Joseph David Emerson, 44, was arrested on Sunday in Portland, where the twin-engine aircraft landed safely after it was diverted during what the airline called a "credible security threat" on a flight from Everett, Washington, to San Francisco. Emerson was off-duty at the time and riding as a validated "jump seat" passenger in the cockpit of the plane - a routine mode of transport for commercial airline pilots hitching flights back home or to their next assignment, according to the Federal Aviation Administration (FAA). He was booked into jail on 83 counts of attempted mu...