tucumseh
Just to remind you of the evidence of Mr Ellacott that the Chinook had passed over him - "I then heard the sound of a propeller going around for about 4 or 5 seconds and then I heard an explosion .... Visibility at this time was only about nine or ten feet maximum". "It was difficult to say how far I was from the point of the explosion, but I don't think I could have been any more than 100 yards."
The speed assessed by AAIB at impact equated to slightly more than 250 ft per second - which equates to more than 80 yards a second.