Airsick: Flight Crews Venting in Court About Toxic Fumes

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By Steven M. Sellers

Toxic fumes on two recent commercial jetliner flights reportedly were so strong that the planes had to be emergency landed because of sickened crew members. In one of those incidents, an international flight in May from Florida to England, more than a dozen passengers also fell ill.

These and other persistent reports of “fume events” contaminating cabin air on flights by major air carriers including Alaska Airlines Inc., American Airlines Inc., and British Airways PLC are raising questions about a ventilation system used in nearly every commercial airliner worldwide.

And some of the fallout is reaching U.S. courts, where product liability suits by crew members who say they’ve suffered related neurological and other health problems are pending against The Boeing Co., one of the world’s biggest airplane makers.

Whether these alleged fume sickenings are rare anomalies, or symptoms of a design defect the $1.5 trillion U.S. air transportation industry has downplayed for decades, depends on who you ask.

Defense lawyers, jet manufacturers, federal regulators, and airline industry trade groups tell Bloomberg BNA claims of toxic cabin air are disproved by multiple studies.

But plaintiff lawyers say continuing incidents of fume events establish the validity of tort cases brought by flight crews and passengers. Their assertions may get additional support from a new report for the World Health Organization that warns of rising “aerotoxic syndrome.”

Recently-filed federal legislation also seeks more flight crew training, enhanced reporting of fume events, and air monitoring devices on jetliners.

The debate centers on “bleed air” systems used by major jetliner manufacturers Airbus Group SE, Boeing, Bombardier Inc., and Embraer SA.

Developed in the 1950s, the systems compress outside air with the help of a jet’s turbine engine, and then “bleed” it into a manifold for mixing with recirculated cabin air. The problems can come, plaintiffs’ attorneys and some researchers say, when engine seals start to leak.

Pioneers Or Just Blowing Smoke?

The risks are real, and public awareness of the connection between fume events and airborne illnesses will only increase litigation, plaintiff lawyers say.

“When you do the digging and you look at the background and you see that the issues surrounding bleed air and the toxic compounds the bleed air introduces into the cabin, it’s extremely well-founded,” said aviation lawyer Michael Danko, of Danko Meredith in Redwood Shores, Calif.

“Passengers don’t immediately equate their injury to the fume event, and they don’t realize how prevalent it is, so there isn’t a wave of litigation, said Danko, an experienced jet pilot.

Boeing has been the biggest target of the handful of cases filed so far, including two suits pending in Illinois Circuit Court, Cook County.

Those cases may be “pioneers” that explore an emerging toxic tort, said Danko, who isn’t involved in the litigation.

Flight attendants in Woods v. The Boeing Co. and Escobedo v. The Boeing Co. say their neurological symptoms–which include tremors, vertigo, and memory loss–stem from a defectively designed Boeing airplane.

Defense lawyers say fume event claims are based on the false premise that cabin air poses health risks different than other environments.

“There’s really no evidence that cabin air is any different in what we might consider toxicity to what people are breathing day-in and day-out in the office environment, said Alan Farkas, of Smith Amundsen in Chicago.

“When you look at the cases that have been filed so far, it doesn’t seem that they’ve really been able to muster evidence to address the lack of a causal connection,” said Farkas, who represents aircraft manufacturers in product liability and other litigation.

Bleed Air Systems

When protective engine seals leak, toxic vapors from super-heated engine oils, hydraulic fluids and deicers can leak into cabin air, according to a 2015 Federal Aviation Administration report on bleed air contaminants.

The fluids contain volatile organic compounds that can produce a chemical or oily odor, triggering nausea, lightheadness and neurological symptoms, the report says.

Other odorless and colorless fumes, such as carbon monoxide, also pose airborne health risks, according to a 2015 report by the Global Cabin Air Quality Executive, a non-profit organization based in West Sussex, England, that focuses on bleed air contamination.

Multiple studies show that cabin air is safe overall, but Susan Michaelis, a visiting researcher with the University of Stirling in Scotland, isn’t convinced.

