Introduction

Many people think airplanes today fly mainly on autopilot and are controlled by computers. But every instruction given to an airplane comes from the ground, by voice over the radio. Pilots are not allowed to change direction or altitude or take off or land without permission from the controller on the ground. This keeps planes from colliding.

These instructions are really important, so a procedure is always followed. Air traffic controllers speak instructions over the radio to a specific plane. For example, the controller might say “Air Canada 123, turn right to a heading of 270 degrees.” The pilots flying the Air Canada plane then “read back” the instruction. After they have read back the instruction, the controller confirms that it was read back correctly, usually by saying “Roger” or “that’s correct.”

This project was designed to see how many times this procedure works as it should, and if it works better with some types of flights.