Flight Attendants Sue Boeing Over Alleged Exposure to Fumes. Is There a Secret Menace in Cabin Air?
June 24, 2015
FOUR ALASKA AIRLINES cabin attendants have filed a lawsuit against Boeing alleging exposure to fumes during a Boston to San Diego flight aboard one of the carrier’s 737s. All four say they became ill, two of them to the point of unconsciousness. This is the latest in an on-again off-again series of complaints claiming that potentially dangerous engine fumes can be drawn into a plane’s cabin via the air conditioning system.
I’m not at all dismissing this issue as frivolous, but there are aspects to the Alaska story that make me curious. For example, the idea that four flight attendants became ill, and two of them were rendered unconscious, yet not a single passenger was affected. How is that possible? What were the passenger experiences on this flight, and why have none of them come forward?
According to the flight attendants’ lawyers, this is because the women had been on the plane longer than the passengers, including time spent in the cabin prior to boarding. Maybe, but one problem with that explanation is that the engines aren’t running when a plane is at the gate. Prior to boarding, conditioned air (cold or heated) is normally supplied through an external source; or, less commonly, via the plane’s APU, a small auxiliary engine located in the rear fuselage under the tail.
That’s not to say this didn’t happen, or that the “fume event” phenomenon doesn’t exist. But if and when it does occur, it’s unusual. In normal operation there is no mix between engine fluids — fuel, oil or hydraulics — and the air conditioning system. On the whole, cabin air is exceptionally clean.
(Note: It’s not uncommon to smell fumes for a few moments during engine start, especially with crosswinds or tailwinds. This is is due to exhaust being drawn into the exterior air conditioning inlets, and is otherwise unrelated to the controversy in question. It usually subsides once engine power stabilizes.)
And I’m unsure what makes this problem particular to Boeing planes, if in fact it is. Airbus and other manufacturers similarly use engine “bleed air” to power pretty much all of a plane’s pneumatics: cabin pressurization and air conditioning, anti-icing, etc. Of all mainline Boeing and Airbus models, Boeing’s 787 is the only one that doesn’t rely on engine bleed. It’s possible, once you get into the details of the systems, that there’s something in the design of Boeing’s other planes that allows burned oil to seep into the plumbing when and where it should not.
And if so, to me the bigger concern isn’t the very rare incident where fumes are so powerful that people are made immediately sick, or worse, but the effects of long-term exposure to smaller trace amounts. According to a British study, fume events occur on approximately .05 percent of flights. Their criteria isn’t made clear, but in some ways, and especially for those of us who fly all the time, the possibility of repeated small-scale exposures makes the phenomenon more worrying rather than less. And while any exposure is potentially harmful, how do airborne levels of such compounds stack up against those that people endure routinely in other settings — for example in their cars, when driving in heavy traffic? We are exposed to potentially unsafe chemicals everywhere: from the air we breathe,from the food we eat, from the plastics in thousands of consumer products and materials.* How does this compare? Frankly, as a pilot, I’m more worried about radiation exposure than about engine fumes.
For what it’s worth, I’ve flown Boeing planes for the better part of ten years as a crewmember, and of course I’ve been flying on them my whole life as a passenger, and I have never once knowingly experienced one of these “fume events,” and neither has anybody I know. Until this week you’d have been hard pressed to find an airline pilot or flight attendant who’d ever heard of the issue.
That doesn’t mean it’s not real, or that it doesn’t deserve a close look, but I disagree with any suggestion that the air on planes is categorically unsafe for the average flyer.
FOR MORE ABOUT THE FACTS AND FALLACIES OF CABIN AIR, SEE MY EARLIER DISUCSSION HERE.
* Ken Geiser is a friend of the author