Why is Ethiopian Airlines so successful?
Many national airlines in Africa have struggled over the years, several have gone bust and a few - like South African Airways - are a constant drain on taxpayers.
But Ethiopian is one of the big success stories in African aviation. In 2016 it made more profit than all of the other African airlines put together.
So why does this model work, when for other state-owned carriers in Africa, it doesn't?
The BBC's Alastair Leithead sat with the chief executive of Ethiopian Airlines, Tewolde GebreMariam, to find out more.