BAE Systems helped win the Battle of Britain in 1940 with its Spitfire and Mosquito fighters; today it is a leading military contractor and major foreign player in the US defense market. BAE's main operating groups -- cyber security, financial crime, communications intelligence, and digital transformation -- provide products and services that include electro-optical sensors, flight controls, commercial and financial security, ship repair and modernization, and aircraft. BAE's fighter aircraft include the Hawk, Tornado, and the next-generation Eurofighter Typhoon. North America is BAE's biggest market (maintained by BAE Systems Inc.), with the US Department of Defense (DoD) its largest single customer.