As mentioned when i looked at the tail during a stall i was not the pilot. I was a student at the time and my instructor asked me to look at the tail during a stall. It is actualy queit shocking.
I have also heard of the main spar life span. This leave 4 options of explanation of why so many are left in service:
1) There must have been a hell of a lot of Tomahawks made
2) There is no life span on the spar
3) Owner/operators ignor the life span
4) It must be a hideous amount of hours that will take forever to clock up.