Proposed Australian-built variant with Hercules 17 engines, not built.
Valetta prototype for Ministry of Supply with two Hercules 634 engines.
Viking 1 for the Argentine government with two Hercules 630 engines.
Viking C2 for the Royal Air Force with two Hercules 130 engines.
Viking 1B for Air India with two Hercules 634 engines.
Viking 1 for Suidair International with two Hercules 630 engines.
Its production lines were closed down in favour of the Hercules engine.
Extra sound insulation was used to drown out the mighty Hercules engines and earplugs provided.
This revised design was the Type 317 and two prototypes with Hercules engines were ordered on 22 March 1937.
A total of over 57,400 Hercules engines were built.