AF would not have flown into this large cell if they had an opperable radar. Maybe the radar lost sensitivity and made that cell look benign. I had an MD80 flight one day with a radome with a lot of cracks and delamination that was worthless in bad weather. I finally gave up and asked the controller for a suggested course. He said it doesn't really matter because you are in the middle of it. Thank God that is not the norm but I can see AF having the same situation.