section_path: Vehicle/History/Aircraft
section_name: Aircraft
paragraph_text: Aircraft
  
  With the development of effective anti-aircraft artillery in the period before the Second World War, military pilots, once the "knights of the air" during the First World War, became far more vulnerable to ground fire. As a response, armour plating was added to aircraft to protect aircrew and vulnerable areas such as engines and fuel tanks. Self-sealing fuel tanks functioned like armour in that they added protection but also increased weight and cost.