If my memory serves me correctly, the PPL specifies aircraft up to a cetain weight limit. Is it not 12,500 lbs in Europe, or 5.7 tonnes? I'm sure that one needs at least a CPL to fly something larger, and of course a TR would be required even if flights were to be conducted VFR and out of airways.
My knowledge of aviation law is strictly limited to those regulations that I am potentially likely to bust - and as my licence covers the category, this aint one of them!