Toxic Fumes On Planes Are Knocking Out Pilots And Making Passengers Sick

Illustration for article titled Toxic Fumes On Planes Are Knocking Out Pilots And Making Passengers Sick
Photo: Erik S. Lesser / Stringer (Getty Images)

When passengers board airliners, they expect everything to be sorted with the aircraft. Decades of safety innovations and regulations have made flying the safest form of travel. But as revealed in an explosive report by the Los Angeles Times, planes are filling up with toxic fumes, injuring crew and passengers alike, while the Federal Aviation Administration and airline industry do nothing.


In July 2015, Spirit Airlines Flight 708 landed in Boston and parked at its designated gate. However, there was one problem: the captain and co-pilot had no memory of landing or taxiing the Airbus A319. From the Los Angeles Times report:

The plane had begun its descent into Boston. Inside the cockpit, the captain was slumped in his seat. Sitting beside him, copilot Eric Tellmann was starting to pass out. Tellmann managed to strap on his oxygen mask, then grabbed the captain’s arm and forced him to follow suit. Reviving slowly, the captain looked at Tellmann through his mask, and his eyes grew wide with fear.A strange smell had permeated the plane that day. Passengers and flight attendants were coughing and wiping teary eyes. The pilots briefly lifted their masks and could still smell the odor as the runway drew nearer.

Tellmann and the captain parked the Airbus A319 at the gate. But they had no memory of landing or taxiing Spirit Airlines Flight 708. Tellmann went to the hospital for treatment and spent the next week at home in bed, vomiting and shaking and feeling “like a freight train had run over us,” he said in a letter to his union about the July 2015 event.

A mysterious smell. Strange symptoms. A trip to the emergency room.

The signs were all there: Something had gone seriously wrong with the plane’s air supply.

The air you breathe on a commercial jet airliner is known as bleed air. Bleed air comes from the engines and provides pressure for the cabin and air for the environmental control system. When it’s working as designed, it’s harmless. However, when there’s a problem like bad seals, hot engine oil and hydraulic fluid can leak into the air system, potentially releasing toxic fumes into the cabin.

When this happens it’s called a fume event. While the airlines and safety regulators have known about them for decades, they maintain these events aren’t common, and the levels of chemicals aren’t high enough to pose serious medical risks.

However, the Times’ investigation revealed some frightening data that suggests fume events are far more common than airlines admit:

But a Times investigation found that vapors from oil and other fluids seep into planes with alarming frequency across all airlines, at times creating chaos and confusion: Flight attendants vomit and pass out. Passengers struggle to breathe. Children get rushed to hospitals. Pilots reach for oxygen masks or gasp for air from opened cockpit windows.

Such events are documented in airport paramedic records, NASA safety reports, federal aviation records and other filings reviewed by The Times.

Tellmann, the Spirit Airlines pilot, was one of hundreds of airline crew members and passengers who reported being sickened or impaired on flights in recent years. A Times analysis of NASA safety reports from January 2018 to December 2019 identified 362 fume events that airline crew members reported to the agency, with nearly 400 pilots, flight attendants and passengers receiving medical attention. During at least 73 of those flights, pilots used emergency oxygen. Four dozen pilots were described as impaired to the point of being unable to perform their duties.

Because they’re made voluntarily, the NASA safety reports are the “tip of the iceberg,” according to a recent study by a researcher from the National Institute for Occupational Safety and Health.


Holiday travelers are flouting COVID-19 warnings while airlines tout the HEPA filters in aircraft. These filters, N95 masks and surgical masks don’t protect passengers from toxic fumes, however. Before the coronavirus pandemic, about five flights a day in the U.S. experienced a fume event, according to the Times.

So how did we get here? With weak regulations that favor private companies over people’s lives, of course. From the Times again:

Airlines have been asking Boeing to install air sensors for years. But the company decided against developing the technology. Senior Boeing engineers worried that data from sensors would prove damaging in lawsuits by sick passengers and crew members, according to internal emails and sworn depositions obtained by The Times.

An internal Boeing memo described it as a “risk” to give air sensors to even one airline, according to a deposition of a Boeing executive.

“Flight attendant, pilot unions, and congressional supporters could use this effort as evidence that sensors are needed and ... to drive their agenda forward to have bleed air sensors required on all aircraft,” said the 2015 memo, which Boeing turned over in litigation.


The industry’s regulator, the Federal Aviation Administration, declined to comment on The Times’ findings and provided a statement saying it “currently has no plans” to require air sensors or filters.

“Studies have shown cabin air is as good as or better than the air found in offices and homes,” the FAA said.

