AAIB investigation to Piper PA-31-350, N66886
Forced landing following double engine failure, near Stonehaven, 9 April 2014.
Summary:
The aircraft was on a ferry flight from Seattle in the USA to Thailand via Canada, Greenland, Iceland, Scotland and across Europe. However the flight crew abandoned the aircraft in Greenland late in December 2013 after experiencing low oil pressure indications on both engines. This may have been due to the use of an incorrect grade of oil for cold weather operations. The aircraft remained in Greenland until 28 February 2014, when a replacement ferry pilot was engaged. Although the engine oil was not changed prior to departing Greenland, the flight continued uneventfully to Wick, in Scotland. Following some maintenance activity on the right engine, the aircraft departed for Le Touquet in France. However, approximately 25 minutes after takeoff, the engines successively lost power and the pilot carried out a forced landing in a ploughed field. Examination of the engines revealed that one piston in each engine had suffered severe heat damage, consistent with combustion gases being forced past the piston and into the crankcase.
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