Airplane Things You Don't Know The Purpose Of

- [Presenter] Ever since Orville and Wilbur Wright flew at Kitty Hawk airplanes have had wings, controls, and some kind of motor. But planes have evolved over the last 100 years. The commercial airliner you fly in now has features that Orville and Wilbur wouldn't have dreamed of. In this video, I'll show you 10 things you might not know about modern aircraft, from the mysterious to the curious. - Amazing! - [Presenter] Number 10. The mysterious triangle symbol over your seat. When you board a modern jet aircraft you're probably looking for your seat number and for the nearest emergency exit. If you look more closely you might notice a small triangle over your window. That's not a secret society symbol. It's a reference mark for the flight crew. There is a triangle at the front or leading edge and back or trailing edge of each wing. The center of the wing is ideally the center of gravity of the plane for balancing the controls. Imagine balancing a long tray with a glass on it on your finger. It's easiest if the glass or downward force balances the upward force from your finger. If you move the glass to away from your finger the tray will want to tip. So if the flight's not full a flight crew member might ask you to move between these rows to distribute the load for easier control of the plane which translates to less drag and better fuel efficiency as well. It's also a quick way to spot which window shade to pull up if the crew needs to inspect the wing during flight. Number nine. The flange sticking out of the wing. While you're waiting to leave the gate you're probably staring out the window at the wings that are going to carry you off this earth. On some aircraft like the A320 you might notice some metal stubs sticking out of the middle of the wing like a sore thumb. No, that's not for lifting the plane. This is part of the evacuation system. If the plane is forced to land somewhere that you can't use the stairs or the terminal boarding bridge the crew will deploy inflatable chutes from the emergency exits. But if you use one of the over-wing exits you'll have to step out onto a slippery metal surface. Those stubs or wing flanges are anchors for tying guide ropes. That little stub will guide you safely off the wing without stubbing your toe. Number eight. The hum when you board the plane. Have you ever noticed that there's an omnipresent drone when you're waiting for the last passenger to board the plane? (droning hum) The engines aren't powered up yet but something is running. That's the sound of the auxiliary power unit or APU. The APU is what provides electricity to the plane temporarily between the time the plane unplugs from the terminal until it is ready for take-off. The APU is usually a small turbine that powers a generator for electricity and a compressor for air pressure. The APU powers everything from the cabin lights and fans up to starting the main engine. It even provides a fire protection system. This system uses less fuel than running the main engine since it's only designed for cabin operations not for driving the plane. The flight crew will start the APU before letting any passengers board so you can sit in comfort and safety while they prepare the plane for departure. If you pay attention you can see the lights dim temporarily and hear when they switch from terminal power to APU. Now you know why your movie was interrupted for a few moments. Number seven. Tomato Juice. Do you find yourself ordering a tomato juice when you're on a plane? Ever wonder why you suddenly crave a salty vegetable drink that you wouldn't give a second glance to on the ground? It's the same reason you think airline food is bland. Everything on board a plane is conspiring against enjoying the food. Scientists have studied this and it's not just your imagination. First, the noise of the engines dulls your ability to taste sweet things. Food scientists at Cornell found out that sound levels at 85 dB, the same level as airplane engines, reduce the effect of sweetness on tastebuds. And that fan over your head is blowing air that is much drier than you're probably used to at home. Lower humidity means you can't smell as well. On top of that, as the plane climbs to cruising altitude the pressure inside drops. You feel that when you pop your ears. That pressure drop affects your sense of taste too. So next time you wonder whether to order the fish or the chicken, just order a Bloody Mary with extra Tabasco and savor that serving of tasty tomato. Number six. Opening window shades for landings and take-offs. I bet you thought the window shades were installed on planes so you could sleep during long flights. But then the flight attendant asks you to open the shade before take-off and when they're going to land. Ha! Why don't they just look out their own window? Yes, the shades are there to give passengers control over their own environment, but safety takes priority over comfort. The most critical part of any flight is when it's near the ground. Those windows aren't just there for sightseeing. If something happens to the power on board the only light besides the illuminated arrows to the exits will come from the windows. And if someone has to open an emergency exit then need to check outside for debris, fire, water, or other hazards first. The Federal Aviation Administration requires that planes can be evacuated within 90 seconds. So remember that window shades work both ways and make sure yours is up whenever taking off or landing. It will give you a great view before you're too high to see the sights. And it might just help you see your way to the door in an emergency. Number five. Winglets. Airplanes are always a tug of war between the thrust of the engines and aerodynamic drag. One big source of drag is something you might not see unless the temperature