This Turbo DC-3 is currently based in Angola. The airplane departs Luanda every morning around 9 am, to return between 5 and 6 pm. Parking and handling takes place on the ramp of the domestic terminal. The FR24 data track stops just outside the urban area of Luanda, so I am not sure what its destination is, nor what the purpose is of the operation. Looking at previous locations where this airplane has been seen flying, places like the Canadian Arctic and Indonesian Borneo, my guess would be that it is oil related.