3 ms·

I'm not sure if those fuel savings would be worth getting rid of the integrated pre-takeoff engine thrust test, though.

• blackflame 7y ago
  Yea what is generating the power for those motors?
  • imglorp 7y ago
    APU, normally. A smaller turbine generator, just enough to run electrical and hydraulic things, usually, and maybe to start the main engines. I think they shut off APUs after the mains come up. They use almost nothing compared to, say, an Olympus engine on the Concorde at idle.
    • blackflame 7y ago
      An apu doesn't generate nearly enough power to taxi the aircraft. Since a large APU is essentially another turbine, you're back to using a turbine to propel the aircraft. If this really were a place to save money then the simplest solution would just have the tug pull it all the way to the runway. That way the aircraft doesn't need to take on additional weight for motors/apus which will sap fuel economy during flight.