♦Commercial aircraft typically have two electric generators for power, called Integrated Drive Generators (IDGs). The third generator is located in the auxiliary power unit (APU) at the tail of the aircraft.

♦If an aircraft’s two main generators fail, the APU generator takes over. If any of these three generators fail, the flight can still receive full power. Even if all three main generators fail, each engine has a backup generator. These backup generators provide AC (alternating current) power to the aircraft’s systems, keeping the engines running.

♦The aircraft is equipped with a computer-based Electrical Load Management System (ELMS) for all types of power management, which determines which generator should be switched on at what time, but if the three main generators and two backup generators also stop working, then the entire load will come on the aircraft’s two Permanent Magnetic Generators (PMG), whose job is to light the small headlights with the movement of the wheels.

♦If PMG power also fails, the last option for power is a ram air turbine (RAT). The RAT system is installed slightly behind the aircraft’s landing gear. Simply put, it’s a wind generator. If all other systems fail, the RAT automatically deploys.

♦RAT generates power by rotating in the air and transmits it to the system, but if for some reason the RAT system also fails then there is no option left to save the aircraft from crashing.