Some people get anxious the moment they take the exit for the airport. Others just kick back, relax, and enjoy the view (if not the recirculated air). Whether you’re a nervous flyer or a laid-back traveler, you probably find it pretty impressive that a plane can safely and quickly transport so many people. But you probably haven’t read up on the scarier details about what goes on miles above the ground.
We wouldn’t recommend the following as reading for the nervous traveler waiting at the gate. (Go read about the best ways to ease your pre-flight anxiety instead.) But if you can stomach these unnerving facts, read on to find out everything your airline doesn’t want you to know about the plane you trust to get you from point A to point B.
1. Airplanes get struck by lightning
Nobody wants their house, car, or office building to get struck by lightning. And it sounds even scarier to travel in a plane that gets struck by lightning. But as Scientific American reports, researchers estimate on average, “each airplane in the U.S. commercial fleet is struck lightly by lightning more than once each year.” And airplanes can actually trigger lightning when they travel through a heavily charged region of a cloud.
Fortunately, engineers ensure that modern planes can withstand lightning strikes. (The last plane crash blamed on lightning happened in 1967.) What will happen if your plane gets struck by lightning? You’ll probably just see a flash and hear a loud noise. (But if you’re in the right place at the right time, a lightning bolt could expose you to radiation, too.)
2. If you opened an airplane window, everybody would die
Have you ever gotten stuck on the tarmac, waiting for the plane to either make it to the runway or get to the gate? Then, you’ve probably wished you could open a window to get some fresh air. But you can’t open the windows on a plane. Scientific American reports if you did so during a flight, everybody would die.
The air becomes so thin at 10,000 feet that airplane cabins need to be pressurized above that altitude. That keeps travelers from suffering the effects of a lack of oxygen. At 35,000 feet — the typical altitude for a commercial jet — the air pressure drops to only a quarter of its measure at sea level. And the temperature outside hits negative 60 degrees Fahrenheit. If you were exposed to those conditions, you’d die. Thus, airplane windows definitely do not open.
3. An airplane’s oxygen masks aren’t actually filled with oxygen
Never paid close attention to the flight attendants’ safety demonstration? You probably still know about the plane’s emergency oxygen masks. But do you know how the airplane delivers the oxygen you’ll breathe through the mask? The Huffington Post learned the air in your mask starts as a cocktail of chemicals stored in an “oxygen generator.” If the cabin pressure drops, the masks release. (And you need to put your mask on within about 30 seconds of a pressure change. If you delay, you risk passing out.)
When you pull on your mask, the chemicals — usually sodium perchlorate and an iron oxide — mix together. The chemical reaction yields oxygen. It also creates a burning smell. The mask will only provide enough air for 12 to 20 minutes. But that allows plenty of time for the pilot to navigate to a safe altitude.
4. Your flight exposes you to more radiation than the TSA’s body scanner
Have you heard frequent flyers get exposed to sizable amounts of radiation? Then, you’ve likely assumed that radiation comes from the TSA’s whole body scanner or maybe even from the agency’s baggage X-ray machines. But that’s not actually true. Scientific American explains, “The major source of radiation exposure from air travel comes from the flight itself.” That’s because at a high altitude, the air literally gets thinner.
The farther you get from the Earth’s surface, the fewer molecules of gas you’ll find per a given volume of space. And as Scientific American notes, “Thinner air thus means fewer molecules to deflect incoming cosmic rays — radiation from outer space.” Every flight you take exposes you to radiation from space. And that could ultimately increase your chances of developing cancer.
5. Secret military planes can cause safety issues for commercial flights
Whether you fly on a giant airliner or a small jet, your crew communicates with air traffic control. And the pilots do everything they can to avoid collisions with surrounding aircraft. So it’s a little unnerving to learn secretive military planes can fly without identifying themselves.
As Scientific American notes, these planes pose a safety threat to civilian aircraft flying over Europe. In fact, Russian warplanes have caused a series of near-collisions with commercial airliners. So when military planes don’t file a flight plan, don’t talk to air traffic control, and turn off their transponders, they jeopardize the safety of civilian flights.