“These substances leak when there are power changes in the engines,” said Michaelis, who co-authored a World Health Organization report on cabin air risks in June.

“The aviation industry, regulators, airlines, manufacturers and supporting government departments all advise that a whole host of studies have been undertaken showing the air is safe,” said Michaelis, a former flight instructor who says she herself was sickened by fume events in the 1990s.

But “it is not acceptable to use ground-based industrial limits in an environment such as an aircraft,” said Michaelis.

Yet, fume events—which airlines must report to the FAA—are rare compared to the estimated 3.6 billion worldwide passengers and 500,000 crew members who fly each year.

In 2015, for example, about 98 fume events were reported to the FAA out of almost 9 million flights.

The airline industry contends that infrequency reflects a low risk, but the plaintiff lawyers say it’s the tip of the iceberg.

Finding Fume Events

Fume events typically require an emergency landing, and the incidents must be reported to the FAA.

A recent example is a May 30 incident that forced an Alaska Airlines flight to make an unscheduled stop in Kansas City, Mo.

In recorded radio communications posted on, a website that catalogs aviation incidents, a pilot informed air traffic controllers of a “burning smell” and asked that medical responders examine sickened flight attendants upon landing.

Nine days before, a Thomson Airways flight from Orlando, Fla., to Bristol, U.K., turned around after two flight attendants and more than a dozen passengers fell ill because of fumes.

In another incident reported last October, 22 cabin crew members and two pilots were taken to a hospital after a British Airways flight from San Francisco to London was diverted to Vancouver, B.C.

And, in January 2016, an American Airlines flight from London to Los Angeles headed back to London when some passengers and flight attendants reported lightheadedness.

Boeing Design Defect?

Boeing, based in Chicago, says that since it began operation in 1916, it has produced more than 10,000 commercial jetliners—nearly half of the worldwide fleet.

Despite those high production numbers, fume event cases have been rare, with only a handful of cases filed.

And these cases, some of which were voluntarily dismissed, have amounted to only a very small fraction of Boeing’s aircraft-related personal injury cases, which comprise 32.2 percent of its federal litigation over the last five years, according to Bloomberg Law Litigation Analytics.

The most notable case to date was that of former American Airlines flight attendant Terry Williams, who sued Boeing and McDonnell Douglas Corp. in 2009.

She claimed her chronic neurological symptoms stemmed from exposures to toxic air from Boeing’s bleed air systems. The parties reached a confidential settlement in 2010.

Five Alaska Airlines flight attendants make similar claims against Boeing in the Cook County cases, where discovery is underway.

In one of the cases, Vanessa Woods and three other flight attendants allege they encountered a “burnt oil” and “dirty sock” smell on Boeing 737 in 2013, sickening all of them and causing one to faint.

The crew members were hospitalized, and two were unable to continue working as flight attendants because of their symptoms, according to the complaint.

In the other pending case, involving a different Boeing airliner, Vashti Escobedo claims she smelled an “odd odor” on a flight, lost her sense of balance, and was later diagnosed with carbon monoxide poisoning.

Correlation vs. Causation

Flight crews have brought the vast majority of cases so far, including complaints filed in Europe. The paucity of passenger suits is explained by a traveling public unaware of the link between in-flight symptoms and fume events, plaintiff lawyers said.

But they also acknowledge the challenge of proving a clear connection between an illness and ephemeral fume events.

“You have perhaps an association, but as defendants will always tell you, an association is not equal to causation,” said Danko.

Multiple illnesses on a single flight, however, increase the odds, he said.

“Now you have a very strong argument because you can rule other causes out,” Danko said. “That’s the strongest kind of case you can have.”

Boeing’s 787 Dreamliner, the only commercial jetliner that uses electric air compressors instead of turbine-based systems, also gives plaintiff lawyers help in arguing their design defect claims.

That plane was put into service in 2011, but it’s commercial development is evidence of a feasible and safe alternative to the bleed air systems used on thousands of other jetliners worldwide, Danko said.

