Lieutenant Patrick V. Murphy, age 22, was leading his 101st Airborne infantry platoon near Vietnam’s A Shau Valley in 1968 when a Soviet-made RPG antitank rocket blew his leg off. He was the only one in a series of four leaders of his platoon to make it out alive—first choppered to a field hospital, then, after two dozen surgeries and two years of rehab, back home to Maryland. The decorated combat veteran earned a master’s degree in business administration, married a pretty Army nurse, and took a job with an obscure federal agency, the Civil Aeronautics Board.
Fast-forward 27 years. Now a senior US Department of Transportation official in charge of negotiating international aviation agreements, Murphy returned to Vietnam, this time to make a deal with Hanoi to open commercial flights between the two former enemies. Once again, Murphy almost didn’t make it back—no longer because of enemy fire, but because of some nasty bug he picked up on the Boeing 747 that flew him across the Pacific.
Waking from a nap on the 11-hour flight, the half-asleep vet made a near-fatal mistake: he didn’t bother to pull on his shoes before walking in his socks to the lavatory, where he likely came in contact with some horrible bacteria that was lurking on the floor. By the time he landed at Noi Bai Airport, Murphy was woozy and feverish. Systemic septicemia, a life-threatening, fast moving bacterial infection in the bloodstream, had set in. Thanks to a fast-thinking embassy doctor and a quick evacuation to a Bangkok hospital, Murphy survived; years later, he and I became business partners in a Washington consulting firm.
Murphy’s dual bouts with mortality in Vietnam may be unique, but getting sick from air travel surely isn’t. Flying can literally be sickening. Beyond the fares and fees and food and discomfort, beyond the myriad hassles, the nastiest part of flying may be unseen—the unpleasant stuff in the cabin air and the seatback pockets, and on the little knob that locks the lavatory door. You don’t have to be hypochondriac to get a little grossed out.
To be clear, air travel can be unhealthy, but it’s exceedingly unlikely to kill you. The risk of contracting something really bad—such as tuberculosis, severe acute respiratory syndrome (SARS) or, like Murphy, septicemia—is tiny. But your odds of catching something—the makings of a bad head cold, a gastrointestinal virus—appear to be far greater aloft than on the ground. In a 2004 Canadian study published in the Journal of Environmental Health Research, one-fifth of all 1,100 passengers surveyed after a series of flights lasting two and a half hours reported having caught a cold. The air travelers were at least five times (maybe as much as 113 times) as likely to catch cold than non-fliers, though other factors, such as travel stress and exposure to germs before or after flying, could have played a role. Still, how healthy can it be to be sealed for hours in a densely packed, superdry pressurized metal tube with a couple hundred other random folks?
Health isn’t something the airline industry likes to talk about. When USA Today tried to survey US airlines in 2007 on how each handled in-flight medical emergencies, the airline trade association flatly refused to cooperate. Understandably. Health scares keep people off airplanes. In the decade since September 11, fear grew that global air travel had become a major vector for potential pandemics like avian flu (H5N1) and the deadly form of pneumonia known as SARS. Although SARS killed about 900 people worldwide during a 2003 outbreak, the panic surrounding it nearly cratered Asian tourism for months, punishing the airline and tourism industries of China, Taiwan, Hong Kong, Singapore, and other Asian countries.
Fear is one thing, but how bad really is the health risk of flying? The truth seems to lie somewhere between germ-phobic hysteria and the sunny bromides of some in the industry. There clearly are risks, the medical experts say—after all, a speeding high-altitude jet isn’t the most “natural” environment for humans—but there’s plenty of debate about the extent of those risks, and even about what really happens to our bodies and our health after we climb aboard.
Cheek by Jowl
There’s no way around one fact of airborne life: very close quarters, sometimes for hours on end. And our exposure to the airborne environment is intensifying as flights grow longer, capable of half-circling the Earth nonstop, and ever more consistently packed solid. Some airlines have even eliminated one of the lavatories in order to add more paying seats. So a coast-to-coast jet like the Boeing 757 with 160-odd passengers in the Economy cabin may be reduced to only two lavatories—creating an 80-to-1 lavatory-passenger ratio, far tighter than the more traditional 50-to-1 ratio generally offered. (Federal rules don’t dictate bathroom ratios.) And aircraft interior designers are developing even tighter lavatories—assuming that’s anatomically possible—to let airlines squeeze up to six more seats on new versions of the popular Boeing 737.
It all means more up-close-and-personal time with our hundreds of plane mates and so a greater risk of catching something. The likelihood of contracting onboard tuberculosis, for example, a disease that sickens about 9 million people across the globe each year, seems to depend largely on three things: how long you are on the plane, how close you are to an actively infected passenger, and cabin ventilation. According to the World Health Organization, the greater risk is on flights longer than eight hours where you’re sitting within two rows of the sick person. That’s not to say the risk is great—a 2004 analysis by the University of Texas Health Center put the probability of catching TB from another passenger with active TB symptoms during an 8.7-hour flight at about one in a thousand, similar to infection rates in other confined spaces.