6. Collisions on the runway can be extremely dangerous, too
Think you don’t have anything to worry about when your plane is on the runway, whether it’s taking off or landing? Then, think again. CNN reports the deadliest commercial airplane accident in history occurred on March 27, 1977. Two Boeing 747s collided on a runway on the Spanish island of Tenerife. The collision killed 583 people.
Of course, such incidents occur only very rarely. And as Business Insider notes, “Most airplane crashes result not from a single error or failure, but from a chain of improbable errors and failures, together with a stroke or two of really bad luck.” You have only a very small chance of experiencing a plane crash. But crashes can happen not only in the air, but also on the runway.
7. Passengers occasionally die on a plane
Most people have heard planes often transport human remains. And though nobody likes the idea of a coffin cozying up to their checked baggage, that’s just one of those things you should try not to think about. Have you ever considered what happens when a passenger dies mid-flight?
Quartz reports such a passenger can’t legally be pronounced dead until a doctor or other authority on the ground takes a look. Airlines handle the situation in different ways. Many will try to move the body to an empty row of seats (or at least move the dead passenger’s seat mates). And some planes, particularly those for long-haul flights, have a “corpse cupboard” to store a body if there aren’t enough empty seats.
8. Whatever you eat on an airplane, it probably won’t taste good
If you’ve only ever flown in the economy cabin, you’ve probably assumed that was why your meal didn’t taste so great. But researchers have found there’s another reason why airplane food doesn’t taste good. According to a report from The Conversation, the atmospheric pressure is slowly reduced as your plane ascends. Reduced atmospheric pressure and lower oxygen levels dull your appetite.
But air travel can also change your sensitivity to certain flavors. Slightly acidic flavors, or bitter flavors, often end up tasting worse. (Don’t order a cup of coffee or a glass of Sauvignon Blanc on your next flight.) Plus, the dry atmosphere even changes the makeup of your saliva. That, in turn, also affects the taste of your food. It often increases the intensity of sour tastes in foods and drinks.
9. Some seats might be safer than others in the event of a crash
Ever wondered which seats are safest in the event of a plane crash? Near the front? At the back? Behind the wing? In an aisle seat? You can speculate all you want. And authorities, including the Federal Aviation Administration and the National Transportation Safety Board, posit that there’s no such thing as a safest seat. But as Condé Nast Traveler reports, the data say otherwise.
Based on analyses of data on commercial plane crashes, researchers have concluded it’s safest to sit near the back of the plane. In fact, middle seats in the rear third of the plane seem most likely to keep you alive. Seats near the emergency exits also fare well. On the other hand, aisle seats in the middle third of the plane seem to have the highest fatality rate. Nonetheless, your chances of survival depend on the type of impact and the circumstances, as well as on how you react in the event of a crash.
10. The plane puts your eardrums through a lot of pressure
Most of us know to swallow, chew gum, or yawn to make our ears pop when we fly. But few of us know exactly why that’s necessary. And fewer stop to consider the physics of what’s going on. Scientific American explains our middle ears contain pockets of air. This air typically maintains the same pressure as the air outside of our bodies. But “when the pressure in our environment changes, we are able to equalize it by allowing air to flow through the Eustachian tube in and out from the back of our nose.”
Usually, people swallow or yawn. But sometimes, you change elevation quickly, such as during takeoff or landing. And other times, the airflow through the Eustachian tubes gets restricted by a cold or inflammation. In those cases, “our swallowing and yawning cannot make up the difference quickly enough, and we start to feel the pain caused by this imbalance.”
11. Airlines don’t effectively screen pilots for mental illness
As could be expected in any other population, a small fraction of pilots experience suicidal thoughts and severe depression. Nobody likes to think about it. And that seems to include airlines. As Wired notes, “Even the most strenuous screening and training procedures cannot guarantee a mentally or emotionally troubled person does not step into the cockpit.”
