As It Descended Through The Altitude Of The Cloud Ceiling, The Rate Of Descent Reached 16,200 Feet Per Minute
Analysis: The non-instrument-rated helicopter pilot was returning to his home airport as the height of the overcast ceiling gradually decreased along the route of flight, consistent with the forecast conditions. While flying along the river valley at an altitude of 1,800 to 1,900 ft above mean sea level (100 to 200 ft below the clouds), the helicopter flew beneath an area of light-intensity precipitation echoes as detected by weather surveillance radar. It is likely that, at this time, the pilot encountered reduced visibility in very light rain and potential clouds.