More info tomorrow...
RVDT, I'll pass on the requests to the engineers in the morning...
The wear from the elements (lack of TLC) is normal for our heli's operating in the bush in Southern Africa. Lots of landings on dirt/sand and it takes a bit of the T out of the TLC. Most of the "corrosion" is more dirt than anything else. As for having an engineer to do an inspection after the last flight every day... that's a luxury that only happens in the "real world". The helicopters in question operate at seperate locations and it was definately not a FOD intake. Both have very similar marking with the B model starting a crack on the spar. "Just to warn others doing a preflight: the tail rotor check on the spar (pushing both blades to hear the creak of a crack) was only heard on every 15-20th time it was pushed."
Both machines are used for adventure flights and are never overloaded: B taking off with a max of 35% fuel and the B2 with 40% max. with the pedals never being pushed to the end of the full travel limits.
Flights varying from 5-15 minutes in length.
Both problems were picked up as the machines were coming up for the MPI. Riggings were done by the same company who says it has to be pilot error. I'll have to get the log cards from both to check those out and start the process of elimination.
Spoke to another engineer about it today, showed him the pics and we went push/pull again on one of his machines, and he says rigging - no other possibly way. The problem is, how can we check the rigging since both tail rotors were taken off before we were told about it?
Both tail rotors felt balanced with no unusual vibrationsand both pilots weren't aware of any unusual knocking etc. being experienced while flying.