ATR42 is considerably smaller. Dash 8-400 is comparable to the larger ATR72. Dash 8 seems to be gaining a rep for dodgy undercarriages lately, with a
few instances of them folding up on landing, but I suppose there isn't so far to fall.
The aircraft descended through icing conditions, and the anti-icing and de-icing equipment on the aircraft was activated. Investigators say that
residual icing remained on the aircraft after they shut down at the airport. The crew departed the airport without performing de-icing activities,
despite having the equipment available.
Probably didn't do a full preflight. With only 45 minutes on the ground, they most likely did a walkaround looking for leaks, did their checklists,
and went. With the interisland flights, they only did an actual preflight before the first go in the morning. They barely got out of the cockpit
after landing on most flights, because the turn was so quick.