PORTLAND, OR -- An off-duty Alaska Air pilot arrested Sunday in Portland now faces federal charges for allegedly attempting to shutdown the engines of a passenger plane while in flight. 

Joseph Emerson was arrested by Port of Portland Police after the Horizon Air flight made an emergency landing while enroute to San Francisco from Everett, WA. According to court records, Emerson was riding in a cockpit jump seat when the disturbance occurred. After landing, the two pilots told officers, "Approximately halfway between Astoria, Oregon, and Portland, after engaging with them in casual conversation, Emerson attempted to grab and pull two red fire handles that would have activated the plane’s emergency fire suppression system and cut off fuel to its engines," according to the US Attorney's Office. After a brief struggle, Emerson was removed from the cockpit and placed in wrist restraints in the rear of the aircraft. 

During the plane's decent into Portland, the US Attorney's Office says, "Emerson tried to grab the handle of an emergency exit. A flight attendant stopped him by placing her hands on top of his." 

Emerson faces multiple state charges, including Attempted Murder. He's now also charged with one count of Interfering with Flight Crew Members and Attendants in federal court.