When I did the Robinson Safety Course I believe Richard said that the top 3 were;
- CFIT
- Loss of rotor RPM control
- Wire strikes
I think these were derived from US stats where wire strikes are more common because they hoon around at zip feet. Not sure if these are Robinson only stats, but I'd bet they're fairly consistent across all makes.
I guess (like a lot of stats) you can read them more than one way. Was an engine failure followed by loss of rotor rpm control by the pilot a hardware or warmware problem?
Do your walkrounds, make sure the machine is well maintained, fly within your limits and weather conditions - live long and prosper!