In the U.S., airlines don’t put pilots through any formal psychological testing. And according to Wired, “There is no meaningful way of screening the 50,000 or so airline pilots in the US and Canada. You simply cannot line them all up in front of a clinical psychologist each year.” Mental health advocates want to ensure that pilots can speak up about their depression without jeopardizing their careers. But that seems a long way off.
12. It’s not possible to open an airplane door mid-flight
If you watch spy movies or action flicks, you’ve probably seen some film’s protagonist throw open an airplane door to jump out mid-flight. But as National Geographic learned, it’s not actually possible to open an airplane door mid-flight — at least not if the cabin remains pressurized.
The internal pressure in the cabin forces the door outward against the seal. You’d have to pull the door inward with more strength than a person could muster in order to get the door to open. Ultimately, that’s a good thing (for the same reasons it’s good you can’t open a window). But we still find it unnerving to think about.
13. Pilots often fall asleep in the cockpit
You probably don’t mind dozing off during a long, boring flight. But you certainly don’t want your pilot doing the same. Nonetheless, pilots, co-pilots, and relief pilots can — and do — fall asleep in the cockpit, thanks to their punishing schedules. The New York Daily News reported in 2015 that “there have been 320 fatigue-related aviation accidents and almost 750 deaths in the last 35 years.”
FAA regulations limit the amount of time that a pilot can be on duty. But pilots report being sleep-deprived despite those regulations. And European regulations allow even longer days for pilots. Better hope your pilot grabbed a Starbucks drink before boarding the plane.
14. An airplane’s drinking water really isn’t safe to drink
Thinking of asking the flight attendant for a glass of water? How about a cup of coffee or tea brewed with the plane’s tap water? You should probably reconsider. Business Insider reports most flight attendants won’t drink any of those beverages. The reason why? “An EPA study found that 1 in every 8 planes fails the agency’s standards for water safety.”
The drinking water gets stored in tanks that are difficult to sterilize. So you risk exposing yourself to dangerous bacteria if you drink the tap water. You’re better off buying a bottle of water at the terminal. Or opt for a canned drink or even a restaurant drink at the gate before you get on the plane.
15. Airplane toilets use a pneumatic vacuum to flush
We could name plenty of things to dislike about airplane bathrooms. But one of the worst? Definitely the terrifyingly loud sound of the toilet flushing. Urban legend has it you can get stuck to the toilet seat if you flush while still sitting on the toilet. That doesn’t appear to be true. And Snopes has debunked the story of one such incident.
But Gizmodo reports airplanes do use vacuum toilets that rely on strong suction and slick walls to flush waste away. “Pressing the flush button opens a valve in the bottom of the bowl, exposing the contents to a pneumatic vacuum. That vac sucks the load down the plane’s sewer line into a 200-gallon holding tank — vapors and all.” Waste remains in the tank until the plane is on the ground. There, a crew vacuums it out.
16. Flying exposes you to high levels of flame retardants
You probably don’t need to worry about this one unless you work on board an airplane — or if you log a truly impressive number of miles each month. But researchers have found airplanes expose those on board to high levels of flame retardants. Scientific American reports, “Whether flight attendants, pilots and cleaning crews face any health risks from the chemicals is unknown. But researchers worry that long hours breathing recycled cabin air could have some effects, particularly in pregnant women.”
Airplanes are full of combustible materials. So flame retardants obviously play an important role in the plane’s fire safety. However, some research indicates flame retardants don’t actually slow the spread of fires. They might even increase emissions of carbon monoxide and hydrogen cyanide.
17. Human error is responsible for about half of plane crashes
Most airlines wouldn’t want you to know this. But according to a report from The Conversation, pilot error is to blame for about 50% of plane crashes. “Aircraft are complex machines that require a lot of management. Because pilots actively engage with the aircraft at every stage of a flight, there are numerous opportunities for this to go wrong,” the publication explains.
Other top causes of plane crashes? Mechanical failure accounts for about 20% of aircraft losses. Bad weather takes the blame in about 10% of plane crashes. Another 10% of aircraft losses are caused by sabotage, despite heightened security. And other forms of human error — including mistakes made by air traffic controllers, dispatchers, loaders, fuelers or maintenance engineers — account for the balance.