We lost a VJ here on the week end and it seems there are some common issues here. The (very capable) pilot turned downwind and the VJ waffled a couple of times after the turn then entered a spin, stopped then spun in the other direction and continued to the inevitable. I estimated the wind speed to be around +20kts, also the temps were up so I am sure air density played a part. I have my own views on downwind turns and aircraft contol and CofG set-up but I shall keep them to myself as I dont want to start an argument, but it seems to me that there is something inherently wrong with the Vipers aerodynamics that make its flight envelope a little unpredictable. It would be nice to know the actual cause of these accidents so other guys dont find out the hard way, it is a very sad thing to witness the demise of a beautiful model.