Name: Why You Board the Plane from the Left
Uploaded: 2020-03-13T19:10:03.000Z
Duration: 8 min 44 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Okay, I say the word “Airplane” and what do you imagine? I know, a very funny movie

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with really bad jokes, yeah, but let’s try harder. Okay. “Big, white, a rounded nose,

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relatively small tires, two oddly angled wings with their tips curling up, normally late

taking off. Oh, and you always get on board through the left side!” Yep, spot on! But

- Commercial aircraft usually have their wings angled backward - that's why they're also

called swept wings. This shape helps planes be as fast as they are. The air moves over

a wing at a higher speed than under it. This creates shockwaves that would otherwise slow

the plane down. But these unique swept wings miraculously (kidding - it's just physics)

reduce the airflow speed above the wing. There are no more shockwaves, and the plane can

- Besides being angled toward the rear, many plane wings also have curved tips. Those are

called winglets. When a plane is flying, there’s a pressure difference between the wing's lower

and upper surface. This difference is big enough to produce wingtip vortices (they're

something like mini-tornadoes, which sounds pretty dangerous to me). Wingtip vortices

lead to slower speeds, more fuel consumption, higher CO2 emission, and safety issues. If

another plane is following one that's creating such vortices, it can lose stability and end

up in an emergency situation! Luckily, engineers invented winglets to separate the two regions

with different pressure, preventing those vortices from appearing.

- Ok, but why is the entire wing tilted upward instead of being perfectly parallel with the

ground? This upward angle is crucial for the airplane's stability. That stability is at

risk when a jet comes across some obstacle, like a bump from turbulence, that can make

it roll to either side. When that happens, the more upward wing gets less lift and naturally

goes down. The wing that rolled downward becomes more parallel to the ground and generates

more lift – making it go up. And voila! The plane levels out on its own, all thanks

- Let’s delve deeper into that oh-so-important lift – after all, it’s one of the forces

that help a plane stay in the air and move forward. The angle the oncoming air meets

the wing at is known as the angle of attack. The lift greatly depends on this angle. Take

a wing and start tilting it upward (like when a plane is taking off) - and you'll see that

the lift is getting better! But only until a certain point. If you tilt the wing too

much, the lift will get weaker or disappear altogether! Then the plane will stall in the

air and eventually fall. If the wings are tilted down, the lift decreases. You can notice

it when a plane is pitching down before landing. Long story short: aircraft wings are an engineering

- Another thing you may spot if you're watching an airplane about to touch the ground is that

its landing gear is a bit tilted. On some planes, the rear set of the wheels touches

the ground first – like stepping with your heel. The tilt serves several purposes: to

soften the landing and absorb the touchdown shock, to level the plane and prevent it from

pitching forward, and to let the gear fit properly in the gear well.

- And since I've started talking about those wheels, you ever notice how small they are

for such a massive machine? Well, if you made airplane wheels bigger, it would add extra

load, and aircraft would waste more fuel carrying them. And the more fuel a plane consumes,

the more money an airline loses. That's why manufacturers have a tough task: they need

to make airplane wheels and tires as small, sturdy, and safe as possible, and they’ve

- Airplane tires are also famous for being super inflated: the pressure inside is 6 times

greater than what’s in your car's tires and 4 times bigger than a person can withstand!

Surprisingly, thanks to this pressure (as well as the material they're made of), airplane

tires don't burst under the immense weight of a landing aircraft.

- If you're flying at night, you may see flashing lights on your airplane's wings. The light

on the left wingtip is red, and the one on the right is green. I know you can’t see

both lights from where you’re stuck back in the middle of the economy section, so trust

me on this one. That lighting scheme helps pilots figure out the direction of oncoming

planes in the dark and avoid a collision. The green and red lights on commercial aircraft

- Most airliners have nicely rounded noses, but there are jets with pointy ones – so

what decides it? Your aircraft's nose shape simply means that you aren't going to travel

faster than the speed of sound. During the flight, a plane's blunt nose pushes the air

in front of the jet, allowing it to roll over the airplane's body more freely and without

any serious resistance. The faster a plane is, the sharper its nose will be since they

need to cut through the air without meeting too much resistance. That's why almost all

supersonic aircraft (ones that travel faster than the speed of sound) have pointy noses.

Just like the pointy-nosed witches on broomsticks. Yes, they can go supersonic too. Didn’t

know that, did you? Then why not build commercial airplanes with

pointed noses – won't it make t hem faster? Nope! If a plane's speed is subsonic (lower

than the speed of sound), the blunt nose causes less drag - that's one of the forces that

keeps aircraft in the air but, at the same time, slows them down. Plus, pointed noses

are longer than blunt ones, so they may prevent pilots from seeing the runway clearly.

- Commercial airplanes have doors on both sides, but in most cases, you board on the

left. For one thing, it's a tradition. Earlier, airports were organized in such a way that

a plane had to taxi up to the terminal building and discharge passengers there. Pilots sat

on the left side and needed to see where they were going to put the plane's door right in

front of the terminal entrance. If they misjudged the distance, they could hit the wing against

the building. These days, left-side boarding is more of a safety concern. The right side

is used for fueling the plane and loading and unloading baggage and cargo. If passengers

were also entering aircraft from the right side, it would mess up the whole process and

probably lead to accidents. Boarding from the left side may also have something to do

with ship design. A ship's left side is a port side where people get on and off. Airplane

and jetway manufacturers might’ve just followed this maritime practice.

- Modern commercial planes have at least 6 entrances (or exits): 2 in the front of the

passenger cabin, 2 in the back, and 2 emergency exits over the wings. C’mon, you remember

that talk they give up right before takeoff? Then why don't airlines save time by letting

people in through all the entrances at once? Ok, maybe not the wing ones, but what about

the other 4? Well, you can't use the right side because of the whole baggage and fueling

thing I just mentioned. So, now we’re down to a front and rear door on the left. Some

airlines do use both for boarding and deplaning. But those are mostly low-cost carriers that

bring passengers to planes by buses and use mobile stairways. But if people board an aircraft

through a jetway, using both doors won't work. Jetways only reach the front left entrance.

To reach the rear ones, they’d have to go around the wing. In other words, jetways would

have to be longer, which equals not only more money spent but also more terminal space taken,

which is already tight. And finally, the rear and opposite-side doors are sometimes used

to load food and drinks and take out the trash. If passengers were boarding through them,

it wouldn't buy any additional time – it’d actually slow everything down.

- But returning to buses and mobile stairs: why them, why not good ol’ jet bridges that

can protect you from the elements every single time? Some airports are just too busy and

don't have enough gates. It's either using buses and mobile stairs or waiting for hours

for an available gate. Plus, if you're flying with a low-cost airline, it’ll try to save

as much money as possible (after all, it's low-cost for a reason!). Since jetways and

parking right near the gate cost a lot, budget carriers prefer much more distant parking