paperwork strikes again!
I was once in the same perdicament with a bolkow. For years installing the duals was no problem. Im fact, did it in front of the rule makers.
Then the rules changed.
Commercial helicopter- pilot can do it with E.M.T. (maintenace task training)
Private helicopter single engine. Pilot can do it in accordance with the regs.
"Wait a minute" I am told one day. "your Bolkow has two engines and is privetly registered,"
"yaa so what" I says
"well you dont fit into either catagory" "so you cant do it"
"so you mean to tell me cause this aircraft has two engines I cant put the duals in"
"yes sir"
I am still confused to this day