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  • Ok, here's a little riddle for youthey're long, white, and you can see them in the sky.

  • What is it?

  • I used to think it was Old Man W inter farts.

  • But no.

  • If you answered contrails from a jet, then you're the winner!

  • But what causes them?

  • Let's find out!

  • Ever noticed how on a cold day, you see your own puff of breath when you exhale?

  • The exact same thing happens to a plane.

  • The temperature at 25,000 feet or higher, which is cruising altitude, is really low,

  • around -30 degrees Fahrenheit.

  • While the engine burns the fuel, it releases different substances (mostly water and carbon

  • dioxide) into the atmosphere.

  • The cold air condenses, and sometimes even freezes the hot exhaust fumes, creating those

  • whitetailswhich look a lot like smoke.

  • That’s why theyre often called "condensation trails", or contrails.

  • To give you an idea, planes like the Boeing 747 eject around 2 gallons of water every

  • 3 seconds!

  • That’s a lot of water to condense!

  • Ok, but why are these contrails sometimes long and sometimes short?

  • Well, this depends on the weather.

  • Long contrails form in humid conditions, while low humidity makes them much shorter.

  • And that’s how these white lines can help you predict the weather.

  • If you see long contrails, it might mean that a storm is coming.

  • If a plane leaves short lines then don’t worry: the weather will be good.

  • Even though traveling by plane is common nowadays, these huge steel birds are still surrounded

  • by secrets and myths that give birth to a lot of questions.

  • Pardon the pun, but it’s high time to get more answers!

  • 1.

  • Why can’t planes fly when it’s extremely hot?

  • Hot air is less dense than cool air.

  • This means the air molecules are spread further apart from each other, so they come into contact

  • with the plane’s wings less.

  • As a result, it’s harder for a plane to take off.

  • It’d need a higher take-off speed, which would require a longer runaway.

  • Besides, planes rely on different internal machinery, and a good part of it already runs

  • hot.

  • That’s why, when the temperature is 120 Fahrenheit or higher, the plane might be delayed,

  • since the possibility of overheating the electronics is dangerous.

  • 2.

  • Can a plane fly on one engine?

  • Yes, it can!

  • Especiaily if it has one engine.

  • Ha ha.

  • Okay, even though, thanks to technological improvements, engine failures have become

  • pretty rare, they still happen sometimes due to damage.

  • However, losing an engine in-flight isn’t even considered a serious problem by pilots.

  • This is mainly because planes that fly over oceans, or for long-distance routes, have

  • special certificates that indicate the exact time they can operate safely with one engine.

  • For example, the Boeing 787 can fly around 330 minutes without the second engine.

  • 3.

  • Do planesoxygen masks have only 15 minutes of air?

  • Yes, they do, but that’s enough for an emergency.

  • If the cabin is depressurized at a high altitude, the passengers won’t be able to breathe,

  • so they use oxygen masks.

  • At the same time, the pilot will start descending right away to get lower than 10,000 feet,

  • where it’s possible to breathe normally again.

  • And this descent won’t take longer than 15 minutes.

  • 4.

  • What are those white spiral marks on airplane engines?

  • These spirals of different sizes and shapes are for the safety of the ground crew.

  • The ground crew has to wear hearing protection, so they can't hear the roaring engines of

  • a plane.

  • But when they see the spirals swirling, they know it's not safe to approach the area.

  • Also, these spiral marks help to tell which plane is about to take off if there are several

  • of them on the ground.

  • 5.

  • Is there thesafestseat on an airplane?

  • Most airlines claim that the safest seat is just a myth.

  • But statistics of airplane crashes beg to differ.

  • They say that this seat is at the back.

  • If you happen to sit near the tail of a plane, you're about 40% more likely to survive a

  • crash than those in the front.

  • If you need a more specific answer, it’s the middle seats in the rear section.

  • 6.

  • Why are there black triangles inside a plane’s cabin?

  • These black stickers are located on about four windows in a cabin.

  • Each of them is aligned with the edge of the wings.

  • If a flight attendant believes there might be something wrong with the moving parts of

  • the wingsslats or flatsthey know exactly which window provides the best view

  • to check them.

  • Also, you should choose a seat between those triangles if you tend to get motion sickness.

  • The plane’s center of gravity is at the wings, so youll have a smoother trip.

  • 7.

  • Why are airplane windows round?

  • Actually, at the beginning of the commercial flying era, they were square.

