I remember having flown on the Dash 7 with Time Air (now part of Canadian Regional) numerous times and Air BC a few times, too. I flew on them mostly between Edmonton City Centre Airport, then called Edmonton Municipal Airport (YXD), and Grande Prairie (YQU), Alberta.
These things were designed for STOL (Short Take Off and Landing) performance, so it could operate out of airports with short runways. I do remember them being able to take off and land while using no more runway space than a Cessna 172 could!
Trouble was, the plane wasn't terribly fuel efficient compared to the twin-engined turboprops like the Fokker F27. It had four engines, that's why. Not to mention that it was loud and vibrated not much differently than a really small plane. The seats weren't very comfortable, either the last time I flew on one(YVR-SEA return, AirBC, 1989). When the Dash 8-300 came along, being a stretched version of the Series 100, it sounded the death knell for the Dash 7. The Dash 8-300 can carry up to 50 passengers - similar to a Dash 7's capacity. Two engines obviously offered better fuel economy than four and the Dash 8-300 had better range than the Dash 7, too. Both AirBC and Time Air were quick to replace their Dash 7s with Dash 8-300s along with Dash 8-100s (AirBC, however, didn't really order the Series 300 until later, and not as many as Time Air did).
This photo below shows a Dash 7 in DeHavilland Canada (its manufacturer) colors.
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Photo © Pierre Langlois