averages out to be one hazmat incident on a passenger plane every two and a half days. 

The Federal Aviation Administration allows the transportation of certain hazardous materials, or "dangerous goods," as cargo on passenger planes, but federal law requires that the airline and pilot be notified. 

But CBS News has discovered that notification doesn't always happen. 

CBS News reviewed the last five years of data in NASA's Aviation Safety Reporting System, which includes 879 anonymous reports of in-flight hazmat incidents on passenger planes. The data shows that neither pilots nor the airlines were told the hazardous materials were even on board their planes in 62% of those cases, even though notification is required by law. 

Captain Tajer said he's never encountered this problem with his employer. 

"That doesn't happen on American Airlines," Captain Tajer said. "There's a procedure when they have cargo and there are things shipped, that box is checked and there are rules to be followed." 

When asked about other airlines where the data shows it does happen, Tajer was blunt. 

"I'm concerned," Tajer said. "[If I were the pilot on one of those flights] I'd be enraged. How dare you not follow the procedures and let me know what's on the airplane?" 

Tajer said the FAA should be paying close attention to the issue of safe transport of hazardous materials on airplanes. 

"And why do I render that judgment? Not because I don't think the FAA is doing its job, but because this is so impactful to the safety of passengers in our industry. That oversight is key." 

CBS News asked that same question of U.S. Secretary of Transportation Pete Buttigieg, whose office oversees the FAA. 

"Well, the FAA is constantly revising and updating its rules," Buttigieg said. "I think as we go into this year, where the law authorizing the FAA comes up, what we need to look at is not just the passenger side but also the goods and material side and see if we've got everything in line (regulated) that we need to." 

"Clearly, (what happens in) the 2020s are not like things were when we were at the dawn of commercial aviation, or even five or ten years ago," Buttigieg said. "And we do need to do more." 

One group is trying to do more by doing something different when it comes to lithium batteries. 

A startup called Pure Lithium has developed a new battery that the company says won't burn because they changed the chemistry of what makes the battery work.  

The invention is the brainchild of Pure Lithium cofounder Donald R. Sadoway, an MIT emeritus professor of materials chemistry.

"My approach is to invent a battery chemistry that cannot burn," Sadoway said as he showed CBS News around his company's lab.  

"And that's what is going on here. It's the pursuit of a battery that has high energy density," Sadoway said. "But you can take a blowtorch to it. It will not catch fire." 

The battery is made of lithium metal, not lithium ion. Sadoway's team demonstrated how the battery can already power a small portable video game. 

"It could start off large enough to power a phone," Sadoway said, "but ultimately, it may be large enough that we can stack these together and power an automobile." 

"We have stretched this (lithium-ion) chemistry to the maximum capacity that we can get out of it safely" in batteries, said Pure Lithium's co-founder and CEO Emilie Bodoin.  

"We're in love with batteries as a world, but we need new batteries," Bodoin said. "To invent this next-generation battery that won't burn requires a completely different paradigm shift." 

Bodoin and Sadoway said while they've been able to build this battery that won't burn, they now have to develop it for the mass market and scale up production — no small task. 

"While we can sit here and be very confident that we will beat the market in the earliest somewhere between seven and 10 years, I would like to honestly under-promise and over-deliver," said Bodoin. "So, you may see it (the non-flammable battery) sooner, but hard tech takes a long time and we're doing something incredibly, incredibly radical." 

While we wait for safer batteries to be mass produced, some airlines are taking action to control the growing number of fires. 

They are using specialized "thermal containment" bags designed for flight crews to use if a lithium battery starts heating up to the point where it's smoking or burning. 

Mechanical engineers at the University of Texas at Austin say the bags can effectively contain fire and keep it from spreading, but don't extinguish it. 

Christopher Lee says those bags weren't available on the flight he was working. And CBS News found that some airlines don't use them at all.  

There's also some confusion regarding FAA policy. 

One regional commuter airline told CBS News it "has FAA approved containment bags installed on each aircraft." 

They may have the bags, but the FAA offers no such approval.  

According to a March 16, 2023 Advisory Circular the agency shared with CBS News, while "the FAA has no objection to the use of the various commercially manufactured containment products" … "no FAA test standards exist for these containment products nor does the FAA have a mechanism in place for the approval of these products." 

When asked if he would have liked to have access to such a specialized bag with on his airplane, flight attendant Christopher Lee didn't hesitate. 

"They would be very helpful to have," Lee said. "Just another tool to use." 

CBS News asked Secretary Buttigieg whether they should be required by the FAA. 

"Well, that's exactly what we're working on right now," Buttigieg said. "Any time we're going to impose by law a certain technology or a certain strategy, we need to make sure that it is appropriate, that it's informed by the right data. But clearly, we need to make sure that we continue taking steps that are going to contain any kind of hazard here." 

Buttigieg joined with several other experts who told CBS News that public awareness among travelers is crucial and that travelers should always follow the directions given by airline staff regarding lithium-ion batteries and battery-powered devices. FAA guidance published on its website includes: 

• Spare (uninstalled) lithium-ion and lithium metal batteries, including power banks and cellphone battery charging cases, must be carried in carry-on baggage only.  

• When a carry-on bag is checked at the gate or at planeside, all spare lithium batteries and power banks must be removed from the bag and kept with the passenger in the aircraft cabin.  

• Damaged or recalled batteries and battery-powered devices, which are likely to create sparks or generate a dangerous evolution of heat must not be carried aboard an aircraft (e.g. carry-on or checked baggage) unless the damaged or recalled battery has been removed, or otherwise made safe.  

Airline passengers should also follow directions from flight crew about turning off laptops and unplugging chargers during take-off and landing, and travelers should ask a flight attendant for help in retrieving cellphones that fall between their seats.