3. What is RAT?
A Ram Air Turbine (RAT) is a small turbine that is installed in an aircraft and
used as an alternate or emergency hydraulic or electricalpower source.
The RAT generates power from the airstream based on the speed of the aircraft
and is connected to an electrical generator or to a hydraulic pump.
4. Ingeneral, modern aircraft onlyutilize theRAT in emergency: either in the event of
loss of hydraulic systems or following the loss of primary electrical generation.
Inthese cases the RAT will power vital systems suchas flight controls or flight-critical
instrumentation, navigationand communicationequipment.
5. About the equipment
Provides emergencypower to essential systems whenall enginefails.
Hydraulic power for powered actuationof flight control surfaces.
Electrical power for flight control computers, essential instruments, radio, cockpit
lightning,windshield, and pitot tube de-icing.
6. A typical large RAT on a commercial aircraft can be capable of producing, depending on
the generator, from 5 to 70 kW
Smaller, low airspeed models may generate as little as 400 watts.
The Airbus A380 has the largest RAT propeller in the world at 1.63 metres (5.3 ft) in
diameter
around 80 centimetres (2.6 ft) is more common.
