There are no hard and fast rules on it, Carol. It can never hurt to let an author know you're doing a FFT based on their story, but you don't have to seek their permission first. Most authors will be only too delighted that you've chosen their story to highlight. Although, purely as a matter of courtesy, if I was going to do a FFT and the author seriously objected, I probably wouldn't, just because there wouldn't seem to be any point if the author was so violently opposed to the idea.
And previous FFTs come more or less under the same umbrella as various authors using a similar theme for a story - just like we have lots of stories that are TOGOM rewrites. Same deal. If you wanted to ask/inform first it might be an extra courtesy, but there's no requirement to do so.
LabRat
