The organizers of a rally of vintage planes flying across Africa say a British pilot has gone missing while flying a 1943 Piper Cub plane.

Vintage Air Rally said in a statement on Facebook that Maurice Kirk, 72, had not arrived at his expected destination in Gambella, Ethiopia, on Tuesday.

The group said that before Kirk disappeared he had been advised to return to the Sudanese capital, Khartoum, after departing Ad-Damazin, Sudan, heading to Gambella. Kirk had withdrawn from the rally before he went missing, it said.

It said Kirk is believed to have made a precautionary landing somewhere in Ethiopia, where a search is on to find him.

The Vintage Air Rally describes itself as a "flying rally across Africa, from Crete to Cape Town," for early aircraft.