Fast Prop Planes
For RC, the average speed of quarter 40 racing plane is about 175-190 mph. Some of the FAI Racing planes that are used on an International basis are around the 200 mph range.
There are also non-racing type planes like the Diamond Dust and Whiplash that fall in the 120-200 mph range depending on the engine used.
Not thats its never been done, but there are few prop RC planes that have seen 200+ mph. Its very difficult to get a plane up to those speeds, let alone be able to fly it.