Post major maintenance/life extension at Yak UK Ltd a YAK 50 loses oil pressure over the Lake District at 1250ft. Engine runs until dry before seizing, gearbox u/s and windmilling prop at 3100ft followed by glide, wheels up as per ops (no flaps on the 50) into a rough field with an upslope of 12-14 degrees at 500ft amsl.
First impact to full stop 47 metres, first belly impact approx 35 metres.
Aircraft did not go through a wall, starboard aileron did contact with a fence post.
Wind reported at Carlisle less than 5kts – windmills visible not turning and shutdown. Ground soft. When the engine seized it caused the reduction gearbox to disintegrate hence a windmillling prop and engine shut down with mags off and fuel cut. On inspection the cylinders completely solid, engine core since scrapped. Aircraft repaired and will be airworthy. US ‘Strong’ parachute worn.