Tuberculosis aside, some more exotic and deadly diseases like SARS and swine flu that spread through airborne droplets (think coughs and sneezes) have been tied directly to air travel. Most famous was Air China Flight 112 from Hong Kong to Beijing in March 2003. On the three-hour flight were 120 passengers, including a 73-year-old Chinese gentleman who was coughing lightly throughout it. Within eight days, 20 fellow passengers and two crew members were stricken with SARS, and five subsequently died. What freaked people out was that victims included passengers seated as far as seven rows ahead and five rows behind the sick man, though it isn’t clear whether the spread came from breathing common air or from other means (such as touching a contaminated surface).
Remain Seated
Beyond communicating disease, when we’re packed in on board, we’re largely immobile. There’s no real room or opportunity to “move about the cabin”—and that’s a health concern too. Pilots recommend we stay belted “just like we do up here” in case of “unexpected turbulence” (not to mention the expected variety). Getting out of our seats is not encouraged. Moving up and down the aisles interferes with flight attendants trying to serve drinks or sell headsets or collect trash. And it can still make people nervous: Is he going to rush the cockpit?
The whole pull-down-the-shades, watch-the-screen, light-deprived cabin environment seems designed to keep us soporific, slouched securely in our seats, tapping on our laptops or iPads, staring at the cycle of movies and sitcom reruns, dozing in the torpor of the low-oxygen cabin. The problem is that “just sitting there” can pose a significant health risk; long-haul immobility can even kill.
This nearly happened to a fiftyish senior economic official in my office at the Department of Transportation, whose job took him all over the world to international aviation conferences. When he didn’t show up at a morning staff meeting in Washington, we learned he had been hospitalized, having collapsed in the aisle after landing in Frankfurt on the way home from Singapore. After 13 hours dozing and reading and eating in his economy seat, he had stood up to grab his bag from the overhead bin and promptly hit the deck. Medics at Frankfurt’s massive international hub had seen it all before—a classic case of deep vein thrombosis (DVT), also known as “Economy Class syndrome.” Virtual immobility during long flights—probably exacerbated by low cabin pressurization and dehydration—causes blood to pool and become “thick” or “sticky” in the veins of the calf. If the resulting blood clot breaks off and moves to the heart or lungs, sudden death can occur.
Our economist was lucky to get quick, skilled treatment, but the risk he faced is growing as flights get longer and passengers get older and less fit. The prestigious British medical publication The Lancet estimated in 2001 that, based on a randomized trial, as many as 10 percent of long-haul fliers over age 50 may suffer thrombosis in the calf, albeit temporary and without symptoms. A study in 1986 of 61 sudden natural deaths among long-distance passengers arriving at London’s Heathrow Airport over a three-year period found 18 percent were due to pulmonary embolism. The risk appears to grow with the length of the flight; a 2009 study in the Annals of Internal Medicine, reported in USA Today, found the risk of blood clots on airplanes grew 26 percent for every additional two hours of flight time beyond four hours. No surprise that Hawaii, a long flight from almost anywhere, is a hot spot of Economy-class syndrome.
Just 20 years ago, 12 hours was seen as a kind of outside limit on nonstop flights. Today, some two-dozen international commercial flights every day run over 15 hours. Even on typical domestic flights—which averaged some 17 percent longer in 2011 than in 2003—we’re also packed in longer. The average flight distance is longer in part because Southwest, JetBlue, and other carriers that don’t rely on connecting hubs now fly longer nonstops, including cross-country. But even where flight distances are the same, flight durations—and thus our stretches of onboard immobility—are lengthier, as we’ve seen.
What We Breathe
For years, nothing has freaked out health-anxious fliers—or triggered quite so many popular misconceptions—as the air we breathe on board. How much of the worry is justified remains hotly debated; facts tend to be selected carefully to support opposing views.
Fact: A fully loaded jet has one of the smallest volumes of air per person of just about any enclosed public place. It is a simple matter of space and economics. Planes are tight places to start with, the more densely-packed the better from the standpoint of both revenue-seeking airlines and bargain-seeking fliers.
Fact: How much air we get on board matters. Good ventilation seems to reduce the risk of infection. In 1977, an Alaska Airlines Boeing 737 with 54 people aboard was stuck on the ground in Kodiak, Alaska, for close to four hours without an operating ventilation system; within three days, 72 percent of the passengers showed symptoms of influenza, spread by a single sick passenger. With ventilation turned off, onboard carbon dioxide levels are predicted to rise quickly above “comfort levels” established by ASHRAE, the official standard-setting body. So air travelers may actually face their greatest exposure to airborne germs not while flying but, rather, when the plane pulls up to the gate, the chime sounds, and everybody scrambles, huffing and puffing, to get up and grab their carry-ons and wait for the door to open. That’s also when cabin ventilation switches from air filtered by jet engine–powered systems to other sources of air, including the plane’s auxiliary power unit or the airport’s ground-based, diesel-powered turbines that may lack equally sophisticated germ filters.
Fact: Cabin air may be “just as good,” in a sense, as the air in modern office buildings—today’s jets exchange their air completely much more frequently than office buildings do. But each individual flier typically gets only about half the amount of “outside” airflow (roughly 7 to 10 cubic feet every minute) as the national standard-setting experts recommend for indoor environments like offices. More important: airplane cabins cram together lots more breathing humans per square foot than do offices. As in a busy elevator, these “other people” contribute their exhalations and gases and coughs and sweat and dead skin—and their viruses and bacteria—to the airborne mix. Everybody shares.
