Why do planes have to fly above the clouds?

It's ideal to stay out of clouds, but they don't necessarily have to fly above the clouds.

Airplanes don't have to fly above the clouds, but jet-powered commercial airliners are more efficient at high altitudes than they are when close to the ground, so they are flown above the clouds. Flying above the clouds also reduces turbulence from weather, since most of the weather is well below the aircraft. And flying high also makes it possible to fly at higher speeds without using as much fuel.

In fact, flying low, where the air is much thicker, slows down jet airplanes so much that they may have to land early if they are forced to descend lower for any reason. For example, if a pressurization problem forces an airliner to descend to a low altitude, it probably won't have enough fuel to continue to its destination (although it will divert in any case, since flying without pressurization isn't acceptable in a modern airliner).

Small airplanes often fly much lower, well below the clouds. But they also fly very slowly, and they are constantly bounced around by the weather.

You don't. It is possible to fly below the clouds. However, you must think about the jetstream currents, low pressure systems, turbulence, and things of that sort.

Besides the efficiency aspect of the flight above the clouds, think about being the passenger on the airplane. Do you really want to fly for hours looking at nothing but the grayness outside of your window? Also think about the shape of the earth, it is round. The higher you fly the shorter the distance between point a and point b.

Air is thinner- and therefore less resistance=more speed.

Air is less turbulent above clouds.

Plus- it's fun to look DOWN on a cloud.

They don't. Planes fly through clouds all the time.

But clouds tend to contain "bumpiness" that passengers don't like so we try to fly above them to make the ride more comfortable.

It is because most of the weather that could cause problems to the flight are at or below the clouds because that is where they originate from mostly. Calm air and the jetstream are above the clouds allowing planes to fly with ease. Planes dont have to fly above, they choose to.

Aeroplane Above The Clouds

certainly, if the pilot is device rated. it is not uncommon to have cloud ranges to suitable out at 4 or 5 thousand ft. i've got taken off with an 800ft ceiling and been in bright sunshine at 5000 ft many cases. they only can not fly above each and every of the clouds in all situations. the restrictions on altitude on small planes is largely desperate via despite if or or not the engine is turbocharged, which slows the lack of ability of engine means as air stress drops. A non-turbocharged engine will run out of oxygen at relating to a similar altitude that human beings do. In maximum non-rapid plane, finished throttle will produce approximately seventy 5% of sea point means at 7000 to 8000 ft, and could in many cases only enable mountaineering to 13 to fourteen thousand ft. Above that, the human beings decide on oxygen and the engine desires turbocharging.

A few reasons they do.
Howard Hughes said it best, airplanes will fly with more comfort above the weather.
By flying over 18,000 feet they avoid turbulence, at least the majority of it
The benefit from this is thinner air which is less resistance and better fuel economy.
Airliners also are segregated from general aviation for traffic reasons, less of it.
General aviation tends to stay at lower altitudes, under the clouds, but depending on cloud height, we can fly over them for the smoother ride.
Planes dont' have to fly above clouds, it is just smoother.