Why do planes fly at 35,000 feet...?

Question

Is it statutory requirement for all flights, and why 35,000 feet? Why not 30,000, or 40,000? Be interested to know.

Thanks

Answer 1

Not all flights fly at 35,000 feet. For one thing, it would result in a lot of mid-air collisions. Flights that are in opposite directions will be assigned different altitudes to keep them separated at a safe distance.

I've been on flights that were anywhere between 29,000 and 42,000 although the mid-thirties are common.

It is based on the type of aircraft, the length of the route, weather, and fuel economy.  Regional jets tend to be routed at lower altitudes because some of them fly slower and they hold up faster jets. A short flight will be routed lower than a long flight because it requires too much fuel to climb to a high altitude only to descend again. Longer flights will often be assigned higher altitudes because aircraft burn less fuel at higher altitudes and it's worth the extra fuel to climb higher.  Sometimes flights will be assigned an altitude in order to avoid turbulence or bad weather at another altitude.

Answer 2

Not sure but I guess it keeps them out of small aircraft's way plus it is above most clouds and bad weather so flies in a calm weather zone which is much safer.

Answer 3

Not all planes fly at 35,000. They can be anywhere from 10,000 up to 41,000. It depends on a few things. In a congested area, Air Traffic Control may ask certain flights to fly at different altitudes to avoid route conflicts, or to bypass weather. Thunderstorms extend farther up into the sky than planes can fly. They can fly under or around them. Altitude also depends on the type of aircraft. Generally, bigger and more powerful planes can fly higher and faster than smaller ones.

Answer 4

Sure i'll tell you

it needs to fly at that distance from earth because if it doesnt it would go straight into space. Remember the earth is round?

If it flies below this, it would be in the clouds or below the clouds and if there is thunder or rain the plane would be damamged

This was a question in my science book so i wrote the answer here

;)

Answer 5

It's not just 35,000. It tends to be between 33 & 38 although concorde flew much higher. An aircrafts speed is limited by it's airspeed, at low altitude an aircraft will be able to do around 350 knots. at very high altitude because the air is so thin that an aircraft doing 350knots would actually be going about 500 knots. Oh and it's better on fuel economy too.

Answer 6

The air is thinner, and so there is less air resistance, meaning better fuel economy.

Answer 7

It is not a statutory requirement to fly at 35,000 feet, it's all down to fuel costs and the optimum flying height.

For every weight of aircraft, there is an optimum flying height, so some will fly at 35, 40 or even 45 thousand feet, a calculation based on the weight of the aircraft, the amount of climbing to do and the distance involved.