Charles Gray wrote in message . ..
I've seen a few ideas for Tilt-rotors that involve the idea of using
the props up to about 300 MPH, and then feathering them and folding
them back against the body of the engine, converting ti to a pure
turbofan.
Is this just speculation, or has there been any real work done on
this, and if so, could someone please post a link?
Thanks!

New one on me. Highly doubtful, too, because it's a whole extra
mechanism that you'd have to integrate into a weight-sensitive system,
and the drag that the props would create when they aren't yet folded
but also aren't creating thrust themselves would probably be a killer.
Might as well go for a turbofan-only engine solution and just add a
third one on top of the tail empennage with a downward-vectoring
nozzle for ascents and descents, that you'd have to idle and bring
back to horizontal for ingress/egress.

Hmm. *runs to PTO building*