The family of an American missionary pilot missing off the coast of West Africa says aviation officials on Sao Tome island waited 24 hours before reporting his disappearance or starting a search.

Officials of Sao Tome and Principe could not be reached for comment despite repeated attempts by telephone.

The daughter of Jerry Krause of Waseca, Minnesota, says the family is sending an envoy to Sao Tome to clarify what happened after the control tower lost contact with the pilot and his Beechcraft 1900C as it was approaching the airport amid a tropical storm on the afternoon of April 7.

She says his plane was only reported missing after her mother called the U.S. Embassy in Mali nearly 24 hours after Krause's last contact with Sao Tome control tower.