  • But after some time, airlines started flying at higher altitudes, requiring the cabin to

  • be pressurized.

  • But the frequent pressurization and depressurization caused the window corners to deform and even

  • break.

  • Turned out, round windows can withstand the pressure of cruising altitude much better.

  • So, square windows were soon replaced for good.

  • 8.

  • Why does the plane’s food taste bad?

  • Apart from the fact that, on board, youll get only defrosted dishes whichve lost

  • a big part of their flavor, the pressurization of the cabin is to blame.

  • The air in the cabin might be drier than a desert, literally.

  • And this numbs a lot of your taste buds.

  • Besides, quite often the cabin air can cause your nasal cavities to swell, making the food

  • taste even more unappealing.

  • 9.

  • Is it possible to avoid turbulence?

  • Turbulence is disturbances in airflow.

  • The causes can vary; some by weather conditions, someby cumulonimbus clouds, which actually

  • are also weather conditions.

  • While it’s impossible for planes to steer clear of turbulence altogether, pilots do

  • a lot to lessen it by bypassing areas of heavy turbulence for passengerscomfort.

  • But if youre a nervous flyer, here’s a tip for youchoose morning flights,

  • because the air is less bumpy at this time.

  • Do you think flying is scary?

  • Let me know in the comments!

  • 10.

  • Why do your ears pop during flying?

  • Ears pop because there’s a rapid change in pressure when a plane reaches a cruising

  • altitude or lands.

  • There’s not enough time for the pressure inside the inner ear and the air pressure

  • outside to equalize.

  • And the air trapped inside your inner ear causes the eardrum to pop.

  • If you don’t want ear-popping to turn into pain, try chewing gum or yawing to help your

  • eardrums adjust faster.

  • This is also the reason youll sometimes hear babies crying during the descent.

  • They have a hard time equalizing their ears.

  • 11.

  • Are a plane’s tray tables the dirtiest things on board?

  • Sadly, tray table surfaces have eight times more bacteria than the lavatory flush buttons.

  • Unfortunately, quite often, cleaning crews don’t have enough time between flights to

  • take care of everything properly.

  • So, don’t forget to wipe the tray table down with a sanitizing wipe, and don’t let

  • your food sit on it.

  • By the way, seat pockets and seatbelt buckles are almost as dirty.

  • 12.

  • What citizenship does a baby born on board get?

  • Therere several options.

  • A newborn can become the citizen of the country where the airline is registered; the country

  • over which they were born; or the country where the plane landed.

  • The decision is usually made by the airline, depending on the laws of the countries involved.

  • However, the first option is the most common.

  • Sometimes such babies get a bonus from the airline –a free first-class trip to any

  • part of the world on their 18th birthday.

  • 13.

  • Why are most planes white?

  • First, because extra paint would add around 1200 pounds to its weight.

  • And the heavier the plane, the more fuel it burns.

  • Airlines simply don’t want to pay the extra money.

  • Also, the white color keeps a plane cool by reflecting sunlight.

  • And there are safety reasons: it’s easier to spot any cracks, damage, or oil spills

  • on a white surface.

  • Plus, in case of a crash, the white fuselage will be able to attract the rescuer’s attention

  • faster.

  • 14.

  • Why are there no parachutes on board?

  • Putting one on and jumping out of the plane correctly is no easy feat.

  • You probably wouldn’t be able to do it in an emergency situation.

  • Training for skydivers requires many hours, in which they learn all the details about

  • handling a parachute and how to land safely.

  • What’s more, even the most experienced skydivers don’t jump from an altitude higher than

  • 15,000 feet.

  • On top of that, adding just parachutes (without helmets and supplemental oxygen) for all passengers

  • would mean making a plane 8,000 pounds heavier.

  • Hey long ago, I used to wear my sport parachute in the airliner, because I didn’t want to

  • check it as luggage.

  • I still remember the looks the other passengers gave me.

  • Boy that was fun!

  • Hey, if you learned something new today, then give the video a like and share it with a

  • friend!

  • And here are some other cool videos I think you'll enjoy.

  • Just click to the left or right, and stay on the Bright Side of life!

Ok, here's a little riddle for youthey're long, white, and you can see them in the sky.

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為什麼飛機後會有白色的痕跡? (Why There Are White Trails After a Plane)

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    林宜悉 發佈於 2021 年 01 月 14 日
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