How Fast Does an Airplane Go?

The average commercial airplane flies at a speed of about 600 miles per hour. This means the plane is covering almost 10 miles each minute.

According to the Guinness Book of World Records, the fastest aircraft so far is NASA's X-43A unmanned jet. It flew at more than Mach 9. For comparison, the speed of sound, about 760 miles per hour, is considered Mach 1. In 2004, the X-43A reached speeds of almost 7,000 miles an hour. The fastest jet with an air-breathing pilot, the SR-71, belongs to the United States Air Force. This traveled at more than three times the speed of sound.