Why Do airplanes have to go up at a very high altitude when traveling?

Answer 1

The air is thinner and less wind resistance.

Answer 2

Lots of people think it's a less drag thing due to thinner air. I would disagree.
There are several other beneficial reasons for seeking altitude:
1) fuel efficiency of the jet engine due to cooler air at altitude. There is a tradeoff between reduced density and cooler air for efficiency. Remember, reduced density also affects the lift of the wing so the aircraft has to fly faster at higher altitudes to generate enough lift. Higher speed means more thrust and a tradeoff in fuel economy. There is a sweet spot where the drag, lift and thrust work out to be the best and I think it is somewhere around the Tropopause. After the jets hit the stratosphere at about 35,000ft the temperature doesn't decrease any more so it doesn't make much sense to fly higher to get cooler air because the density will drop off with no temperature reduction benefit.
2) Above the weather and icing conditions and MOST of the turbulence
3) Take advantage of the Jet Stream and higher winds aloft
4) Pilots sound cooler when they say "we have levelled off at 37,000 feet" than when they say "we're scud-running through the fog"

Answer 3

IT IS A FACT THAT THE HIGHER THE ALTITUDE THE LESS DENSE IS THE ATMOSPHERIC AIR. THIS DECREASE IN DENSITY IS RELATED TO THE DECREASE IN ATMOSPHERIC AIR PRESSURE ( p= mg/A). g decreasing with increasing altitude

Therefore the higher the altitude the less the air resistance (drag) . Less drag means more speed and more fuel economy.

The high altitude keeps the plane above clouds and weather disturbances eg cyclonic conditions etc

Noise pollution on ground is minimised.

High altitude tailwinds could be made use of to increase speed and fuel efficiency again.

Of course there are factors that limit the maximum altitude of an aircraft and these include 1. the distance the aircraft is flying 2. The decreasing atmospheric pressure with altitude . The higher it flies the steeper the pressure gradient( inside and outside the aircraft )and the greater the exploding stress on the aircraft's body and frame .

Answer 4

There are many factors that pilots should take into consideration when choosing the cruising altitude, but generally higher is better because the air gets thinner, and with the same amount of indicated airspeed the actual speed of the plane is much higher. Think of it this way: a given amount of air molecules strike the airplane and produce drag. If the molecules are farther away from each other (thinner air), you travel a longer distance hitting the same amount of mulecules. Longer distance in a given time equals higher speed. Higher speed on a given distance (the distance is given between two cities) equals less time, and less time means less fuel consumption and happy passengers.

Answer 5

They don't have to, it's a matter of choice.
1) for commercial service it's more comfortable for passengers because there is less turbulence at higher altitudes.
2) We can avoid most storms by flying over them.
3) As long as an aircraft can catch a tailwind, the higher you go the faster the wind speed, thus a higher ground speed for the aircraft.
4) For jet aircraft the overall performance is better at higher altitudes.

Climbing to cruise at high altitudes is only practical for long haul flights. Commuter flights, & local short haul air carriers will stay at lower altitudes mainly because they may not get to 20 thousand feet or more before they reach their destination, & have to start a decent for landing.
So not all commercial carriers cruise in the stratosphere.

Answer 6

Not all airplanes have to "go up at a very high altitude."

Answer 7

Depends.Jets normally reach higher altitudes,while GA planes fly at lower altitudes.

Answer 8

Cooler Air, More Mas perform best,When you see a jet at low altitude, He is using a lot of fuel.

Answer 9

airplanes fly at High altitudes becasue they redues traffice, less fuel consumption due to thinner air.

Answer 10

The engines are more efficient because the air is thinner, which causes less drag on the airframe to overcome.

Answer 11

yes there are lots of considerations which has to b there before gettin to an altitude......weather....fuel.......distance!!!!!all are important factors in deciding the height......air traffic is also an reason to change altitude!!!!!!!!!