We have 250hr cadets flying right hand seat in an A330 and cripple 7 doing the business all over the world through rain, hail and snow. So I can not believe that a cadet in a Dash 8 would have too much of a problem.
These aircraft are two pilot right? Wouldn't the experienced Captain see things going astray and take over?
Perhaps the training department needs to look at intervention training as well as its line training. If you train people properly it doesn't matter how many hours they have.
the Don