Air
they fly
Jet airplanes fly at high altitudes because it is more fuel efficient. Flying at higher altitudes uses less fuel than flying at lower altitudes.
ALL aircraft fly in the Troposphere regardless of distance.
Jet exhaust, which is now mostly hot air.
The fact that jet airplanes' contrails form cirrus clouds suggests that they fly at altitudes where the temperature and humidity are conducive to contrail formation, typically above 20,000 feet. This indicates that jet airplanes generally fly at high altitudes, where the air is colder and less dense, allowing contrails to persist and spread out into cirrus clouds.
Jet aircraft generally fly above FL300 (30,000ft) to maximise efficiency. Not just fuel efficiency but also to minimise flight time.
on airplanes yes... in space sort of... if you had a jet pack... but sadly people can't fly like birds yet. =(
Commercial, jet engined aircraft, such as the 747, fly at approximately 40 000 feet. Propeller aircraft fly at lower altitudes
hyuikk465
The stratosphere
To be an airplane with jet engines? All jet airplanes leave contrails.
I would say the engine turbines, because that's what powers the jet and without it the plane wont fly long or even fly at all!