After touchdown, but it rolled sideways not end over end. This kept the fuselage intact and ripped off the wings (where all the fuel is) which is why everyone survived.
Maybe that would be a general great idea.. slide the people capsule away from the bomb in the final moments of a crash landing. But that would make it necessary to have the people capsule bolted on - with explosive destructible bolts and i think air-companies are not mentally ready yet for the crumble zone airplane.
Many airplanes (not sure about the CRJ) also have a center wing tank, which is directly under the fuselage, so would be kinda hard to separate cleanly. Also, explosive bolts might start a fire that wouldn't have started without the bolts...
And they purge the fuel, if its a controlled emergency landing.. but in a uncontrolled emergency.. to let go of the wings seems a good option for events to go.
No, they don't. The CRJ, and in fact most smaller airliners including the A320 and 737 do not have the ability to dump fuel.
In larger aircraft that do have the ability to dump fuel, the reason is to make the airplane lighter so it does not have do an overweight landing and the subsequent high-cost overweight landing inspection. It is not done to reduce the probability of a post-crash fire.
What you describe in the second sentence - rotating around the vertical-axis - is typically termed a spin .
I think parent was saying the roll was along the planes' length rather than tail-over-nose, the latter usually result in the aircraft breaking up as the torque will be really high.
Thanks - those are correct terms for aircraft in flight, that don't apply to out-of-control vehicles on the ground. An airplane that loses traction and rotates about it's vertical axis is spinning, not yawing.