In other words, germ freaks should probably worry more about proximity to sniffling seat mates than about airflow. As an NYU medical expert observed, air purification can’t protect passengers against the common cold. “All the passenger next to you has to do is sneeze, and you’re done,” he told the New York Times in March 2011.
It is better in First Class—but only because there are fewer passengers sharing the up-front real estate and the air that comes with it. (Very roughly speaking, Economy passengers each have about half the personal space of each Business Class passenger, even less compared to each First Class passenger.) Premium passengers don’t get the “good air” first. It doesn’t emanate from the cockpit, waft its way in relative purity through First Class, then plow back through Economy. In reality, cabin air moves downward from the ceiling along the entire length of most jet airliners and ultimately leaves the cabin through floor ducts or grilles beneath the windows.
Fact: Cabin air is not all “fresh”—only about half comes in from outside the plane through the jet engines. Moving through the engine compressors, the air gets very hot, then is cooled down by heat exchangers and fed into the plane’s main air-conditioning “packs.” This outside fresh air mixes with cabin air that’s been recirculated and fed through high-efficiency “particulate arrestor” filters, which are supposed to clean away impurities. Airlines boast these HEPA filters are the same kind used in hospital emergency rooms, and they do remove microscopic particles larger than 0.3 microns—less than one two-hundredth the width of an average human hair. That’s fine enough to catch pet dander and vapors and bacteria like strep and TB as well as viruses suspended in larger droplets, as in a sneeze.
Fact: Airlines really don’t limit “good air” to cut fuel costs. Nor, by all accounts, do they reduce cabin ventilation rates to save money. Early versions of the Boeing 747 did let pilots reduce ventilation for purposes of “economy”—but that was when half-full planes were not uncommon; new Boeing models reportedly don’t have that option, though pilots can turn off air packs for safety reasons, such as a malfunction. Some Airbus planes do have a “Lo” or “Econ” setting that can reduce airflow about 20 percent on relatively empty flights, but it’s reportedly rarely used. Recirculating some of the cabin air does save fuel—jet engines need to pump less outside air to the cabin—but the savings are modest. And while breathing recirculated air certainly sounds bad, it’s not really like inhaling your neighbor’s breath. Research indicates that, with high-performance filtering and the ceiling-to-floor airflow, re-circulated air is no more likely to transmit disease than outside air is. Happily, and for fairly obvious reasons, lavatory air is exhausted directly overboard, not recirculated back into the passenger cabin.
That doesn’t mean it’s Irish Spring in the cabin, though. Not since 1990 has tobacco smoke billowed from the rear of each section of the cabin, permeating much of the atmosphere (smoking was banned on short flights in 1988), but there remain plenty of other contaminants unique to commercial airplanes:
Toxic fumes can enter the cabin from engine-oil leaks or oil-seal problems, or via hydraulic or de-icing fluids. Boeing paid a flight attendant an undisclosed sum in late 2011 to settle claims regarding toxic fumes in the cabin of a 2007 flight from Memphis to Dallas.
Ozone, the key component gas in smog, irritates the nose and eyes; as little as one in ten million parts of air, the most FAA regulations allow in cabins at certain altitudes, can cause airway irritation and reduce lung function. Airlines fly where ozone concentrations are high—between troposphere and stratosphere, particularly near the Poles.
Pesticides can enter cabins via “disinsection” of aircraft. Some foreign health authorities require arriving planes to be sprayed—sometimes with a neurotoxin called permethrin. The goal is to keep stowaway mosquitoes and rodents from importing tropical diseases like malaria, dengue fever, or Lassa fever from remote areas. The EPA is investigating whether the chemicals affect infant and fetal brain development; a 2012 National Research Council review found pesticides in the cabin to be a “moderate concern.”
Allergens are inescapable as carriers, for a hefty fee, let small pets fly in under-seat containers in the passenger cabin, suspending dander, skin flakes, and tiny saliva particles in the cabin air. A Swiss report in 2010 found common cat allergens on 100 percent of aircraft seats tested, according to MSNBC. DOT has rejected demands, though, for “peanut-free” areas or a ban on peanuts (that would have eliminated Southwest Airlines’ entire meal service).
Cosmic radiation from massive solar explosions, normally absorbed or shielded by the Earth’s atmosphere, can be 100 times more intense at jet cruising altitudes and near polar latitudes where that protective atmosphere is thinner. Most experts say not to worry, at least not unless you’re a pregnant crewmember who regularly flies long-haul, but FAA has a handy online tool for concerned fliers to predict their likely radiation dose from planned flights.
Not exactly pleasant, but compare today’s cabin air environment to the so-called Golden Age of elegant air travel in the 1930s. Here’s how legendary aviation writer Ernest Gann described it then:
We sweat in the cockpit, though much of the time we fly with the side windows open. The airplanes smell of hot oil and simmering aluminum, disinfectant, feces, leather, and puke … the stewardesses, short-tempered and reeking of vomit, come forward as often as they can for what is a breath of comparatively fresh air.
