Flying has become an increasingly common way to travel, with more than 37 million commercial flights flown in 2017. However, even if you’re a frequent flier, there may still be some things you don’t know. Below, find 10 surprising facts about air travel that may be new to you, or at least fresher than the blankets on your next flight…
10. The tiny hole at the bottom of your window is keeping you safe
When you’re stuck in an aluminum tube for hours at a time, staring out the window at the clouds might provide a welcome diversion from the cramped seats, crappy food, and unruly fellow passengers you may encounter as part of your in-flight “experience.” And when you look out that window, you may have noticed something strange about the window itself—the pin-sized hole near the bottom. That tiny hole is called a “bleed hole” or “breather hole,” and it’s there for a reason.
As your plane makes its way up to its cruising altitude, air pressure drops. The plane’s pressurization system keeps the air pressure much higher in the plane then in the surrounding air, ensuring that oxygen levels remain high enough for the people on the plane. This pressure differential puts a lot of stress on the plane’s windows, but each window is made up of three panes of glass to keep passengers safe. The innermost layer is mainly to keep the other two safe from passengers. The middle pane is the one with the tiny hole, which ensures that the outermost pane is the one to bear the pressure (and that it is the one that would break if the pressure became too much. If anything happened to the outermost pane, the middle pane would be able to “take over” handling the pressure differential without compromising the passenger cabin. The bleed hole also serves to manage the temperature differential between the cabin and the surrounding air, keeping the windows (mostly) clear of fogging and frost.
9. Airplane bathrooms can be unlocked from the outside
Airplane lavatories have improved from their early incarnations, some of which just released waste directly into the air. Nonetheless, most people wouldn’t describe them as pleasant or seek to spend any unnecessary time in them. In recent years, aircraft bathrooms have become even more cramped, as airlines seek to maximize the number of seats they can squeeze onboard, making visiting the lavatory an even more claustrophobic experience for passengers. Those rare few who still can’t get enough of the aircraft lavatory should be aware of one fact—it is possible to unlock the lavatory door from the outside.
The mechanism for doing so varies from plane to plane. In some versions of the Airbus A380, for example, one must simply lift the “lavatory” sign and slide the knob over to unlock the door. While this might seem like a great way to prank a friend (or a helpful trick for dealing with a misbehaving child), a Virgin America flight attendant says this technique is often used in reverse, to lock the door of an empty bathroom shut during turbulence, further noting that unlocking an occupied bathroom would be done only to ensure passenger safety, in the event the occupant has been in there a long time and is unresponsive, or if the smoke alarm goes off.
8. Hot beverages are best avoided when you’re in the air
While a cup of coffee or tea may seem like the perfect way to wake up after a red-eye flight, you might be better off waiting until you’re inside the airport to enjoy a hot beverage. Not only will the diaretic effect of coffee and tea have you making extra visits to the tiny plane bathroom, the water used to make your drink may be pretty gross.
After an EPA study in 2004 showed 15% of water samples taken from more than 300 planes had coliform bacteria, new standards were introduced to ensure airlines cleaned and tested their water tanks for bacteria. However, the water systems on some planes are only cleaned and tested once a year. EPA data from 2012 shows that 12% of commercial planes still had at least one positive test for coliform bacteria. Coliform bacteria won’t make most people sick, but does show that the plane’s water systems are not the cleanest water source, and that more dangerous bacteria, such as E. coli, could potentially exist in that environment. While US carriers serve bottled water to passengers, water from the plane’s system is still used to make tea, coffee, and cocoa, and it doesn’t generally get heated to the temperatures needed to kill all bacteria. The danger is likely small, but it’s enough to keep some flight attendants from drinking coffee and tea onboard, and maybe enough that you’d rather get your caffeine fix from soda or wait till you’re in the terminal to grab a coffee or tea.
7. There’s a reason why airplane bathrooms still have ashtrays, even though smoking is banned
You may have noticed an odd feature in the airplane lavatory—an ashtray on the back of the door. Confusingly, it’s often located right under the sign that reminds you that smoking is prohibited. On most US domestic flights, smoking has been prohibited since 1990, and it’s been outlawed on flights between the US and foreign destinations since 2000. But ashtrays can still be found even on brand new planes—why?
