A four-seater plane carrying only the American pilot has disappeared, Nigerian media Tuesday quoted Cameroonian aviation sources as saying. The plane, owned by the US company Global Aviation, took off from Kano in northern Nigeria on Monday evening towards Libreville, Gabon. It was due to make a stopover in Douala, Cameroon, where it never arrived, dpa quoted Daily Post as reporting. The plane's last contact with a control tower was two hours before arrival in Douala. Nigeria Airspace Management Agency director Ibrahim Abdulsam said it was up to Cameroon to investigate the disappearance. Search operations have yielded no result so far.