They come from a regular internal audit and QAR data. They can set triggers on certain items. For example, certain configurations (or lack of) at certain altitudes can trigger a data point for the safety department.
They treat them as the same type with only a few conditions regarding recency. For example, out of three simulator checks you need to do one in each type (330/330/350 or 350/350/330 for example).
Also need to do at least one takeoff and landing in each (in addition to the three takeoffs and landings in 90 days), in 60 days.
Otherwise they treat them the same. I routinely get rostered to fly one type on a short sector, get in, change aircraft to the other type and fly it somewhere else.
Literally only an hour to adapt to the other type.
