Hilico
Although you'll experience vortex ring in training, and read about it in the books, you're also very welcome to post questions here.
We've had some very good threads which started with a simple student or PPL question.
Someone gives the 'book' answer, somebody else says the 'book' is wrong and .............. etc
pohm1
I agree. It may be more likely to occur at a high rate of descent, but I stand by my 'medium' rate of descent posted above. Although the books often say 500' per minute, I believe it's been known to happen as low as 300 fpm. It will be interesting to see what Nick's page says.