Kind of makes you appreciate today’s somewhat stuffy cabins.
What We Touch
What we touch on board is at least as nasty as what we breathe. Germs are everywhere on cabin surfaces. Think about the humble little lock on the airplane lavatory—that metal knob you pull across the slot to secure the bathroom door on pretty much any jet. On a typical plane, hundreds of hands will grip that knob every day—before and after their owners have completed their lavatory business. Hand-washing in tiny airplane sinks—holding down one of the already-germy faucet handles to wash the other hand—won’t eliminate the germ load.
Or those sticky tray tables. In 2007, a University of Arizona researcher found that 60 percent of those tested on three major airlines were positive for the super-resistant, often-fatal methicillin-resistant Staphylococcus aureus (MRSA) bacteria. A germ that kills 20,000 Americans annually, MRSA tends to get into the body through open skin and cuts. Surfaces on the New York subway were more sanitary, according to the study. Then there are the seatbacks and overhead luggage bins that hundreds of travelers with sniffles or worse grip to steady themselves every day while passing down the airplane aisle. As reported in the New York Times in March 2011, the common cold and flu virus can survive for up to 72 hours on plastic surfaces, according to microbiologists; presumably that includes tray tables.
But the germiest areas in the entire cabin could well be the seatback pockets—the time-honored repositories of chewing gum, lunch leftovers, used tissues, and other unpleasantries. As the Wall Street Journal’s Scot McCartney recounts in gruesome detail in his aptly named “Middle Seat” column riff on airborne nastiness, the middle seatback pocket in particular—where parents tend to deposit soiled diapers and God knows what else—is a place where road warriors know never, ever to thrust a hand. And note to true germaphobes: those little air nozzles above your seat—called gaspers (really)—are twisted by scores, maybe even hundreds, of dirty little fingers before yours. Who knows how often they get a thorough scrubbing?
What may be the industry’s greatest recent contribution to passenger health is the likely unintended consequence of a cost-cutting move—eliminating free pillows and blankets in coach. These objects came in direct contact with passengers’ faces and skin, sometimes after, say, a dozen or so other passengers had the chance to thoroughly enjoy them, allowing successive users to touch, even inhale, the contents—sweat, saliva, the soles of the shoes of someone who used that pillow to raise his legs. These “amenities” were cleaned (or discarded)—eventually. But unless they appeared “visibly soiled” to the overnight cleaning crew, it could be awhile. Not that the airlines hadn’t noticed the hygiene issue. When US Airways, for instance, started selling clean pillows and blankets to coach passengers in late 2008 (other carriers followed suit through 2011), the airline’s spokesman was quick to tout their superiority to the previous “free” version of the amenities. “It’s a better product because you know what you’re getting,” he told Bloomberg News. “No one will be worried about where their pillow or blanket has been.” Comforting.
The cabin itself gets cleaned, of course, but there, too, it’s a matter of degree. There’s the “tidying up” after every flight—essentially dumping the used newspapers and lunch remains, and, when time permits, straightening the seat belts. Then nightly, after a thousand or so humans have made the metal tube their airborne home, cleaning crews—Southwest calls theirs “aircraft appearance technicians,” but many airlines use outside contractors—wipe down lavatories, tray tables, and other surfaces, search seatback pockets, and vacuum the carpets. Airlines vary, but a serious “deep clean” of the cabin may wait a month or more. This “major effort clean” is an overnight affair—carpets and seat coverings shampooed, interior walls and fixtures washed, galleys disinfected, air vents cleaned, and toilets scrubbed.
Deep-cleaning a Boeing 777 can take a dozen workers up to eight hours; a jumbo A380 can take more than twice the effort. Then every five years or so, the aircraft undergoes a complete months-long maintenance overhaul usually known as a “D check” or “heavy maintenance visit.” The whole aircraft interior is substantially dismantled, carpet is replaced, seat covers stripped off, and interior furnishings refurbished. The result is amazing: according to one pilot-blogger on Airliners.net, this super-cleaning reportedly removes up to 300 pounds of dirt from a large jet.
Cabin hygiene has improved over the last decade as the industry has climbed from the financial depths; it could hardly have gotten much worse. Airlines in bankruptcy can be less than fastidious. For example, according to a Chicago Tribune report in January 2009, what are now monthly or more-frequent deep cleans at United had earlier become semiannual affairs; occasionally they were deferred for as long as eighteen months. Things had gotten so bad in the industry that simple, basic cleanliness became a competitive selling point. Lufthansa’s online ads touted the “cleanest” airplanes. United invited reporters to observe their most finicky aircraft-cleaning managers at work. Emirates proudly accepted an award in 2008 (sponsored by a cleaning-product supplier) as the World’s Most Hygienic Airline. Apparently its “mini deep clean” included injecting “biocide fog” into the cabin ventilation system. Plus, there’s a specialist “de-infestation” team that “makes sure there are no cockroaches on the aircraft,” according to a Dubai business news service.