and humidity are just right. Have you ever noticed little swirls of mist trailing from the wingtips. Those are wingtip vortices. These little whirlwinds tug at the tips of the wings as the smooth layer of air flowing over the wing that gives it lift breaks away. Every tug is like a dog pulling at your pant legs as you're trying to walk. Slowing you down and wasting energy. On a plane, that translates into fuel. Those little winglets sticking up at the end of the wing stop the vortex from forming which reduces drag and saves fuel, which saves you money. Number four. Side stick. Back in the day of the first planes pilots were known as stick and rudder men steering the plane by the power of their arms and legs pushing on control cables. Those planes were much smaller and flew much slower than your modern jet though. Commercial aircraft are designed with electronic systems that take fingertip commands from the flight deck to massive ailerons that would dwarf that first balsa wood plane at Kitty Hawk. These fly by wire systems are controlled using a side stick that looks like the joystick from a computer game, giving today's pilots an ergonomic replacement for battling that old steering column. The side sticks are actually linked together so the pilot and co-pilot can both roll and pitch the plane. Now don't think they're battling each other like a video game. There is a button to choose which pilot is in control. It's got a few more buttons including a push to talk button for talking on the radio and another for switching the autopilot on or off. It has built in sensors that allow the pilot or co-pilot to take immediate control by applying sufficient pressure. Don't worry. It's also connected to warning lights and alarms to notify the pilot when the autopilot is disengaged and which pilot has control. Number three. Bleed air system. While the Wright Brothers' flier barely flew above the dunes at Kitty Hawk, today, jetliners fly higher than the tallest mountains. Climbers talk about the death zone above 3,000 meters. So when the plane reaches cruising altitude, it has to keep enough pressure inside for people to stay alive. Without pressurized air you'd soon be sounding a little drunk before falling asleep as your brain is deprived of oxygen. Now to fly at these rarefied heights part of the design of any high flying airplane is how to keep the air flowing. One source of the pressurized air on jet airliners is called the bleed air system. Bleed air comes from a side port on one of the jet turbines. It is only a small percentage of the air blasting through the jet and is controlled to keep a comfortable atmosphere in the cabin. The air is also heated as it passes through the turbine. Otherwise the cabin would drop to the outside air temperature which is around minus 60 degrees Celsius at 10,000 meters cruising altitude. So that engine hanging off the wing isn't just propelling you forward, it's also supplying you with enough air pressure so you and the flight crew won't pass out. Number two. The eye level indicator on cockpit window. Pilots come in all sizes, and just like your car, planes have adjustable seats for them. And just like you might use the hood ornament as your reference when you adjust your car seat and mirrors pilots have a reference for pilots to make sure they're in the right spot to see their controls and outside. It's called the eye level indicator and it's just a small knob on the cockpit window. While the pilot operates the seat adjustment levers he or she keeps their eye on the little red ball on the indicator until it lines up with the white ball. So that 50% of their view covers outside the window and 50% on their instruments inside. Not only that, this ensures the pilots are positioned so all the controls and switches are in the same place every time they sit down. This low-tech solution is all that's needed to make sure your pilot can gauge approaching objects and reach the appropriate controls to react without taking their eyes off the ball. Number one. The hole in your window. Since cabin pressure is so important you might think a hole in your window is a good thing but if you look closely you'll see every window has one about the size of a strand of spaghetti. That hole let's the pressure between the cabin and the air between the panes equalize. Like your house windows the layers insulate from the extreme cold of high altitude flight. But unlike your house airplane windows have to deal with large changes in pressure as the air climbs and descends. There are actually three layers in an airplane window. The inner pane is plastic and just protects the glass from scratches. The middle pane has the small hole that let's the air between the panes expand and contract, but still provides insulation. If you didn't have the middle pane you'd be looking through a layer of ice as the moisture in the cabin air condenses on the cold outside glass. That's just a few things you might not have known about airplanes. Do you know of any other interesting features of planes? Let me know in the comment section down below. Also please be sure to like this video if you enjoyed it and subscribe, hitting that bell icon to never miss another video. Thanks for watching.

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Keywords: airplane, aircraft, plane, planes, airplanes, aviation, things, top 10, triangle, symbol, symbols, flange, wing, apu, tomato juice, winglets, sidestick, contols, captain, explain, why, how, the purpose of, the reason, window hole, beamazed, be amazed, facts, everyday items, flight, airline, everyday objects, you didn't know, airport, things you didn't know, flights, travel, attendants, how to, interesting, things you did not know the use for, things you don’t know the purpose of

Id: iMkVwr-K4WA

Length: 10min 11sec (611 seconds)

Published: Tue May 23 2017