But those studies looked at normal flights in which no fume events were reported. No major research has ever measured the chemicals in fume events as they occur.

In 2003, Congress ordered the FAA to measure the toxic chemical levels in such events, but the airlines refused to let flight attendants carry air samplers aboard, according to an FAA-funded research report.


Airbus, the world’s other major manufacturer of airliners, told the Times that the odors aren’t harmful and don’t pose any major risk to passengers and crew. Of course, without sensors or testing during a fume event, there’s no way to know that the air is indeed safe. It’s a vicious cycle, where lack of testing reinforces ignorance of risk. And while Federal authorities have never attributed any commercial airline crashes to fume events, they do keep forcing airliners to make unscheduled landings.

Oh, you thought it couldn’t get worse? Well, guess what: airlines aren’t required to tell passengers if a fume event has occurred or what chemicals they may have been exposed to. In fact, one of the main reasons sensors aren’t installed on planes is concern over lawsuit liability over injured parties:

A Boeing senior engineer, George Bates, acknowledged in a 2018 deposition that there were internal concerns that sensors would collect data that could be used by sick passengers or crew members in litigation against Boeing. “The biggest impeding factor is the legal issues,” Bates wrote in a 2008 email.

Bates elaborated in an internal email in 2011: “How long will it take until the readings have to be recorded and available not only for maintenance, but for the lawyers?” he wrote. Another Boeing engineer on the email chain agreed that making sensor data available was “crazy!”

Bates had expressed concern about fume events in the past when he noticed that Boeing 757s were being diverted about once every two weeks. Engine seals, he said, were leaking so much oil that crews complained of “blue smoke” thick enough that flight attendants couldn’t see halfway down the aisle.

“Given the number of … events for the 757 ... I would have thought the FAA would have forced the issue,” Bates wrote in an email to colleagues. “Bottom line is I think we are looking for a tombstone before anyone with any horsepower is going to take interest.”


While most people recover from the effects of a fume event within a few days, others have been diagnosed with life-altering health conditions, some of which spelled the end of careers.

This is only a snippet of the eye-opening Times report, which I encourage you to check out in full here.

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Nothing like an aviation article to bring out all the armchair experts on aircraft systems and manufacturing. I just had to love this sentence though “With weak regulations that favor private companies over people’s lives, of course...”. have no idea. spend, I don’t know... 20-25 years in aerospace ranging from a licensed mechanic to flight crew and then lets talk about FAA regulations, but if you want to believe that the FAA is light on regulations for manufacturers you go ahead.

There is not enough space on this site to clearly articulate to you the volumes of regulations that have to be followed to the letter, and spirit, by aircraft manufacturers before a $100+ million investment is certified to fly once, but it doesn’t mean that an engine bearing or part can’t ever fail. The comparison to the automotive manufacturing world or ANY other manufactured product is jokeworthy with the exception being spacecraft and/or nuclear submarines.

At the end of the day here’s the thing: Airplanes are extremely complex machines that are designed and constructed to a level of perfection that unless you’ve been part of the aerospace industry, you just take it for granted.

Yes, cabin air is bleed air taped off the compressor section of the engine - that’s a fact. It’s also a fact that anything that’s in the air that the engine is ingesting may also end up in the cabin which may include anything that fails within the nose cone of the engine: hydraulic pumps, bearings, horrific air pollution over heavily populated area’s of northern Africa, Shanghai China and many other regions at 25K over the city. Once on a memorable flight into Cairo it smelled like the cabin was filled with burning garbage and that smell didn’t go away for hours. Also, during taxi and while waiting behind another aircraft in line for an extended period will definitely cause a higher level of foulness in the cabin since the engines are breathing another aircrafts exhaust. However, the absolute best smell is that of freshly injected bird whose bloody feathered body has just met the inside of a GE Turbofan and is cooking inside the engine (feathers and all) which isn’t an aroma that leaves the cabin anytime soon. My point is this: there is no amount of regulation, engineering, manufacturing scrutiny, or filtering that will remove every possible scenario of unpleasantness related to air travel since engines consume outside air. If you installed air quality alarms do you really expect the flight crew to make an announcement everytime and tell people not to worry its just the choking air quality over your city entering the airplane while we descend at reduced power (reduced power also equals less airflow in the cabin too). If you really want something legitimate to worry about look into the reality of the O2 system that the masks are attached to that will drop from the ceiling and ask yourself how long your going to last breathing a combination of toxic cabin air and oxygen since the O2 masks just provide a small source of air in a 10 cent plastic mask. Furthermore, it won’t matter if you don’t have smoke goggles to protect the noxious fumes from entering your tear ducts. Just something to ponder.