Mark James Boyd wrote: [snip] " . . . during a PCC a bellcrank broke and
this was caused by the pressure exerted by the "helper."
Nice to have this happen on the ground, and I can't
think of how this could have been detected without
a PCC. So now I think a PCC is useful too..."

Having a helper exert this much force is good???

I retain my renegade attitude to PCC's - they may be suitable for some
things if done right (and breaking gliders is not doing it right in my
book - the above is not an isolated example) but other checks are far
more useful, and less damaging, for some gliders, e.g. my Ka6E.

Chris N.