The Piper Chieftain, a light twin-engine plane belonging to Mainland Air, was flying over Oamaru about 1pm, when the left engine stopped.
The two pilots had to land the plane on one engine, Mainland Air chief executive officer Phil Kean confirmed.
"The engine failed and [the pilots] went through all the emergency procedure drills and everybody was safe — that’s the best part of the story," Mr Kean said.
"They were high, and that’s always a good thing to have on your side, so you’ve got room to play with.
"I’m very proud; they are trained to do those procedures and they pulled it off very very well, obviously."
The engine would be stripped back and analysed to determine what went wrong, he said.
A St John spokesman confirmed an ambulance was called to the scene to pick up the patient and take them to Dunedin Hospital.
Police were notified but were not required, a spokeswoman said.
