David and Jean Hewitt were on the caravan park which adjoins Caernarfon Airport, when the crash happened yesterday morning.
They said the plane clearly appeared to be coming in too slowly and too low, and didn't reach the runway, but clipped trees and flipped over.
More top news
Finance Secretary Mark Drakeford is to become the first Assembly Member to announce that he'll stand in the contest to replace Carwyn Jones
A wet and murky night to come, but at least it will remain mild!
Missed tonight's episode? Catch up on Monday's Wales at Six