The story I read had them getting a neighbor's backhoe and going down 4-5 meters to get most of it. Ground was more or less a bog, so it probably went in fairly deep on impact, and settled more over time.
With personel effects recovered, should not be too hard to identify the piolt, hopefully some family will be found to return effects found.
Since metal detecting is another of the hobbies I persue, this was a great find.