TEPIC, Mexico (AP) _ A single-engine Piper aircraft piloted by an American crashed in bad weather in mountains a few miles outside this Pacific coast town, killing the pilot and one of two Mexican passengers, the airport director said Saturday.

Absalon Reyes de Talamantes, director of the Tepic airport, identified the pilot as Park Dobson Jr. of Alliance, Neb., and said the Mexican who perished in the crash Friday was Jesus Lizarraga.

The second passenger, Antonio Tirado, suffered ''minor injuries'' and is being treated at a local hospital, Reyes said.

He said the plane was en route from the Pacific resort of Mazatlan, 104 miles northwest of Tepic, when it crashed about noon near the village of La Joya, five miles north of Tepic, the capital of Nayarit state.

Authorities have not finished their investigation of the accident, but preliminary information indicated it was caused by ''adverse weather conditions,'' including a heavy cloud layer, Reyes said.