Yes, flies work on drift gear. Most of the guys in the Midwest use flies on mono with about 18 inches to 3 feet of leader between the fly and the lead. Not too many of the fatliners around on the smaller rivers. It works awesome. We use wooly boogers, stoneflies, nymphs, streamers, skunks, wigglers, flash flies, egg patterns, etc. If the water is clear, lenghten the leader. Don't tell anyone that this works, or they might try it too. Oh shucks, I spilled the beans. You can tie any of these in the configuration of a jig, using a jig hook and dumbell eyes. I would not run a fly under a float, as the straight or downturned eye will have the fly look like it was lynched at a town hanging. Good luck, it will work.