Aerial anarcho,
from what I understand, this aircraft was commercially operated by an AOC holder (Eppsaviation).Acc to their website they operate 4 KingAirs, 4 Lears and the now lost Chally.
This accident has to be checked out as a 747 crash should be... I guess, thats simply what the AAIB is doing and what takes some time.
And surely you wouldn´t like to have these guys running around close to an active runway, would you?