Canadaairbuspilot said
You add 50 feet to your MDA gives you about 320 AGL. There would be time to decide you have no runway insight and go around. If at 320 feet AGL you break out right at minimums (on path) I doubt you'd have enough room to dive it down to where they hit the ground. If you broke out a little earlier with the "lights only" you would thing the vis good enough (I know it was fluctuating) to see that the path the airplane was on was not working.
Not necessarily 320'.
EXEMPTION FROM PARAGRAPH 602.128(2)(b) OF THE CANADIAN AVIATION REGULATIONS - Transport Canada
Most operators apply the exemption above to use the MDA as the DA. The 50' figure commonly thrown around relates to the height above the runway threshold intended by the constant descent angle, and is about where the flare should begin. Agree that not much 'diving' could take place even if the crew wanted to. Impact was at least 2000' short of target.