Martin Hollmann is one of the best known aircraft designers in the world. He was the president of Aircraft Designs, Inc. and a past Federal Aviation Administration (FAA), Consultant Designated Engineering Representative (DER). His goal was to make flying safe. He worked on uncountable aircraft.
In 1974, he designed his two-seat gyroplane, which has now a permanent place at the Hiller Aviation Museum, San Carols, CA. Later he built and flew his Bumble Bee. They are still flying to this day. The plans for both are still for sale.
In 1993, he designed the Stallion. He sold kits and some people are still working on it.
The four place prototype is now for sale. AircraftDesigns.com