Frame rate is somewhat irrelevant.
Synching the shutter speed/duration of each frame to rotor revs is what its all about.
For a small fee I'll stop the blades on any heli
Except you all know how to do it now
It also works with many subjects that are at constant speed with constant intervals.
You should be able to figure out then how railway sleepers can appear stationary when filmed from a moving train...
Mickjoebill