Abstract
Autopilot is a complex but very interesting system. We're going to tell you about the Autopilot in planes. The Adiru is one of the two parts of an Autopilot, the one that gets information from the outside, such as speed, altitude, etc. and transmits it to the computers that calculates and makes the plane follow the right trajectory according to the pilot's intention. The Adiru is of two parts, the Air Data Module (ADM) and the Inertial Reference Unit (IRU). The ADM is to give to the AP all the data concerning pressure, temperature, and different speeds relative to them. The IRU calculates the exact position of the plane using an Inertial Navigation System (INS), and a GPS, to get an accurate position. In most of the commercial planes today, we can find three different Adiru's. The first one goes to the Captain, the second one to the First Officer, and the last one is for standing by. The three always compare their values, and if one of them gives wrong results coming from wrong calculation or wrong measures, it is directly eliminated for the rest of the flight. Moreover, the three Adiru's have their own set of sensors, so that if a sensor is dead, the unit it belongs to is disconnected.