Put it this way: airline cabins are cleaner now than they were in 2008, but just how much remains uncertain. Nor is it fair to blame all the germy-ness of air travel on actual flying. Long before you step aboard, thousands of index fingers have punched the same “Print” button on the kiosk screen you’re using to check in with your e-ticket. Most everyone goes shoeless (required), some sockless (not recommended), through security checkpoints, traipsing fungi and worse across the same patch of floor as thousands of others. And God knows what gets dumped in the gray TSA bins from which we fish out our change, key chains, and toiletries on passing through security. When do you think they disinfect those bins?
What Passes Our Lips
Watch any two-year-old and you know: humans take in more nasty stuff through the mouth than through the lungs or skin. In just a few decades, airline cuisine in the back of the plane has evolved—or, rather, devolved—from unremarkable to laughable to nearly nonexistent. Even where there is food, though—for international flights or buy-on-board offerings on some domestic flights—from the standpoint of health, you might still consider going hungry, at least if you believe federal food inspectors.
For the most part, airline food is prepared by a small handful of airline caterers (all but a few carriers long ago dropped more expensive in-house “flight kitchens”) who’ve drawn fire from the federal Food and Drug Administration for occasionally less-than-appetizing practices. Here’s how FDA inspectors described what they found at the Denver facility of the world’s largest airline caterer, LSG SkyChefs, in a December 2009 warning letter to the company:
“Live and dead roach-like insects too numerous to count” and “live and dead roaches” in the silverware and hot kitchen areas; numerous roaches and flies in other food-preparation areas, “employees handling food with bare hands or with unwashed gloved hands,” and “holes in wall surfaces, creating areas for insect and vermin harborage.” Not to mention “brown leaking fluid draining from at least two garbage bins, apparently creating standing pools of the brown fluid.” Kitchen-floor samples found Listeria, a dangerous bacterium that can cause food poisoning. And LSG was not alone. The FDA also found problems at facilities of two other big US airline caterers, Gate Gourmet and Flying Food Group—ranging from high coliform counts and “unclean hands” of employees, to improperly chilled fish, beef, and chicken. FDA reports for 46 of the 91 caterer kitchens showed suspected violations or objectionable practices at 27 of them, according to a USA Today report in June 2010. For their part, the big catering companies say they have quickly, aggressively, and “proactively” addressed FDA’s concerns; in the words of one, their “goal is to be 100 percent compliant with all safety regulations.”
Caterer preparation areas aside, there are plenty of other ways for airline food to go bad. Lapses in refrigeration are one risk. The shrimp served on the evening flight to China may sit for hours in various venues—caterer holding rooms, trucks hauling them to the airport, the elevator truck to the plane, then the catering carts that slide into the aircraft galleys—before they grace the First Class tray tables. Those carts are themselves supposed to be refrigerated, but how often do their doors stay open during meal services? And did you know that even well-regarded airlines like Air New Zealand and Qantas reuse the plastic cutlery on international flights, washing and repacking it in those little wrappers—up to ten times in some cases?
With “free” food all but eliminated in domestic Economy, the tap water on board is a bigger worry. Let’s be clear, there’s no reported history of any widespread health problem associated with contaminated onboard water but for more than a few airline crew members, the rule is simple: Don’t drink it. Don’t even brush your teeth with it. Some flight attendants won’t even wash their hands with it or drink coffee or tea made with it. (No, Virginia, they don’t make the coffee with bottled water.) Nobody paid all that much attention to the water on planes until 2002, when Zach, a 13-year-old kid from Alamo, California, put the results of his school science project online. He had tested the tap water on family flights to Australia and New Zealand and his water-testing kit revealed “really gross” (his description) masses of bacteria. Noticing Zach’s online report, enterprising Wall Street Journal reporters conducted their own water sampling on 14 flights in 2002. Here’s what they reported finding in the water they tested, from a story in November that year: “A long list of microscopic life you don’t want to drink, from Salmonella and staphylococcus to tiny insect eggs. Worse, contamination was the rule, not the exception: Almost all of the bacteria levels were tens, sometimes, hundreds, of times above U.S. Government limits.”
Among the ingredients: Pasteurella pneumotropica, a rodent-borne bacteria; Pseudomonas, a resistant cause of skin and respiratory infections; and, Citrobacter, a fecal bacteria that can cause diarrhea. The EPA says safe drinking water should contain no more than 500 colony-forming units (CFU) of bacteria per milliliter. The Wall Street Journal’s experts found more than four million units in a single sample, roughly the same concentration as in a tainted raw hamburger.
The EPA’s own tests in 2004 appeared to confirm the problem, though the airline industry trade association questioned the testing methods used. Inspectors found that about 15 percent of all water samples on 327 randomly selected commercial flights tested positive for coliform bacteria—an indication of the possible presence of disease-causing organisms. Water on two of the EPA-tested planes had E. coli, a leading cause of food poisoning that’s found in the intestines, suggesting the lavatory tap water might even be contaminated with feces. It was not exactly the kind of publicity the airlines were looking for. Rather than prolong it, the industry quickly agreed to a “voluntary” EPA onboard water–testing program with more frequent sampling and disinfection that will take full effect in 2013.
