credit: daveswarbirds.com
As a side issue, it does seem that autorotative flight training is limited by descent time. Would it not be beneficial to keep a few small autogyros and use them to gain longer experience of flight with unpowered rotor? I suppose the surviving autogyros are now in museums, but could not some designs be put back into production for training and sport purposes?
Did I just want to break up the discussion with a nice piccie? Er, yes m'lud, guilty as charged.