In commercial aviation, the aircrew are called flight crew. Some flight crew position names are derived from nautical terms and indicate a rank or command structure similar to that on ocean-going vessels, allowing for quick executive decision making during normal operations or emergency situations. Historical flightdeck positions include:
Captain, the pilot designated as the "pilot in command" (PIC), and the highest-ranking member or members of a flight crew.
First Officer (FO, also called a co-pilot), another pilot who is not the pilot-in-command, and is normally seated to the right of the captain. (On helicopters, an FO is normally seated to the left of the captain, who occupies the right hand seat).
Second Officer (SO), a person lower in rank to the First Officer, and who typically performs selected duties and also acts as a relief pilot. The rank of Second Officer was traditionally a Flight Engineer, who was often the person who handled the engine controls. In the 21st century, second officers on some airlines are pilots who act as "cruise relief" on long haul flights.
Third Officer (TO), a person lower in rank to a Second Officer, and who typically performs selected duties and can also act as a relief pilot. Largely redundant in the present day.
'Relief Crew' members in the present day are fully licensed and trained Captains and First Officers who accompany long-haul airline flights, and who relieve the primary pilots during designated portions of the flight to provide them with rest or sleep breaks (some large wide-body airliners are equipped with special pilot sleeper berths, but more typically reserved seats in the section closest to the flight deck, or cockpit, are used for the relief crew). The number of relief crew members assigned to a flight depends in part on the length of the flight and the official air regulations the airline operates under.
Flight Engineer (FE), a position originally called an 'Air Mechanic'. On older aircraft, typically between the late-1920s and the 1970s, the Flight Engineer was the crew member responsible for engines, systems and fuel management. As aircraft became increasingly sophisticated and automated, this function has been mostly assumed by the primary pilots (Captain and FO), resulting in a continued downsizing in the number of aircrew positions on commercial flights. The Flight Engineer's position is commonly staffed as a Second Officer. Flight engineers can still be found in the present day (in greatly diminished numbers), used on airline or air freight operations still flying such older aircraft. The position is typically crewed by a dual-licensed Pilot-Flight Engineer in the present day.
Airborne Sensor Operator, An airborne sensor operator (aerial sensor operator, ASO, Aerial Remote Sensing Data Acquisition Specialist, Aerial Payload Operator, Police Tactical Flight Officer, Tactical Coordinator etc.) is the functional profession of gathering information from an airborne platform (Manned or Unmanned) and/or oversee mission management systems for academic, commercial, public safety or military remote sensing purposes. The airborne sensor operator is considered a principal flight crew or aircrew member.
Navigator (archaic), also called 'Air Navigators' or 'Flight Navigators'. A position on older aircraft, typically between the late-1910s and the 1970s, where separate crew members (sometimes two navigation crew members) were often responsible for the flight navigation, including its dead reckoning and celestial navigation, especially when flown over oceans or other featureless areas where radio navigation aids were not originally available. As sophisticated electronic air navigation aids and universal space-based GPS navigation systems came online, the dedicated Navigator's position was discontinued and its function was assumed by dual-licensed Pilot-Navigators, and still later by the aircraft's primary pilots (Captain and FO), resulting in a continued downsizing in the number of aircrew positions on commercial flights. Modern electronic navigation systems made the navigator redundant by the early 1980s.
Radio Operator (archaic). A position on much older aircraft, typically between the mid-1910s and the 1940s, where a separate crew member was often responsible for handling telegraphic and voice radio communications between the aircraft and ground stations. As radio sets became increasingly sophisticated and easier to operate, the function was taken over directly by a FO or SO, and still later by the pilot-in-command and co-pilot, making the radio operator's position redundant.
Purser or In-flight Service Manager or Cabin Services Director, is responsible for the cabin crew as a team leader.
Flight attendant or Cabin Crew, is the crew member responsible for the safety of passengers. Historically during the early era of commercial aviation, the position was staffed by young 'cabin boys' who assisted passengers. Cabin boys were replaced by female nurses, originally called 'stewardesses'. The medical background requirement for the flight attendant position was later dropped.
Loadmaster, is a crew member on a cargo aircraft responsible for loading freight and personnel, and for calculating the aircraft's weight and balance prior to flight, which must be within the aircraft manufacturer's prescribed limits, for safe flight. On non-cargo aircraft, weight and balance tasks are performed by the flight crew.
USAF, RAF and RAAF aircrew and maintenance personnel with their C-17s
From the start of military aviation, additional crew members have flown on military aircraft. Over time these duties have expanded:
Airborne Imagery Analyst (AIA), imagery intelligence specialist assigned as Non-traditional Aircrew to airborne IMINT platforms such as the RAF Raytheon Sentinel.
Airborne Mission Systems Specialist, an aircrew member who operates some form of electronic or other type equipment such as computers, radars, or intelligence gathering equipment to assist or complete the aircraft's mission.
Airborne Sensor Operator, An airborne sensor operator (Aerial Sensor Operator, Tactical Coordinator, EWO etc.) is the functional profession of gathering information from an airborne platform (Manned or Unmanned) and/or oversee mission management systems for tactical, operational and strategic remote sensing purposes.
Crew chief, an enlisted aircraft mechanic responsible for the maintenance and preparation of the aircraft.
Flight attendant, a crew member who tends to passengers on military aircraft. This position is similar to the duties performed by commercial flight attendants.
Flight engineer, a crew member responsible for engines, systems and fuel management.
Loadmaster, crew member responsible for loading freight and personnel and the weight and balance of the aircraft.
Navigator, a crew member responsible for air navigation. Still actively trained and licensed in some present day militaries, as electronic navigation aids can not be assumed to be operational during warfare.