I'm see some reoccurring problems on private, commercial and CFI helicopter rides. They are basic knowledge and stick skills issues or in other words, things that should be a problem by check ride time. So let me get on with it.....
Oral: Emergency procedures. For example: Low G recover, Recovery from RBS, Settling with power and LTE. With the exception of Settling with Power, we can't train and test these so it's imperative that we know how to recover correctly from memory.
Flight: Auto-rotations: Number 1 failure item, failure to maintain RRPM within limits. Number 2 item, failure to establish a stabilized Auto-rotation. I usually see an unstable auto on the 180s. Poor pitch control leading to poor airspeed control and chasing RRPM are usually the result.