Thank you very much Cardinal. You've shed some light on a part that seems to have passed unnoticed through my TR course. Considering the fact that pilot input, once the overspeed situation has become uncontrollable, is useless, does this warrant shutting donw the engine as soon as it's detected? Having a prop that isn't featharable and an engine that isn't running isn't the best of prospects. If even the slightest bit of power can be produced, would it not be better to keep it running than to possibly end up with a deap prop still in fine pitch. Although, since the feather position on the CL has to be passed to select fuel off , such a situation I guess would not come as a surprise.
I'll need to revise on the PCU and look at the mechanics behind it for the Saab, but thanks again for your reply!
/LnS