what is the white line left in the sky after aeroplanes? and how come only some aeroplanes leave this trail?

Answer 1

water vapour

Answer 2

There's 2 answers. Firstly it can be the engines which burn fuel to produce CO2 and H20. If the air is dry enough then it will just hold the extra water and be invisible. If the air is moist then the extra water will be visible vapour and is basically starting to form clouds.

It's also caused when moist air flows over the wing. As the pressure of the air is changed by the wing then it can hold less water so some is released as visible vapour. It is more likely to form at the wing tip and you can sometimes see it while you are in the plane if you watch the wing. Again you are most likely to see it when the air humidity is almost enough to cause clouds. If you are in a plane above clouds then watch the wing as you descend to land and you should see it just before you enter the cloud bank.

It's very simmilar to the way that clouds form as air is pushed over mountains. And for an example of this look at http://www.geocities.com/sukla_dasgupta/Photographs/cloud_over_mountain.jpg

Answer 3

It is water vapour and can be seen when the atmospheric conditions are right. If you can imagine your standing on a small rowing boat holding a large rock and you throw it as hard as you can off the back of the boat you will find that the boat will move opposite to the direction you threw the rock. jet planes work in a similar fashion, not only does a jet engine burn jet fuel and produce thrust which prop ells the plane forward, they very cleverly inject water into this thrust which increases the weight thrown out of the engine and therefore providing more power to the aeroplane. hope this helps

Answer 4

so as that phenomenon is called a contrail ( a condensed version of "Condensation path") and your grandpa isn't too a ways off. truly even as an airplane is going by skill of the sky the nice and comfortable exhaust from its engines may reason water to condense right into a path in the back of the airplane. If the air is chilly sufficient, and the airplane is severe sufficient then those trails grow to be ice, and are available into view to us, way down lower than.

Answer 5

fumes after leaving the aircraft are warm but the air up there is very cold so when this happens white cloud of condensation trails the plane creating low pressure known as a contrail. if low pressure is at 27000ft then the contrail will appear at around 27000ft depending on the size of the aircraft.

Answer 6

It's a scratch left in the paint up there when the tailfin (the bit that sticks up at the back) goes up a bit too high

Vapour trail left by the burnt fuel from the engines

Answer 7

Ice crystals. When hydrocarbon fuels are burnt, they give off water as a by-product. At altitude, (dependant on temperature)this water freezes behind the aircraft leaving the vapour or contrails behind. Saw one yesterday that must have been 20 miles long. Must have been really cold up there.

Answer 8

Jets burn fuel, which is a hydrocarbon. When it burns it produces water vapour. (Look at you car exhaust when you first start it.) That water vapour, under the right circumstances of pressure, temperature and humidity, condenses to visible water, hence teh vapour or contrails you see in the sky. Propeller aircraft do not normally fly at the height of jets and so rarely encounter the correct conditions of pressure, humidity and temperature

Answer 9

vapour trails caused by hot fumes coming out of the engines at high altitudes where air temp is about -40, The lower it gets the warmer the air so no trails.

Answer 10

This is called vapour trail. this is caused by cool air usally about 20000 feet depending on the temperature up in the sky

Answer 11

its condensation primarily and all planes leave the trail but it all depends on height if you dont see a trail and on another you do its because the one that has no trail is on a lower flight path and conditions are not so cold as to produce vapour