A 72-year-old British pilot attempting to fly a 1940s plane the length of Africa has gone missing somewhere between Sudan and Ethiopia, BBC has reported.
Maurice Kirk, who lives in Bristol, was part of a vintage air rally flying from Crete to Cape Town.
He had continued to fly despite being asked to withdraw from the event after two engine failures and a lack of navigational equipment.
Vintage Air Rally said a search and rescue operation was due to begin.
Mr Kirk, who also has links to Taunton in Somerset and the Vale of Glamorgan in South Wales, went missing on a three-hour leg of the cross-African flight from southern Sudan into western Ethiopia.
Organisers of the Vintage Air Rally said he had been asked to withdraw from the rally because of a lack of satellite tracking or a working compass on his 1943 Piper Cub plane.
He previously reported suffering two engine failures, but had apparently decided to continue.