In the US, the bathroom ashtrays are there because the FAA mandates that they be. While initially, this make seem like another nonsensical law, there’s actually a pretty obvious reason why it makes sense to keep the ashtrays: not everyone obeys the law against smoking on planes. On a flight from Portland to Sacramento, one woman, who claimed she needed to smoke to deal with “anxiety,” became so violent after a flight attendant stopped her from smoking in the bathroom that she had to be restrained by passengers and crew until the plane could make an emergency landing.
Given that there are some people who are going to try to sneak in a cigarette no matter what the law says, no matter what kind of hefty fines might be assessed, it makes sense to make sure the cigarettes can be put out safely, and not tossed in a trash bin full of flammable paper towels. The legally mandated presence of ashtrays on planes has its roots in the tragic case of Varig Flight 820 in 1973. An onboard fire, possibly started by a lit cigarette tossed in the lavatory trash bin, killed most of those aboard (via smoke inhalation) before it could make an emergency landing, prompting the FAA to ensure that all commercial aircraft were equipped with ashtrays going forward.
6. Some planes have teeny-tiny bedrooms for the crew
On long-haul flights (those over 10.5 hours), you may have noticed that the crew members serving you rotate during the course of the flight. With some flights (like those from LA to Singapore and from New Zealand to Qatar) clocking in close to 18 hours, it makes sense that more than one crew of pilots and flight attendants would be needed to staff the plane, rotating between work and rest.
But where does the crew go when they are resting? While they all have seats in the main cabin for takeoff and landing, you don’t see the crew snoozing in them during the course of the flight. That’s because planes that fly these long-haul flights are equipped with special little bedrooms for the pilots and flight attendants (usually the pilots and flight attendants sleep in different quarters because of their different schedules). These sleeping cabins are either above or below the main passenger cabin, and are accessible by little staircases or, in some cases, via an overhead storage bin. Configurations vary based on the airline/plane, but generally include single beds, an overhead light for reading, and a privacy curtain. A KLM flight attendant reports that KLM crew beds come equipped with a set of mandatory KLM PJs, so that the crew is recognizable if they are called into service during an emergency.
5. Occasionally, a plane lands with more passengers than appear on the original manifest
This one isn’t as cryptic as it sounds. Pregnant passengers are generally permitted to fly up until their 36th week of pregnancy, though some carriers will require a note from a doctor or midwife after 28 weeks. However, as many moms will attest, due dates aren’t always accurate. Some babies make their entrance earlier than expected, and occasionally, these surprise preterm births happen at 36,000 feet up.
When babies are born on international flights, determining citizenship can be quite a tricky matter. Usually, the child will be accorded the citizenship of one or both of its parents. Some countries, including the US, will also grant citizenship to a baby that is born within national airspace. Additionally, 70 countries have ratified or acceded to the UN Convention on the Reduction of Statelessness, which says that a baby born on an aircraft is entitled to citizenship in the country where the plane is registered, but only if that baby would otherwise be “stateless.” Perhaps out of gratitude for the positive news coverage they bring for air carriers, some (though not all) babies born in flight have received perks from the airline where they made their debuts—including scholarships and free flights.
4. Flight crews want to get the door closed and the plane pushed back as fast as possible, even if they know they’ll be a tarmac delay
We know that everyone wants to get the plane in the air as fast as possible (well, except for that one guy casually blocking aisle with the full-size suitcase he insists will fit in the overhead bin), but the pilots and flight attendants are motivated not just by the desire to depart and land on time (for which they may receive some bonus pay), but also by the fact that, on many airlines, the crew isn’t paid until the plane door is closed and the parking brake of the plane is disengaged. Flight crews may receive some pay for long delays at the gate, but the pay gets much better when the plane pushes back.
While some airlines only pay the flight crew for the time they are actually in the air, most pay them once they leave the gate. While most pilots and flight attendants want to avoid delays altogether, if there’s going to be a delay, they’d much rather it be on the tarmac (where they get full pay) versus at the gate (where they get minimal or no pay).
