See, that's what I'm looking for. The turn radius never occurred to me.
I have several Electra manuals, but no information on turn radius.
Aircraft Turn Information Calculator is a turn radius calculator.
Given the plane's takeoff weight of 93,000 lbs, the stall speed is 110 knots. I don't have a better speed to work with than the 160 knot estimated impact speed. The bank was said to be steadily increasing, so that throws a wrinkle in it.
At any rate, the calculator says a 43 degree bank would give a diameter under 5000 feet, and a 70 degree bank would give a 1660 foot diameter. So if the bank was as steep as the official reports say, the plane would have crashed closer to the runway.
This is fascinating, thank you very much. I'll have to follow this further.