Connected to a hydraulic pump or electric generator, the ram air turbine (known as a RAT) is a small wind turbine installed on an aircraft and used as a power source. Generating power by airstream, the RAT can create energy due to the aircraft’s speed. Modern aircraft today generally would only use a RAT in an emergency, in cases where primary or auxiliary power sources are lost. In these scenarios, the RAT will power the aircraft most vital systems, such as hydraulics, flight controls, and instrumentation. While some RATs can only produce hydraulic power, this is then converted to power electrical generators.