What authorities describe as an off-duty pilot’s attempt to shut down the engines of a Horizon Air flight has renewed attention on the mental fitness of those allowed in the cockpit. Joseph Emerson had been flying passengers himself just three days before police said he tried to engage an emergency fire suppression system mid-flight. He was catching a ride from Washington state to San Francisco on Sunday in the extra seat in the cockpit. He was subdued by the flight crew. The plane landed safely in Portland, Oregon. Emerson has pleaded not guilty to attempted murder charges. He told police after his arrest that he’d had a nervous breakdown.