carry a knife. >> i know we have marshals on the planes to protect us. >> reporter: the flight attendant union says it will further endanger the passengers. calling the decision dangerous and ill-advised. and these two groups will be challenging the tsa's proposed new rule changes. they have a little more than a month to do it. wolf? >> the box cutters, they obviously will not be allowed under any circumstances, right? >> reporter: that's right. no box cutters. and larger knifes like this one. this particular knife, it looks in place so that the blade doesn't move. very different from a pocket knife. this also will not be allowed but those smaller knives and that sports equipment is enough to generate quite a bit of criticism about the tsa's plans. wolf? >> it doesn't take effect for at least 45 days or something like