OK ... I have some ideas ... but interested how you lot would attack this from a scratchbuild point.
My vision is a standard light trainer with 3 small props in short shrouds. One out in extremity of each wings span giving lateral and main weight lift, third further back to balance the model.
The two wing units could rotate 90 degrees to give full back thrust and proportional thrust through 90 degrees to vertically down. The rear unit being throttled to balance the two forward ... once full forward flight - the rear unit stops.
Or a forward standard prop with the 3 vertical units, both systems throttled to perform their functions.
OK - over to you lot ... any ideas ?
Remember this is a scratchbuild not a "buy it" solution thread.
(Yes I'm bored !)