Hawker Siddeley HS 748

As used by Mt Cook Airlines in NZ

The HS 748 was developed during the late 1950s as a move to re-orient the company towards the civil and export markets. Powered by the popular Rolls-Royce Dart turboprop engine, it was specifically designed as a modern feederliner to act as a replacement for the aging Douglas DC-3s then in widespread service. 

Originally intended to seat a smaller number of passengers, market research indicated that a seating capacity of around 40 passengers would be optimal for the type. As a means to differentiate the new airliner from competitors, it was designed to possess a high level of performance, including its short takeoff and landing (STOL) capabilities and overall ruggedness. First flying on 24 June 1960, the series 1 HS 748 entered revenue service in 1961. A total of 360 were built to 1988.

For lots more, see the book The Aircraft of Air New Zealand and affiliates since 1940.