What happened
In late December 2013, a ferry flight was underway from Seattle, USA, with an intended route through Canada, Greenland, Iceland, Scotland, and Europe. During the transit through Greenland, the flight crew decided to abandon the mission after both engines displayed indications of low oil pressure. This interruption lasted until February 28, 2014, when a new ferry pilot took command of the aircraft.
While the engine oil was not replaced during the stay in Greenland, the flight proceeded to Wick, Scotland, without further incident. Following maintenance work performed on the right engine, the aircraft departed for Le Touquet, France. Roughly 25 minutes into the flight, both engines experienced a loss of power. The pilot was forced to perform an emergency landing in a ploughed field.
Findings
Post-accident inspections of the engines identified that a single piston in each engine had sustained significant heat damage. This damage was consistent with the presence of combustion gases leaking past the piston and entering the crankcase. It was previously noted that the initial engine issues in Greenland may have been caused by using an incorrect grade of oil for operations in cold temperatures.