From the above posts, it is therefore possible that these pilots where signed out as P1 B1900, by a Comercial pilot intstructor who himself does not have an ALTP.
Certain countries reuqire two rated pilots at the controls such as the UK. Even though USA N-registered aircraft are in UK land, both pilots have to be type rated. FACT!
No pilot can fly in French airspace in command such an aircraft on his sixtieth birthday, regardless of registration. Even over fly!
My point is, what ever is good for ZS registered aeroplanes is not always acceptable for countries north of the Limpopo.
My understanding is that these B1900's are flown in Algeria, on petroleum contracts, mainly and some aid elsewhere. I wonder what would happen when they are ramp checked by these authorities or if they are aware of these circumstances?