For long range, wide body planes A380 and B777, what is the power generated by RAT (Ram Air Turbine)? And which all are the systems which the RAT drives?

  • $\begingroup$ This will vary substantially between aircraft. It is better if you zoom it in on one model despite there then being several questions. $\endgroup$ Jun 10, 2015 at 11:58
  • $\begingroup$ editted the question to two aircrafts $\endgroup$ Jun 10, 2015 at 12:01

1 Answer 1


According to the Flight Crew Operations Manual of the Boeing 777:


The RAT, when deployed, provides hydraulic power only to the primary flight control components connected to the center hydraulic system.

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Which leaves out:

  • Nose gear
  • Main gear
  • Steering
  • Brakes
  • Flaps
  • Thrust reversers


The RAT powers both C1 TRU and C2 TRU, which powers the captain's and first officer's flight instruments, respectively.

The RAT can supply electrical and hydraulic power simultaneously. However, if the RAT is unable to maintain its RPM, the electrical load is shed and provided by the main battery, until RPM is satisfactory.


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