Vessel size change event?

[Diazo]

Okay, bit of a different question, but how would you go about triggering code to run when the size (such as a KAS crane playing out cable, or swinging out an IR arm) of a vessel changes? Note that I'm specifically looking for how to do this when the parts on the ship don't change.

The second, simpler, question is how do I get the size of a vessel in flight mode?

D.