When they fly, they basically turn horizontal, relying on body lift + vectored thrust. They're small enough, with high enough power/weight ratios, that that's enough. Apparently there's no need for a tilt-rotor, because the whole airplane becomes a tilt-rotor.
Similar principal as cruise missiles, which have short stubby wings to augment body lift + vectored thrust. When the airframe gets light enough, you don't need much in the way of wings.
There were a few drawbacks. It required a seat that pivoted 90° forward, so that when pilots could see when taking off and when landing.
Unpowered landings would inevitably result in damage to the airframe.
Powered landings looked like space-x rockets, and were at the time difficult to pull off, as their instrumentation and and flight systems weren't developed enough to reliably land vertically.
They noted the airframe would have a habit of spinning when hovering vertically.
It was cancelled after a failed test flight, but with modern technology I think one could be built flightworthy.
The plane does look cool, and would fulfill a critical role of a jet aircraft that can be launched without a runway.
Note that most of the downsides there relate to having a pilot that you want to survive in an emergency. Get rid of the pilot, and you get rid of a lot of constraints on size, weight, G-forces, survivability, emergency response, etc.
That thing is amazing. I suspect optimised for shorter distance and dynamism, whereas I think the 280 is basically a faster helicopter that can cruise longer distance? Not expert, just wondered about the tradeoffs given the relatively bad safety record of the v22 Osprey it replaces. So this is an Osprey, but better and safer because simpler mechanics.
On new approaches, I saw something about new US missile research where they get rid of the fins and point the nose to turn. My Google-fu is failing me though.