One reason the water on airplanes can be dicey is that, in most cases, water tanks are filled where they land—that includes Lagos, Mumbai, and Oaxaca, not just Seattle and St. Louis. What else can they do? Flying tons of homegrown US Grade-A water around the world would be hugely expensive in fuel. A long-range Boeing 777 holds well over a ton of water, more than 300 gallons. And once impure water, foreign or domestic, gets into the airplane’s massive tanks, bacteria and other tiny organisms can remain there, even after they’re emptied and the plane is assigned to other routes. Even if the water itself is pure, how well does the local airport ground handler who pumps it into the plane sanitize its own water cabinets, trucks, carts, and hoses?
Airlines want the “bad-water” issue to go away and, in fact, airplane water quality seems to be improving significantly. Still, sampling conducted from 2005 to 2008 by the EPA and reported in 2009 continued to show limited instances of coliform. So the EPA’s understated advice to “concerned passengers” in 2005 still makes sense for the cautious: Worried fliers “may want to request canned or bottled beverages and refrain from drinking tea or coffee unless made with bottled water.” No kidding.
“Physiological Needs”
The technological leap from biplane to jumbo jet didn’t overlook that one hygiene essential, the airplane toilet. In the early days of flying, the head was about as rudimentary as it gets—a bucket emptied overboard. The loo in the early versions of the legendary DC-3, the commercial aviation workhorse before and shortly after World War II, consisted of a plastic-lined bucket with a wooden seat above it, fondly known as the “honey bucket.”
“Blue water” toilets followed. Still found on some older jets, an electrical circulating pump sloshes chemical solution through rings around the stainless-steel bowl, emptying into a central tank that is drained into tanker trucks at the destination. These commodes used a lot of costly-to-carry water and often got stopped up with diapers, pantyhose, and other items too big for the plumbing lines.
The airplane toilet “revolution” really arrived with the vacuum-powered toilet first installed by Boeing in the early 1980s. Flushing in flight opens a valve in the sewer line for about 15 seconds; this causes the air-pressure difference at altitude to suck out the contents into a sealed tank located in the aircraft belly. These beauties not only need far less water (roughly a half gallon); they rocket the waste away into onboard tanks—at up to 68 miles per hour on Airbus jets. Still, there’s a downside. When you flush, the vacuum’s force can spray whatever’s in the toilet into a fine aerosol that remains suspended in the bathroom air. Some of it ends up coating the lavatory floor and walls, potentially adding to the coating of fecal bacteria on the faucets and door handles. Advice to germophobes: put down the lid and don’t breathe until you get out of there—without touching that grimy little knob on the door, of course.
The most enduring myth about airplane toilets, though, is the “bluewater bomb.” Stories of lavatory ice crashing to the ground are so pervasive that the FAA’s Chicago district office once had to issue an official “blue ice” disclaimer, updated in November 2010, to calm residents around O’Hare. (“One possible explanation” for the reports, the FAA said helpfully, was that flocks of Canada geese eat fruit and, “if the fruit is blue, it will come out blue when the bird passes it.”) Just to set the record straight, though: Toilet waste is not dumped outside airplanes in flight. That valve is located on the outside of most aircraft so that ground crews can service and drain it; it cannot be opened in the air. But don’t get too comfortable. Standing in the flight path, it’s still possible (but very unlikely) to get hit with a little ice—galley and lavatory sinks vent outside the aircraft.
High Altitude in Death Valley
Humans need a lot of oxygen to survive, but there’s not nearly enough available in the outside air at cruising altitudes. At 35,000 feet above sea level, most people pass out from oxygen starvation in less than a minute. Modern aircraft compensate by pressurizing the air to concentrate the available oxygen. That makes it feel, oxygen-wise, as if you’re at a much lower altitude—say, an 8,000-foot Rocky Mountain pass where the atmospheric oxygen concentration is 75 percent of what it is at sea level. Even at that “virtual” altitude, though, cabin pressurization does weird things to the body. Air trapped inside you—in the middle ear, the sinuses, and the abdomen—naturally expands. Normally, the pressure equalizes as air flows through your ears’ Eustachian tubes and sinuses, unless you have a cold or sinus infection or other obstruction. In that case, it hurts like hell—also the main reason that babies are forever screaming their heads off on landing or takeoff.
The pressure of air in your lungs is what forces oxygen into your blood, across the lungs’ alveoli. At higher altitudes, less oxygen gets to the bloodstream. On longer flights, this can cause a kind of low-grade oxygen deprivation—or mild hypoxia—that leads to headaches, fatigue, even fainting, the single most common health event aboard airplanes. So why not just make the “virtual” altitude lower than 8,000 feet, pressurize the plane more so we feel like we’re back at sea level? Mainly because it would be too tough on the airplane. More pressure inside the cabin stresses the airplane fuselage—pushing outward against the aluminum skin and structure of the plane—resulting in more maintenance costs and potentially shorter life span for the aircraft.
For jet designers in the 1950s, the 8,000-foot “cabin altitude” was essentially a compromise between passenger comfort and fuselage durability. Early postwar studies actually recommended that jet-cabin altitudes be set at a more comfortable level of 5,000 to 6,000 feet. Besides, when regulators chose 8,000 feet in 1957, they likely had in mind fit young military pilots, not aging Baby Boomers. For the latter, a big draw for Boeing’s new 787 is that it lowers passengers’ “virtual” altitude down to about 6,000 feet; Airbus claims its A380 is closer to 5,000 feet. That said, 21 million residents of metropolitan Mexico City don’t think twice about living 7,400 feet above sea level, nor do denizens of Flagstaff, Arizona, and Santa Fe, New Mexico (both at about 7,000 feet elevation).
