Jo Despretz lived in France. He also had the dream of flight, but not the finances to do it the classic way. So he was inventive and he designed and build his own tandemwing. It became the Jidney J-13 Flash in 1963.
When you compare it to the work of Peyret, Payen and Mignet, you will notice the difference. Despretz choose to place the front wing low.
Despretz first used a rough wind tunnel to get data about his proposal.
He constructed this tandemwing in 400 hours in 3 months time. The engine was a small 45 HP Zlinska Percy II 4 cylinder engine.
The first edition had a front wing span of 4,6 m and a rear wing span of 5,5 m. The first edition had a central front wheel, a tail wheel and two wingtip supports (no wheels, just material that glided over the ground).
Here you see the first edition with short wings and central landing gear with wingtip supports.
Later he added extra wing surface to get a bit more performance. Front 5,8 m, rear 6,7 m. And he added a trigear landing gear.
