This thread wouldn't be complete without mention of the
Mini-500.
Re: the Helistat, its spiritual successor the
Skyhook International JHL-40 -- which was to have used four complete CH-47 drivetrains -- appears to have gone the way of every other heavylift airship concept, with the original 2012 EIS date long forgotten and with the program now on indefinite hold pending the availability of $100M of public funding...
I/C