Those turboprop planes don't fly as high as turbofan plane. The Dash-8 tops out at around 25-27k ft. compared to ~40k ft. for most modern jetliners. When you a

Those turboprop planes don't fly as high as turbofan plane. The Dash-8 tops out at around 25-27k ft. compared to ~40k ft. for most modern jetliners. When you are going over the alps, that extra altitude can really help.