On commercial flights, the first officer pilot is the second pilot on the plane. Your responsibilities in this career are to assist the captain to fly the plane. As the co-pilot, if the captain is incapacitated, you take command of the plane. On many flights, the first officer and the captain share the duties of piloting the plane, taking turns while the other one monitors controls and provides backup as needed. In commercial airline command structure, there is also a designation for the senior first officer, which is typically someone who qualifies as a captain, but the airline does not have enough flights to make that person a captain.