I don't know how many on the forum remember but, although I was the “conceptual” designer of the Sparrowhawk, Chuck Beaty and Ernie Boyette were truly the fathers.
I was the COO of Groen Brothers Aviation at the time. I remember reading repeated stories about fatal accidents involving the RAF 2000. We (GBA) asked Don LaFleur and Dan Haseloh to allow us to design some changes for the RAF 2000. We offered pro bono publico engineering support for the endeavor. Don and Dan turned us down. They indicated that the RAF 2000 was perfectly safe as it was and that even a horizontal stabilizer would “spoil” its handling.
At the time, I owned a RAF 2000 with a not very effective horizontal stabilizer. I had long admired how Ernie and Chuck had designed the Dominator. I called Ernie and told him I planned to have our engineering staff design and fabricate a RAF 2000 modification kit using my RAF as the test bed. Ernie said, “go for it.”
I sketched a side view of a RAF with drop keel, inverted PSRU, and a landing gear high enough to make it work. It looked like an enclosed, rather ugly, Dominator.
I turned the sketch over to our engineers and asked them to devote some time to the new project. We were working hard on the Hawk 5 project so bleeding off engineering assets was painful. It was worth it.
Early on in the design effort it became apparent that we could/should continue the project to include a complete aircraft. American Autogyros Inc. was formed in Buckeye, Arizona, as a division of GBA, in 2002. I believe I did the first test flight in 2003.
This abbreviated timeline of Sparrowhawk development is an attempt to explain the debt we owe to Chuck and Ernie for their inspiration. I've lost touch with both of them, but I wish them well and thank them for their help over the years.
Jim