Outside Death Valley, though, few people live in the extreme dryness of an airplane cabin, with roughly 10 percent relative humidity (think Death Valley in the summer at midday). The lack of humidity derives from the extreme cold of the air that ultimately enters the cabin from outside the plane at cruising altitude. At temperatures around minus 65 degrees Fahrenheit, that outside air holds precious little water—less than 1 percent absolute humidity. The only reason humidity inside the cabin is even tolerable—on the order of 10 times higher than outside the plane—is the passengers themselves. To put it delicately, the main source of onboard humidity is—sorry again—the breath and perspiration and other bodily effluents of passengers. The more crowded the plane and the more recirculated air, the moister it gets.
Ultra-dryness for long periods means more than just dry skin and chapped lips; it’s also a likely culprit in colds and other infections that so often follow us off the plane. Humidity levels may have as much to do with whether you’re about to suffer a raging head cold or gastrointestinal problem as germs in cabin air or viruses on sticky tray tables. Our key defense mechanism against colds is the “mucociliary clearance system,” a thin layer of mucus kept in motion by the cilia—tiny, beating hairlike tissues in the nose—that trap invading germs and move them from the nose and throat to the stomach acids that destroy them. Dry cabin air can thicken the mucus to the point where the cilia cannot move it, inviting more nasty stuff in to cause upper-respiratory infections.
None of this has escaped the notice of airplane manufacturers. Higher cabin humidity, just like higher pressurization and lower virtual altitude, has become a selling point for new planes like the Boeing 787 “Dreamliner.” Boeing promises to keep relative humidity in the 787 cabin at close to 16 percent. Meanwhile, Lufthansa is providing its First Class A380 cabins a relatively sultry 20 to 25 percent humidity level, and cockpits in fancy corporate jets sometimes get special humidifiers. Still, the high water mark, so to speak, is the “spa showers” that Emirates Airlines reserves for its ultra–First Class A380 passengers—even though the $10,000 one-way New York–Dubai fare entitles you to only five minutes of blissful drenching.
For the rest of us mere mortals, there’s perennial talk of equipping planes with humidifiers but debate continues about their safety, effectiveness, and the cost of hauling around enough humidifier water to make a noticeable difference on long flights. Drier is better for delicate airplane systems—including avionics and sophisticated computers. British Airways tried adding humidity to early model jumbo jets in the 1980s, but mineral deposits in the water gummed up water passageways and spray bars so badly that the air-conditioning system reportedly started shooting out small white pellets. Then there’s the problem of corrosive condensation on the cold outer skin of the plane, like on the outside of a cold glass on a warm, humid day. Insulation blankets that fit between the outer shell of a 737-300 and the airplane’s cabin walls have been found soaked with up to 80 pounds of unwanted water. Humidifying cabin air remains a serious challenge.
Four Chimes
On some airlines, four chimes ringing in quick succession in the cabin is the signal that there’s a medical emergency onboard; passengers are likely to hear them more often as the flying population ages. Health problems—preexisting and those triggered on board—cause more than a dozen serious in-flight medical emergencies on US planes every day. Airlines understandably hate to talk about them, and the government doesn’t require them to. An analysis done for USA Today by MedAire, a firm that provides 24/7 emergency medical advice to some 60 airlines around the world, sheds some light. It found that the rate of in-flight emergencies nearly doubled in six years—up from 19 per million passengers in 2000 to 35 per million in 2006, and that fliers over age 50 accounted for 59 percent of emergencies and 83 percent of in-flight deaths in 2006. In 2010, MedAire alone fielded more than 19,000 airborne medical emergency calls.
Some 2 to 13 percent (studies vary widely) of such emergencies are serious enough to require the plane to divert from its scheduled destination—figure at least twice a day on average. Probably the most common onboard problem, in one study more than half of all incidents, involves vasovagal syncope—better known as fainting. Losing consciousness briefly is usually harmless; the passenger is overtired, overstressed, undernourished, or overheated and just needs to recline and drink water. But here’s the tricky part for unlucky onboard diagnosticians: in rare cases, fainting can mean a massive heart attack or brain hemorrhage that, if left untreated for long, will leave the victim a vegetable, or dead. After fainting and gastrointestinal problems, cardiac events are relatively rare, but they account for a quarter to nearly half of those medical emergencies that result in flight diversions, and are the cause of most onboard deaths.
Far down the list of full-diversion-triggering emergencies, maybe 3 to 4 percent, are psychological events like panic attacks, even though they must be among the most common in-flight medical problems. After all, roughly one-third of US fliers has some degree of anxiety about flying, surveys say, though only about one in 16 Americans has a phobia that keeps them off airplanes entirely, according to the National Institute of Mental Health. Add to that the stresses inherent in today’s crowded, claustrophobic, and increasingly lengthy flying experience and for some, anxiety can turn to panic. Veteran flight attendants can be experts at treating potentially explosive phobias with little more than some calming words, a reassuring hand, a glass of water, and maybe a few corny jokes—probably one reason only 1 to 2 percent of in-flight freak-outs require flight diversions, according to an FAA study of mid-1990s flights.
