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To elaborate on the question: I know that in modern fossil fuel-driven aircraft turning the engines off during descent and/or landing approach isn't feasible for safety reasons (which makes total sense to me) - but, given that electric engines are quite easy/quick to turn on & off compared to toboprops and turbofans, is it likely that lowering altitude with the engines turned off for a big portion of the descent (let's say, untill an arbitrary altitude would be reached, e.g. 500m or something along those lines) would become a norm in the airline industry?

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    $\begingroup$ The props would need to be fully featherable - otherwise the non-spinning prop blades would create a lot of drag; or the wind blowing would force the props to spin and reverse drive the electric motor, which would also create drag if that was used to create electricity to recharge the batteries, similar to regenerative braking in electric cars. $\endgroup$ – CrossRoads Oct 7 at 14:21
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    $\begingroup$ @CrossRoads during decent that could be desirable, use the potential and kinetic energy to recoup some electrical energy like hybrid cars do. $\endgroup$ – Notts90 Oct 7 at 14:25
  • $\begingroup$ Could be - very situation dependent tho. $\endgroup$ – CrossRoads Oct 7 at 14:42
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It's unlikely the pilot would be switching the "propulsion master" off, but it's very probable that "idle power" on the throttle or thrust lever would in fact be a stopped or stopped/feathered motor. It's likely that regen braking would be electrically available, but it's probably something you wouldn't want to use in flight, for the same reasons you don't engage reverse thrust on jet engines before touchdown (in fact, there are some aircraft where you do, for a subset of the engines, in part because of the time needed to engage reversers).

Having instant throttle response available is very important, so "off" shouldn't be the same "off" you'd use when parking and tying down -- but having genuinely zero thrust could be useful for certain kinds of approaches (others, you want/need to carry some power to ensure you stay enough above stall to maneuver without steepening the glide slope).

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