The 3 shorter links are not working for me.
I guess several things could have contributed to this:
One should not fly these types (or my TB20) in IMC below 0C for extended periods enroute. Eventually you will pick up ice, and around Greece they get some serious embedded convective stuff. This is why I bang on about getting cloud tops and scrapping the flight if they are likely to be above the aircraft ceiling, and this applies to both VFR on top, and IFR. A lot of pilots do fly through fronts and just get chucked about but some don't make it.
No VFR aviation charts are available for Greece - apart from the 1998 U.S. ONC G3 etc series. Of course these will show terrain. But you have to buy them from specialist outlets. It would not totally suprise me if some pilots don't carry them.
The majority of pilots even today don't know about the wide range of internet weather sources.
There are also pilots who - and this is very evident to me from some crashes we talked about here in the past - probably did not look at the weather before they went.