Subtitles section Play video Print subtitles Okay, I say the word “Airplane” and what do you imagine? I know, a very funny movie with really bad jokes, yeah, but let’s try harder. Okay. “Big, white, a rounded nose, 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 WHY is all that so? Well let me tell ya. - 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 reach incredible speeds. - 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 to the wings' upward tilt. - 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 marvel! - 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 accomplished that! - 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 must be on from sunset to sunrise. - 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 places, mobile bridges, and buses. That’s it. Gotta fly! Hey, if you learned something new today, feel free to give the video a like and share it with a friend! And here are some other videos I think you'll enjoy. Just click to the left or right, and stay on the Bright Side of life!
B1 BRIGHTSIDE plane aircraft wing airplane lift Why You Board the Plane from the Left 7 1 林宜悉 posted on 2020/03/13 More Share Save Report Video vocabulary