This is just a study from a NASA engineering team for a VTOL personal air vehicle. It has an unusual tail sitter arrangement like the experimental Lockheed XFV but there are some very interesting innovations that may transform the dead end that Lockheed engineers faced to a successful vehicle.---
As you can see from the screenshots or better yet from the very good animation video below, the 'Puffin' uses a split tail to form a very wide standing base. Even better, the pilot instead of sitting with its back down on launch and standing in flight like the XFV, he (or she) now is standing upright on take - off and he is laying down like piloting a hand-glider in flight. This is an overall much more comfortable position especially in the crucial stages of take-off and landing.
The puffin uses electric propulsion and its rotors have a strange two plane blade arrangement. The electric motors can spool to two different speeds resulting 400 ft/sec blade tip speed at hover and 200 ft/sec at cruise. This concept allows a more efficient energy management and also lower overall noise (by 30-40db in flight). A similar in principal two speed rotor used in the A160 Hummingbird unmanned helicopter gives it a record braking 24h loiter time.
