Aviators flying vintage planes the length of Africa were showing them off in the skies over a Kenyan game park on Sunday, a day after one of the aircraft was wrecked in a forced landing.

The Vintage Air Rally, including biplanes built in the 1920s and 1930s, has flown from Europe past Egypt's pyramids and through Sudan and Ethiopia, where participants were briefly detained because of a dispute over whether they had proper authorization.

"They are tough conditions for the aeroplanes. It's hot, it's high and in the afternoons we get the thunderstorms," rally organiser Sam Rutherford told reporters as the planes flew over a game park on the outskirts of Nairobi.

"We did lose an aircraft," he said of Saturday's incident, when a vintage Boeing Stearman suffered an engine failure and made a forced landing northwest of Nairobi. The plane was "written off" but the crew were fine, Rutherford said.

The rally also briefly lost track of veteran pilot Maurice Kirk and his plane after the stop in Ethiopia last week. He was located on Saturday after landing in South Sudan, but not on an airfield, the organisers said.

Kirk and his plane are no longer part of the rally.

The remaining planes and support aircraft will continue their journey south on Monday, heading to Tanzania. They aim to reach Cape Town, South Africa, in two weeks.

The rally began in Greece with several teams flying 24 aircraft, including support planes. The organisers did not say how many planes were still involved, but said it was not a surprise some would not complete the journey.