# How fast do airplanes go?

Speed varies from plane to plane but average speed of a plane is five hundred and eighty miles per hour.

Jet airlines can fly at the speed of 600 mph. And some others can go at the 2000 mph. It depends from aircraft to aircraft. Small jet planes can travel faster than the large passenger jet planes. The take-off speed varies for every aircraft. The speed of planes depends on its designing, load, height above sea level, temperature and winds. Most jet airplanes take-off at the speed of 150 to 180 miles per hour.

Commercial jet planes can have the speed ranging five hundred to six hundred miles per hour on the ground but in the air usually the speed remains constant and can reach up to 650 miles per hour If the winds are too strong.

Pilots usually measure the speed as â€œmachâ€ which is the percentage of sound speed. Speed of sound is mach 1. But it is not fixed speed it varies according to the air pressure. Mach 1 is approximately equal to 663 mph. Airlines planes go mostly at the speed of mach 0.7. Military planes can go up to the speed of mach 5.

According to the Guinness Book of records the fastest speed of an airplane recorded is 2193 miles per hour or 4520 miles per hour according to the World Book of Encyclopedia.