This Is What Pilots Do When A Commercial Airplane Loses All Electric Power

ram air turbine (1)

All commercial airplanes have a backup for everything. A backup engine, auxiliary fuel pumps, dual spark plugs, dual electrical displays, and circuitry, so the chances of aircraft accident are very very rare.

Source: Aeronaves & Manutenção

But how is it managed? What happens in a scenario where even the backups fail? What happens when an airplane loses all sort of power, particularly electrical power.

Source: Aeronaves & Manutenção

An aircraft would lose all electrical power when all its batteries and the auxiliary power unit (APU) fails. For an unfortunate situation like this, all commercial airplanes are equipped with a Ram Air Turbine (RAT). The air turbine pops out of the bottom of aircraft and generates electricity from the airstream by ram pressure due to the speed of the plane. The RAT is essentially a mini wind turbine.

Source: ArcAir

The best part of using a RAT instead of a backup APU is that it will never run out of power as long as the plane is flying requiring no fuel at all. It provides a reliable operation on demand, with full flight envelope performance at a very low cost. The Ram air turbine deploys automatically when power on board is insufficient. It drops by a spring load mechanism and gravity.

Source: Aircraft systems

When the RAT is in use as the power supply, the plane runs in an extreme low-power mode. There is no in-flight entertainment and no lighting. The power produced by the ram air turbine is enough to run basic navigation, basic fly by wire, and limited control of flight surfaces. The power, however, is sufficient for an emergency landing.

Source: Code 7700

So this is how pilots save the day!


  1. etv Reply

    Typically, you’ll want to land with full flaps; most pilots do that anyway, but it will help slow the aircraft during rollout.

  2. JB Reply

    Andrew, James is just trying to shift the credit to the aeronautical engineers who really deserve the credit instead of the pilot. He was not referring to someone on the plane. The article says it deploys automatically so the pilot has nothing to do with it and the device would not even be there if not for the engineer that included it in the airplanes design?. I hope you will apologize and think twice before calling someone a fool next time.

  3. Jan Reply

    As far as I am concerned, not all commercial airplanes have RAT. Certainly not B737.

  4. james Reply

    this is how pilots save the day ? seriously not the engineers or anything

    • Andrew Reply

      What do you expect James. If this is the only equipment readily available, of course the pilot had to use with all his abilities to save lives onboard. I suppose you won’t understand anyway as you’re not a trained pilot. Plus majority of flights nowadays does not have an engineer during flight, just the pilot and the co-pilot. Please…for fuck sake….use some general knowledge instead of making yourself look like a fool here. To those who click FAIL and LOL, you guys are pathetic as well.

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