Depending on how hard you crash will determine your breakage. These parts do bend or break alot.

Main blades
Main shaft

If you hit a little harder then you will need ....

Feathering shafts
Blade holders
The large plastic drive gear

It really depends on the crash I've got quite a few extra parts because not every crash breaks the same part.

I've changed the following

Main Shaft
Blades
Feathering shaft
Blade holders
Drive gear
Tail boom
Belt
Flybar and a few other items I just can't remember them all !!