Thanks for the up-date Janice.
It's possible that KB261 did not crash on the airfield itself. The 'funnels' mentioned are the approach 'lanes' at each end of the runway and, as the name suggests, are a funnel-shaped area on the ground, often marked by lights on poles, which, when entered, 'funnel' the approaching aircraft towards the center line of the runway, with the pilot visually assessing his angle (and altitude) to the runway.
Depending on the area, topography etc of the airfield, these 'funnels' can extend to well over 1,000 feet from the runway threshold, with the angle from the runway central axis being around 30 degrees on each side.
As KB261 was seen to "dive into the round" from "around 1,000 feet", it's likely that it was some way from the runway threshold, and very possibly / probably still over land outside the airfield boundary, perhaps within 1/4 mile, or slightly more.