--- title: Why planes fly — a lesson of Mova's school · trees and pragmatics description: «Why planes fly», a lesson of the technology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: This upward push is called lift. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/) / Why planes fly # Why planes fly Lesson 22 of the technology course of Mova's primary school: 15 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/technology/22-why-planes-fly/). - [1](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/1/) — This upward push is called lift. - [2](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/2/) — Fly a kite on a windy day: its face is tilted into the wind, so it turns the rushing air downwards, and the air pushes the kite up into the sky. - [3](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/3/) — A wing does the same, only it is far better shaped and the plane itself races through the air. - [5](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/5/) — High up the air is thin and freezing, so the cabin is pumped full of air, the pilots and computers watch every number, and the wings even bend and change shape on purpose. - [7](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/7/) — A big jet must travel at around 250 to 300 km/h along the runway before it can lift off. - [8](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/8/) — A jet engine sucks air in with a big fan, squeezes it, burns fuel in it and blasts hot gas out of the back; in a modern airliner engine most of the push comes from the big fan at the front. - [9](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/9/) — Pilots fly with a stick or yoke, pedals and throttles, and read screens showing speed, height and direction; an airliner always has two pilots, and on many airlines they eat different meals so that one bad meal cannot make both ill. - [10](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/10/) — An autopilot is a computer that holds height, speed and direction and follows a planned route, while the pilots watch and take over; some planes can even land themselves in thick fog. - [11](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/11/) — Flaps and slats slide out of the wing at take-off and landing, making it bigger and more curved so the plane can fly slowly without falling. - [12](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/12/) — Turbulence is bumpy air, like waves in the sky; planes are built to handle much worse, and the wings bend upwards a lot in flight on purpose. - [13](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/13/) — Keeping your seat belt fastened whenever you are seated protects you if the plane hits sudden bumps. - [15](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/15/) — The cabin is pumped full of air, but its pressure is still lower than on the ground, so ears pop as the plane climbs and descends; swallowing, yawning or sucking a sweet helps. - [16](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/16/) — If the cabin loses pressure, oxygen masks drop down, because in the thin air up there a person without a mask soon passes out; adults put their own mask on first, so they stay awake to help others, and the masks last long enough for the plane to descend to thicker air. - [17](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/17/) — A glider has no engine; it is towed up and then floats on rising warm air, and gliders can stay up for hours and fly hundreds of kilometres. - [18](https://md.mova.elamur.ai/free/en/corpora/school/technology/22-why-planes-fly/18/) — Most airliners have 2 engines, and some very big ones have 4. - ← previous: [Trains and the Underground](https://md.mova.elamur.ai/free/en/corpora/school/technology/21-trains-and-the-underground/) - next →: [Airports, the black box, helicopters and drones](https://md.mova.elamur.ai/free/en/corpora/school/technology/23-airports-black-box-helicopters-drones/) - ↑ back to [Technology](https://md.mova.elamur.ai/free/en/corpora/school/technology/)