The prototype Dart-engined Herald made its first flight on 11 March 1958 and the first production Herald Series 100 flew on 30 October 1959. The Series 100 accommodated between 38 and 47 passengers. The Series 200 was the main production version with a forward fuselage 1.07m longer than that of the Series 100. Accommodation was provided for 50-56 passengers.
The Series 300 (a modified Series 200 developed to meet US airworthiness requirements) was followed by the Series 400 military transport with a side loading door and accommodation for 50 troops, paratroops, 24 stretchers or freight, eight of which went to the Royal Malaysian Air Force. The projected Series 500 was followed by the Dart 532/9 turboprop-engined Series 600.
The final two versions were the Series 700 long-range version of the Series 600, accommodating up to 60 passengers or 52 passengers and baggage over 1,980km stages, and the Series 800 military version of the 700.