It had been on the market with Strutt & Parker for ten months at an asking price of £9m, although it reportedly fetched £7.5m.
Peason is the half-sister of Lord Cowdray and moved into the house in 1996.
An air navigation beacon was installed nearby at Northchapel not long after the tragedy.
The aircraft, which was bound for Heathrow Airport, appears to have been flying at a considerably lower altitude along the correct flight path due to instrument error.
A garage was destroyed and the roof of Upper Blackdown House in the estate was badly damaged. The weather at the time was slightly misty with intermittent drizzle but there was reasonable visibility.
The plane which smashed through trees in the grounds of the Blackdown Estate continued for several hundred yards across a meadow killing 65 sheep and fatally injuring 23 more before disintegrating close to the house.