Raffaello D'Andrea TED talk on quads https://www.youtube.com/watch?v=w2itwFJCgFQ I saw this video posted 2 times on this forum but nobody mentioned what I thought was pretty incredible, which was their algorithm developed to fly a quad on only 2 of the 4 motors. If implemented, it seems like a really great way to save a quad from becoming a 3 pound falling rock just from the loss of a prop or motor. I guess you could lose 2 motors with this algorithm, but I think they would have to be opposing. I've had a shitty DJI-supplied prop nut come off and both times the phantom just fell out of the sky, luckily not too high and over grass. I have since replaced them with locking nuts, but if this algorithm was implemented, it could throw it into a controlled spin to land safely (well, safe to everyone but the phantom, which may suffer damage from landing in a spin) This seems like a huge potential to be part of the puzzle to making quads a lot safer.