Jets generally fly at or above the tropopause because below it, in the troposphere, is where all of Earth's weather occurs and it is best to avoid weather complications so they fly above it.
they fly almost above 15km, where atmospheric pressure is very low.
Some models of fighter jets have flown suborbital trajectories with apogees above 50 miles (80.47 km).
To avoid turbulence, most commercial jets fly in the upper layer of the troposphere, which varies in height depending on latitude, typically 40,000 feet (5 km). This is on the border of the tropopause, just above the troposphere, and the lower layer of the stratosphere in some cases.
Yes, jets are airplanes but they are called supersonic airplanes.
jets
If you mean fly on thermals like some gliders, NO.
No
Most jets actually fly around storms instead of above them. The updrafts which exist above storm clouds are extremely strong and very dangerous to fly in. Commercial jets only fly in the troposphere, at an average altitude of 37,000 feet (11 km). Above that level, the air simply isn't dense enough to produce enough lift for normal aircraft.
No. The fastest wind gust ever recorded in a tornado was 302 mph. By comparison, commercial jets regularly fly at 500 mph. Some fighter jets can fly at over 1,000 mph.
Passenger planes can't fly at 55,000 feet. Gulfstream business jets can fly 51,000 feet altitude, and airliners like to cruise at 35,000 feet. Some military planes, like the U-2, can fly at 55,000 feet or greater.
they have wings and engines