FluidFow,
Interesting analysis !
If I continue my rough calculations and pursue my theory of high altitude stall and how it came to it, I arrive at a distance travelled by the aircraft of ~25-30nm.
1 Minute decelleration from 270kts IAS (~480 kts) to 220kts (~400kts).
Average speed: ~440kts
=> Distance travelled ~ 7.33nm.
Stall
4 Minutes decelleration from 400kts to 100kts
Average speed: ~250kts
=> Distance travelled ~16.7nm
Assuming not a linear but a more progressive deceleration (due to drag increasing progressively with increasing AoA especially after the stall).
I would rather expect the distance travelled to be closer to 30nm.
If we now assume a radius of turn of 3nm and a circle of 240°
we would have a distance travelled while circling of ~12.5nm
That would leave us 12-18nm and would bring us pretty close to the slick. Maybe 2-3nm beyond.
So I would venture to expect the crash area to be closer to the slick than in your grafic if we would pursue the logic of the above scenario.
All pure speculation though.
But the scenario can still be made consistent.