The Dash 8, (for reasons which I never fully understood
Would it have been because the DHC8 was to be a miniature DHC7, i.e. the -7 was a 50 seater and the -8 a 36 seater, then the -8 became a 50 seater, then something like a 60 seater and it took a lot of years before it became something like a 70 seater.