Judge Siraj Desai said the air crew had not followed procedures on their second attempt to land at George airport.
"The complacency of the pilot in command was surprising and ... the co-pilot failed under the circumstances to do what a reasonable pilot would have done," the Cape High Court judge said at the conclusion of the inquest on Monday.
"It is the court's view that the death of the deceased Wessel Johannes (Hansie) Cronje was brought about by an act or omission prima facie amounting to an offence on the part of pilots," Judge Desai said.
Warnings ignored
During the inquest it emerged that the pilots Willie Meyer and Ian Noakes - apparently believing they were flying over the sea - had ignored 13 ground proximity warnings given by navigation equipment on the Hawker Siddeley light aircraft.