On Sunday, August 23, 2015 at 5:38:19 PM UTC-4, howard banks wrote:
Nice pictures but what we really need are clear closeups of the fracture surfaces and a clear description of the location of the origin of the fracture and the supporting structure, on the airframe and the undercarriage.

RAS is not the appropriate forum for the ongoing investigating of this failure. I understand that the limited information posted here is going to frustrate some people. I thought it was only fair to give a limited 'heads up'.

I'll say this. Nobody was injured. The failure occurred at 30-35 knots on launch. Towplane ground looped right. Glider went left. Glider pilot pulled the release promptly and never came close to colliding with the towplane.. Glider pilot was holding a lanyard attached to the tow release handle.