What’s unique about medical emergencies at 35,000 feet is obvious: the availability of timely, qualified medical help is a crapshoot. Flights over the US mainland can almost always find a place to land within an hour or so, but for planes flying over the mid-Pacific or the Poles, it’s another story. FAA rules for extended-range flights permit advanced commercial jets to range up to three hours from an emergency landing strip; a relative few are specially certified to stray as far as five and a half hours away. Even if it takes only an hour to get on the ground, though, that’s still a very long time if you’re having a stroke or major coronary. And don’t count on sophisticated emergency medical assistance on remote Pacific atolls or tiny Aleutian islands with emergency airstrips.
When it comes to assistance in an urgent medical situation on board, what’s on the plane is what you get. That’s one reason that registered nurses were among the first official non-pilot airline personnel, the original “air stewardesses” introduced by Boeing Air Transport in May 1930. (For $125 a month, these young women also carried bags and checked for oil and gas leaks.) Even today, flight attendants are the first line of assistance.
Surprisingly often there’s also a doctor, nurse, or emergency medical technician on board. Northwest Airlines estimated there was one on 96 percent of its flights, as USA Today reported in 2008. As for medical equipment, US airlines carry a first-aid kit meant for flight attendants. For use by volunteer doctors, there’s also a 15-pound suitcase stuffed with medical devices for resuscitation and injections, and medications for heart attacks and allergic reactions, as well as a tank or two of oxygen and an automated external heart defibrillator. If there are no medical professional volunteers to help, it’s up to the flight attendants, who are trained in first aid.
Though heart attacks have long been the major cause of in-flight death, onboard automatic defibrillators are relatively new. UK-based Virgin Atlantic led the way in 1990, an American Airlines flight attendant made the first US in-flight save with one in 1998, and another 81 lives were saved in the decade that followed. Still, emergency defibrillation works only about a quarter of the time at best, and then only on certain kinds of sudden heart conditions.
Just in case the onboard medical volunteer treating your heart attack happens to be a psychiatrist instead of a cardiologist, most airlines also contract with a ground-based 24/7 medical advisory service for emergency diagnostic and treatment help. They’re limited in what they can do, though. Diagnosing someone remotely by radio necessarily omits the most basic first step—actual examination of the patient. Communications can get scrambled, too. Since nobody gets into the secured cockpit after September 11, medical information must still be relayed in most cases by cabin intercom from the back of the cabin to the pilots, who then pass it on to the ground-based doctors—remember playing the “telephone” game? The director of MedAire described to the New York Times the process of ground-based diagnosis and treatment as a matter of “experience and gestalt.”
Ultimately, the captain makes the call whether to divert to the nearest airport; health experts—on board and on the ground—can only advise. There’s a lot at stake in the decision, and it’s rarely easy. Balanced against an often ambiguous medical risk—is it indigestion or a massive heart attack?—is more than just the hefty cost of landing at an unintended airport: on long hauls, estimate more than $100,000, counting fuel, overtime, new crew, and passenger accommodations, depending on the location. There’s also the disruption of hundreds of other passengers’ travel plans, as well as potential safety issues if an emergency landing involves an unusually “heavy” aircraft with unexpended fuel or an unfamiliar approach in bad weather to a little-used airstrip. Think of it this way: the last place you want to be in a medical emergency is in an aluminum tube 40,000 feet above the Arctic on a stormy night.
Death Onboard
Precise statistics are hard to come by, but a passenger probably dies on a US commercial airliner every few days on average, about half the time because of a heart attack. The risk of dying on board from illness has become considerably greater than dying in an aircraft accident. Airlines don’t have to report onboard medical emergencies to the FAA unless they involve injury or death of a pet, in which case a detailed monthly report is required.
Human death on board is frequent enough, though, that airlines have protocols for how to handle it. Mostly, crews try to isolate the body as much as possible, often moving it to an empty row or to the more spacious First Class cabin and covering it with blankets. (First Class passengers waking from a nap to find themselves seated next to a corpse might be justified in questioning the wisdom of buying their $6,000 tickets.) On a full flight, this can mean just laying it down, covered, on the galley floor, as far as possible from other passengers. Some long-haul carriers routinely carry body bags.
There aren’t a lot of good options, especially on a typically full airplane. Storing the body in a lavatory is not advised. When rigor mortis sets in, it can be a mess trying to remove the remains from the cramped space. So Airbus came up with a solution on its ultra-long-range aircraft, the A340-500, which Singapore Airlines flies daily up to 19 hours between Singapore and Newark over some of the most remote points on Earth, skirting the North Pole on the shortest routing. To minimize the discomfort of other passengers flying for nearly an entire night and day with a corpse in full view, the ingenious aircraft designers in Toulouse came up with a new design feature for the jetliner: a discreet pull-out cupboard adjacent to one of the exit doors. Long enough to store a body, with straps to prevent movement in turbulence, the mortuary drawer (aka the “corpse cupboard”) respectfully holds the deceased without disturbing the survivors.