On 14 November 2010, a Piper PA-31-350 aircraft registered VH-MKK was being operated on a passenger charter flight from Marree, South Australia to Broken Hill, New South Wales. During the climb the pilot detected an unusual noise in the right engine followed by a gradual decrease in engine performance. The pilot elected to return to Marree Airport, however during the turn back the aircraft was unable to maintain altitude and the pilot elected to conduct a forced landing about 22 km south-east of the Airport.
The pilot did not feather the right engine as he assessed that the right engine was still producing some power.
The aircraft was substantially damaged during the landing, however all passengers and crew were able to exit the aircraft safely.
A post-flight engine inspection found four bearing retainer plate screws missing from the magneto which allowed oil to enter the magneto. It is probable that this led to a magneto failure and subsequent engine failure.
As a result of the accident, the aircraft operator conducted a brief with all company pilots revising engine failure procedures. They also discussed the symptoms of a windmilling propeller and partial engine failure indications and procedures.
The operator has also amended their procedures to mandate that all IFR renewal flights are to be conducted in the Piper PA-31 Chieftain aircraft type.