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A comment on The age of electric flight is finally upon us. Parent comment

Re:The age of electric flight is finally upon us by mannykannot on Friday June 21, 2019 @02:42PM (#20245244)
In addition to the point verelo raised about the repair/replacement cost of having used a parachute (vs. replacing a motor), I was thinking specifically of a wingtip-motor failure at takeoff (typically the worst-case scenario), possibly too low for a parachute (some figures here: [1]).

This is a 9-passenger airplane, maybe too large for current recovery parachutes? (though I imagine that will change.)

[1] https://www.cirruspilots.org/copa/safety_programs/b/pull_ear...

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Re:The age of electric flight is finally upon us by sandworm101 on Saturday June 22, 2019 @04:25PM (#20251552)
2 parachutes.
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Re:The age of electric flight is finally upon us by mannykannot on Saturday June 22, 2019 @11:32PM (#20253146)
Maybe, but that does not solve low-altitude problems, if indeed there is one. It is possible that two small-airplane sized parachutes will inflate faster than a single larger-airplane parachute, but apparently current small-airplane parachutes do not inflate fast enough to save you at low altitude.

Actually, this has me thinking: not all low-altitude situations are the same - an airplane with a downwards trajectory, such as one in a spiral dive, will need more height to save than one that is in a glide, such as after a power failure. This is why even a zero-zero ejector seat will not always save you, if you are descending rapidly at low altitude.

Even so, replacing a motor, if that is all it takes, is going to be cheaper than repairing or replacing an airframe that has undergone a parachute recovery.

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Re:The age of electric flight is finally upon us by sandworm101 on Sunday June 23, 2019 @09:23PM (#20259848)
https://www.youtube.com/watch?v=jgfG2DfPB6I

(Action starts at about 02:05)

I guess it depends on one's definition of low altitude. Rocket-deployed parachutes open very fast.

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Re:The age of electric flight is finally upon us by mannykannot on Monday June 24, 2019 @07:45AM (#20262498)
With respect to engine failure at takeoff, low altitude begins at the point where, if the engine fails, you will not be able complete a landing on a runway (or overrun area, if there is one.) With respect to my original question, if the remaining engines give sufficient performance, using a parachute would not be the standard response even if you had the height and speed for it to work.
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