Initial radar data indicated that the helicopter was on a steady southeast course, at 131 knots ground speed, and 900 feet above ground level (agl). The last 8 seconds of radar data indicated that the helicopter descended 600 feet. The last radar return was at 1341:32, approximately 140 feet agl, and 0.25 miles from the accident site. The pilot did not transmit a radio distress call.
don't know if this is calculated correctly, a bit fuzzy at the moment,
so 8 secs@ 131 kts is 584 yards? and 4500ftm = 200 yds or 1 in 3 down to the 140 feet agl. probably thought he had it there ( so no mayday) and slowing and then the bit in red is 1 yard down for every 10 forwards.
i have no idea of auto descent normal rate, but assume to acheive the 4500 he must have had the coll full down and the high 131 A/S, but the last 440 yds looks like a much reduced forward airspeed, on the average.
but the horrible picture seems to show a slower rate across ground, almost going into the dreaded J curve for the last sixty or seventy feet.
very sad.