Yep, perhaps just coanda effect with control surfaces on the bottom. Sort of like what the AESIR guys did: https://www.youtube.com/watch?v=KXVtUCABiv8 https://

Yep, perhaps just coanda effect with control surfaces on the bottom. Sort of like what the AESIR guys did: https://www.youtube.com/watch?v=KXVtUCABiv8 https://www.youtube.com/watch?v=KXVtUCABiv8