3. Pilots have secret distress signals, though sometimes they mess them up
Pilots have ways to communicate, both verbally and nonverbally, that their plane is in distress. Obviously, we don’t know all the current ways that pilots signal problems on board to outside observers, but we do know some of what has been used in the past.
In the air, depending on the nature of the emergency, pilots are trained to set their transponder code (or “squawk” in pilot lingo) to a number corresponding to their situation, in order to alert air traffic control. Squawking 7500 signals hijacking, 7600 stands for loss of communications, and 7700 is a general emergency signal. Additionally, for a hijacking, a pilot would add the word TRIP following the aircraft designator (for example, “United TRIP 319”) when communicating with air traffic controllers, as an indicator that he or she was unable to communicate freely (likely due to monitoring by the hijacker[s]). In 2011, on a flight from Chicago to Frankfurt, a United pilot spilled coffee on the communications equipment, resulting in an accidental squawk of code 7500. The plane’s crew was able to confirm with officials on the ground about the communications error, though the plane was still diverted to Canada because of the issue. Another in-air distress signal involves flying the plane repeatedly in a triangular pattern, a maneuver that indicates to radar stations that the plane is unable to establish radio contact.
In the past, the plane’s wing flaps have been used to communicate distress on the ground. If the wing flaps were lowered while the plane was still on the ground, or full flaps were left down after landing, this signaled a request for immobilization of the aircraft and armed intervention. In 1986, a pilot inadvertently triggered a response by a SWAT team by taxiing for takeoff with the aircraft’s wing flaps down.
While some of these above techniques have been rendered less necessary by the fortified cockpit doors that became standard after the 9/11 attacks, there are still situations where these, and other distress signals, can provide necessary information about the plane’s situation to allow those on the ground to formulate a proper emergency response.
2. Pilots and copilots can’t eat the same meal
“Fish or chicken?” This question may be a vestige of the past on most domestic flights, but many international carriers still offer passengers a choice of entrée for long-haul flights. For the pilot and co-pilot though, the answer is pretty much set: they’ll each eat a different entrée. The reason for this is pretty obvious: eating different meals reduces the chance that both pilots will be incapacitated by food poisoning during the course of the flight.
This rule is not law, but is a policy at many airlines. A China Eastern pilot reports that generally the pilot takes a first class meal and the co-pilot takes one from business class. Lufthansa also confirms that it has an “unwritten rule” that pilots and co-pilots should avoid eating the same thing before the flight (for the same reason). Not every airline has this rule (though pilots may still follow it out of common sense), and even when pilots avoid the same meals, it’s not foolproof. In 1982, 10 crew members (including the pilot, co-pilot, and flight engineer) became sick on a flight from Lisbon to Boston. Luckily the plane was less than an hour from its destination, and it was able to land safely. The crew had eaten different meals, but were sickened by the same dessert—tapioca pudding.
1. Your best chance for a free upgrade is to die mid-flight
There are many purported tricks for scoring a free seat in first class, but unless you are an elite frequent flier or pay for an upgrade (with money or miles), your chances of moving up from economy to first class are remote. There’s one exception—but not one many of us would be willing to pursue. If you die mid-flight, your body is likely to get a post-mortem upgrade.
Airline protocol means that, technically, very few people ever die on a flight, since death must be declared by a doctor to be officially recorded. However, when it’s clear to all onboard that a passenger has passed away, airline personnel are trained to move the body to a relatively private location. This could mean an empty row of seats, but those can be hard to come by on crowded flights. The first class cabin generally has more empty seats and offers more room to maneuver the deceased, so that’s where bodies are often moved, and usually covered by a blanket to avoid traumatizing the other passengers. Previous solutions relied on deception: one British Airways flight attendant recalls that “many years ago,” dead passengers were simply handled Weekend at Bernie’s-style–propped up with a drink, eyeshades, and a newspaper in the hopes that other travelers would assume they were just sleeping.
Singapore Airlines used to have a so-called “corpse cupboard” on A340s it used for long-haul flights, though when the planes were taken out of service, the company noted the compartments had never been called into action. There’s one place you won’t end up if you die on a plane: the bathroom. Because rigor mortis could make it hard to get the deceased out again, flight attendants are discouraged from moving dead passengers into the lavatory.