Did you know RAT is used in the aviation industry by aircraft I am not talking about the animal but about the device which is used by the commercial aircraft Known as Ram Air Turbine (RAT).
It is a small turbine fan used to generate power in the case of failure of the engine or Auxiliary Power Unit (APU) to ensure that the electric system keeps working.
Source Quora
In the worst case, if ย the engines failed then the aircraft's power supply stops but the ย Auxiliary Power Unit (APU) acts as the backup in some cases, APU did not ย work in such a scenario RAT is used to provide power to an electronic ย system
RAM uses the crossing winds to generate power due to this RAT power supply is not fixed it is variable as it depends on Air Speed.ย
But if the power sources are not working then how does Pilot deploy the RAT?
For that aircraft manufacturers provides a backup battery system that helps in the deployment of RAT.
The Airbus A380 has the ย largest RAT which is approximately a diameter of 64 inches that has the ย potential to produce 5 to 70KW of power depending on Air Speed.
How Airlines Ensure Reliable Power Supply for Their Aircraft