The average speed of an airplane depends on the size and type of the airplane. A Boeing 747, which is a popular commercial plane, has a typical cruise speed of .85 Mach or 567 miles per hour when at 35,000 feet.
The average speed of an airplane during takeoff is much lower. A Boeing 737 usually reaches between 155 to 178 miles per hour when lifting off the runway. An airplane's average speed during landing varies depending on conditions and must be determined as many as 10 miles in advance. A speed of 157 miles per hour is typical for a plane such as the Boeing 777.