Many thanks to all for the responses and its been interestign doing abit more research
In my opinion (a very humble one when it comes to aerodynamics and strcutures) it seem to be one of those ideas that looks really good in theory but when it comes to implemntation there are alot of issues thata dd up to make it perhaps less satisfactory than the conventional one;_
Wetted area not very different
complicated airflow between the tail surfaces at the fuselage join
very complciated control mechanism to deal with the two operating modes
Again many thanks, it does make for a neat and attractice design on the Bonanza tho so i can see why Beech liked the idea and gave it a go
PB