No person shall use the airport for the conduct of commercial aviation activities or the carriage of passengers, freight, express or mail or for student flying, communications or any other commercial purpose without first securing a written permit from the Airport Manager; provided, however, that this shall not apply to fixed base operators located on the airport who hold valid lease agreements with the city or any agency having operational rights to use the airport. The city may assess a fee for a commercial use permit for non-fixed base operators.
(`78 Code, § 4.12.010.)