And while that poses challenges for law enforcement, it also presents one very important concern for travelers:
Are passengers in danger if drugs are being smuggled in the cabin of an airplane and somehow get loose from their packaging?
With most illegal narcotics, the answer is generally no, the risk to passengers of accidental ingestion is minimal.
But there's one enormous exception: Fentanyl.
"First, you got to understand that fentanyl in the size of two grains of salt can be a deadly overdose," notes Sheriff Grady Judd of Polk County, Fla., who has pointed to LAX as quite possibly the nation's premier hub for drug smuggling.
Law enforcement experts like Martin Estrada, the U.S. Attorney for California's Central District, acknowledge that large quantities of fentanyl are moving through LAX, including via passenger carry-on baggage in airplane cabins.
"We've come across a number of different types of cases. Sometimes the drugs are transported using checked baggage," Estrada tells Eyewitness News. "Other times because the drugs are so valuable, they want to keep them in their possession. So they will come in through carry-on luggage. And we catch kilogram quantities, pound quantities all the time in that way."
In one recent case, he says, a woman was caught trying to smuggle 10,000 fentanyl pills through a neck pillow she brought with her onto the plane.
Transportation Security Administration officials acknowledge that screeners are generally focused on looking for weapons and explosives, not drugs, when they search baggage. And since many people travel with various medications, a few pills won't set off any alarms, says Jason Pantages, head of the TSA at LAX.
"If somebody just saw pills in a bag, I don't know that they would stop it just for pills because it kind of gets outside of the scope of our search authority," Pantages says.
What could happen
Law enforcement officials warn that close contact with fentanyl can lead to accidental - and possibly deadly - ingestion. They've told stories of first responders being overcome simply by being around fentanyl.
That's why people like Sheriff Judd and other law enforcement officials are so concerned.
"You don't even have to bring a kilo on board," Judd says. "You can bring a few ounces on board, an ounce on board, and all of a sudden, it gets distributed...."
Medical experts say fentanyl's danger lies in accidental ingestion through the nose and mouth. Simple skin contact is less likely to cause a reaction.
"Our skin is our armor, right?" said Dr. Reginald Jones with Dignity Health California Hospital. "Our skin is very, very good at protecting us. But it's the mucosa. It's the nose and the mouth and the eyes. And so, if you breathe in, of course it will get absorbed."
Jones is the chairman of surgery and head emergency-room doctor at Dignity Health California Hospital. He has dealt with fentanyl in many different ways and says, yes, we could feel the effects when near it.
Powder-form fentanyl loose in the cabin of an airplane "could be very dangerous," he says, depending on the quantity dispersed.
The factor that can somewhat ease the fears of passengers is that it would take a large quantity dispersed in the air for someone to accidentally breathe in enough to cause an overdose, he said.
"It would probably be a really rare event."
That's important because sources tell Eyewitness News that besides traffickers, addicts are also bringing fentanyl on board and smoking, snorting or ingesting it, making everyone vulnerable.
Are flight crews prepared?
Sara Nelson, president of the flight attendants' union, says there's not enough training for flight crews on how to handle fentanyl overdoses.
"Flight attendants are very concerned about fentanyl overdoses and how to deal with that," Nelson says. "We're seeing that as a more common occurrence on our planes. But the training is not sufficient."
Narcan, which can help quickly treat overdoses, is rare on most domestic flights, she says.
The federal aviation reauthorization bill was signed into law last month. It mandates planes carry Narcan, but it doesn't stipulate how much or when to get it on board.
It also doesn't mandate fentanyl training for flight attendants or pilots. In the world we live in, experts say carrying your own Narcan is always a good idea.
So when and if planes do carry Narcan, will there be enough?
These are all important questions as this new vulnerability of fentanyl in the cabin is addressed.
"So at the end of the day, is it (an accidental ingestion of fentanyl) likely? No," says Sheriff Judd. "Is it probable? No. Is it possible? Oh yeah. It's possible."
Previous installments in David Ono's investigation into drug smuggling at LAX
LAX may be drug smuggling gateway of the world
How L.A. became the cartels' global distribution center