Well, to take then the speculative rumour mill a step more along the path.
600kgs of what and where?
Is that then a Caravan loaded with....
Pilot.
Three (male) pax.
Small allowance of personal baggage.
Fuel for somewhere in Angola. (How far away was destination? Full tanks-is Jet A1 cheaper in Angloa for example.)
600 kilos building supplies or cargo.
???? Rife speculation of course.
You will readily calculate that 4 men @ 75kgs each is 300 kgs. Was there really only a further 300 kgs of fuel, baggage and freight on board and in any way, was that significant.
Also, to those who have five hundred hours on type, is that just enough experience to know your way around the POH without need to reference to it?