Why do planes fly at such high altitude?

Question

It's the simple things I wonder about more than the big complex things. But yeah why do planes fly so high? It's not like they're gonna hit any buildings even at 3000 feet. The tallest thing in the world is a radio antenna and its only 2000 feet high. So why do planes fly at like 10000 feet? Doesn't that just make the engines have to work harder because there's less air up there? And it can't be noise because I work at a place right next to an airport and even when planes come in to land you can rarely hear them.

Answer 1

they fly at high altitude for the following reasons:

1. fuel efficiency. despite the thinner air, a jet makes the most of whats available. be cause the air is less dense, the plane moves through it easier.

2. the jet stream: a high speed wind actually runs at heights between 30-35 thousand feet. if its going your way, it can actually add speed to your aircraft.

3. terrain avoidance: yes most mountains don't reach 30 thousand plus feet in height. making the plane stay above them assures no one hits one.

4. its where the highways in the sky are according to international agreement. so planes wont run into one another, there are areas of separation in height and lateral movement. to keep big planes from hitting little planes that must fly at visual flight rules, they fly higher.

5. its safer for the smaller aviation aircraft. bigger aircraft produce horrible amounts of turbulence in their wakes: by getting them away from the little guys, its safer for the little guys.

6. as stated above, its gets them above the worst of the weather.

7. probably the most important in my book: its a better view up their. you can actually see the shape of lake Michigan from 35 thousand feet.

Answer 2

The higher in altitude you go, the lower the pressure. The lower the pressure, the less resitant the air becomes. Basically just makes everything much more efficient. Also, the higher you are, the more time you have to react to emergencies. So safety then becomes a factor as well in that regard. Then finally, a majority of the weather takes place below 30,000 feet, so it is a great advantage to fly above the weather, both from a safety standpoint and a comfort standpoint. Then finally you have airspace congestion. If you limited all aircraft to fly under 10,000 feet, there would be some real safety concerns, and trying to maintain the new vertical separation standards would become quite dangerous..

Answer 3

The increase in the Earth's circumference at 36,000 feet above sea level is only about 0.08%, so it is not significant for air travel. There are two main reasons for flying at high altitude. The first reason is that it's cheaper. The higher you fly, the thinner the air becomes, and so the less air resistance that you have to overcome to fly. This in turn means less thrust required, and thus less fuel burned. The extreme is when you leave the atmosphere entirely, at which point there is no air resistance and you don't need any thrust to continue moving. At high altitudes, you can fly faster while burning less fuel than at low altitudes. The second key reason is that flying high keeps you above most of the weather, which reduces turbulence and diminishes the likelihood that you'll have to detour or delay a flight. There are some other minor reasons. One other advantage to flying high, for example, is that there's nothing on the ground you can hit. At 36,000 feet, you're above everything, even Mount Everest. This means you can plan and fly routes without worrying about terrain.

Answer 4

With the high price of jet fuel it is fuel efficiency. Jet engines are just more efficient at higher altitudes.
One or two of those other things are a factor but when they generate a flight plan the most important factor is the cost of the flight. If there is a significant weather reason we may opt for a lower altitude or a different route but the overriding reason is cost. 35 years ago when the cost of fuel was much lower we flew lower but as the cost of fuel went up, Pilots and Dispatchers began operating as close to the aircraft's optimum altitude as they can with consideration for ride and safety.

Answer 5

This has to do with the curvature of the earth. Because the earth is a sphere you can travel greater distances in a smaller amount of time. Also because the air is thinner at higher altitudes the plane won't burn fuel as quickly, so this saves the airline money as well.

Answer 6

first, the air is less dense, equals to less drag, equals to more efficient flight.

for jet propelled aricraft, they perform better at higher altitudes because the cooler temperature cools down the jet engines alot faster. less air won't affect efficiency as jet engines work based on the compression-combustion idea.

also, the loud sounds of the jet/gas engines of the aircraft wont disturb people on the ground.

lastly, propeller-based aircraft work better at lower altitude.

Hope this helps, Peace.

Answer 7

because a jet-plane has a longer range if you fly high(this means that flying from A to B, less fuel is needed), while the endurance is not influenced by altitude, while propeller-plane has a longer endurance if flying low altitude, and range is not influenced by altitude,

Answer 8

The aircraft run more efficiently at higher altitudes as the air is thinner which creates less drag and they are more fuel efficient.

Answer 9

The engine uses less fuel at higher altitudes

Answer 10

Less stress on the airframe its much more gas efficient and much smoother I doubt that on a bad weathered day you want to fly right threw the clouds