Just happened on this topic I hadn't seen before. Here's what I can add to the subject.
riggerrob said:
For many years, Purcell ran a consulting firm know as "Flightsail."
Actually the name of Purcell's firm was Flight Dynamics Inc., based in Raleigh, North Carolina. Thomas H. Purcell, Jr. had previously worked as a design engineer for the Bensen Aircraft Corp. "Flightsail" was the name he gave to the whole series of captive glider designs he produced in the 1960s and 1970s. Despite some likeness to the Rogallo wing design, the
Flightsail series were not considered strictly as Rogallo wing types because there's very little billow in the sail.
The
Flightsail VII, however, was quite a different bird. It was a two-seat recreational high-wing cabin monoplane amphibian flown in 1970 and marketed as plans.
Apart from these, Flight Dynamics designed and sold plans in the 1960s for a captive helicopter, a VTOL trainer and a helicopter skycrane, although there is no evidence that any of these ever made it to a real-life flying article. In the 1970s they also marketed plans for the
Seagull flexwing hang glider/float-equipped tow glider and the
Seasprite twin-hulled captive aircraft.
After the demise of Flight Dynamics, Purcell designed and built yet another design in 1990, the X-11
Pelican, an amphibian with pylon-mounted tractor Rotax engine and inverted V-tail.
[Could this topic be renamed "Thomas H. Purcell's 'Flightsails' and other designs", maybe?]