A Second Officer usually refers to the third in the line of command for a flight crew on a commercial or non-military aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

. Usually the Second Officer is a flight engineer

Flight engineer

Flight engineers work in three types of aircraft: fixed-wing , rotary wing , and space flight .As airplanes became even larger requiring more engines and complex systems to operate, the workload on the two pilots became excessive during certain critical parts of the flight regime, notably takeoffs...

 who is also a licensed pilot

Aviator

An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...

. A Second Officer on some airlines is part of a relief crew. Rarely, such relief pilots are called Third Officer

Third Officer (civil aviation)

Third Officer is a lesser used civil aviation rank. It was primarily used by Pan American World Airways, particularly on its "Clippers" during the infancy of extended range airline routes...

. The title derives from the nautical title indicating a third in command officer.

See also

• Captain (civil aviation)
• First Officer (civil aviation)
• Third Officer (civil aviation)
  Third Officer (civil aviation)
  Third Officer is a lesser used civil aviation rank. It was primarily used by Pan American World Airways, particularly on its "Clippers" during the infancy of extended range airline routes...