The film is a mix of fact and fiction.
William Lancaster was a British aviator who vanished in the Sahara in 1933 whilst attempting to set an England-South Africa speed record. He was married, but had a long-term affair with an Australian woman, Jessie Miller, who was also a pilot.
Miller did not go to search for Lancaster. His body was found in 1962 by French troops. His diary was sent to Miller. His plane was recovered in 1975 and acquired by the Queensland Museum in Australia. The plane, the Southern Cross Minor, had been purchased by Lancaster from Charles Kingsford Smith, a noted Australian aviator.