Riding on Air (1937)

When he wins $5000 in an essay contest for a breakfast cereal, small town reporter and amateur aviator Elmer Lane becomes a target for con man Doc Waddington. After the naive newsman involves gullible local businessmen in the scheme, and they discover they've been flim-flammed, his credibility with his friends and fiancée is shattered. In order to restore his reputation, the novice pilot needs to solve a murder and expose a bootlegging smuggling ring.