But that also raises a dilemma for jet manufacturers.

For existing aircraft, “there’s no way to fix it, you have to take them out of service, and that’s never going to happen,” Danko said.

But for Farkas, the defense lawyer, it’s wrong to assume a jet’s engines are the only possible source of airborne illnesses among flight crews.

“There are other areas the flight attendants are exposed to—the ovens, coffeemakers—and all sorts of things in their day that are common to flight attendants,” such as where they stay, how they travel, perfumes and other factors, he said.

Safe Air Assurances

Despite the persistent fume event reports, most studies show that cabin air “is as good as or better than the air found in offices and homes,” and is safe in the “vast majority” of commercial flights, FAA spokeswoman Alison Duquette said in an email.

But she added that the FAA is “concerned that if certain mechanical failures occur, the cabin environment may contain contaminants.”

Perry Flint, a spokesman for the International Air Transport Association, the trade organization for 275 of the world’s airlines, echoed that view, adding that “regulators monitor cabin air quality to ensure safety and airlines comply with their requirements.”

Boeing also stands by its airplanes.

“Cabin air quality inside Boeing airplanes is safe,” Boeing spokesman Bret Jensen said in an email. “Extensive research on cabin air conducted by independent researchers, universities, industry and government agencies has repeatedly demonstrated that contaminant levels are generally low and that health and safety standards are met.”

“However, we continue to work with scientists to improve our understanding of cabin environmental factors and study other potential technologies such as sensors and advanced filtering,” he said.

The safe air claims got a boost in March, when the European Aviation Safety Agency released two studies finding cabin air to be at least as good as that found in “normal indoor environments,” and that turbine engine oil fume levels were too low to pose a risk to human health.

Others Unconvinced

Other researchers—and a U.S. Senator—aren’t as sure.

A recent amendment to the FAA reauthorization bill, S. 1405, proposed by Sen. Richard Blumenthal (D.-Conn.), would require enhanced regulatory and industry efforts to ensure safe cabin air.

The Association of Flight Attendants, which represents nearly 50,000 flight attendants at 19 airlines, and the Allied Pilots Association, the collective bargaining agent for American Airlines pilots, endorsed the Cabin Air Safety Act in statements issued June 28.

“The Cabin Air Safety Act would mandate training of airline personnel regarding how to identify toxic fumes, require the Federal Aviation Administration to record and monitor reports of such events, require follow-up investigations, and mandate installation of carbon monoxide sensors on aircraft,” the APA said.

Michaelis and other researchers agree that more needs to be done.

“The industry continues to selectively use the science that suits it and analyzes contaminants found using these limits to deceptively suggest to the flying public and workers that all is fine,” she said.

In their June report for the World Health Organization, Michaelis and pathologist C. Vyvyan Howard say “aerotoxic syndrome” may be an emerging occupational disease, and warn that the absence of an internationally-accepted investigative protocol for fume events hampers the full understanding of them.

“While many experts have suggested that oil leakage is associated only with rare failure events, others now recognize that chronic exposure is caused by the so-called tiny amounts of oil vapors released by oil leaking continuously over the seals during engine power changes,” the report says.

High-altitude ozone is yet another area of concern for other researchers.

An FAA-sponsored study by the Airline Cabin Environment Research Center, based in Auburn University in Alabama, is looking into whether ozone in high-altitude air may create respiratory symptoms by its interaction with compounds in airline seat upholstery and other accouterments.

Flight Plan

Whether these issues will be explored in the pending Illinois cases remains to be seen. But Danko, the plaintiff lawyer, sees an inevitable wave of litigation ahead.

“There’s no question in my mind that the cases will be increasing because we know they’re well-founded, the problem is essentially recognized by the industry, it is very widespread, and there are no steps being taken to correct the problem,” he said.

To contact the reporter on this story: Steven M. Sellers in Washington at

To contact the editor responsible for this story: Steven Patrick at

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