On Tuesday, February 2, 2016 at 5:02:50 PM UTC-5, Jonathan St. Cloud wrote:
This comment has nothing to do with the latest Nimbus 4DM accident:

However, in regards to some comments about a glider spin developing into a spiral. If you have not had that happen it can be a real surprise. I was spin training in a 2-32 that would do 1/2 turn in a spin and then go in spiral. The sight picture was the same, only different was rudder opposite the rotation did not work. I spotted the problem after about ¾ of a rotation but was very surprised that the spiral did not look any different than the spin I had always assumed I could tell the difference. Now picture this is a slippery modern glider of any wing length, nose 70 degrees down or more. Would very quickly go through VNE.

The most fun flying I have done is in a Nimbus 4D or ASH-25 as a shared experience is the essence of human nature. Two pilots can make one very good flight!

You should be able to tell the difference. Look at your airspeed indicator. In the spin the air speed will be low or at least stable and in the spiral it will be high and quickly increasing. That was the case on all gliders I spanned. Turn and bank indicator ball in the spin will be all the way to the outside of the turn.