"The airmule thing is now doing level flight tests. Still tethered and not out of ground effect yethttps://www.youtube.com/watch?v=s94JDmwlZZoThis should be possible to replicate at hobby scale, need some featherweight servos on the vanes, and two big…"

"Regular ducted fan will still chop up birds and fingers no problem, even if its a lot safer than exposed propellers. This thing looks like combining ducted fan benefits with the efficiency of a large props, and also has extra safety because of the…"

"There is an interesting variation of a "ducted fan" - search for Urban Aero airmule.They have only two large props in the fan, and they achieve control by perpendicular vanes in front of the fans.This _should_ be doable with two feather servos…"