What are the small 'aircraft' called that give off white gas?

Question

they're always seen in the summer in blue skies really high up in the sky. Thanks!

Answer 1

The "gas" is not gas, it is water vapor called "contrails".  At high altitude, the exhaust gases from the jet engines (of any jet airplane, reguardless of the size), are "firm" enough for water to consense on them.  This condensed water looks white, like a cloud.

Typically the airplanes flying high enough to cause this to happen are jet airliners - they are not small, they are just high up in the sky.  They are actually the bigger planes in the sky.

Answer 2

I don't think its a gas. I think its water vapour (condensation of the cold moisture on the warm exhaust gas molecules).

Answer 3

lol, there only small because they are so high up.

Contrails, produced by jet engine aircraft

Answer 4

Any plane gives off white vapour trails - it depends on the atmospherics and the amount of fuel they are using/dumping.

Answer 5

I think you will find HOTP has hit the nail on the head

Answer 6

I assume you are talking about contrails... These are either fog or ice crystals left in a trail behind the airplane. These happen at certain atmospheric conditions because of the exhaust of aircraft engines. The byproducts of combustion include H20 - good old water. With the low pressure and cold temperatures at high altitude, you don't have to add much water to fully saturate the air and create supersaturated air - like a cloud or fog. The engine takes the cold air, heats it up so it can hold more water before making fog and combusts that air in the engine. The exhaust then exits the engine at a warm temperature, but quickly cools in the aft section of the engine and after leaving the engine. As it cools, "fog" forms (typically then turns to ice crystals) and leaves a contrail behind the aircraft. These eventually disapate as the air mixes with the air near it.

Answer 7

They are not small planes they are just far away

Answer 8

Figments of your imagination!