Flying high over Cameroon in the middle of the African night. Around the equator, many storms grow into enormous sizes, often requiring us to deviate our course and fly around them for long distances. 

Combined with the already notoriously unreliable radio-communication in Africa, the thunderstorms distort the very little radio signals that we have with the local Air Traffic Controller. On top of that, many countries still lack reliable radar stations and rely on our position reports to make up their mental picture of all the traffic in their airspace. 

To prevent unwanted surprises and possible close encounters with other aircraft, all pilots are also broadcasting on a common frequency so we can keep each other up to date on our altitude and routings. In this case we already heard an Air France Boeing 777 taking off from Douala and climbing to her cruising level. Because of the major thunderstorm on her route, she was deviating around it. Thereby crossing our path and altitude if we would not intervene. 
Both the 777 and us kept each other up to date on our position, organizing our own separation in those treacherous airspaces with no communication with local Air Traffic Control. While passing below us by a 1000ft, we both kept our landing lights on to make each other visible against the otherwise flashing and dark sky, continuously aware of each other’s position.
Standard operation in Africa.