You should probably take a look at this NTSB report:
http://www.ntsb.gov/ntsb/brief.asp?e...06X00741&key=1
A SF34 Captain moved the power levers below flight idle and the result was overspeed / overtorque ... the rest is history
It's very simple to develop the NP overspeed in the saab 340, there is a bottoming governor on the CT7-9B (saab 340b, don't know the CT7 design, i i only fly the B) - when engaged the power lever change the blade angle. That alone can result in an overtorque and in some condition in overspeed. Hope i managed to give you the information needed.
Kids, don't try this at home
