LOS ANGELES (CBSLA.com) — Authorities say the pilot of a Seattle-bound flight lost consciousness Thursday evening, which forced the Boeing 737 to make an emergency landing in Portland.

The Alaska Airlines plane departed LAX at 6:37 p.m., say officials with the airline.

Flight 473 was landed safely by the first officer after the pilot “temporarily lost consciousness,” Paul McElroy of Alaska Airlines said.

“All of our pilots are trained to single-handedly fly our airplanes,” McElroy said.

The pilot who passed out has been flying with the airline for nearly 30 years.

The airlines’ spokesperson said the pilot was treated by a doctor who happened to be among the passengers.

The pilot’s condition is unknown and the airline could not say what caused him to pass out.

Flight 473 had 116 passengers and five crew aboard.