An aircraft’s Ram Air Turbine is a small auxiliary propellor that can be deployed in the event of a power loss. It works by generating power from the airstream passing over it as the plane flies, causing the turbine to rotate. The turbine can be connected to a generator or a hydraulic pump. This way, it can help to power either an aircraft’s electrical or control systems.
According to Skybrary, these devices are typically located in compartments in an aircraft’s wings or fuselage. The amount of power that a RAT generates is dependent on the speed of the plane at the time of its usage. They work using the concept of ram pressure. The greater the aircraft’s speed, the more power the RAT will generate.
It’s a nifty little creation that you might not know exists, as it’s only ever called for in an emergency scenario such as a loss in power. And it’s pretty good at doing that, with the RAT actually credited with saving as many as 1,700 lives through its deployment over the years.