The Trislander is a single-pilot aircraft. What will happen if the solo pilot collapsed or started flying erratically? The pilot might be overwhelmed by an emergency. The value of having two pilots was displayed in the year 2009 when a US Airways plane struck a flock of geese shortly after takeoff and lost power in both engines. The captain and first officer together managed to land the Airbus A321 on the Hudson River. No one died. Commercial airline passengers expect and deserve two pilots in the cockpit.